The integration of temporally shifted visual feedback in a synchronization task: The role of perceptual stability in a visuo-proprioceptive conflict situation.

PubMed

Ceux, Tanja; Montagne, Gilles; Buekers, Martinus J

2010-12-01

The present study examined whether the beneficial role of coherently grouped visual motion structures for performing complex (interlimb) coordination patterns can be generalized to synchronization behavior in a visuo-proprioceptive conflict situation. To achieve this goal, 17 participants had to synchronize a self-moved circle, representing the arm movement, with a visual target signal corresponding to five temporally shifted visual feedback conditions (0%, 25%, 50%, 75%, and 100% of the target cycle duration) in three synchronization modes (in-phase, anti-phase, and intermediate). The results showed that the perception of a newly generated perceptual Gestalt between the visual feedback of the arm and the target signal facilitated the synchronization performance in the preferred in-phase synchronization mode in contrast to the less stable anti-phase and intermediate mode. Our findings suggest that the complexity of the synchronization mode defines to what extent the visual and/or proprioceptive information source affects the synchronization performance in the present unimanual synchronization task. Copyright © 2010 Elsevier B.V. All rights reserved.

Dissociation between active and observational learning from positive and negative feedback in Parkinsonism.

PubMed

Kobza, Stefan; Ferrea, Stefano; Schnitzler, Alfons; Pollok, Bettina; Südmeyer, Martin; Bellebaum, Christian

2012-01-01

Feedback to both actively performed and observed behaviour allows adaptation of future actions. Positive feedback leads to increased activity of dopamine neurons in the substantia nigra, whereas dopamine neuron activity is decreased following negative feedback. Dopamine level reduction in unmedicated Parkinson's Disease patients has been shown to lead to a negative learning bias, i.e. enhanced learning from negative feedback. Recent findings suggest that the neural mechanisms of active and observational learning from feedback might differ, with the striatum playing a less prominent role in observational learning. Therefore, it was hypothesized that unmedicated Parkinson's Disease patients would show a negative learning bias only in active but not in observational learning. In a between-group design, 19 Parkinson's Disease patients and 40 healthy controls engaged in either an active or an observational probabilistic feedback-learning task. For both tasks, transfer phases aimed to assess the bias to learn better from positive or negative feedback. As expected, actively learning patients showed a negative learning bias, whereas controls learned better from positive feedback. In contrast, no difference between patients and controls emerged for observational learning, with both groups showing better learning from positive feedback. These findings add to neural models of reinforcement-learning by suggesting that dopamine-modulated input to the striatum plays a minor role in observational learning from feedback. Future research will have to elucidate the specific neural underpinnings of observational learning.

Positive force feedback in human walking

PubMed Central

Grey, Michael J; Nielsen, Jens Bo; Mazzaro, Nazarena; Sinkjær, Thomas

2007-01-01

The objective of this study was to determine if load receptors contribute to the afferent-mediated enhancement of ankle extensor muscle activity during the late stance phase of the step cycle. Plantar flexion perturbations were presented in late stance while able-bodied human subjects walked on a treadmill that was declined by 4%, inclined by 4% or held level. The plantar flexion perturbation produced a transient, but marked, presumably spinally mediated decrease in soleus EMG that varied directly with the treadmill inclination. Similarly, the magnitude of the control step soleus EMG and Achilles' tendon force also varied directly with the treadmill inclination. In contrast, the ankle angular displacement and velocity were inversely related to the treadmill inclination. These results suggest that Golgi tendon organ feedback, via the group Ib pathway, is reduced when the muscle–tendon complex is unloaded by a rapid plantar flexion perturbation in late stance phase. The changes in the unload response with treadmill inclination suggest that the late stance phase soleus activity may be enhanced by force feedback. PMID:17331984

The effects of self-controlled feedback on learning of a "relaxed phonation task".

PubMed

Ma, Estella P-M; Yiu, Gigi K-Y; Yiu, Edwin M-L

2013-11-01

This study examined the effects of self-controlled feedback paradigm on motor learning of a relaxed phonation task. It investigated whether providing the learner with more control over practice condition has positive influences on the performance and learning of "relaxed phonation" skill. Vocally healthy individuals were randomly assigned into either self-controlled feedback group (SELF) or clinician-controlled feedback group (YOKED). All participants were engaged in a reading aloud task. Throughout the task, their perilaryngeal muscle activities were measured at thyrohyoid (TH) and orofacial (OF) sites using surface electromyography (EMG). The EMG values measured at the TH site were provided to participants as terminal biofeedback. Participants were required to minimize the EMG values. The SELF group received EMG biofeedback whenever they requested it, whereas the YOKED group received the same feedback schedule as chosen by their self-controlled counterparts. The pooled data for all participants revealed that there was a significant reduction of muscle tension across baseline, training, and retention phases. Generalization was shown to reading of untrained passage. Interestingly, significant reduction of muscle tension across training and retention tests was found in the control OF site but not in the target TH site. The results failed to demonstrate significant differences between SELF and YOKED groups. It provided no clear evidence to conclude that self-controlled feedback paradigm was beneficial to learning of relaxed phonation. Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

Manipulation of peripheral neural feedback loops alters human corticomuscular coherence

PubMed Central

Riddle, C Nicholas; Baker, Stuart N

2005-01-01

Sensorimotor EEG shows ∼20 Hz coherence with contralateral EMG. This could involve efferent and/or afferent components of the sensorimotor loop. We investigated the pathways responsible for coherence genesis by manipulating nervous conduction delays using cooling. Coherence between left sensorimotor EEG and right EMG from three hand and two forearm muscles was assessed in healthy subjects during the hold phase of a precision grip task. The right arm was then cooled to 10°C for ∼90 min, increasing peripheral motor conduction time (PMCT) by ∼35% (assessed by F-wave latency). EEG and EMG recordings were repeated, and coherence recalculated. Control recordings revealed a heterogeneous subject population. In 6/15 subjects (Group A), the corticomuscular coherence phase increased linearly with frequency, as expected if oscillations were propagated along efferent pathways from cortex to muscle. The mean corticomuscular conduction delay for intrinsic hand muscles calculated from the phase–frequency regression slope was 10.4 ms; this is smaller than the delay expected for conduction over fast corticospinal pathways. In 8/15 subjects (Group B), the phase showed no dependence with frequency. One subject showed both Group A and Group B patterns over different frequency ranges. Following cooling, averaged corticomuscular coherence was decreased in Group A subjects, but unchanged for Group B, even though both groups showed comparable slowing of nervous conduction. The delay calculated from the slope of the phase–frequency regression was increased following cooling. However, the size of this increase was around twice the rise in PMCT measured using the F-wave (regression slope 2.33, 95% confidence limits 1.30–3.36). Both afferent and efferent peripheral nerves will be slowed by similar amounts following cooling. The change in delay calculated from the coherence phase therefore better matches the rise in total sensorimotor feedback loop time caused by cooling, rather than just the change in the efferent limb. A model of corticomuscular coherence which assumes that only efferent pathways contribute cannot be reconciled to these results. The data rather suggest that afferent feedback pathways may also play a role in the genesis of corticomuscular coherence. PMID:15919711

Dissociation between Active and Observational Learning from Positive and Negative Feedback in Parkinsonism

PubMed Central

Kobza, Stefan; Ferrea, Stefano; Schnitzler, Alfons; Pollok, Bettina

2012-01-01

Feedback to both actively performed and observed behaviour allows adaptation of future actions. Positive feedback leads to increased activity of dopamine neurons in the substantia nigra, whereas dopamine neuron activity is decreased following negative feedback. Dopamine level reduction in unmedicated Parkinson’s Disease patients has been shown to lead to a negative learning bias, i.e. enhanced learning from negative feedback. Recent findings suggest that the neural mechanisms of active and observational learning from feedback might differ, with the striatum playing a less prominent role in observational learning. Therefore, it was hypothesized that unmedicated Parkinson’s Disease patients would show a negative learning bias only in active but not in observational learning. In a between-group design, 19 Parkinson’s Disease patients and 40 healthy controls engaged in either an active or an observational probabilistic feedback-learning task. For both tasks, transfer phases aimed to assess the bias to learn better from positive or negative feedback. As expected, actively learning patients showed a negative learning bias, whereas controls learned better from positive feedback. In contrast, no difference between patients and controls emerged for observational learning, with both groups showing better learning from positive feedback. These findings add to neural models of reinforcement-learning by suggesting that dopamine-modulated input to the striatum plays a minor role in observational learning from feedback. Future research will have to elucidate the specific neural underpinnings of observational learning. PMID:23185586

Digital Phase-Locked Loop With Phase And Frequency Feedback

NASA Technical Reports Server (NTRS)

Thomas, J. Brooks

1991-01-01

Advanced design for digital phase-lock loop (DPLL) allows loop gains higher than those used in other designs. Divided into two major components: counterrotation processor and tracking processor. Notable features include use of both phase and rate-of-change-of-phase feedback instead of frequency feedback alone, normalized sine phase extractor, improved method for extracting measured phase, and improved method for "compressing" output rate.

Teaching leadership in trauma resuscitation: Immediate feedback from a real-time, competency-based evaluation tool shows long-term improvement in resident performance.

PubMed

Gregg, Shea C; Heffernan, Daithi S; Connolly, Michael D; Stephen, Andrew H; Leuckel, Stephanie N; Harrington, David T; Machan, Jason T; Adams, Charles A; Cioffi, William G

2016-10-01

Limited data exist on how to develop resident leadership and communication skills during actual trauma resuscitations. An evaluation tool was developed to grade senior resident performance as the team leader during full-trauma-team activations. Thirty actions that demonstrated the Accreditation Council for Graduate Medical Education core competencies were graded on a Likert scale of 1 (poor) to 5 (exceptional). These actions were grouped by their respective core competencies on 5 × 7-inch index cards. In Phase 1, baseline performance scores were obtained. In Phase 2, trauma-focused communication in-services were conducted early in the academic year, and immediate, personalized feedback sessions were performed after resuscitations based on the evaluation tool. In Phase 3, residents received only evaluation-based feedback following resuscitations. In Phase 1 (October 2009 to April 2010), 27 evaluations were performed on 10 residents. In Phase 2 (April 2010 to October 2010), 28 evaluations were performed on nine residents. In Phase 3 (October 2010 to January 2012), 44 evaluations were performed on 13 residents. Total scores improved significantly between Phases 1 and 2 (p = 0.003) and remained elevated throughout Phase 3. When analyzing performance by competency, significant improvement between Phases 1 and 2 (p < 0.05) was seen in all competencies (patient care, knowledge, system-based practice, practice-based learning) with the exception of "communication and professionalism" (p = 0.56). Statistically similar scores were observed between Phases 2 and 3 in all competencies with the exception of "medical knowledge," which showed ongoing significant improvement (p = 0.003). Directed resident feedback sessions utilizing data from a real-time, competency-based evaluation tool have allowed us to improve our residents' abilities to lead trauma resuscitations over a 30-month period. Given pressures to maximize clinical educational opportunities among work-hour constraints, such a model may help decrease the need for costly simulation-based training. Therapeutic study, level III.

Effect of Real-Time Feedback on Screw Placement Into Synthetic Cancellous Bone.

PubMed

Gustafson, Peter A; Geeslin, Andrew G; Prior, David M; Chess, Joseph L

2016-08-01

The objective of this study is to evaluate whether real-time torque feedback may reduce the occurrence of stripping when inserting nonlocking screws through fracture plates into synthetic cancellous bone. Five attending orthopaedic surgeons and 5 senior level orthopaedic residents inserted 8 screws in each phase. In phase I, screws were inserted without feedback simulating conventional techniques. In phase II, screws were driven with visual torque feedback. In phase III, screws were again inserted with conventional techniques. Comparison of these 3 phases with respect to screw insertion torque, surgeon rank, and perception of stripping was used to establish the effects of feedback. Seventy-three of 239 screws resulted in stripping. During the first phase, no feedback was provided and the overall strip rate was 41.8%; this decreased to 15% with visual feedback (P < 0.001) and returned to 35% when repeated without feedback. With feedback, a lower average torque was applied over a narrower torque distribution. Residents stripped 40.8% of screws compared with 20.2% for attending surgeons. Surgeons were poor at perceiving whether they stripped. Prevention and identification of stripping is influenced by surgeon perception of tactile sensation. This is significantly improved with utilization of real-time visual feedback of a torque versus roll curve. This concept of real-time feedback seems beneficial toward performance in synthetic cancellous bone and may lead to improved fixation in cancellous bone in a surgical setting.

Method and apparatus for large motor control

DOEpatents

Rose, Chris R [Santa Fe, NM; Nelson, Ronald O [White Rock, NM

2003-08-12

Apparatus and method for providing digital signal processing method for controlling the speed and phase of a motor involves inputting a reference signal having a frequency and relative phase indicative of a time based signal; modifying the reference signal to introduce a slew-rate limited portion of each cycle of the reference signal; inputting a feedback signal having a frequency and relative phase indicative of the operation of said motor; modifying the feedback signal to introduce a slew-rate limited portion of each cycle of the feedback signal; analyzing the modified reference signal and the modified feedback signal to determine the frequency of the modified reference signal and of the modified feedback signal and said relative phase between said modified reference signal and said modified feedback signal; and outputting control signals to the motor for adjusting said speed and phase of the motor based on the frequency determination and determination of the relative phase.

Increased Response to Altered Auditory Feedback in Dyslexia: A Weaker Sensorimotor Magnet Implied in the Phonological Deficit

PubMed Central

Groen, Margriet A.; Ito, Takayuki; Francisco, Ana A.; Gracco, Vincent L.; Pugh, Ken R.; Verhoeven, Ludo

2017-01-01

Purpose The purpose of this study was to examine whether developmental dyslexia (DD) is characterized by deficiencies in speech sensory and motor feedforward and feedback mechanisms, which are involved in the modulation of phonological representations. Method A total of 42 adult native speakers of Dutch (22 adults with DD; 20 participants who were typically reading controls) were asked to produce /bep/ while the first formant (F1) of the /e/ was not altered (baseline), increased (ramp), held at maximal perturbation (hold), and not altered again (after-effect). The F1 of the produced utterance was measured for each trial and used for statistical analyses. The measured F1s produced during each phase were entered in a linear mixed-effects model. Results Participants with DD adapted more strongly during the ramp phase and returned to baseline to a lesser extent when feedback was back to normal (after-effect phase) when compared with the typically reading group. In this study, a faster deviation from baseline during the ramp phase, a stronger adaptation response during the hold phase, and a slower return to baseline during the after-effect phase were associated with poorer reading and phonological abilities. Conclusion The data of the current study are consistent with the notion that the phonological deficit in DD is associated with a weaker sensorimotor magnet for phonological representations. PMID:28257585

Self-Controlled Feedback Facilitates Motor Learning in Both High and Low Activity Individuals

PubMed Central

Fairbrother, Jeffrey T.; Laughlin, David D.; Nguyen, Timothy V.

2012-01-01

The purpose of this study was to determine if high and low activity individuals differed in terms of the effects of self-controlled feedback on the performance and learning of a movement skill. The task consisted of a blindfolded beanbag toss using the non-preferred arm. Participants were pre-screened according to their physical activity level using the International Physical Activity Questionnaire. An equal number of high activity (HA) and low activity (LA) participants were assigned to self-control (SC) and yoked (YK) feedback conditions, creating four groups: Self-Control-High Activity; Self-Control-Low Activity; Yoked-High Activity; and Yoked-Low Activity. SC condition participants were provided feedback whenever they requested it, while YK condition participants received feedback according to a schedule created by their SC counterpart. Results indicated that the SC condition was more accurate than the YK condition during acquisition and transfer phases, and the HA condition was more accurate than the LA condition during all phases of the experiment. A post-training questionnaire indicated that participants in the SC condition asked for feedback mostly after what they perceived to be “good” trials; those in the YK condition indicated that they would have preferred to receive feedback after “good” trials. This study provided further support for the advantages of self-controlled feedback when learning motor skills, additionally showing benefits for both active and less active individuals. The results suggested that the provision of self-controlled feedback to less active learners may be a potential avenue to teaching motor skills necessary to engage in greater amounts of physical activity. PMID:22969745

Identifying motivators and barriers to student completion of instructor evaluations: A multi-faceted, collaborative approach from four colleges of pharmacy.

PubMed

McAuley, James W; Backo, Jennifer Lynn; Sobota, Kristen Finley; Metzger, Anne H; Ulbrich, Timothy

To identify motivators and barriers to pharmacy student completion of instructor evaluations, and to develop potential strategies to improve the evaluation process. Completed at four Ohio Colleges of Pharmacy, Phase I consisted of a student/faculty survey and Phase II consisted of joint student/faculty focus groups to discuss Phase I data and to problem solve. In Phase I, the top three student-identified and faculty-perceived motivators to completion of evaluations were to (1) make the course better, (2) earn bonus points, and (3) improve the instructor's teaching. The top three student-identified barriers to completion of evaluations were having to (1) evaluate multiple instructors, (2) complete several evaluations around the same time, and (3) complete lengthy evaluations. Phase II focus groups identified a number of potential ways to enhance the motivators and reduce barriers, including but not limited to making sure faculty convey to students that the feedback they provide is useful and to provide examples of how student feedback has been used to improve their teaching/the course. Students and faculty identified motivators and barriers to completing instructor evaluations and were willing to work together to improve the process. Copyright © 2016 Elsevier Inc. All rights reserved.

Oxytocin selectively facilitates learning with social feedback and increases activity and functional connectivity in emotional memory and reward processing regions.

PubMed

Hu, Jiehui; Qi, Song; Becker, Benjamin; Luo, Lizhu; Gao, Shan; Gong, Qiyong; Hurlemann, René; Kendrick, Keith M

2015-06-01

In male Caucasian subjects, learning is facilitated by receipt of social compared with non-social feedback, and the neuropeptide oxytocin (OXT) facilitates this effect. In this study, we have first shown a cultural difference in that male Chinese subjects actually perform significantly worse in the same reinforcement associated learning task with social (emotional faces) compared with non-social feedback. Nevertheless, in two independent double-blind placebo (PLC) controlled between-subject design experiments we found OXT still selectively facilitated learning with social feedback. Similar to Caucasian subjects this OXT effect was strongest with feedback using female rather than male faces. One experiment performed in conjunction with functional magnetic resonance imaging showed that during the response, but not feedback phase of the task, OXT selectively increased activity in the amygdala, hippocampus, parahippocampal gyrus and putamen during the social feedback condition, and functional connectivity between the amygdala and insula and caudate. Therefore, OXT may be increasing the salience and reward value of anticipated social feedback. In the PLC group, response times and state anxiety scores during social feedback were associated with signal changes in these same regions but not in the OXT group. OXT may therefore have also facilitated learning by reducing anxiety in the social feedback condition. Overall our results provide the first evidence for cultural differences in social facilitation of learning per se, but a similar selective enhancement of learning with social feedback under OXT. This effect of OXT may be associated with enhanced responses and functional connectivity in emotional memory and reward processing regions. © 2015 Wiley Periodicals, Inc.

The added value of user involvement during the development of a feedback system regarding physical functioning for community-dwelling elderly people

PubMed Central

Vermeulen, Joan; Neyens, Jacques C. L; Spreeuwenberg, Marieke D; Van Rossum, Erik; Hewson, David; De Witte, Luc P

2012-01-01

Background The number of frail elderly people is increasing. Unfortunately, the number of caregivers is not increasing at the same pace, which affects older people, caregivers and healthcare systems. Because of these developments, self-management is becoming more important in healthcare. To support community-dwelling elderly people in their self-management, a system was developed that monitors their physical functioning. This system provides feedback to elderly people and their caregivers regarding physical indicators of frailty. The feedback is provided to elderly people via the screen of a mobile phone. It is important that elderly people understand the content of the feedback and are able to use the mobile phone properly. If not, it is unlikely that the system can support self-management. Many interactive health technologies that have been developed do not fulfil their promises. An important reason for this is that human and other non-technology issues are not sufficiently taken into consideration during the development process. Objective To collaborate with elderly people during the development and evaluation of a feedback system for community-dwelling elderly people regarding physical functioning. Methods An iterative user-centered design that consists of five phases was used to develop and evaluate the feedback system. These five phases were: 1) Selection of users, 2) Analysis of users and their context, 3) Identification of user needs, 4) Development of a prototype, and 5) Evaluation of the prototype. Three representatives of a target group panel for elderly people were selected in phase 1. They shared their needs and preferences during three expert group meetings that took place during the development process. This resulted in the development of a prototype which was first evaluated in a heuristic evaluation. Once adjustments were made, 11 elderly people evaluated the adjusted prototype using a think aloud procedure. They rated the usability and acceptability of the developed interface on a scale from 1 till 7 using an adapted version of the Post-Study System Usability Questionnaire (PSSUQ). Results A feedback system was developed that provides feedback regarding physical indicators of frailty via a touch screen mobile phone. The interface uses colours, smiley’s, and spoken/written messages to provide feedback that is easy to understand. The heuristic evaluation revealed that there were some problems with consistency and the use of user language. The think aloud evaluation showed that the 11 elderly people were able to navigate through the interface without much difficulty despite some small problems related to the lay-out of the interface. The mean score on an adapted version of the PSSUQ was 5.90 (SD 1.09) which indicates high user satisfaction and good usability. Conclusions The involvement of end-users significantly influenced the lay-out of the interface that was developed. This resulted in an interface that was accepted by the target group. Evaluation of the prototype revealed that the usability of the interface was good. The feedback system will only succeed in supporting self-management when elderly people are able to use the interface and understand the feedback. The input of elderly people during the development process contributed to this.

Real-time optical signal processors employing optical feedback: amplitude and phase control.

PubMed

Gallagher, N C

1976-04-01

The development of real-time coherent optical signal processors has increased the appeal of optical computing techniques in signal processing applications. A major limitation of these real-time systems is the. fact that the optical processing material is generally of a phase-only type. The result is that the spatial filters synthesized with these systems must be either phase-only filters or amplitude-only filters. The main concern of this paper is the application of optical feedback techniques to obtain simultaneous and independent amplitude and phase control of the light passing through the system. It is shown that optical feedback techniques may be employed with phase-only spatial filters to obtain this amplitude and phase control. The feedback system with phase-only filters is compared with other feedback systems that employ combinations of phase-only and amplitude-only filters; it is found that the phase-only system is substantially more flexible than the other two systems investigated.

Impact of Feedback on Three Phases of Performance Monitoring

PubMed Central

Appelgren, Alva; Penny, William; Bengtsson, Sara L

2013-01-01

We investigated if certain phases of performance monitoring show differential sensitivity to external feedback and thus rely on distinct mechanisms. The phases of interest were: the error phase (FE), the phase of the correct response after errors (FEC), and the phase of correct responses following corrects (FCC). We tested accuracy and reaction time (RT) on 12 conditions of a continuous-choice-response task; the 2-back task. External feedback was either presented or not in FE and FEC, and delivered on 0%, 20%, or 100% of FCC trials. The FCC20 was matched to FE and FEC in the number of sounds received so that we could investigate when external feedback was most valuable to the participants. We found that external feedback led to a reduction in accuracy when presented on all the correct responses. Moreover, RT was significantly reduced for FCC100, which in turn correlated with the accuracy reduction. Interestingly, the correct response after an error was particularly sensitive to external feedback since accuracy was reduced when external feedback was presented during this phase but not for FCC20. Notably, error-monitoring was not influenced by feedback-type. The results are in line with models suggesting that the internal error-monitoring system is sufficient in cognitively demanding tasks where performance is ∼ 80%, as well as theories stipulating that external feedback directs attention away from the task. Our data highlight the first correct response after an error as particularly sensitive to external feedback, suggesting that important consolidation of response strategy takes place here. PMID:24217138

Analysis of the WRF-Chem simulations contributing to the AQMEII-Phase II exercise with respect to aerosol impact on precipitation

NASA Astrophysics Data System (ADS)

Werhahn, Johannes; Balzarini, Allessandra; Baró, Roccio; Curci, Gabriele; Forkel, Renate; Hirtl, Marcus; Honzak, Luka; Jiménez-Guerrero, Pedro; Langer, Matthias; Lorenz, Christof; Pérez, Juan L.; Pirovano, Guido; San José, Roberto; Tuccella, Paolo; Žabkar, Rahela

2014-05-01

Simulated feedback effects between aerosol concentrations and meteorological variables and on pollutant distributions are expected to depend on model configuration and the meteorological situation. In order to quantity these effects the second phase of the AQMEII (Air Quality Model Evaluation International Initiative; http://aqmeii.jrc.ec.europa.eu/) model inter-comparison exercise focused on online coupled meteorology-chemistry models. Among others, seven of the participating groups contributed simulations with WRF-Chem (Grell et al., 2005) for Europe. According to the common simulation strategy for AQMEII phase 2, the entire year 2010 was simulated as a sequence of 2-day time slices. For better comparability, the seven groups using WRF-Chem applied the same grid spacing of 23 km and shared common processing of initial and boundary conditions as well as anthropogenic and fire emissions. The simulations differ by the chosen chemistry option, aerosol module, cloud microphysics, and by the degree of aerosol-meteorology feedback that was considered. Results from this small ensemble are analyzed with respect to the effect of the different degrees of aerosol-meteorology feedback, i.e. no aerosol feedback, direct aerosol effect, and direct plus indirect aerosol effect, on large scale precipitation. Simulated precipitation fields were compared against daily precipitation observations as given by E-OBS 25 km resolution gridded dataset from the EU-FP6 project ENSEMBLES (http://ensembles-eu.metoffice.com) and the data providers in the ECA&D project (http://www.ecad.eu). As expected, a first analysis confirms that the average impact of aerosol feedback is only very small on the considered spatial and temporal scale, i.e. due to the fact that initial meteorological conditions were taken every 3rd day from a one day non-feedback spin-up run. However, the analysis of the correlations between simulation and observations for the first and the second day indicates for some particular situations and regions a slightly better correlation when the aerosol indirect effect is accounted for.

Temperature feedback control for long-term carrier-envelope phase locking

DOEpatents

Chang, Zenghu [Manhattan, KS; Yun, Chenxia [Manhattan, KS; Chen, Shouyuan [Manhattan, KS; Wang, He [Manhattan, KS; Chini, Michael [Manhattan, KS

2012-07-24

A feedback control module for stabilizing a carrier-envelope phase of an output of a laser oscillator system comprises a first photodetector, a second photodetector, a phase stabilizer, an optical modulator, and a thermal control element. The first photodetector may generate a first feedback signal corresponding to a first portion of a laser beam from an oscillator. The second photodetector may generate a second feedback signal corresponding to a second portion of the laser beam filtered by a low-pass filter. The phase stabilizer may divide the frequency of the first feedback signal by a factor and generate an error signal corresponding to the difference between the frequency-divided first feedback signal and the second feedback signal. The optical modulator may modulate the laser beam within the oscillator corresponding to the error signal. The thermal control unit may change the temperature of the oscillator corresponding to a signal operable to control the optical modulator.

The Evolution of Different Forms of Sociality: Behavioral Mechanisms and Eco-Evolutionary Feedback

PubMed Central

van der Post, Daniel J.; Verbrugge, Rineke; Hemelrijk, Charlotte K.

2015-01-01

Different forms of sociality have evolved via unique evolutionary trajectories. However, it remains unknown to what extent trajectories of social evolution depend on the specific characteristics of different species. Our approach to studying such trajectories is to use evolutionary case-studies, so that we can investigate how grouping co-evolves with a multitude of individual characteristics. Here we focus on anti-predator vigilance and foraging. We use an individual-based model, where behavioral mechanisms are specified, and costs and benefits are not predefined. We show that evolutionary changes in grouping alter selection pressures on vigilance, and vice versa. This eco-evolutionary feedback generates an evolutionary progression from “leader-follower” societies to “fission-fusion” societies, where cooperative vigilance in groups is maintained via a balance between within- and between-group selection. Group-level selection is generated from an assortment that arises spontaneously when vigilant and non-vigilant foragers have different grouping tendencies. The evolutionary maintenance of small groups, and cooperative vigilance in those groups, is therefore achieved simultaneously. The evolutionary phases, and the transitions between them, depend strongly on behavioral mechanisms. Thus, integrating behavioral mechanisms and eco-evolutionary feedback is critical for understanding what kinds of intermediate stages are involved during the evolution of particular forms of sociality. PMID:25629313

The evolution of different forms of sociality: behavioral mechanisms and eco-evolutionary feedback.

PubMed

van der Post, Daniel J; Verbrugge, Rineke; Hemelrijk, Charlotte K

2015-01-01

Different forms of sociality have evolved via unique evolutionary trajectories. However, it remains unknown to what extent trajectories of social evolution depend on the specific characteristics of different species. Our approach to studying such trajectories is to use evolutionary case-studies, so that we can investigate how grouping co-evolves with a multitude of individual characteristics. Here we focus on anti-predator vigilance and foraging. We use an individual-based model, where behavioral mechanisms are specified, and costs and benefits are not predefined. We show that evolutionary changes in grouping alter selection pressures on vigilance, and vice versa. This eco-evolutionary feedback generates an evolutionary progression from "leader-follower" societies to "fission-fusion" societies, where cooperative vigilance in groups is maintained via a balance between within- and between-group selection. Group-level selection is generated from an assortment that arises spontaneously when vigilant and non-vigilant foragers have different grouping tendencies. The evolutionary maintenance of small groups, and cooperative vigilance in those groups, is therefore achieved simultaneously. The evolutionary phases, and the transitions between them, depend strongly on behavioral mechanisms. Thus, integrating behavioral mechanisms and eco-evolutionary feedback is critical for understanding what kinds of intermediate stages are involved during the evolution of particular forms of sociality.

Real-time feedback can improve infant manikin cardiopulmonary resuscitation by up to 79%--a randomised controlled trial.

PubMed

Martin, Philip; Theobald, Peter; Kemp, Alison; Maguire, Sabine; Maconochie, Ian; Jones, Michael

2013-08-01

European and Advanced Paediatric Life Support training courses. Sixty-nine certified CPR providers. CPR providers were randomly allocated to a 'no-feedback' or 'feedback' group, performing two-thumb and two-finger chest compressions on a "physiological", instrumented resuscitation manikin. Baseline data was recorded without feedback, before chest compressions were repeated with one group receiving feedback. Indices were calculated that defined chest compression quality, based upon comparison of the chest wall displacement to the targets of four, internationally recommended parameters: chest compression depth, release force, chest compression rate and compression duty cycle. Baseline data were consistent with other studies, with <1% of chest compressions performed by providers simultaneously achieving the target of the four internationally recommended parameters. During the 'experimental' phase, 34 CPR providers benefitted from the provision of 'real-time' feedback which, on analysis, coincided with a statistical improvement in compression rate, depth and duty cycle quality across both compression techniques (all measures: p<0.001). Feedback enabled providers to simultaneously achieve the four targets in 75% (two-finger) and 80% (two-thumb) of chest compressions. Real-time feedback produced a dramatic increase in the quality of chest compression (i.e. from <1% to 75-80%). If these results transfer to a clinical scenario this technology could, for the first time, support providers in consistently performing accurate chest compressions during infant CPR and thus potentially improving clinical outcomes. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Methods and apparatus for broadband frequency comb stabilization

DOEpatents

Cox, Jonathan A; Kaertner, Franz X

2015-03-17

Feedback loops can be used to shift and stabilize the carrier-envelope phase of a frequency comb from a mode-locked fibers laser or other optical source. Compared to other frequency shifting and stabilization techniques, feedback-based techniques provide a wideband closed-loop servo bandwidth without optical filtering, beam pointing errors, or group velocity dispersion. It also enables phase locking to a stable reference, such as a Ti:Sapphire laser, continuous-wave microwave or optical source, or self-referencing interferometer, e.g., to within 200 mrad rms from DC to 5 MHz. In addition, stabilized frequency combs can be coherently combined with other stable signals, including other stabilized frequency combs, to synthesize optical pulse trains with pulse durations of as little as a single optical cycle. Such a coherent combination can be achieved via orthogonal control, using balanced optical cross-correlation for timing stabilization and balanced homodyne detection for phase stabilization.

The Effects of a Local Negative Feedback Function between Choice and Relative Reinforcer Rate

PubMed Central

Davison, Michael; Elliffe, Douglas; Marr, M. Jackson

2010-01-01

Four pigeons were trained on two-key concurrent variable-interval schedules with no changeover delay. In Phase 1, relative reinforcers on the two alternatives were varied over five conditions from .1 to .9. In Phases 2 and 3, we instituted a molar feedback function between relative choice in an interreinforcer interval and the probability of reinforcers on the two keys ending the next interreinforcer interval. The feedback function was linear, and was negatively sloped so that more extreme choice in an interreinforcer interval made it more likely that a reinforcer would be available on the other key at the end of the next interval. The slope of the feedback function was −1 in Phase 2 and −3 in Phase 3. We varied relative reinforcers in each of these phases by changing the intercept of the feedback function. Little effect of the feedback functions was discernible at the local (interreinforcer interval) level, but choice measured at an extended level across sessions was strongly and significantly decreased by increasing the negative slope of the feedback function. PMID:21451748

Functional neuroimaging of the Iowa Gambling Task in older adults.

PubMed

Halfmann, Kameko; Hedgcock, William; Bechara, Antoine; Denburg, Natalie L

2014-11-01

The neural systems most susceptible to age-related decline mirror the systems linked to decision making. Yet, the neural processes underlying decision-making disparities among older adults are not well understood. We sought to identify neural response patterns that distinguish 2 groups of older adults who exhibit divergent decision-making patterns. Participants were 31 healthy older adults (ages 59-88, 53% female), defined as advantageous or disadvantageous decision-makers based on Iowa Gambling Task (IGT) performance, who completed an alternate version of the IGT while undergoing functional MRI. The groups were indistinguishable on neuropsychological testing. We contrasted the BOLD signal between groups during 3 phases of the decision-making process: Prechoice (preselection), Prefeedback (postselection), and Feedback (receipt of gains/losses). We further examined whether BOLD signal varied as a function of age in each group. We observed greater activation among the IGT-Disadvantageous relative to -Advantageous older adults in the prefrontal cortex during the early phases of the decision-making process (Prechoice), and in posterior brain regions (e.g., the precuneus) during the later phases (Prefeedback and Feedback). We also found that with increasing age, IGT-Advantageous older adults showed increasing activation in the prefrontal cortex during all phases and increasing activation in the posterior cingulate during earlier phases of the decision process. By contrast, the IGT-Disadvantageous older adults exhibited a reduced or reversed trend. These functional differences may be a consequence of altered reward processing or differing compensatory strategies between IGT-Disadvantageous and -Advantageous older adults. This supports the notion that divergent neurobiological aging trajectories underlie disparate decision-making patterns. PsycINFO Database Record (c) 2014 APA, all rights reserved.

High-frequency chaotic dynamics enabled by optical phase-conjugation

PubMed Central

Mercier, Émeric; Wolfersberger, Delphine; Sciamanna, Marc

2016-01-01

Wideband chaos is of interest for applications such as random number generation or encrypted communications, which typically use optical feedback in a semiconductor laser. Here, we show that replacing conventional optical feedback with phase-conjugate feedback improves the chaos bandwidth. In the range of achievable phase-conjugate mirror reflectivities, the bandwidth increase reaches 27% when compared with feedback from a conventional mirror. Experimental measurements of the time-resolved frequency dynamics on nanosecond time-scales show that the bandwidth enhancement is related to the onset of self-pulsing solutions at harmonics of the external-cavity frequency. In the observed regime, the system follows a chaotic itinerancy among these destabilized high-frequency external-cavity modes. The recorded features are unique to phase-conjugate feedback and distinguish it from the long-standing problem of time-delayed feedback dynamics. PMID:26739806

A Two-Phase Approach to Developing SNAP: an iPhone Application to Support Appointment Scheduling and Management for Women with a BRCA Mutation.

PubMed

Scherr, Courtney Lynam; Feuston, Jessica L; Nixon, Dawn M; Cohen, Stephanie A

2018-04-01

Professional organizations provide surveillance guidelines for BRCA1 and BRCA2 (BRCA) carriers with intact breasts and/or ovaries to facilitate early cancer detection. However, literature indicates adherence to surveillance guidelines is inconsistent at best. Using the Messaging Model for Health Communication Campaigns framework, we undertook a two-phase formative research approach to develop an intervention to promote adherence to surveillance guidelines. Discussion groups identified preferred intervention format and function in phase I. Findings indicated carriers desired a phone application (app) to assist with surveillance management and appointment tracking. Thus, an iPhone app for carriers to track appointments based on published surveillance guidelines was developed. In phase II, we obtained feedback from BRCA carriers via a survey during a prototype demonstration at a regional conference. Participants in phase II wanted reminder capabilities and the ability to add and modify information fields. This feedback informed intervention modifications, resulting in the Scheduling Necessary Advised Procedures (SNAP) iPhone app currently being pilot tested by BRCA carriers throughout the USA.

Digital phase-lock loop

NASA Technical Reports Server (NTRS)

Thomas, Jr., Jess B. (Inventor)

1991-01-01

An improved digital phase lock loop incorporates several distinctive features that attain better performance at high loop gain and better phase accuracy. These features include: phase feedback to a number-controlled oscillator in addition to phase rate; analytical tracking of phase (both integer and fractional cycles); an amplitude-insensitive phase extractor; a more accurate method for extracting measured phase; a method for changing loop gain during a track without loss of lock; and a method for avoiding loss of sampled data during computation delay, while maintaining excellent tracking performance. The advantages of using phase and phase-rate feedback are demonstrated by comparing performance with that of rate-only feedback. Extraction of phase by the method of modeling provides accurate phase measurements even when the number-controlled oscillator phase is discontinuously updated.

Nonhomogeneous transfer reveals specificity in speech motor learning.

PubMed

Rochet-Capellan, Amélie; Richer, Lara; Ostry, David J

2012-03-01

Does motor learning generalize to new situations that are not experienced during training, or is motor learning essentially specific to the training situation? In the present experiments, we use speech production as a model to investigate generalization in motor learning. We tested for generalization from training to transfer utterances by varying the acoustical similarity between these two sets of utterances. During the training phase of the experiment, subjects received auditory feedback that was altered in real time as they repeated a single consonant-vowel-consonant utterance. Different groups of subjects were trained with different consonant-vowel-consonant utterances, which differed from a subsequent transfer utterance in terms of the initial consonant or vowel. During the adaptation phase of the experiment, we observed that subjects in all groups progressively changed their speech output to compensate for the perturbation (altered auditory feedback). After learning, we tested for generalization by having all subjects produce the same single transfer utterance while receiving unaltered auditory feedback. We observed limited transfer of learning, which depended on the acoustical similarity between the training and the transfer utterances. The gradients of generalization observed here are comparable to those observed in limb movement. The present findings are consistent with the conclusion that speech learning remains specific to individual instances of learning.

Nonhomogeneous transfer reveals specificity in speech motor learning

PubMed Central

Rochet-Capellan, Amélie; Richer, Lara

2012-01-01

Does motor learning generalize to new situations that are not experienced during training, or is motor learning essentially specific to the training situation? In the present experiments, we use speech production as a model to investigate generalization in motor learning. We tested for generalization from training to transfer utterances by varying the acoustical similarity between these two sets of utterances. During the training phase of the experiment, subjects received auditory feedback that was altered in real time as they repeated a single consonant-vowel-consonant utterance. Different groups of subjects were trained with different consonant-vowel-consonant utterances, which differed from a subsequent transfer utterance in terms of the initial consonant or vowel. During the adaptation phase of the experiment, we observed that subjects in all groups progressively changed their speech output to compensate for the perturbation (altered auditory feedback). After learning, we tested for generalization by having all subjects produce the same single transfer utterance while receiving unaltered auditory feedback. We observed limited transfer of learning, which depended on the acoustical similarity between the training and the transfer utterances. The gradients of generalization observed here are comparable to those observed in limb movement. The present findings are consistent with the conclusion that speech learning remains specific to individual instances of learning. PMID:22190628

Kisspeptin system in ovariectomized mice: Estradiol and progesterone regulation.

PubMed

Marraudino, Marilena; Martini, Mariangela; Trova, Sara; Farinetti, Alice; Ponti, Giovanna; Gotti, Stefano; Panzica, GianCarlo

2018-06-01

The kisspeptin system is clustered in two main groups of cell bodies (the periventricular region, RP3V and the arcuate nucleus, ARC) that send fibers mainly to the GnRH neurons and in a few other locations, including the paraventricular nucleus, PVN. In physiological conditions, gonadal hormones modulate the kisspeptin system with expression changes according to different phases of the estrous cycle: the highest being in estrus phase in RP3V and PVN (positive feedback), and in ARC during the diestrus phase (negative feedback). In this work we wanted to study these hormonal fluctuations during the estrous cycle, investigating the role played by progesterone (P) or estradiol (E 2 ), alone or together, on the kisspeptin system. Gonadectomized CD1 female mice were treated with P, E 2 or both (E 2  + P), following a timing of administration that emulates the different phases of estrous cycle, for two cycles of 4 days. As expected, the two cell groups were differentially affected by E 2 ; the RP3V group was positively influenced by E 2 (alone or with the P), whereas in the ARC the administration of E 2 did not affect the system. However P (alone) induced a rise in the kisspeptin immunoreactivity. All the treatments significantly affected the kisspeptin innervation of the PVN, with regional differences, suggesting that these fibers arrive from both RP3V and ARC nuclei. Copyright © 2018 Elsevier B.V. All rights reserved.

Functional role of delta and theta band oscillations for auditory feedback processing during vocal pitch motor control

PubMed Central

Behroozmand, Roozbeh; Ibrahim, Nadine; Korzyukov, Oleg; Robin, Donald A.; Larson, Charles R.

2015-01-01

The answer to the question of how the brain incorporates sensory feedback and links it with motor function to achieve goal-directed movement during vocalization remains unclear. We investigated the mechanisms of voice pitch motor control by examining the spectro-temporal dynamics of EEG signals when non-musicians (NM), relative pitch (RP), and absolute pitch (AP) musicians maintained vocalizations of a vowel sound and received randomized ± 100 cents pitch-shift stimuli in their auditory feedback. We identified a phase-synchronized (evoked) fronto-central activation within the theta band (5–8 Hz) that temporally overlapped with compensatory vocal responses to pitch-shifted auditory feedback and was significantly stronger in RP and AP musicians compared with non-musicians. A second component involved a non-phase-synchronized (induced) frontal activation within the delta band (1–4 Hz) that emerged at approximately 1 s after the stimulus onset. The delta activation was significantly stronger in the NM compared with RP and AP groups and correlated with the pitch rebound error (PRE), indicating the degree to which subjects failed to re-adjust their voice pitch to baseline after the stimulus offset. We propose that the evoked theta is a neurophysiological marker of enhanced pitch processing in musicians and reflects mechanisms by which humans incorporate auditory feedback to control their voice pitch. We also suggest that the delta activation reflects adaptive neural processes by which vocal production errors are monitored and used to update the state of sensory-motor networks for driving subsequent vocal behaviors. This notion is corroborated by our findings showing that larger PREs were associated with greater delta band activity in the NM compared with RP and AP groups. These findings provide new insights into the neural mechanisms of auditory feedback processing for vocal pitch motor control. PMID:25873858

Utilizing time-frequency amplitude and phase synchrony measure to assess feedback processing in a gambling task.

PubMed

Watts, Adreanna T M; Tootell, Anne V; Fix, Spencer T; Aviyente, Selin; Bernat, Edward M

2018-04-29

The neurophysiological mechanisms involved in the evaluation of performance feedback have been widely studied in the ERP literature over the past twenty years, but understanding has been limited by the use of traditional time-domain amplitude analytic approaches. Gambling outcome valence has been identified as an important factor modulating event-related potential (ERP) components, most notably the feedback negativity (FN). Recent work employing time-frequency analysis has shown that processes indexed by the FN are confounded in the time-domain and can be better represented as separable feedback-related processes in the theta (3-7 Hz) and delta (0-3 Hz) frequency bands. In addition to time-frequency amplitude analysis, phase synchrony measures have begun to further our understanding of performance evaluation by revealing how feedback information is processed within and between various brain regions. The current study aimed to provide an integrative assessment of time-frequency amplitude, inter-trial phase synchrony, and inter-channel phase synchrony changes following monetary feedback in a gambling task. Results revealed that time-frequency amplitude activity explained separable loss and gain processes confounded in the time-domain. Furthermore, phase synchrony measures explained unique variance above and beyond amplitude measures and demonstrated enhanced functional integration between medial prefrontal and bilateral frontal, motor, and occipital regions for loss relative to gain feedback. These findings demonstrate the utility of assessing time-frequency amplitude, inter-trial phase synchrony, and inter-channel phase synchrony together to better elucidate the neurophysiology of feedback processing. Copyright © 2017. Published by Elsevier B.V.

Personalized Feedback on Staff Dose in Fluoroscopy-Guided Interventions: A New Era in Radiation Dose Monitoring.

PubMed

Sailer, Anna M; Vergoossen, Laura; Paulis, Leonie; van Zwam, Willem H; Das, Marco; Wildberger, Joachim E; Jeukens, Cécile R L P N

2017-11-01

Radiation safety and protection are a key component of fluoroscopy-guided interventions. We hypothesize that providing weekly personal dose feedback will increase radiation awareness and ultimately will lead to optimized behavior. Therefore, we designed and implemented a personalized feedback of procedure and personal doses for medical staff involved in fluoroscopy-guided interventions. Medical staff (physicians and technicians, n = 27) involved in fluoroscopy-guided interventions were equipped with electronic personal dose meters (PDMs). Procedure dose data including the dose area product and effective doses from PDMs were prospectively monitored for each consecutive procedure over an 8-month period (n = 1082). A personalized feedback form was designed displaying for each staff individually the personal dose per procedure, as well as relative and cumulative doses. This study consisted of two phases: (1) 1-5th months: Staff did not receive feedback (n = 701) and (2) 6-8th months: Staff received weekly individual dose feedback (n = 381). An anonymous evaluation was performed on the feedback and occupational dose. Personalized feedback was scored valuable by 76% of the staff and increased radiation dose awareness for 71%. 57 and 52% reported an increased feeling of occupational safety and changing their behavior because of personalized feedback, respectively. For technicians, the normalized dose was significantly lower in the feedback phase compared to the prefeedback phase: [median (IQR) normalized dose (phase 1) 0.12 (0.04-0.50) µSv/Gy cm 2 versus (phase 2) 0.08 (0.02-0.24) µSv/Gy cm 2 , p = 0.002]. Personalized dose feedback increases radiation awareness and safety and can be provided to staff involved in fluoroscopy-guided interventions.

Continuous-Wave Single-Frequency Operation of Fabry-Perot Laser Diodes by Self-Injection Phase Locking Using Feedback from a Fiber Bragg Grating

NASA Technical Reports Server (NTRS)

Duerksen, Gary L.; Krainak, Michael A.

1998-01-01

Single-frequency operation of uncoated Fabry-Perot laser diodes is demonstrated by phase- locking the laser oscillations through self-injection seeding with feedback from a fiber Bragg grating. By precisely tuning the laser temperature so that an axial-mode coincides with the short-wavelength band edge of the grating, the phase of the feedback is made conjugate to that of the axial mode, locking the phase of the laser oscillations to that mode.

Bimanual Coordination Learning with Different Augmented Feedback Modalities and Information Types

PubMed Central

Chiou, Shiau-Chuen; Chang, Erik Chihhung

2016-01-01

Previous studies have shown that bimanual coordination learning is more resistant to the removal of augmented feedback when acquired with auditory than with visual channel. However, it is unclear whether this differential “guidance effect” between feedback modalities is due to enhanced sensorimotor integration via the non-dominant auditory channel or strengthened linkage to kinesthetic information under rhythmic input. The current study aimed to examine how modalities (visual vs. auditory) and information types (continuous visuospatial vs. discrete rhythmic) of concurrent augmented feedback influence bimanual coordination learning. Participants either learned a 90°-out-of-phase pattern for three consecutive days with Lissajous feedback indicating the integrated position of both arms, or with visual or auditory rhythmic feedback reflecting the relative timing of the movement. The results showed diverse performance change after practice when the feedback was removed between Lissajous and the other two rhythmic groups, indicating that the guidance effect may be modulated by the type of information provided during practice. Moreover, significant performance improvement in the dual-task condition where the irregular rhythm counting task was applied as a secondary task also suggested that lower involvement of conscious control may result in better performance in bimanual coordination. PMID:26895286

Bimanual Coordination Learning with Different Augmented Feedback Modalities and Information Types.

PubMed

Chiou, Shiau-Chuen; Chang, Erik Chihhung

2016-01-01

Previous studies have shown that bimanual coordination learning is more resistant to the removal of augmented feedback when acquired with auditory than with visual channel. However, it is unclear whether this differential "guidance effect" between feedback modalities is due to enhanced sensorimotor integration via the non-dominant auditory channel or strengthened linkage to kinesthetic information under rhythmic input. The current study aimed to examine how modalities (visual vs. auditory) and information types (continuous visuospatial vs. discrete rhythmic) of concurrent augmented feedback influence bimanual coordination learning. Participants either learned a 90°-out-of-phase pattern for three consecutive days with Lissajous feedback indicating the integrated position of both arms, or with visual or auditory rhythmic feedback reflecting the relative timing of the movement. The results showed diverse performance change after practice when the feedback was removed between Lissajous and the other two rhythmic groups, indicating that the guidance effect may be modulated by the type of information provided during practice. Moreover, significant performance improvement in the dual-task condition where the irregular rhythm counting task was applied as a secondary task also suggested that lower involvement of conscious control may result in better performance in bimanual coordination.

The New Parent Checklist: A Tool to Promote Parental Reflection.

PubMed

Keys, Elizabeth M; McNeil, Deborah A; Wallace, Donna A; Bostick, Jason; Churchill, A Jocelyn; Dodd, Maureen M

To design and establish content and face validity of an evidence-informed tool that promotes parental self-reflection during the transition to parenthood. The New Parent Checklist was developed using a three-phase sequential approach: Phase 1 a scoping review and expert consultation to develop and refine a prototype tool; Phase 2 content analysis of parent focus groups; and Phase 3 assessment of utility in a cross-sectional sample of parents completing the New Parent Checklist and a questionnaire. The initial version of the checklist was considered by experts to contain key information. Focus group participants found it useful, appropriate, and nonjudgmental, and offered suggestions to enhance readability, utility, as well as face and content validity. In the cross-sectional survey, 83% of the participants rated the New Parent Checklist as "helpful" or "very helpful" and 90% found the New Parent Checklist "very easy" to use. Open-ended survey responses included predominantly positive feedback. Notable differences existed for some items based on respondents' first language, age, and sex. Results and feedback from all three phases informed the current version, available for download online. The New Parent Checklist is a comprehensive evidence-informed self-reflective tool with promising content and face validity. Depending on parental characteristics and infant age, certain items of the New Parent Checklist have particular utility but may also require further adaptation and testing. Local resources for information and/or support are included in the tool and could be easily adapted by other regions to incorporate their own local resources.

Phase detector for three-phase power factor controller

NASA Technical Reports Server (NTRS)

Nola, F. J. (Inventor)

1984-01-01

A phase detector for the three phase power factor controller (PFC) is described. The phase detector for each phase includes an operational amplifier which senses the current phase angle for that phase by sensing the voltage across the phase thyristor. Common mode rejection is achieved by providing positive feedback between the input and output of the voltage sensing operational amplifier. this feedback preferably comprises a resistor connected between the output and input of the operational amplifier. The novelty of the invention resides in providing positive feedback such that switching of the operational amplifier is synchronized with switching of the voltage across the thyristor. The invention provides a solution to problems associated with high common mode voltage and enables use of lower cost components than would be required by other approaches.

Reward and punishment enhance motor adaptation in stroke.

PubMed

Quattrocchi, Graziella; Greenwood, Richard; Rothwell, John C; Galea, Joseph M; Bestmann, Sven

2017-09-01

The effects of motor learning, such as motor adaptation, in stroke rehabilitation are often transient, thus mandating approaches that enhance the amount of learning and retention. Previously, we showed in young individuals that reward and punishment feedback have dissociable effects on motor adaptation, with punishment improving adaptation and reward enhancing retention. If these findings were able to generalise to patients with stroke, they would provide a way to optimise motor learning in these patients. Therefore, we tested this in 45 patients with chronic stroke allocated in three groups. Patients performed reaching movements with their paretic arm with a robotic manipulandum. After training (day 1), day 2 involved adaptation to a novel force field. During the adaptation phase, patients received performance-based feedback according to the group they were allocated: reward, punishment or no feedback (neutral). On day 3, patients readapted to the force field but all groups now received neutral feedback. All patients adapted, with reward and punishment groups displaying greater adaptation and readaptation than the neutral group, irrespective of demographic, cognitive or functional differences. Remarkably, the reward and punishment groups adapted to similar degree as healthy controls. Finally, the reward group showed greater retention. This study provides, for the first time, evidence that reward and punishment can enhance motor adaptation in patients with stroke. Further research on reinforcement-based motor learning regimes is warranted to translate these promising results into clinical practice and improve motor rehabilitation outcomes in patients with stroke. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Why don't you like me? Midfrontal theta power in response to unexpected peer rejection feedback.

PubMed

van der Molen, M J W; Dekkers, L M S; Westenberg, P M; van der Veen, F M; van der Molen, M W

2017-02-01

Social connectedness theory posits that the brain processes social rejection as a threat to survival. Recent electrophysiological evidence suggests that midfrontal theta (4-8Hz) oscillations in the EEG provide a window on the processing of social rejection. Here we examined midfrontal theta dynamics (power and inter-trial phase synchrony) during the processing of social evaluative feedback. We employed the Social Judgment paradigm in which 56 undergraduate women (mean age=19.67 years) were asked to communicate their expectancies about being liked vs. disliked by unknown peers. Expectancies were followed by feedback indicating social acceptance vs. rejection. Results revealed a significant increase in EEG theta power to unexpected social rejection feedback. This EEG theta response could be source-localized to brain regions typically reported during activation of the saliency network (i.e., dorsal anterior cingulate cortex, insula, inferior frontal gyrus, frontal pole, and the supplementary motor area). Theta phase dynamics mimicked the behavior of the time-domain averaged feedback-related negativity (FRN) by showing stronger phase synchrony for feedback that was unexpected vs. expected. Theta phase, however, differed from the FRN by also displaying stronger phase synchrony in response to rejection vs. acceptance feedback. Together, this study highlights distinct roles for midfrontal theta power and phase synchrony in response to social evaluative feedback. Our findings contribute to the literature by showing that midfrontal theta oscillatory power is sensitive to social rejection but only when peer rejection is unexpected, and this theta response is governed by a widely distributed neural network implicated in saliency detection and conflict monitoring. Copyright © 2016 Elsevier Inc. All rights reserved.

Self-controlled practice enhances motor learning in introverts and extroverts.

PubMed

Kaefer, Angélica; Chiviacowsky, Suzete; Meira, Cassio de Miranda; Tani, Go

2014-06-01

The purpose of the present study was to investigate the effects of self-controlled feedback on the learning of a sequential-timing motor task in introverts and extroverts. Fifty-six university students were selected by the Eysenck Personality Questionnaire. They practiced a motor task consisting of pressing computer keyboard keys in a specific spatial and temporal pattern. The experiment consisted of practice, retention, and transfer phases. The participants were distributed into 4 groups, formed by the combination of personality trait (extraversion/introversion) and type of feedback frequency (self-controlled/yoked). The results showed superior learning for the groups that practiced in a self-controlled schedule, in relation to groups who practiced in an externally controlled schedule, F(1, 52) = 4.13, p < .05, eta2 = .07, regardless of personality trait. We conclude that self-controlled practice enhances motor learning in introverts and extroverts.

Group Feedback for Continuous Learning

ERIC Educational Resources Information Center

London, Manuel; Sessa, Valerie I.

2006-01-01

This article explores relationships between feedback, group learning, and performance. It considers how feedback to individuals and the group as a whole supports continuous group learning. Feedback source, purpose, clarity, and valence may affect perceptions, processing, and outcomes of feedback. How feedback is processed and used may be…

From guidelines to practice: a pharmacist-driven prospective audit and feedback improvement model for peri-operative antibiotic prophylaxis in 34 South African hospitals.

PubMed

Brink, Adrian J; Messina, Angeliki P; Feldman, Charles; Richards, Guy A; van den Bergh, Dena

2017-04-01

Few data exist on the implementation of process measures to facilitate adherence to peri-operative antibiotic prophylaxis (PAP) guidelines in Africa. To implement an improvement model for PAP utilizing existing resources, in order to achieve a reduction in surgical site infections (SSIs) across a heterogeneous group of 34 urban and rural South African hospitals. A pharmacist-driven, prospective audit and feedback strategy involving change management and improvement principles was utilized. This 2.5 year intervention involved a pre-implementation phase to test a PAP guideline and a 'toolkit' at pilot sites. Following antimicrobial stewardship committee and clinician endorsement, the model was introduced in all institutions and a survey of baseline SSI and compliance rates with four process measures (antibiotic choice, dose, administration time and duration) was performed. The post-implementation phase involved audit, intervention and monthly feedback to facilitate improvements in compliance. For 70 weeks of standardized measurements and feedback, 24 206 surgical cases were reviewed. There was a significant improvement in compliance with all process measures (composite compliance) from 66.8% (95% CI 64.8-68.7) to 83.3% (95% CI 80.8-85.8), representing a 24.7% increase ( P  <   0.0001). The SSI rate decreased by 19.7% from a mean group rate of 2.46 (95% CI 2.18-2.73) pre-intervention to 1.97 post-intervention (95% CI 1.79-2.15) ( P  =   0.0029). The implementation of process improvement initiatives and principles targeted to institutional needs utilizing pharmacists can effectively improve PAP guideline compliance and sustainable patient outcomes. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Implementation and impact of an audit and feedback antimicrobial stewardship intervention in the orthopaedics department of a tertiary-care hospital: a controlled interrupted time series study.

PubMed

Tavares, Margarida; Carvalho, Ana Cláudia; Almeida, José Pedro; Andrade, Paulo; São-Simão, Ricardo; Soares, Pedro; Alves, Carlos; Pinto, Rui; Fontanet, Arnaud; Watier, Laurence

2018-06-01

A prospective audit and feedback antimicrobial stewardship intervention conducted in the Orthopaedics Department of a university hospital in Portugal was evaluated by comparing an interrupted time series in the intervention group with a non-intervention (control) group. Monthly antibiotic use (except cefazolin) was measured as the World Health Organization's Anatomical Therapeutic Chemical defined daily doses (ATC-DDD) from January 2012 to September 2016, excluding the 6-month phase of intervention implementation starting on 1 January 2015. Compared with the control group, the intervention group had a monthly decrease in the use of fluoroquinolones by 2.3 DDD/1000 patient-days [95% confidence interval (CI) -3.97 to -0.63]. An increase in the use of penicillins by 103.3 DDD/1000 patient-days (95% CI 47.42 to 159.10) was associated with intervention implementation, followed by a decrease during the intervention period (slope = -5.2, 95% CI -8.56 to -1.82). In the challenging scenario of treatment of osteoarticular and prosthetic joint infections, an audit and feedback intervention reduced antibiotic exposure and spectrum. Copyright © 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

RF power recovery feedback circulator

DOEpatents

Sharamentov, Sergey I [Bolingbrook, IL

2011-03-29

A device and method for improving the efficiency of RF systems having a Reflective Load. In the preferred embodiment, Reflected Energy from a superconducting resonator of a particle accelerator is reintroduced to the resonator after the phase of the Reflected Energy is aligned with the phase of the Supply Energy from a RF Energy Source. In one embodiment, a Circulator is used to transfer Reflected Energy from the Reflective Load into a Phase Adjuster which aligns the phase of the Reflected Energy with that of the Supply Energy. The phase-aligned energy is then combined with the Supply Energy, and reintroduced into the Reflective Load. In systems having a constant phase shift, the Phase Adjuster may be designed to shift the phase of the Reflected Energy by a constant amount using a Phase Shifter. In systems having a variety (variable) phase shifts, a Phase Shifter controlled by a phase feedback loop comprising a Phase Detector and a Feedback Controller to account for the various phase shifts is preferable.

Static inverter with synchronous output waveform synthesized by time-optimal-response feedback

NASA Technical Reports Server (NTRS)

Kernick, A.; Stechschulte, D. L.; Shireman, D. W.

1976-01-01

Time-optimal-response 'bang-bang' or 'bang-hang' technique, using four feedback control loops, synthesizes static-inverter sinusoidal output waveform by self-oscillatory but yet synchronous pulse-frequency-modulation (SPFM). A single modular power stage per phase of ac output entails the minimum of circuit complexity while providing by feedback synthesis individual phase voltage regulation, phase position control and inherent compensation simultaneously for line and load disturbances. Clipped sinewave performance is described under off-limit load or input voltage conditions. Also, approaches to high power levels, 3-phase arraying and parallel modular connection are given.

Stereotype threat engenders neural attentional bias toward negative feedback to undermine performance.

PubMed

Forbes, Chad E; Leitner, Jordan B

2014-10-01

Stereotype threat, a situational pressure individuals experience when they fear confirming a negative group stereotype, engenders a cascade of physiological stress responses, negative appraisals, and performance monitoring processes that tax working memory resources necessary for optimal performance. Less is known, however, about how stereotype threat biases attentional processing in response to performance feedback, and how such attentional biases may undermine performance. Women received feedback on math problems in stereotype threatening compared to stereotype-neutral contexts while continuous EEG activity was recorded. Findings revealed that stereotype threatened women elicited larger midline P100 ERPs, increased phase locking between anterior cingulate cortex and dorsolateral prefrontal cortex (two regions integral for attentional processes), and increased power in left fusiform gyrus in response to negative feedback compared to positive feedback and women in stereotype-neutral contexts. Increased power in left fusiform gyrus in response to negative feedback predicted underperformance on the math task among stereotype threatened women only. Women in stereotype-neutral contexts exhibited the opposite trend. Findings suggest that in stereotype threatening contexts, neural networks integral for attention and working memory are biased toward negative, stereotype confirming feedback at very early speeds of information processing. This bias, in turn, plays a role in undermining performance. Copyright © 2014 Elsevier B.V. All rights reserved.

A SERIES OF SUPPRESSIVE SIGNALS WITHIN THE DROSOPHILA CIRCADIAN NEURAL CIRCUIT GENERATES SEQUENTIAL DAILY OUTPUTS

PubMed Central

Liang, Xitong; Holy, Timothy E; Taghert, Paul H

2017-01-01

Summary We studied the Drosophila circadian neural circuit using whole brain imaging in vivo. Five major groups of pacemaker neurons display synchronized molecular clocks, yet each exhibits a distinct phase of daily Ca2+ activation. Light and neuropeptide PDF from morning cells (s-LNv) together delay the phase of the evening (LNd) group by ~12 h; PDF alone delays the phase of the DN3 group, by ~17 h. Neuropeptide sNPF, released from s-LNv and LNd pacemakers, produces latenight Ca2+ activation in the DN1 group. The circuit also features negative feedback by PDF to truncate the s-LNv Ca2+ wave and terminate PDF release. Both PDF and sNPF suppress basal Ca2+ levels in target pacemakers with long durations by cell autonomous actions. Thus, light and neuropeptides act dynamically at distinct hubs of the circuit to produce multiple suppressive events that create the proper tempo and sequence of circadian pacemaker neuronal activities. PMID:28552314

Introduction to Group Relations and Organizational Diagnosis.

DTIC Science & Technology

The perspective of Group Relations and Organizational Diagnosis did not emerge from a vacuum. It is rooted in a clinical perspective on the study of... diagnosis became a specialty in its own right. Earlier treatments of organizational diagnosis , like the initial studies of organizational behavior...to the potential advances suggested by an intergroup perspective. The earlier works also varied in the degree to which they contributed to the entry, data collection, or feedback phases of organizational diagnosis .

Effective Feedback to Improve Primary Care Prescribing Safety (EFIPPS) a pragmatic three-arm cluster randomised trial: designing the intervention (ClinicalTrials.gov registration NCT01602705).

PubMed

Barnett, Karen N; Bennie, Marion; Treweek, Shaun; Robertson, Christopher; Petrie, Dennis J; Ritchie, Lewis D; Guthrie, Bruce

2014-10-11

High-risk prescribing in primary care is common and causes considerable harm. Feedback interventions have small/moderate effects on clinical practice, but few trials explicitly compare different forms of feedback. There is growing recognition that intervention development should be theory-informed, and that comprehensive reporting of intervention design is required by potential users of trial findings. The paper describes intervention development for the Effective Feedback to Improve Primary Care Prescribing Safety (EFIPPS) study, a pragmatic three-arm cluster randomised trial in 262 Scottish general practices. The NHS chose to implement a feedback intervention to utilise a new resource, new Prescribing Information System (newPIS). The development phase required selection of high-risk prescribing outcome measures and design of intervention components: (1) educational material (the usual care comparison), (2) feedback of practice rates of high-risk prescribing received by both intervention arms and (3) a theory-informed behaviour change component to be received by one intervention arm. Outcome measures, educational material and feedback design, were developed with a National Health Service Advisory Group. The behaviour change component was informed by the Theory of Planned Behaviour and the Health Action Process Approach. A focus group elicitation study and an email Delphi study with general practitioners (GPs) identified key attitudes and barriers of responding to the prescribing feedback. Behaviour change techniques were mapped to the psychological constructs, and the content was informed by the results of the elicitation and Delphi study. Six high-risk prescribing measures were selected in a consensus process based on importance and feasibility. Educational material and feedback design were based on current NHS Scotland practice and Advisory Group recommendations. The behaviour change component was resource constrained in development, mirroring what is feasible in an NHS context. Four behaviour change interventions were developed and embedded in five quarterly rounds of feedback targeting attitudes, subjective norms, perceived behavioural control and action planning (2×). The paper describes a process which is feasible to use in the resource-constrained environment of NHS-led intervention development and documents the intervention to make its design and implementation explicit to potential users of the trial findings. ClinicalTrials.gov: NCT01602705.

Clinical workplace learning: perceived learning value of individual and group feedback in a collectivistic culture.

PubMed

Suhoyo, Yoyo; Schönrock-Adema, Johanna; Emilia, Ova; Kuks, Jan B M; Cohen-Schotanus, Janke

2018-04-19

Feedback is essential for workplace learning. Most papers in this field concern individual feedback. In collectivistic cultures, however, group feedback is common educational practice. This study was conducted to investigate the perceived learning value and characteristics of individual and group feedback in a collectivistic culture. During two weeks, on a daily basis, clerkship students (n = 215) from 12 clinical departments at Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia, recorded individual and group feedback moments by using a structured form: the providers, focus and perceived learning value of feedback. Data were analysed with logistic regression and multilevel techniques. Students reported 2687 group and 1535 individual feedback moments. Group feedback more often focused on history taking, clinical judgment, patient management, patient counselling, and professional behaviour (OR ranging from 1.232, p < .01, to 2.152, p < .001), but less often on physical examination (OR = .836, p < .01). Group feedback less often aimed at correcting performance deficiencies (OR = .523, p < .001) and more often at comparing performance to the standard (OR = 2.447, p < .001) and planning action to improve performance (OR = 1.759, p < .001). Group feedback was perceived as more valuable than individual feedback (M = 4.08 and 3.96, respectively, β group  = .065, SE = .026, p < .01). In collectivistic cultures, group feedback may add to the array of educational measures that optimize student learning. Congruence between culture and type of feedback may be important for the effectiveness of feedback.

The Persuasive Effect of Social Network Feedback on Mediated Communication: A Case Study in a Real Organization.

PubMed

Varotto, Alessandra; Gamberini, Luciano; Spagnolli, Anna; Martino, Francesco; Giovannardi, Isabella

2016-03-01

This study focuses on social feedback, namely on information on the outcome of users' online activity indirectly generated by other users, and investigates in a real setting whether it can affect subsequent activity and, if so, whether participants are aware of that. SkyPas, an application that calculates, transmits, and displays social feedback, was embedded in a common instant messaging service (Skype(™)) and used during a 7-week trial by 24 office workers at a large business organization. The trial followed an ABA scheme in which the B phase was the feedback provision phase. Results show that social feedback affects users' communication activity (participation, inward communication, outward communication, and reciprocity), sometimes even after the feedback provision phase. At the same time, users were poorly aware of this effect, showing a discrepancy between self-reported and observational measures. These results are then discussed in terms of design transparency and task compatibility.

A van der Waals-like Transition Between Normal and Cancerous Phases in Cell Populations Dynamics of Colorectal Cancer

NASA Astrophysics Data System (ADS)

Qiu, Kang; Wang, Li-Fang; Shen, Jian; Yousif, Alssadig A. M.; He, Peng; Shao, Dan-Dan; Zhang, Xiao-Min; Kirunda, John B.; Jia, Ya

2016-11-01

Based on a deterministic continuous model of cell populations dynamics in the colonic crypt and in colorectal cancer, we propose four combinations of feedback mechanisms in the differentiations from stem cells (SCs) to transit cells (TCs) and then to differentiated cells (DCs), the four combinations include the double linear (LL), the linear and saturating (LS), the saturating and linear (SL), and the double saturating (SS) feedbacks, respectively. The relative fluctuations of the population of SCs, TCs, and DCs around equilibrium states with four feedback mechanisms are studied by using the Langevin method. With the increasing of net growth rate of TCs, it is found that the Fano factors of TCs and DCs go to a peak in a transient phase, and then increase again to infinity in the cases of LS and SS feedbacks. The “up-down-up” characteristic on the Fano factor (like the van der Waals loop) demonstrates that there exists a transient phase between the normal and cancerous phases, our novel findings suggest that the mathematical model with LS or SS feedback might be better to elucidate the dynamics of a normal and abnormal (cancerous) phases.

Motor-symptom laterality affects acquisition in Parkinson's disease: A cognitive and functional magnetic resonance imaging study.

PubMed

Huang, Pei; Tan, Yu-Yan; Liu, Dong-Qiang; Herzallah, Mohammad M; Lapidow, Elizabeth; Wang, Ying; Zang, Yu-Feng; Gluck, Mark A; Chen, Sheng-Di

2017-07-01

Asymmetric onset of motor symptoms in PD can affect cognitive function. We examined whether motor-symptom laterality could affect feedback-based associative learning and explored its underlying neural mechanism by functional magnetic resonance imaging in PD patients. We recruited 63 early-stage medication-naïve PD patients (29 left-onset medication-naïve patients, 34 right-onset medication-naïve patients) and 38 matched normal controls. Subjects completed an acquired equivalence task (including acquisition, retention, and generalization) and resting-state functional magnetic resonance imaging scans. Learning accuracy and response time in each phase of the task were recorded for behavioral measures. Regional homogeneity was used to analyze resting-state functional magnetic resonance imaging data, with regional homogeneity lateralization to evaluate hemispheric functional asymmetry in the striatum. Left-onset patients made significantly more errors in acquisition (feedback-based associative learning) than right-onset patients and normal controls, whereas right-onset patients performed as well as normal controls. There was no significant difference among these three groups in the accuracy of either retention or generalization phase. The three groups did not show significant differences in response time. In the left-onset group, there was an inverse relationship between acquisition errors and regional homogeneity in the right dorsal rostral putamen. There were no significant regional homogeneity changes in either the left or the right dorsal rostral putamen in right-onset patients when compared to controls. Motor-symptom laterality could affect feedback-based associative learning in PD, with left-onset medication-naïve patients being selectively impaired. Dysfunction in the right dorsal rostral putamen may underlie the observed deficit in associative learning in patients with left-sided onset.© 2016 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

Phase Matching in Presence of Feedback: Higher Order Terms and Enhancement of Nonlinear Interactions

DTIC Science & Technology

2003-12-01

Papers submitted for publication: M. Centini, G. D’Aguanno, L. Sciscione, C. Sibilia, M. Bertolotti, M. Scalora , M. Bloemer: “Phase matching in the...M. Centini, G. D’Aguanno, L. Sciscione, C. Sibilia, M. Bertolotti, M. Scalora , M. Bloemer: “Phase matching in the presence of feedback: High order

Closed-Loop Control of Vortex Formation in Separated Flows

NASA Technical Reports Server (NTRS)

Colonius, Tim; Joe, Won Tae; MacMynowski, Doug; Rowley, Clancy; Taira, Sam; Ahuja, Sunil

2010-01-01

In order to phase lock the flow at the desired shedding cycle, particularly at Phi,best, We designed a feedback compensator. (Even though the open-loop forcing at Wf below Wn can lead to phase-locked limit cycles with a high average lift,) This feedback controller resulted in the phase-locked limit cycles that the open-loop control could not achieve for alpha=30 and 40 Particularly for alpha=40, the feedback was able to stabilize the limit cycle that was not stable with any of the open-loop periodic forcing. This results in stable phase-locked limit cycles for a larger range of forcing frequencies than the open-loop control. Also, it was shown that the feedback achieved the high-lift unsteady flow states that open-loop control could not sustain even after the states have been achieved for a long period of time.

The effects of outcome and process feedback

NASA Technical Reports Server (NTRS)

Johnson, Debra Steele

1990-01-01

A study was conducted to examine the effects of process and outcome feedback on performance during a skill acquisition phase and a transfer test phase. The research also examined the role of two moderators: self-efficacy and intrinsic motivation. Subjects were college students participating for course credit. The task involved using a computerized simulation of the Space Shuttle's Remote Manipulation System (RMS). Results provided evidence of the beneficial effects of process feedback during skill acquisition. Results also provided evidence that self-efficacy and intrinsic motivation moderate the effects of feedback type on performance.

Feedback to semi-professional counselors in treating child aggression.

PubMed

Shechtman, Zipora; Tutian, Rony

2017-05-01

To investigate the impact of outcome feedback provided to semi-professional counselors of children and adolescents at risk for aggressive behavior, following group treatment. Participants included 230 aggressive children and adolescents and 64 educators in a quasi-experimental design of 3 conditions: experimental group with feedback, experimental group without feedback, and control group (no treatment). The current study employed a feedback system based on self-report aggression scores measured after each session, provided to teachers, including an alert system and weekly follow-up group support. Outcomes were more favorable for the treatment children than the control group, but feedback had no impact on the results. Outcome feedback provided to group therapists does not have an effect on children and adolescents' reduction of aggression. Further research is needed to identify possible reasons for failure to show feedback effect.

The effect of peer-group size on the delivery of feedback in basic life support refresher training: a cluster randomized controlled trial.

PubMed

Cho, Youngsuk; Je, Sangmo; Yoon, Yoo Sang; Roh, Hye Rin; Chang, Chulho; Kang, Hyunggoo; Lim, Taeho

2016-07-04

Students are largely providing feedback to one another when instructor facilitates peer feedback rather than teaching in group training. The number of students in a group affect the learning of students in the group training. We aimed to investigate whether a larger group size increases students' test scores on a post-training test with peer feedback facilitated by instructor after video-guided basic life support (BLS) refresher training. Students' one-rescuer adult BLS skills were assessed by a 2-min checklist-based test 1 year after the initial training. A cluster randomized controlled trial was conducted to evaluate the effect of student number in a group on BLS refresher training. Participants included 115 final-year medical students undergoing their emergency medicine clerkship. The median number of students was 8 in the large groups and 4 in the standard group. The primary outcome was to examine group differences in post-training test scores after video-guided BLS training. Secondary outcomes included the feedback time, number of feedback topics, and results of end-of-training evaluation questionnaires. Scores on the post-training test increased over three consecutive tests with instructor-led peer feedback, but not differ between large and standard groups. The feedback time was longer and number of feedback topics generated by students were higher in standard groups compared to large groups on the first and second tests. The end-of-training questionnaire revealed that the students in large groups preferred the smaller group size compared to their actual group size. In this BLS refresher training, the instructor-led group feedback increased the test score after tutorial video-guided BLS learning, irrespective of the group size. A smaller group size allowed more participations in peer feedback.

Feedback loop compensates for rectifier nonlinearity

NASA Technical Reports Server (NTRS)

1966-01-01

Signal processing circuit with two negative feedback loops rectifies two sinusoidal signals which are 180 degrees out of phase and produces a single full-wave rectified output signal. Each feedback loop incorporates a feedback rectifier to compensate for the nonlinearity of the circuit.

A three-phase amplification of the cosmic magnetic field in galaxies

NASA Astrophysics Data System (ADS)

Martin-Alvarez, Sergio; Devriendt, Julien; Slyz, Adrianne; Teyssier, Romain

2018-06-01

Arguably the main challenge of galactic magnetism studies is to explain how the interstellar medium of galaxies reaches energetic equipartition despite the extremely weak cosmic primordial magnetic fields that are originally predicted to thread the inter-galactic medium. Previous numerical studies of isolated galaxies suggest that a fast dynamo amplification might suffice to bridge the gap spanning many orders of magnitude in strength between the weak early Universe magnetic fields and the ones observed in high redshift galaxies. To better understand their evolution in the cosmological context of hierarchical galaxy growth, we probe the amplification process undergone by the cosmic magnetic field within a spiral galaxy to unprecedented accuracy by means of a suite of constrained transport magnetohydrodynamical adaptive mesh refinement cosmological zoom simulations with different stellar feedback prescriptions. A galactic turbulent dynamo is found to be naturally excited in this cosmological environment, being responsible for most of the amplification of the magnetic energy. Indeed, we find that the magnetic energy spectra of simulated galaxies display telltale inverse cascades. Overall, the amplification process can be divided in three main phases, which are related to different physical mechanisms driving galaxy evolution: an initial collapse phase, an accretion-driven phase, and a feedback-driven phase. While different feedback models affect the magnetic field amplification differently, all tested models prove to be subdominant at early epochs, before the feedback-driven phase is reached. Thus the three-phase evolution paradigm is found to be quite robust vis-a-vis feedback prescriptions.

Seasonal ENSO phase locking in the Kiel Climate Model: The importance of the equatorial cold sea surface temperature bias

NASA Astrophysics Data System (ADS)

Wengel, C.; Latif, M.; Park, W.; Harlaß, J.; Bayr, T.

2018-02-01

The El Niño/Southern Oscillation (ENSO) is characterized by a seasonal phase locking, with strongest eastern and central equatorial Pacific sea surface temperature (SST) anomalies during boreal winter and weakest SST anomalies during boreal spring. In this study, key feedbacks controlling seasonal ENSO phase locking in the Kiel Climate Model (KCM) are identified by employing Bjerknes index stability analysis. A large ensemble of simulations with the KCM is analyzed, where the individual runs differ in either the number of vertical atmospheric levels or coefficients used in selected atmospheric parameterizations. All integrations use the identical ocean model. The ensemble-mean features realistic seasonal ENSO phase locking. ENSO phase locking is very sensitive to changes in the mean-state realized by the modifications described above. An excessive equatorial cold tongue leads to weak phase locking by reducing the Ekman feedback and thermocline feedback in late boreal fall and early boreal winter. Seasonal ENSO phase locking also is sensitive to the shortwave feedback as part of the thermal damping in early boreal spring, which strongly depends on eastern and central equatorial Pacific SST. The results obtained from the KCM are consistent with those from models participating in the Coupled Model Intercomparison Project phase 5 (CMIP5).

Patient and Partner Feedback Reports to Improve Statin Medication Adherence: A Randomized Control Trial.

PubMed

Reddy, Ashok; Huseman, Tiffany L; Canamucio, Anne; Marcus, Steven C; Asch, David A; Volpp, Kevin; Long, Judith A

2017-03-01

Simple nudges such as reminders and feedback reports to either a patient or a partner may facilitate improved medication adherence. To test the impact of a pill bottle used to monitor adherence, deliver a daily alarm, and generate weekly medication adherence feedback reports on statin adherence. Three-month, three-arm randomized clinical trial (ClinicalTrials.gov identifier: NCT02480530). One hundred and twenty-six veterans with known coronary artery disease and poor adherence (medication possession ratio <80 %). Patients were randomized to one of three groups: (1) a control group (n = 36) that received a pill-monitoring device with no alarms or feedback; (2) an individual feedback group (n = 36) that received a daily alarm and a weekly medication adherence feedback report; and (3) a partner feedback group (n = 54) that received an alarm and a weekly feedback report that was shared with a friend, family member, or a peer. The intervention continued for 3 months, and participants were followed for an additional 3 months after the intervention period. Adherence as measured by pill bottle. Secondary outcomes included change in LDL (mg/dl), patient activation, and social support. During the 3-month intervention period, medication adherence was higher in both feedback arms than in the control arm (individual feedback group 89 %, partner feedback group 86 %, control group 67 %; p < 0.001 and = 0.001). At 6 months, there was no difference in medication adherence between either of the feedback groups and the control (individual feedback 60 %, partner feedback 52 %, control group 54 %; p = 0.75 and 0.97). Daily alarms combined with individual or partner feedback reports improved statin medication adherence. While neither an individual feedback nor partner feedback strategy created a sustainable medication adherence habit, the intervention itself is relatively easy to implement and low cost.

Pitfalls and feedback when constructing topological pressure-temperature phase diagrams

NASA Astrophysics Data System (ADS)

Ceolin, R.; Toscani, S.; Rietveld, Ivo B.; Barrio, M.; Tamarit, J. Ll.

2017-04-01

The stability hierarchy between different phases of a chemical compound can be accurately reproduced in a topological phase diagram. This type of phase diagrams may appear to be the result of simple extrapolations, however, experimental complications quickly increase in the case of crystalline trimorphism (and higher order polymorphism). To ensure the accurate positioning of stable phase domains, a topological phase diagram needs to be consistent. This paper gives an example of how thermodynamic feedback can be used in the topological construction of phase diagrams to ensure overall consistency in a phase diagram based on the case of piracetam crystalline trimorphism.

The cloud-phase feedback in the Super-parameterized Community Earth System Model

NASA Astrophysics Data System (ADS)

Burt, M. A.; Randall, D. A.

2016-12-01

Recent comparisons of observations and climate model simulations by I. Tan and colleagues have suggested that the Wegener-Bergeron-Findeisen (WBF) process tends to be too active in climate models, making too much cloud ice, and resulting in an exaggerated negative cloud-phase feedback on climate change. We explore the WBF process and its effect on shortwave cloud forcing in present-day and future climate simulations with the Community Earth System Model, and its super-parameterized counterpart. Results show that SP-CESM has much less cloud ice and a weaker cloud-phase feedback than CESM.

Effect of Concurrent Visual Feedback Frequency on Postural Control Learning in Adolescents.

PubMed

Marco-Ahulló, Adrià; Sánchez-Tormo, Alexis; García-Pérez, José A; Villarrasa-Sapiña, Israel; González, Luis M; García-Massó, Xavier

2018-04-13

The purpose was to find better augmented visual feedback frequency (100% or 67%) for learning a balance task in adolescents. Thirty subjects were divided randomly into a control group, and 100% and 67% feedback groups. The three groups performed pretest (3 trials), practice (12 trials), posttest (3 trials) and retention (3 trials, 24 hours later). The reduced feedback group showed lower RMS in the posttest than in the pretest (p = 0.04). The control and reduced feedback groups showed significant lower median frequency in the posttest than in the pretest (p < 0.05). Both feedback groups showed lower values in retention than in the pretest (p < 0.05). Even when the effect of feedback frequency could not be detected in motor learning, 67% of the feedback was recommended for motor adaptation.

Unintentional force changes in cyclical tasks performed by an abundant system: Empirical observations and a dynamical model.

PubMed

Reschechtko, Sasha; Hasanbarani, Fariba; Akulin, Vladimir M; Latash, Mark L

2017-05-14

The study explored unintentional force changes elicited by removing visual feedback during cyclical, two-finger isometric force production tasks. Subjects performed two types of tasks at 1Hz, paced by an auditory metronome. One - Force task - required cyclical changes in total force while maintaining the sharing, defined as relative contribution of a finger to total force. The other task - Share task - required cyclical changes in sharing while keeping total force unchanged. Each trial started under full visual feedback on both force and sharing; subsequently, feedback on the variable that was instructed to stay constant was frozen, and finally feedback on the other variable was also removed. In both tasks, turning off visual feedback on total force elicited a drop in the mid-point of the force cycle and an increase in the peak-to-peak force amplitude. Turning off visual feedback on sharing led to a drift of mean share toward 50:50 across both tasks. Without visual feedback there was consistent deviation of the two force time series from the in-phase pattern (typical of the Force task) and from the out-of-phase pattern (typical of the Share task). This finding is in contrast to most earlier studies that demonstrated only two stable patterns, in-phase and out-of-phase. We interpret the results as consequences of drifts of parameters in a dynamical system leading in particular to drifts in the referent finger coordinates toward their actual coordinates. The relative phase desynchronization is caused by the right-left differences in the hypothesized drift processes, consistent with the dynamic dominance hypothesis. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Unintentional force changes in cyclical tasks performed by an abundant system: Empirical observations and a dynamical model

PubMed Central

Reschechtko, Sasha; Hasanbarani, Fariba; Akulin, Vladimir M.; Latash, Mark L.

2017-01-01

The study explored unintentional force changes elicited by removing visual feedback during cyclical, two-finger isometric force production tasks. Subjects performed two types of tasks at 1 Hz, paced by an auditory metronome. One – Force task – required cyclical changes in total force while maintaining the sharing, defined as relative contribution of a finger to total force. The other task – Share task – required cyclical changes in sharing while keeping total force unchanged. Each trial started under full visual feedback on both force and sharing; subsequently, feedback on the variable that was instructed to stay constant was frozen, and finally feedback on the other variable was also removed. In both tasks, turning off visual feedback on total force elicited a drop in the mid-point of the force cycle and an increase in the peak-to-peak force amplitude. Turning off visual feedback on sharing led to a drift of mean share toward 50:50 across both tasks. Without visual feedback there was consistent deviation of the two force time series from the in-phase pattern (typical of the Force task) and from the out-of-phase pattern (typical of the Share task). This finding is in contrast to most earlier studies that demonstrated only two stable patterns, in-phase and out-of-phase. We interpret the results as consequences of drifts of parameters in a dynamical system leading in particular to drifts in the referent finger coordinates toward their actual coordinates. The relative phase desynchronization is caused by the right-left differences in the hypothesized drift processes, consistent with the dynamic dominance hypothesis. PMID:28344070

Online Instructor's Use of Audio Feedback to Increase Social Presence and Student Satisfaction

ERIC Educational Resources Information Center

Portolese Dias, Laura; Trumpy, Robert

2014-01-01

This study investigates the impact of written group feedback, versus audio feedback, based upon four student satisfaction measures in the online classroom environment. Undergraduate students in the control group were provided both individual written feedback and group written feedback, while undergraduate students in the experimental treatment…

Learning the Art of Electronics

NASA Astrophysics Data System (ADS)

Hayes, Thomas C.; Horowitz, Paul

2016-03-01

1. DC circuits; 2. RC circuits; 3. Diode circuits; 4. Transistors I; 5. Transistors II; 6. Operational amplifiers I; 7. Operational amplifiers II: nice positive feedback; 8. Operational amplifiers III; 9. Operational amplifiers IV: nasty positive feedback; 10. Operational amplifiers V: PID motor control loop; 11. Voltage regulators; 12. MOSFET switches; 13. Group audio project; 14. Logic gates; 15. Logic compilers, sequential circuits, flip-flops; 16. Counters; 17. Memory: state machines; 18. Analog to digital: phase-locked loop; 19. Microcontrollers and microprocessors I: processor/controller; 20. I/O, first assembly language; 21. Bit operations; 22. Interrupt: ADC and DAC; 23. Moving pointers, serial buses; 24. Dallas Standalone Micro, SiLabs SPI RAM; 25. Toys in the attic; Appendices; Index.

Development and Early Piloting of a CanMEDS Competency-Based Feedback Tool for Surgical Grand Rounds.

PubMed

Fahim, Christine; Bhandari, Mohit; Yang, Ilun; Sonnadara, Ranil

2016-01-01

Grand rounds offer an excellent opportunity for the evaluation of medical expertise, and other competencies, such as communication and professionalism. The purpose of this study was to develop a tool that would facilitate the provision of formative feedback for grand rounds to improve learning. The resulting CanMEDS-based evaluation tool was piloted in an academic surgical department. This study employed the use of a 3-phase, qualitatively-focused, embedded mixed methods approach. In Phase 1, an intrinsic case study was conducted to identify preliminary themes. These findings were crystallized using a quantitative survey. Following interpretation of these data, a grand rounds evaluation tool was developed in Phase 2. The tool was piloted in the Phase 3 focus group. This study was piloted at an academic surgical center among members of the Department of Surgery, McMaster University, Ontario, Canada. Purposive sampling was used for this study. A total of n = 7 individuals participated in the Phase 1 interviews, and n = 24 participants completed the Phase 1 survey. Participants included a representative sample of medical students, residents, fellows, and staff. The tool was piloted among n = 19 participants. The proposed evaluation tool contains 13 Likert-scale questions and 2 open-ended questions. The tool outlines specific questions to assess grand rounds presenters within the structure of the 7 CanMEDS competency domains. "Evaluation fatigue" was identified as a major barrier in the willingness to provide effective feedback. Further, a number of factors regarding the preferred content, structure, and format of surgical grand rounds were identified. This pilot study presents a CanMEDS-specific evaluation tool that can be applied to surgical grand rounds. With the increasing adoption of competency-based medical education, comprehensive evaluation of surgical activities is required. This form provides a template for the development of competency-based evaluation tools for medical and surgical learning activities. Copyright © 2016 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Intermittent compared to continuous real-time fMRI neurofeedback boosts control over amygdala activation.

PubMed

Hellrung, Lydia; Dietrich, Anja; Hollmann, Maurice; Pleger, Burkhard; Kalberlah, Christian; Roggenhofer, Elisabeth; Villringer, Arno; Horstmann, Annette

2018-02-01

Real-time fMRI neurofeedback is a feasible tool to learn the volitional regulation of brain activity. So far, most studies provide continuous feedback information that is presented upon every volume acquisition. Although this maximizes the temporal resolution of feedback information, it may be accompanied by some disadvantages. Participants can be distracted from the regulation task due to (1) the intrinsic delay of the hemodynamic response and associated feedback and (2) limited cognitive resources available to simultaneously evaluate feedback information and stay engaged with the task. Here, we systematically investigate differences between groups presented with different variants of feedback (continuous vs. intermittent) and a control group receiving no feedback on their ability to regulate amygdala activity using positive memories and feelings. In contrast to the feedback groups, no learning effect was observed in the group without any feedback presentation. The group receiving intermittent feedback exhibited better amygdala regulation performance when compared with the group receiving continuous feedback. Behavioural measurements show that these effects were reflected in differences in task engagement. Overall, we not only demonstrate that the presentation of feedback is a prerequisite to learn volitional control of amygdala activity but also that intermittent feedback is superior to continuous feedback presentation. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Clarity, Consistency and Communication: Using Enhanced Dialogue to Create a Course-Based Feedback Strategy

ERIC Educational Resources Information Center

Nixon, Sarah; Brooman, Simon; Murphy, Becky; Fearon, Damien

2017-01-01

This article examines the outcomes of a study across four discipline areas in order to develop course-based assessment strategies in closer cooperation with students. Second-year students (n = 48) from different disciplines were engaged in two phases of activity-orientated workshops. Phase 1 sought their perceptions of feedback. Phase 2 saw…

Probabilistic Reversal Learning in Schizophrenia: Stability of Deficits and Potential Causal Mechanisms.

PubMed

Reddy, Lena Felice; Waltz, James A; Green, Michael F; Wynn, Jonathan K; Horan, William P

2016-07-01

Although individuals with schizophrenia show impaired feedback-driven learning on probabilistic reversal learning (PRL) tasks, the specific factors that contribute to these deficits remain unknown. Recent work has suggested several potential causes including neurocognitive impairments, clinical symptoms, and specific types of feedback-related errors. To examine this issue, we administered a PRL task to 126 stable schizophrenia outpatients and 72 matched controls, and patients were retested 4 weeks later. The task involved an initial probabilistic discrimination learning phase and subsequent reversal phases in which subjects had to adjust their responses to sudden shifts in the reinforcement contingencies. Patients showed poorer performance than controls for both the initial discrimination and reversal learning phases of the task, and performance overall showed good test-retest reliability among patients. A subgroup analysis of patients (n = 64) and controls (n = 49) with good initial discrimination learning revealed no between-group differences in reversal learning, indicating that the patients who were able to achieve all of the initial probabilistic discriminations were not impaired in reversal learning. Regarding potential contributors to impaired discrimination learning, several factors were associated with poor PRL, including higher levels of neurocognitive impairment, poor learning from both positive and negative feedback, and higher levels of indiscriminate response shifting. The results suggest that poor PRL performance in schizophrenia can be the product of multiple mechanisms. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Implicit video feedback produces positive changes in landing mechanics.

PubMed

Popovic, Tijana; Caswell, Shane V; Benjaminse, Anne; Siragy, Tarique; Ambegaonkar, Jatin; Cortes, Nelson

2018-05-02

Implicit (IF) and explicit (EF) feedback are two motor learning strategies demonstrated to alter movement patterns. There is conflicting evidence on which strategy produces better outcomes. The purpose of this study was to examine the effects of reduced IF and EF video feedback on lower extremity landing mechanics. Thirty participants (24 ± 2 years, 1.7 ± 0.1 m, 70 ± 11 kg) were randomly assigned to three groups: IF (n = 10), EF (n = 10), and control (CG) (n = 10). They performed twelve box-drop jumps three times a week on the training sessions for six weeks. Only IF and EF groups received video feedback on the training sessions. IF was cued to focus their attention on the overall jump, while EF was cued to focus on position of their knees. 3D lower extremity biomechanics were tested on testing sessions with no feedback. All sessions were at least 24 h apart from another. Testing sessions included baseline testing (pretest), testing after 3 training sessions with 100% feedback (pst1), testing after 6 training sessions with 33.3% feedback (pst2), testing after 6 training sessions with 16.6% feedback (Pst3), and testing 1 month after with no feedback (retention - ret). ANOVA compared differences between groups and time at initial contact and peak for hip flexion (HF, °) and abduction angle (HA, °), hip abduction moment (HAM, Nm/kgm), knee flexion (KF, °) and abduction angle (KA, °), knee abduction moment (KAM, Nm/kgm) and VGRF (N) (p < 0.05). A significant main effect for group was found between IF and EF groups for HA (IF = - 6.7 ± 4; EF = - 9.4 ± 4.1) and KAM (IF = 0.05 ± 0.2; EF = - 0.07 ± 0.2) at initial contact, and peaks HA (IF = - 3.5 ± 4.5; EF = - 7.9 ± 4.7) and HAM (IF = 1.1 ± 0.6; EF = 0.9 ± 0.4). A significant main effect for time at initial contact for HF (pre = 32.4 ± 3.2; pst2 = 36.9 ± 3.2; pst3 = 37.9 ± 3.7; ret. = 34.1 ± 3.7), HAM (pre = 0.1 ± 0.1; pst1 = 0.04 ± 0.1; pst3 = 0.1 ± 0.01), KA (pre = 0.7 ± 1.1; pst1 = 0.2 ± 1.2; pst3 = 1.7 ± 1), and KAM (pre = 0.003 ± 0.1; pst3 = 0.01 ± 0.1) was found. We found that implicit feedback produced positive changes in landing mechanics while explicit feedback degraded motor learning. Our results indicate that implicit feedback should be used in programs to lower the ACL injury risk. We suggest that implicit feedback should be frequent in the beginning and not be reduced as much following the acquisition phase.

Feedback-induced phase transitions in active heterogeneous conductors.

PubMed

Ocko, Samuel A; Mahadevan, L

2015-04-03

An active conducting medium is one where the resistance (conductance) of the medium is modified by the current (flow) and in turn modifies the flow, so that the classical linear laws relating current and resistance, e.g., Ohm's law or Darcy's law, are modified over time as the system itself evolves. We consider a minimal model for this feedback coupling in terms of two parameters that characterize the way in which addition or removal of matter follows a simple local (or nonlocal) feedback rule corresponding to either flow-seeking or flow-avoiding behavior. Using numerical simulations and a continuum mean field theory, we show that flow-avoiding feedback causes an initially uniform system to become strongly heterogeneous via a tunneling (channel-building) phase separation; flow-seeking feedback leads to an immuring (wall-building) phase separation. Our results provide a qualitative explanation for the patterning of active conducting media in natural systems, while suggesting ways to realize complex architectures using simple rules in engineered systems.

Activity monitor intervention to promote physical activity of physicians-in-training: randomized controlled trial.

PubMed

Thorndike, Anne N; Mills, Sarah; Sonnenberg, Lillian; Palakshappa, Deepak; Gao, Tian; Pau, Cindy T; Regan, Susan

2014-01-01

Physicians are expected to serve as role models for healthy lifestyles, but long work hours reduce time for healthy behaviors. A hospital-based physical activity intervention could improve physician health and increase counseling about exercise. We conducted a two-phase intervention among 104 medical residents at a large hospital in Boston, Massachusetts. Phase 1 was a 6-week randomized controlled trial comparing daily steps of residents assigned to an activity monitor displaying feedback about steps and energy consumed (intervention) or to a blinded monitor (control). Phase 2 immediately followed and was a 6-week non-randomized team steps competition in which all participants wore monitors with feedback. Phase 1 outcomes were: 1) median steps/day and 2) proportion of days activity monitor worn. The Phase 2 outcome was mean steps/day on days monitor worn (≥500 steps/day). Physiologic measurements were collected at baseline and study end. Median steps/day were compared using Wilcoxon rank-sum tests. Mean steps were compared using repeated measures regression analyses. In Phase 1, intervention and control groups had similar activity (6369 vs. 6063 steps/day, p = 0.16) and compliance with wearing the monitor (77% vs. 77% of days, p = 0.73). In Phase 2 (team competition), residents recorded more steps/day than during Phase 1 (CONTROL: 7,971 vs. 7,567, p = 0.002; 7,832 vs. 7,739, p = 0.13). Mean compliance with wearing the activity monitor decreased for both groups during Phase 2 compared to Phase 1 (60% vs. 77%, p<0.001). Mean systolic blood pressure decreased (p = 0.004) and HDL cholesterol increased (p<0.001) among all participants at end of study compared to baseline. Although the activity monitor intervention did not have a major impact on activity or health, the high participation rates of busy residents and modest changes in steps, blood pressure, and HDL suggest that more intensive hospital-based wellness programs have potential for promoting healthier lifestyles among physicians. Clinicaltrials.gov NCT01287208.

Activity Monitor Intervention to Promote Physical Activity of Physicians-In-Training: Randomized Controlled Trial

PubMed Central

Thorndike, Anne N.; Mills, Sarah; Sonnenberg, Lillian; Palakshappa, Deepak; Gao, Tian; Pau, Cindy T.; Regan, Susan

2014-01-01

Background Physicians are expected to serve as role models for healthy lifestyles, but long work hours reduce time for healthy behaviors. A hospital-based physical activity intervention could improve physician health and increase counseling about exercise. Methods We conducted a two-phase intervention among 104 medical residents at a large hospital in Boston, Massachusetts. Phase 1 was a 6-week randomized controlled trial comparing daily steps of residents assigned to an activity monitor displaying feedback about steps and energy consumed (intervention) or to a blinded monitor (control). Phase 2 immediately followed and was a 6-week non-randomized team steps competition in which all participants wore monitors with feedback. Phase 1 outcomes were: 1) median steps/day and 2) proportion of days activity monitor worn. The Phase 2 outcome was mean steps/day on days monitor worn (≥500 steps/day). Physiologic measurements were collected at baseline and study end. Median steps/day were compared using Wilcoxon rank-sum tests. Mean steps were compared using repeated measures regression analyses. Results In Phase 1, intervention and control groups had similar activity (6369 vs. 6063 steps/day, p = 0.16) and compliance with wearing the monitor (77% vs. 77% of days, p = 0.73). In Phase 2 (team competition), residents recorded more steps/day than during Phase 1 (Control: 7,971 vs. 7,567, p = 0.002; Intervention: 7,832 vs. 7,739, p = 0.13). Mean compliance with wearing the activity monitor decreased for both groups during Phase 2 compared to Phase 1 (60% vs. 77%, p<0.001). Mean systolic blood pressure decreased (p = 0.004) and HDL cholesterol increased (p<0.001) among all participants at end of study compared to baseline. Conclusions Although the activity monitor intervention did not have a major impact on activity or health, the high participation rates of busy residents and modest changes in steps, blood pressure, and HDL suggest that more intensive hospital-based wellness programs have potential for promoting healthier lifestyles among physicians. Trial Registration Clinicaltrials.gov NCT01287208. PMID:24950218

Hybrid optical and electronic laser locking using slow light due to spectral holes

NASA Astrophysics Data System (ADS)

Tay, Jian Wei; Farr, Warrick G.; Ledingham, Patrick M.; Korystov, Dmitry; Longdell, Jevon J.

2013-06-01

We report on a narrow linewidth laser diode system that is stabilized using both optical and electronic feedback to a spectral hole in cryogenic Tm:YAG. The large group delay of the spectral hole leads to a laser with very low phase noise. The laser has proved useful for quantum optics and sensing applications involving cryogenic rare-earth-ion dopants.

An Initiative to Reduce the Episiotomy Rate: Association of Feedback and the Hawthorne Effect With Leapfrog Goals.

PubMed

Zhang-Rutledge, Kathy; Clark, Steven L; Denning, Stacie; Timmins, Audra; Dildy, Gary A; Gandhi, Manisha

2017-07-01

To assess the association of education, performance feedback, and the Hawthorne effect with a reduction in the episiotomy rate in a large academic institution. We describe a prospective observational study of a project conducted between March 2012 and February 2017 to assist clinicians in meeting the Leapfrog Group (www.leapfroggroup.org) target rates for episiotomy. Phases of this project included preintervention (phase 1, March 2012 to April 2014), education and provision of collective department episiotomy rates (phase 2, May 2014 to December 2014), ongoing education with emphasis on a revised Leapfrog target rate (phase 3, January 2015 to February 2016), and provision of individual episiotomy rates to practitioners on a monthly basis (phase 4, March 2016 to February 2017). We analyzed the department episiotomy rates before, during, and after these efforts. Cases of shoulder dystocia were excluded from this analysis. Statistical analysis was performed using a two-tailed Student t test and χ test with P<.05 considered significant. During the study period 1,176 episiotomies were performed in 16,441 vaginal deliveries (7.2%). In phase 2 (2,352 vaginal deliveries), there was a nonsignificant drop in the episiotomy rate with education alone (9.0-8.2%, P=.21). In phase 3 (4,379 vaginal deliveries), the episiotomy rate demonstrated an additional, significant drop to 5.9% (P<.001), but this reduction did not reach the new Leapfrog goal of 5%. In phase 4 (3,160 vaginal deliveries), the hospital episiotomy rate again dropped significantly from 5.9% to 4.37% (P=.007) and met the target rate of 5%. This reduction was sustained over a 12-month time period. During this same time period, the rate of operative vaginal delivery among vaginal births increased (4.5-5.4%, P=.003) and there was no significant change in the rates of third- and fourth-degree perineal laceration (3.8-3.3%, P=.19). Education, performance feedback, and the Hawthorne effect were associated with a reduction in the episiotomy rate in a large academic institution without a reduction in the rate of operative vaginal delivery or an increase in the rate of third- and fourth-degree lacerations.

“Overview and Evaluation of AQMEII Phase 2 Coupled ...

EPA Pesticide Factsheets

This presentation provides an overview of the second phase of the Air Quality Model Evaluation International Initative (AQMEII). Activities in this phase are focused on the application and evaluation of coupled meteorology-chemistry models to assess how well these models can simulate the observed spatio-temporal variability in the optical and radiative characteristics of atmospheric aerosols and associated feedbacks among aerosols, radiation, clouds, and precipitation. To this end, these modeling systems are being applied for annual simulations over both North America and Europe using common emissions and boundary conditions for all modeling groups. We present an overview of these common input datasets, observational datasets for model evaluation, and case studies for diagnostic evaluation. In addition to this overview, we also present results from AQMEII Phase 2 WRF/CMAQ simulations over North America for both 2006 and 2010. The time period between 2006 and 2010 was characterized by a 35% reduction in U.S. SO2 emissions and 20% reduction in U.S. NOx emissions, providing an opportunity for dynamic model evaluation by investigating the impact of emission reductions on ambient concentrations as well as aerosol/radiation feedback effects. We present results of this dynamic evaluation. We also present a brief overview of initial results from WRF-Chem and GEM-MACH simulations performed for the same time period and domain as part of AQMEII Phase 2. The National Exposu

An Intervention Based on Video Feedback and Questioning to Improve Tactical Knowledge in Expert Female Volleyball Players.

PubMed

Moreno, M Perla; Moreno, Alberto; García-González, Luis; Ureña, Aurelio; Hernández, César; Del Villar, Fernando

2016-06-01

This study applied an intervention program, based on video feedback and questioning, to expert female volleyball players to improve their tactical knowledge. The sample consisted of eight female attackers (26 ± 2.6 years old) from the Spanish National Volleyball Team, who were divided into an experimental group (n = 4) and a control group (n = 4). The video feedback and questioning program applied in the study was developed over eight reflective sessions and consisted of three phases: viewing of the selected actions, self-analysis and reflection by the attacker, and joint player-coach analysis. The attackers were videotaped in an actual game and four clips (situations) of each of the attackers were chosen for each reflective session. Two of the clips showed a correct action by the attacker, and two showed an incorrect decision. Tactical knowledge was measured by problem representation with a verbal protocol. The members of the experimental group showed adaptations in long-term memory, significantly improving their tactical knowledge. With respect to conceptual content, there was an increase in the total number of conditions verbalized by the players; with respect to conceptual sophistication, there was an increase in the indication of appropriate conditions with two or more details; and finally, with respect to conceptual structure, there was an increase in the use of double or triple conceptual structures. The intervention program, based on video feedback and questioning, in addition to on-court training sessions of expert volleyball players, appears to improve the athletes' tactical knowledge. © The Author(s) 2016.

Positive and negative feedback learning and associated dopamine and serotonin transporter binding after methamphetamine.

PubMed

Stolyarova, Alexandra; O'Dell, Steve J; Marshall, John F; Izquierdo, Alicia

2014-09-01

Learning from mistakes and prospectively adjusting behavior in response to reward feedback is an important facet of performance monitoring. Dopamine (DA) pathways play an important role in feedback learning and a growing literature has also emerged on the importance of serotonin (5HT) in reward learning, particularly during punishment or reward omission (negative feedback). Cognitive impairments resulting from psychostimulant exposure may arise from altered patterns in feedback learning, which in turn may be modulated by DA and 5HT transmission. We analyzed long-term, off-drug changes in learning from positive and negative feedback and associated striatal DA transporter (DAT) and frontocortical 5HT transporter (SERT) binding in rats pretreated with methamphetamine (mAMPH). Specifically, we assessed the reversal phase of pairwise visual discrimination learning in rats receiving single dose- (mAMPHsingle) vs. escalating-dose exposure (mAMPHescal). Using fine-grained trial-by-trial analyses, we found increased sensitivity to and reliance on positive feedback in mAMPH-pretreated animals, with the mAMPHsingle group showing more pronounced use of this type of feedback. In contrast, overall negative feedback sensitivity was not altered following any mAMPH treatment. In addition to validating the enduring effects of mAMPH on early reversal learning, we found more consecutive error commissions before the first correct response in mAMPH-pretreated rats. This behavioral rigidity was negatively correlated with subregional frontocortical SERT whereas positive feedback sensitivity negatively correlated with striatal DAT binding. These results provide new evidence for the overlapping, yet dissociable roles of DA and 5HT systems in overcoming perseveration and in learning new reward rules. Copyright © 2014 Elsevier B.V. All rights reserved.

Relative Effects of Daily Feedback and Weekly Feedback on Customer Service Behavior at a Gas Station

ERIC Educational Resources Information Center

So, Yongjoon; Lee, Kyehoon; Oah, Shezeen

2013-01-01

The relative effects of daily and weekly feedback on customer service behavior at a gas station were assessed using an ABC within-subjects design. Four critical service behaviors were identified and measured daily. After baseline (A), weekly feedback (B) was introduced, and daily feedback (C) was introduced in the next phase. The results indicated…

Aspheric figure generation using feedback from an infrared phase-shifting interferometer.

NASA Astrophysics Data System (ADS)

Stahl, H. P.; Ketelsen, D.

This paper discusses the usefulness of the infrared phase-shifting interferometric system for providing figure correcting feedback to the optician during the generation of the off-axis parabolic segments and how it is affected by the surface roughness produced by each generator tool.

Reinforcement Learning of Linking and Tracing Contours in Recurrent Neural Networks

PubMed Central

Brosch, Tobias; Neumann, Heiko; Roelfsema, Pieter R.

2015-01-01

The processing of a visual stimulus can be subdivided into a number of stages. Upon stimulus presentation there is an early phase of feedforward processing where the visual information is propagated from lower to higher visual areas for the extraction of basic and complex stimulus features. This is followed by a later phase where horizontal connections within areas and feedback connections from higher areas back to lower areas come into play. In this later phase, image elements that are behaviorally relevant are grouped by Gestalt grouping rules and are labeled in the cortex with enhanced neuronal activity (object-based attention in psychology). Recent neurophysiological studies revealed that reward-based learning influences these recurrent grouping processes, but it is not well understood how rewards train recurrent circuits for perceptual organization. This paper examines the mechanisms for reward-based learning of new grouping rules. We derive a learning rule that can explain how rewards influence the information flow through feedforward, horizontal and feedback connections. We illustrate the efficiency with two tasks that have been used to study the neuronal correlates of perceptual organization in early visual cortex. The first task is called contour-integration and demands the integration of collinear contour elements into an elongated curve. We show how reward-based learning causes an enhancement of the representation of the to-be-grouped elements at early levels of a recurrent neural network, just as is observed in the visual cortex of monkeys. The second task is curve-tracing where the aim is to determine the endpoint of an elongated curve composed of connected image elements. If trained with the new learning rule, neural networks learn to propagate enhanced activity over the curve, in accordance with neurophysiological data. We close the paper with a number of model predictions that can be tested in future neurophysiological and computational studies. PMID:26496502

Comparing the effects of positive and negative feedback in information-integration category learning.

PubMed

Freedberg, Michael; Glass, Brian; Filoteo, J Vincent; Hazeltine, Eliot; Maddox, W Todd

2017-01-01

Categorical learning is dependent on feedback. Here, we compare how positive and negative feedback affect information-integration (II) category learning. Ashby and O'Brien (2007) demonstrated that both positive and negative feedback are required to solve II category problems when feedback was not guaranteed on each trial, and reported no differences between positive-only and negative-only feedback in terms of their effectiveness. We followed up on these findings and conducted 3 experiments in which participants completed 2,400 II categorization trials across three days under 1 of 3 conditions: positive feedback only (PFB), negative feedback only (NFB), or both types of feedback (CP; control partial). An adaptive algorithm controlled the amount of feedback given to each group so that feedback was nearly equated. Using different feedback control procedures, Experiments 1 and 2 demonstrated that participants in the NFB and CP group were able to engage II learning strategies, whereas the PFB group was not. Additionally, the NFB group was able to achieve significantly higher accuracy than the PFB group by Day 3. Experiment 3 revealed that these differences remained even when we equated the information received on feedback trials. Thus, negative feedback appears significantly more effective for learning II category structures. This suggests that the human implicit learning system may be capable of learning in the absence of positive feedback.

Individualized feedback during simulated laparoscopic training: a mixed methods study

PubMed Central

Weurlander, Maria; Hedman, Leif; Nisell, Henry; Lindqvist, Pelle G.; Felländer-Tsai, Li; Enochsson, Lars

2015-01-01

Objectives This study aimed to explore the value of indi-vidualized feedback on performance, flow and self-efficacy during simulated laparoscopy. Furthermore, we wished to explore attitudes towards feedback and simulator training among medical students. Methods Sixteen medical students were included in the study and randomized to laparoscopic simulator training with or without feedback. A teacher provided individualized feedback continuously throughout the procedures to the target group. Validated questionnaires and scales were used to evaluate self-efficacy and flow. The Mann-Whitney U test was used to evaluate differences between groups regarding laparoscopic performance (instrument path length), self-efficacy and flow. Qualitative data was collected by group interviews and interpreted using inductive thematic analyses. Results Sixteen students completed the simulator training and questionnaires. Instrument path length was shorter in the feedback group (median 3.9 m; IQR: 3.3-4.9) as com-pared to the control group (median 5.9 m; IQR: 5.0-8.1), p<0.05. Self-efficacy improved in both groups. Eleven students participated in the focus interviews. Participants in the control group expressed that they had fun, whereas participants in the feedback group were more concentrated on the task and also more anxious. Both groups had high ambitions to succeed and also expressed the importance of getting feedback. The authenticity of the training scenario was important for the learning process. Conclusions This study highlights the importance of individualized feedback during simulated laparoscopy training. The next step is to further optimize feedback and to transfer standardized and individualized feedback from the simulated setting to the operating room. PMID:26223033

Development and field testing of a smartphone "App" for tinnitus management.

PubMed

Henry, James A; Thielman, Emily; Zaugg, Tara; Kaelin, Christine; Choma, Christie; Chang, Bill; Hahn, Shira; Fuller, Bret

2017-10-01

This study's objective was to develop and test a smartphone app that supports learning and using coping skills for managing tinnitus. The app's content was based on coping skills that are taught as a part of progressive tinnitus management (PTM). The study involved three phases: (1) develop a prototype app and conduct usability testing; (2) conduct two focus groups to obtain initial feedback from individuals representing potential users; and (3) conduct a field study to evaluate the app, with three successive groups of participants. Participants were adults with bothersome tinnitus. For Phase 2, two focus groups were attended by a total of 17 participants. Phase 3 involved three consecutive rounds of participants: five from the focus groups followed by two rounds with 10 participants each who had not seen the app previously. In both the focus groups and field studies, participants responded favourably to the content. Certain features, however, were deemed too complex. Completion of this project resulted in the development and testing of the delivery of PTM coping skills via a smartphone app. This new approach has the potential to improve access to coping skills for those with bothersome tinnitus.

Decision feedback loop for tracking a polyphase modulated carrier

NASA Technical Reports Server (NTRS)

Simon, M. K. (Inventor)

1974-01-01

A multiple phase modulated carrier tracking loop for use in a frequency shift keying system is described in which carrier tracking efficiency is improved by making use of the decision signals made on the data phase transmitted in each T-second interval. The decision signal is used to produce a pair of decision-feedback quadrature signals for enhancing the loop's performance in developing a loop phase error signal.

Temperature feedback control for long-term carrier-envelope phase locking.

PubMed

Yun, Chenxia; Chen, Shouyuan; Wang, He; Chini, Michael; Chang, Zenghu

2009-09-20

We report a double feedback loop for the improvement of the carrier-envelope phase stabilization of a chirped mirror based femtosecond laser oscillator. By combining the control of the Ti:sapphire crystal temperature and the modulation of the pump power, the carrier envelope offset frequency, fCEO, was locked for close to 20 h, which is much longer than the typical phase stabilization time with only pump power modulation.

Case-based Learning in Microbiology: Observations from a North West Indian Medical College.

PubMed

Singhal, Anita

2017-12-01

Microbiology is usually taught by conventional lectures, and its retention and application is observed to be poor among medical graduates/practitioners. Introduction of case-based learning (CBL) in microbiology for second-year professional MBBS students. Students were divided into two groups of fifty each. Four clinical cases were used for CBL. One group had two CBL sessions whereas the other had didactic lectures (DLs) and then the groups were crossed over. Case scenario handouts were given to students a week before the session, and smaller groups were formed for discussions and presentations in CBL sessions. Posttest, in multiple choice questions format, was conducted in two phases: First, immediately after the completion of the four CBL and DL sessions, and second, 6 weeks after the first posttest. Student and faculty feedback was taken about CBL sessions. Hundred MBBS students of the fourth semester voluntarily participated in the CBL study. The CBL scores were significantly higher than DL session scores ( P = 0.015). This difference was more marked in scoring done after 6 weeks of session completion ( P < 0.001). Student reported satisfaction in being taught by CBL method in 5-point Likert scale feedback form. Faculty feedback was positive for CBL. CBL helped in retention of knowledge and its application better than DL in our observation. More sessions on commonly encountered case scenarios will be useful for students in recalling basic science knowledge in their later years as practitioners.

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR CODING: QUESTIONNAIRE FEEDBACK FORM (UA-D-46.0)

EPA Science Inventory

The purpose of this SOP is to describe the coding strategy for the Questionnaire Feedback form. This Questionnaire Feedback form was developed for use during the Arizona NHEXAS project and the "Border" study. Keywords: data; coding; questionnaire feedback form.

The National Hu...

A Randomized Controlled Trial to Compare e-Feedback Versus "Standard" Face-to-Face Verbal Feedback to Improve the Acquisition of Procedural Skill.

PubMed

Al-Jundi, Wissam; Elsharif, Mohamed; Anderson, Melanie; Chan, Phillip; Beard, Jonathan; Nawaz, Shah

Constructive feedback plays an important role in learning during surgical training. Standard feedback is usually given verbally following direct observation of the procedure by a trained assessor. However, such feedback requires the physical presence of expert faculty members who are usually busy and time-constrained by clinical commitments. We aim to evaluate electronic feedback (e-feedback) after video observation of surgical suturing in comparison with standard face-to-face verbal feedback. A prospective, blinded, randomized controlled trial comparing e-feedback with standard verbal feedback was carried out in February 2015 using a validated pro formas for assessment. The study participants were 38 undergraduate medical students from the University of Sheffield, UK. They were recorded on video performing the procedural skill, completed a self-evaluation form, and received e-feedback on the same day (group 1); observed directly by an assessor, invited to provide verbal self-reflection, and then received standard verbal feedback (group 2). In both groups, the feedback was provided after performing the procedure. The participants returned 2 days later and performed the same skill again. Poststudy questionnaire was used to assess the acceptability of each feedback among the participants. Overall, 19 students in group 1 and 18 students in group 2 completed the study. Although there was a significant improvement in the overall mean score on the second performance of the task for all participants (first performance mean 11.59, second performance mean 15.95; p ≤ 0.0001), there was no difference in the overall mean improvement score between group 1 and group 2 (4.74 and 3.94, respectively; p = 0.49). The mean overall scores for the e-feedback group at baseline recorded by 2 independent investigators showed good agreement (mean overall scores of 12.84 and 11.89; Cronbach α = 0.86). Poststudy questionnaire demonstrated that both e-feedback and standard verbal feedback achieved high mean Likert grades as recorded by the participants (4.42 [range: 2-5] and 4.71 [range: 4-5], respectively; p = 0.274). e-Feedback after watching a video recording appears to be acceptable and is not quantitatively different than standard feedback in improving suturing skills among novice trainees. Video assessment of procedural skills is reliable. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Effectiveness of a smartphone app in increasing physical activity amongst male adults: a randomised controlled trial.

PubMed

Harries, Tim; Eslambolchilar, Parisa; Rettie, Ruth; Stride, Chris; Walton, Simon; van Woerden, Hugo C

2016-09-02

Smartphones are ideal for promoting physical activity in those with little intrinsic motivation for exercise. This study tested three hypotheses: H1 - receipt of social feedback generates higher step-counts than receipt of no feedback; H2 - receipt of social feedback generates higher step-counts than only receiving feedback on one's own walking; H3 - receipt of feedback on one's own walking generates higher step-counts than no feedback (H3). A parallel group randomised controlled trial measured the impact of feedback on steps-counts. Healthy male participants (n = 165) aged 18-40 were given phones pre-installed with an app that recorded steps continuously, without the need for user activation. Participants carried these with them as their main phones for a two-week run-in and six-week trial. Randomisation was to three groups: no feedback (control); personal feedback on step-counts; group feedback comparing step-counts against those taken by others in their group. The primary outcome measure, steps per day, was assessed using longitudinal multilevel regression analysis. Control variables included attitude to physical activity and perceived barriers to physical activity. Fifty-five participants were allocated to each group; 152 completed the study and were included in the analysis: n = 49, no feedback; n = 53, individual feedback; n = 50, individual and social feedback. The study provided support for H1 and H3 but not H2. Receipt of either form of feedback explained 7.7 % of between-subject variability in step-count (F = 6.626, p < 0.0005). Compared to the control, the expected step-count for the individual feedback group was 60 % higher (effect on log step-count = 0.474, 95 % CI = 0.166-0.782) and that for the social feedback group, 69 % higher (effect on log step-count = 0.526, 95 % CI = 0.212-0.840). The difference between the two feedback groups (individual vs social feedback) was not statistically significant. Always-on smartphone apps that provide step-counts can increase physical activity in young to early-middle-aged men but the provision of social feedback has no apparent incremental impact. This approach may be particularly suitable for inactive people with low levels of physical activity; it should now be tested with this population.

Feedback first: the surprisingly weak effects of magnetic fields, viscosity, conduction and metal diffusion on sub-L* galaxy formation

NASA Astrophysics Data System (ADS)

Su, Kung-Yi; Hopkins, Philip F.; Hayward, Christopher C.; Faucher-Giguère, Claude-André; Kereš, Dušan; Ma, Xiangcheng; Robles, Victor H.

2017-10-01

Using high-resolution simulations with explicit treatment of stellar feedback physics based on the FIRE (Feedback In Realistic Environments) project, we study how galaxy formation and the interstellar medium (ISM) are affected by magnetic fields, anisotropic Spitzer-Braginskii conduction and viscosity, and sub-grid metal diffusion from unresolved turbulence. We consider controlled simulations of isolated (non-cosmological) galaxies but also a limited set of cosmological 'zoom-in' simulations. Although simulations have shown significant effects from these physics with weak or absent stellar feedback, the effects are much weaker than those of stellar feedback when the latter is modelled explicitly. The additional physics have no systematic effect on galactic star formation rates (SFRs). In contrast, removing stellar feedback leads to SFRs being overpredicted by factors of ˜10-100. Without feedback, neither galactic winds nor volume-filling hot-phase gas exist, and discs tend to runaway collapse to ultra-thin scaleheights with unphysically dense clumps congregating at the galactic centre. With stellar feedback, a multi-phase, turbulent medium with galactic fountains and winds is established. At currently achievable resolutions and for the investigated halo mass range 1010-1013 M⊙, the additional physics investigated here (magnetohydrodynamic, conduction, viscosity, metal diffusion) have only weak (˜10 per cent-level) effects on regulating SFR and altering the balance of phases, outflows or the energy in ISM turbulence, consistent with simple equipartition arguments. We conclude that galactic star formation and the ISM are primarily governed by a combination of turbulence, gravitational instabilities and feedback. We add the caveat that active galactic nucleus feedback is not included in the present work.

Molecular genetic analysis of circadian timekeeping in Drosophila

PubMed Central

Hardin, Paul E.

2014-01-01

A genetic screen for mutants that alter circadian rhythms in Drosophila identified the first clock gene - the period (per) gene. The per gene is a central player within a transcriptional feedback loop that represents the core mechanism for keeping circadian time in Drosophila and other animals. The per feedback loop, or core loop, is interlocked with the Clock (Clk) feedback loop, but whether the Clk feedback loop contributes to circadian timekeeping is not known. A series of distinct molecular events are thought to control transcriptional feedback in the core loop. The time it takes to complete these events should take much less than 24h, thus delays must be imposed at different steps within the core loop. As new clock genes are identified, the molecular mechanisms responsible for these delays have been revealed in ever-increasing detail, and provide an in depth accounting of how transcriptional feedback loops keep circadian time. The phase of these feedback loops shift to maintain synchrony with environmental cycles, the most reliable of which is light. Although a great deal is known about cell-autonomous mechanisms of light-induced phase shifting by CRYPTOCHROME (CRY), much less is known about non-cell autonomous mechanisms. CRY mediates phase shifts through an uncharacterized mechanism in certain brain oscillator neurons, and carries out a dual role as a photoreceptor and transcription factor in other tissues. Here I will review how transcriptional feedback loops function to keep time in Drosophila, how they impose delays to maintain a 24h cycle, and how they maintain synchrony with environmental light:dark cycles. The transcriptional feedback loops that keep time in Drosophila are well conserved in other animals, thus what we learn about these loops in Drosophila should continue to provide insight into the operation of analogous transcriptional feedback loops in other animals. PMID:21924977

Enhancement of vegetation-rainfall feedbacks on the Australian summer monsoon by the Madden-Julian Oscillation

NASA Astrophysics Data System (ADS)

Notaro, Michael

2018-01-01

A regional climate modeling analysis of the Australian monsoon system reveals a substantial modulation of vegetation-rainfall feedbacks by the Madden Julian Oscillation (MJO), both of which operate at similar sub-seasonal time scales, as evidence that the intensity of land-atmosphere interactions is sensitive to the background atmospheric state. Based on ensemble experiments with imposed modification of northern Australian leaf area index (LAI), the atmospheric responses to LAI anomalies are composited for negative and positive modes of the propagating MJO. In the regional climate model (RCM), northern Australian vegetation feedbacks are characterized by evapotranspiration (ET)-driven rainfall responses, with the moisture feedback mechanism dominating over albedo and roughness feedback mechanisms. During November-April, both Tropical Rainfall Measuring Mission and RCM data reveal MJO's pronounced influence on rainfall patterns across northern Australia, tropical Indian Ocean, Timor Sea, Arafura Sea, and Gulf of Carpentaria, with the MJO dominating over vegetation feedbacks in terms of regulating monsoon rainfall variability. Convectively-active MJO phases support an enhancement of positive vegetation feedbacks on monsoon rainfall. While the MJO imposes minimal regulation of ET responses to LAI anomalies, the vegetation feedback-induced responses in precipitable water, cloud water, and rainfall are greatly enhanced during convectively-active MJO phases over northern Australia, which are characterized by intense low-level convergence and efficient precipitable water conversion. The sub-seasonal response of vegetation-rainfall feedback intensity to the MJO is complex, with significant enhancement of rainfall responses to LAI anomalies in February during convectively-active MJO phases compared to minimal modulation by the MJO during prior and subsequent calendar months.

Output Feedback Adaptive Control of Non-Minimum Phase Systems Using Optimal Control Modification

NASA Technical Reports Server (NTRS)

Nguyen, Nhan; Hashemi, Kelley E.; Yucelen, Tansel; Arabi, Ehsan

2018-01-01

This paper describes output feedback adaptive control approaches for non-minimum phase SISO systems with relative degree 1 and non-strictly positive real (SPR) MIMO systems with uniform relative degree 1 using the optimal control modification method. It is well-known that the standard model-reference adaptive control (MRAC) cannot be used to control non-SPR plants to track an ideal SPR reference model. Due to the ideal property of asymptotic tracking, MRAC attempts an unstable pole-zero cancellation which results in unbounded signals for non-minimum phase SISO systems. The optimal control modification can be used to prevent the unstable pole-zero cancellation which results in a stable adaptation of non-minimum phase SISO systems. However, the tracking performance using this approach could suffer if the unstable zero is located far away from the imaginary axis. The tracking performance can be recovered by using an observer-based output feedback adaptive control approach which uses a Luenberger observer design to estimate the state information of the plant. Instead of explicitly specifying an ideal SPR reference model, the reference model is established from the linear quadratic optimal control to account for the non-minimum phase behavior of the plant. With this non-minimum phase reference model, the observer-based output feedback adaptive control can maintain stability as well as tracking performance. However, in the presence of the mismatch between the SPR reference model and the non-minimum phase plant, the standard MRAC results in unbounded signals, whereas a stable adaptation can be achieved with the optimal control modification. An application of output feedback adaptive control for a flexible wing aircraft illustrates the approaches.

Graphical Understanding of Simple Feedback Systems.

ERIC Educational Resources Information Center

Janvier, Claude; Garancon, Maurice

1989-01-01

Shows that graphs can reveal much about feedback systems that formula conceal, especially as microcomputers can provide complex graphs presented as animations and allow students to interact easily with them. Describes feedback systems, evolution of the system, and phase diagram. (YP)

Management of behavioural change in patients presenting with a diagnosis of dementia: a video vignette study with Australian general practitioners.

PubMed

Jiwa, Moyez; Nichols, Pam; Magin, Parker; Pagey, Georgina; Meng, Xingqiong; Parsons, Richard; Pillai, Vinita

2014-09-25

To test the impact of feedback on the proposed management of standardised patients presenting with behavioural change with a diagnosis of dementia in Australian primary care. A video vignette study was performed with Australian general practitioners (GPs) in 2013. Participants viewed six pairs of matched videos depicting people presenting changed behaviour in the context of a dementia diagnosis in two phases. In both phases GPs indicated their diagnosis and management. After phase 1, GPs were offered feedback on management strategies for the patients depicted. Analyses focused on identification of change in management between the two phases of the study. Factors impacting on the intention to coordinate care for such patients were tested in a questionnaire based on the Theory of Planned Behaviour. Forty-five GPs completed the study. There was significant improvement in the proposed management of three of the six scenarios after the intervention. Older GPs were more likely to refer appropriately (OR=1.11 (1.01 to 1.23), p=0.04.). Overall referral to support agencies was more likely after the intervention (OR=2.52 (1.53 to 4.14), p<0.001). Older GPs were less likely to intend to coordinate care for such patients (OR=0.89 (0.81 to 0.98) p=0.02). Participants who felt confident about their ability to coordinate care were more likely to do so (OR=3.79 (1.08 to 13.32) p=0.04). The intervention described in this study promoted multidisciplinary management of patients with behavioural problems with a diagnosis of dementia. Increasing practitioner confidence in their ability to coordinate care may increase the proportion of GPs who will respond to patients and carers in this context. Older GPs may benefit in particular. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Data for improvement and clinical excellence: protocol for an audit with feedback intervention in long-term care.

PubMed

Sales, Anne E; Schalm, Corinne

2010-10-13

There is considerable evidence about the effectiveness of audit coupled with feedback, although few audit with feedback interventions have been conducted in long-term care (LTC) settings to date. In general, the effects have been found to be modest at best, although in settings where there has been little history of audit and feedback, the effects may be greater, at least initially. The primary purpose of the Data for Improvement and Clinical Excellence (DICE) Long-Term Care project is to assess the effects of an audit with feedback intervention delivered monthly over 13 months in four LTC facilities. The research questions we addressed are:1. What effects do feedback reports have on processes and outcomes over time?2. How do different provider groups in LTC and home care respond to feedback reports based on data targeted at improving quality of care? The research team conducting this study comprises researchers and decision makers in continuing care in the province of Alberta, Canada. The intervention consists of monthly feedback reports in nine LTC units in four facilities in Edmonton, Alberta. Data for the feedback reports comes from the Resident Assessment Instrument Minimum Data Set (RAI) version 2.0, a standardized instrument mandated for use in LTC facilities throughout Alberta. Feedback reports consist of one page, front and back, presenting both graphic and textual information. Reports are delivered to all staff working in the four LTC facilities. The primary evaluation uses a controlled interrupted time series design both adjusted and unadjusted for covariates. The concurrent process evaluation uses observation and self-report to assess uptake of the feedback reports. Following the project phase described in this protocol, a similar intervention will be conducted in home care settings in Alberta. Depending on project findings, if they are judged useful by decision makers participating in this research team, we plan dissemination and spread of the feedback report approach throughout Alberta.

Effects of virtual reality training using Nintendo Wii and treadmill walking exercise on balance and walking for stroke patients.

PubMed

Bang, Yo-Soon; Son, Kyung Hyun; Kim, Hyun Jin

2016-11-01

[Purpose] The purpose of this study is to investigate the effects of virtual reality training using Nintendo Wii on balance and walking for stroke patients. [Subjects and Methods] Forty stroke patients with stroke were randomly divided into two exercise program groups: virtual reality training (n=20) and treadmill (n=20). The subjects underwent their 40-minute exercise program three times a week for eight weeks. Their balance and walking were measured before and after the complete program. We measured the left/right weight-bearing and the anterior/posterior weight-bearing for balance, as well as stance phase, swing phase, and cadence for walking. [Results] For balance, both groups showed significant differences in the left/right and anterior/posterior weight-bearing, with significant post-program differences between the groups. For walking, there were significant differences in the stance phase, swing phase, and cadence of the virtual reality training group. [Conclusion] The results of this study suggest that virtual reality training providing visual feedback may enable stroke patients to directly adjust their incorrect weight center and shift visually. Virtual reality training may be appropriate for patients who need improved balance and walking ability by inducing their interest for them to perform planned exercises on a consistent basis.

Effects of virtual reality training using Nintendo Wii and treadmill walking exercise on balance and walking for stroke patients

PubMed Central

Bang, Yo-Soon; Son, Kyung Hyun; Kim, Hyun Jin

2016-01-01

[Purpose] The purpose of this study is to investigate the effects of virtual reality training using Nintendo Wii on balance and walking for stroke patients. [Subjects and Methods] Forty stroke patients with stroke were randomly divided into two exercise program groups: virtual reality training (n=20) and treadmill (n=20). The subjects underwent their 40-minute exercise program three times a week for eight weeks. Their balance and walking were measured before and after the complete program. We measured the left/right weight-bearing and the anterior/posterior weight-bearing for balance, as well as stance phase, swing phase, and cadence for walking. [Results] For balance, both groups showed significant differences in the left/right and anterior/posterior weight-bearing, with significant post-program differences between the groups. For walking, there were significant differences in the stance phase, swing phase, and cadence of the virtual reality training group. [Conclusion] The results of this study suggest that virtual reality training providing visual feedback may enable stroke patients to directly adjust their incorrect weight center and shift visually. Virtual reality training may be appropriate for patients who need improved balance and walking ability by inducing their interest for them to perform planned exercises on a consistent basis. PMID:27942130

Verbal communication improves laparoscopic team performance.

PubMed

Shiliang Chang; Waid, Erin; Martinec, Danny V; Bin Zheng; Swanstrom, Lee L

2008-06-01

The impact of verbal communication on laparoscopic team performance was examined. A total of 24 dyad teams, comprised of residents, medical students, and office staff, underwent 2 team tasks using a previously validated bench model. Twelve teams (feedback groups) received instant verbal instruction and feedback on their performance from an instructor which was compared with 12 teams (control groups) with minimal or no verbal feedback. Their performances were both video and audio taped for analysis. Surgical backgrounds were similar between feedback and control groups. Teams with more verbal feedback achieved significantly better task performance (P = .002) compared with the control group with less feedback. Impact of verbal feedback was more pronounced for tasks requiring team cooperation (aiming and navigation) than tasks depending on individual skills (knotting). Verbal communication, especially the instructions and feedback from an experienced instructor, improved team efficiency and performance.

The System-Wide Effect of Real-Time Audiovisual Feedback and Postevent Debriefing for In-Hospital Cardiac Arrest: The Cardiopulmonary Resuscitation Quality Improvement Initiative.

PubMed

Couper, Keith; Kimani, Peter K; Abella, Benjamin S; Chilwan, Mehboob; Cooke, Matthew W; Davies, Robin P; Field, Richard A; Gao, Fang; Quinton, Sarah; Stallard, Nigel; Woolley, Sarah; Perkins, Gavin D

2015-11-01

To evaluate the effect of implementing real-time audiovisual feedback with and without postevent debriefing on survival and quality of cardiopulmonary resuscitation quality at in-hospital cardiac arrest. A two-phase, multicentre prospective cohort study. Three UK hospitals, all part of one National Health Service Acute Trust. One thousand three hundred and ninety-five adult patients who sustained an in-hospital cardiac arrest at the study hospitals and were treated by hospital emergency teams between November 2009 and May 2013. During phase 1, quality of cardiopulmonary resuscitation and patient outcomes were measured with no intervention implemented. During phase 2, staff at hospital 1 received real-time audiovisual feedback, whereas staff at hospital 2 received real-time audiovisual feedback supplemented by postevent debriefing. No intervention was implemented at hospital 3 during phase 2. The primary outcome was return of spontaneous circulation. Secondary endpoints included other patient-focused outcomes, such as survival to hospital discharge, and process-focused outcomes, such as chest compression depth. Random-effect logistic and linear regression models, adjusted for baseline patient characteristics, were used to analyze the effect of the interventions on study outcomes. In comparison with no intervention, neither real-time audiovisual feedback (adjusted odds ratio, 0.62; 95% CI, 0.31-1.22; p=0.17) nor real-time audiovisual feedback supplemented by postevent debriefing (adjusted odds ratio, 0.65; 95% CI, 0.35-1.21; p=0.17) was associated with a statistically significant improvement in return of spontaneous circulation or any process-focused outcome. Despite this, there was evidence of a system-wide improvement in phase 2, leading to improvements in return of spontaneous circulation (adjusted odds ratio, 1.87; 95% CI, 1.06-3.30; p=0.03) and process-focused outcomes. Implementation of real-time audiovisual feedback with or without postevent debriefing did not lead to a measured improvement in patient or process-focused outcomes at individual hospital sites. However, there was an unexplained system-wide improvement in return of spontaneous circulation and process-focused outcomes during the second phase of the study.

Sonification and haptic feedback in addition to visual feedback enhances complex motor task learning.

PubMed

Sigrist, Roland; Rauter, Georg; Marchal-Crespo, Laura; Riener, Robert; Wolf, Peter

2015-03-01

Concurrent augmented feedback has been shown to be less effective for learning simple motor tasks than for complex tasks. However, as mostly artificial tasks have been investigated, transfer of results to tasks in sports and rehabilitation remains unknown. Therefore, in this study, the effect of different concurrent feedback was evaluated in trunk-arm rowing. It was then investigated whether multimodal audiovisual and visuohaptic feedback are more effective for learning than visual feedback only. Naïve subjects (N = 24) trained in three groups on a highly realistic virtual reality-based rowing simulator. In the visual feedback group, the subject's oar was superimposed to the target oar, which continuously became more transparent when the deviation between the oars decreased. Moreover, a trace of the subject's trajectory emerged if deviations exceeded a threshold. The audiovisual feedback group trained with oar movement sonification in addition to visual feedback to facilitate learning of the velocity profile. In the visuohaptic group, the oar movement was inhibited by path deviation-dependent braking forces to enhance learning of spatial aspects. All groups significantly decreased the spatial error (tendency in visual group) and velocity error from baseline to the retention tests. Audiovisual feedback fostered learning of the velocity profile significantly more than visuohaptic feedback. The study revealed that well-designed concurrent feedback fosters complex task learning, especially if the advantages of different modalities are exploited. Further studies should analyze the impact of within-feedback design parameters and the transferability of the results to other tasks in sports and rehabilitation.

Comparison of sensory modes of biofeedback in relaxation training of frontalis muscle.

PubMed

Chen, W

1981-12-01

The purpose of this study was to compare the effectiveness of various sensory modes of EMG biofeedback to relaxation training of the frontalis muscle. 19 male and 29 female subjects were randomly selected from a pool of college volunteers. They were then randomly assigned 12 each to audiofeedback, visual feedback, audiovisual feedback, and no feedback groups. There were 11 20-min. sessions per subject. Subjects in the biofeedback groups were trained to reduce muscle tension voluntarily by utilizing Cyborg J33 EMG portable trainers. The subjects in the three feedback groups exhibited significantly lower muscle tension than did the subjects in the no-feedback control group. There were no significant differences in relaxation among the three feedback groups.

Adaptation of a Motivational Interviewing Intervention to Improve Antidepressant Adherence among Latinos

PubMed Central

Interian, Alejandro; Martinez, Igda; Rios, Lisbeth Iglesias; Krejci, Jonathan; Guarnaccia, Peter J.

2009-01-01

Poor antidepressant adherence is a significant issue in depression treatment that adversely affects treatment outcomes. While being a common problem, it tends to be more common among Latinos. To address this problem, the current study adapted a Motivational Interviewing (MI) intervention to improve adherence among Latinos with depression. The adaptation process included six focus groups that elicited participants’ perspectives (N = 30), applying the intervention with test cases (N = 7) to fine tune the intervention, and eliciting feedback on the intervention (N = 5). The findings generated from these adaptation phases are described, along with a case example. Examples of adaptations to the MI included reframing antidepressant adherence as a way to luchar (struggle) against problems, focusing on motivation for improving depression and not just medication, refining methods for imparting antidepressant information, and inclusion of personalized visual feedback on dose-taking. The findings provide a description of the antidepressant issues experienced by a group of Latinos, as well as considerations for applying MI with this population. The intervention remained grounded in MI principles, but was contextualized for this Latino group. PMID:20438160

Movement preparation and execution: differential functional activation patterns after traumatic brain injury.

PubMed

Gooijers, Jolien; Beets, Iseult A M; Albouy, Genevieve; Beeckmans, Kurt; Michiels, Karla; Sunaert, Stefan; Swinnen, Stephan P

2016-09-01

Years following the insult, patients with traumatic brain injury often experience persistent motor control problems, including bimanual coordination deficits. Previous studies revealed that such deficits are related to brain structural white and grey matter abnormalities. Here, we assessed, for the first time, cerebral functional activation patterns during bimanual movement preparation and performance in patients with traumatic brain injury, using functional magnetic resonance imaging. Eighteen patients with moderate-to-severe traumatic brain injury (10 females; aged 26.3 years, standard deviation = 5.2; age range: 18.4-34.6 years) and 26 healthy young adults (15 females; aged 23.6 years, standard deviation = 3.8; age range: 19.5-33 years) performed a complex bimanual tracking task, divided into a preparation (2 s) and execution (9 s) phase, and executed either in the presence or absence of augmented visual feedback. Performance on the bimanual tracking task, expressed as the average target error, was impaired for patients as compared to controls (P < 0.001) and for trials in the absence as compared to the presence of augmented visual feedback (P < 0.001). At the cerebral level, movement preparation was characterized by reduced neural activation in the patient group relative to the control group in frontal (bilateral superior frontal gyrus, right dorsolateral prefrontal cortex), parietal (left inferior parietal lobe) and occipital (right striate and extrastriate visual cortex) areas (P's < 0.05). During the execution phase, however, the opposite pattern emerged, i.e. traumatic brain injury patients showed enhanced activations compared with controls in frontal (left dorsolateral prefrontal cortex, left lateral anterior prefrontal cortex, and left orbitofrontal cortex), parietal (bilateral inferior parietal lobe, bilateral superior parietal lobe, right precuneus, right primary somatosensory cortex), occipital (right striate and extrastriate visual cortices), and subcortical (left cerebellum crus II) areas (P's < 0.05). Moreover, a significant interaction effect between Feedback Condition and Group in the primary motor area (bilaterally) (P < 0.001), the cerebellum (left) (P < 0.001) and caudate (left) (P < 0.05), revealed that controls showed less overlap of activation patterns accompanying the two feedback conditions than patients with traumatic brain injury (i.e. decreased neural differentiation). In sum, our findings point towards poorer predictive control in traumatic brain injury patients in comparison to controls. Moreover, irrespective of the feedback condition, overactivations were observed in traumatically brain injured patients during movement execution, pointing to more controlled processing of motor task performance. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of visual feedback-induced variability on motor learning of handrim wheelchair propulsion.

PubMed

Leving, Marika T; Vegter, Riemer J K; Hartog, Johanneke; Lamoth, Claudine J C; de Groot, Sonja; van der Woude, Lucas H V

2015-01-01

It has been suggested that a higher intra-individual variability benefits the motor learning of wheelchair propulsion. The present study evaluated whether feedback-induced variability on wheelchair propulsion technique variables would also enhance the motor learning process. Learning was operationalized as an improvement in mechanical efficiency and propulsion technique, which are thought to be closely related during the learning process. 17 Participants received visual feedback-based practice (feedback group) and 15 participants received regular practice (natural learning group). Both groups received equal practice dose of 80 min, over 3 weeks, at 0.24 W/kg at a treadmill speed of 1.11 m/s. To compare both groups the pre- and post-test were performed without feedback. The feedback group received real-time visual feedback on seven propulsion variables with instruction to manipulate the presented variable to achieve the highest possible variability (1st 4-min block) and optimize it in the prescribed direction (2nd 4-min block). To increase motor exploration the participants were unaware of the exact variable they received feedback on. Energy consumption and the propulsion technique variables with their respective coefficient of variation were calculated to evaluate the amount of intra-individual variability. The feedback group, which practiced with higher intra-individual variability, improved the propulsion technique between pre- and post-test to the same extent as the natural learning group. Mechanical efficiency improved between pre- and post-test in the natural learning group but remained unchanged in the feedback group. These results suggest that feedback-induced variability inhibited the improvement in mechanical efficiency. Moreover, since both groups improved propulsion technique but only the natural learning group improved mechanical efficiency, it can be concluded that the improvement in mechanical efficiency and propulsion technique do not always appear simultaneously during the motor learning process. Their relationship is most likely modified by other factors such as the amount of the intra-individual variability.

Effects of Visual Feedback-Induced Variability on Motor Learning of Handrim Wheelchair Propulsion

PubMed Central

Leving, Marika T.; Vegter, Riemer J. K.; Hartog, Johanneke; Lamoth, Claudine J. C.; de Groot, Sonja; van der Woude, Lucas H. V.

2015-01-01

Background It has been suggested that a higher intra-individual variability benefits the motor learning of wheelchair propulsion. The present study evaluated whether feedback-induced variability on wheelchair propulsion technique variables would also enhance the motor learning process. Learning was operationalized as an improvement in mechanical efficiency and propulsion technique, which are thought to be closely related during the learning process. Methods 17 Participants received visual feedback-based practice (feedback group) and 15 participants received regular practice (natural learning group). Both groups received equal practice dose of 80 min, over 3 weeks, at 0.24 W/kg at a treadmill speed of 1.11 m/s. To compare both groups the pre- and post-test were performed without feedback. The feedback group received real-time visual feedback on seven propulsion variables with instruction to manipulate the presented variable to achieve the highest possible variability (1st 4-min block) and optimize it in the prescribed direction (2nd 4-min block). To increase motor exploration the participants were unaware of the exact variable they received feedback on. Energy consumption and the propulsion technique variables with their respective coefficient of variation were calculated to evaluate the amount of intra-individual variability. Results The feedback group, which practiced with higher intra-individual variability, improved the propulsion technique between pre- and post-test to the same extent as the natural learning group. Mechanical efficiency improved between pre- and post-test in the natural learning group but remained unchanged in the feedback group. Conclusion These results suggest that feedback-induced variability inhibited the improvement in mechanical efficiency. Moreover, since both groups improved propulsion technique but only the natural learning group improved mechanical efficiency, it can be concluded that the improvement in mechanical efficiency and propulsion technique do not always appear simultaneously during the motor learning process. Their relationship is most likely modified by other factors such as the amount of the intra-individual variability. PMID:25992626

Genetic influences on functional connectivity associated with feedback processing and prediction error: Phase coupling of theta-band oscillations in twins.

PubMed

Demiral, Şükrü Barış; Golosheykin, Simon; Anokhin, Andrey P

2017-05-01

Detection and evaluation of the mismatch between the intended and actually obtained result of an action (reward prediction error) is an integral component of adaptive self-regulation of behavior. Extensive human and animal research has shown that evaluation of action outcome is supported by a distributed network of brain regions in which the anterior cingulate cortex (ACC) plays a central role, and the integration of distant brain regions into a unified feedback-processing network is enabled by long-range phase synchronization of cortical oscillations in the theta band. Neural correlates of feedback processing are associated with individual differences in normal and abnormal behavior, however, little is known about the role of genetic factors in the cerebral mechanisms of feedback processing. Here we examined genetic influences on functional cortical connectivity related to prediction error in young adult twins (age 18, n=399) using event-related EEG phase coherence analysis in a monetary gambling task. To identify prediction error-specific connectivity pattern, we compared responses to loss and gain feedback. Monetary loss produced a significant increase of theta-band synchronization between the frontal midline region and widespread areas of the scalp, particularly parietal areas, whereas gain resulted in increased synchrony primarily within the posterior regions. Genetic analyses showed significant heritability of frontoparietal theta phase synchronization (24 to 46%), suggesting that individual differences in large-scale network dynamics are under substantial genetic control. We conclude that theta-band synchronization of brain oscillations related to negative feedback reflects genetically transmitted differences in the neural mechanisms of feedback processing. To our knowledge, this is the first evidence for genetic influences on task-related functional brain connectivity assessed using direct real-time measures of neuronal synchronization. Copyright © 2016 Elsevier B.V. All rights reserved.

User Preferences for Content, Features, and Style for an App to Reduce Harmful Drinking in Young Adults: Analysis of User Feedback in App Stores and Focus Group Interviews

PubMed Central

Khadjesari, Zarnie; Fincham-Campbell, Stephanie; Deluca, Paolo; Watson, Rod; Drummond, Colin

2016-01-01

Background Electronic screening and brief intervention (eSBI) is effective in reducing weekly alcohol consumption when delivered by a computer. Mobile phone apps demonstrate promise in delivering eSBI; however, few have been designed with an evidence-based and user-informed approach. Objective This study aims to explore from a user perspective, preferences for content, appearance, and operational features to inform the design of a mobile phone app for reducing quantity and frequency of drinking in young adults engaged in harmful drinking (18-30 year olds). Methods Phase 1 included a review of user reviews of available mobile phone apps that support a reduction in alcohol consumption. Apps were identified on iTunes and Google Play and were categorized into alcohol reduction support, entertainment, blood alcohol content measurement (BAC), or other. eSBI apps with ≥18 user reviews were subject to a content analysis, which coded praise, criticism, and recommendations for app content, functionality, and esthetics. Phase 2 included four focus groups with young adults drinking at harmful levels and residing in South London to explore their views on existing eSBI apps and preferences for future content, functionality, and appearance. Detailed thematic analysis of the data was undertaken. Results In Phase 1, of the 1584 apps extracted, 201 were categorized as alcohol reduction, 154 as BAC calculators, 509 as entertainment, and 720 as other. We classified 32 apps as eSBI apps. Four apps had ≥18 user reviews: Change for Life Drinks Tracker, Drinksmeter, Drinkaware, and Alcohol Units Calculator. The highest proportion of content praises were for information and feedback provided in the apps (12/27, 44%), followed by praise for the monitoring features (5/27, 19%). Many (8/12, 67%) criticisms were for the drinking diary; all of these were related to difficulty entering drinks. Over half (18/32, 56%) of functionality criticisms were descriptions of software bugs, and over half of those (10/18, 56%) were for app crashing or freezing. Drinksmeter and Alcohol Units Calculator were the most highly praised apps overall (23/57 and 22/57; 39% of praise overall). In Phase 2, two main themes were identified. The meaningfulness theme reflected how young adults thought apps needed to be tailored to the interests and values of their age group, particularly emphasizing content and feedback around broader health and well-being factors such as exercise, diet, and image. The community theme suggested that young adults want to be able to engage with other app users, both in groups of friends and with online users for motivation and support. Conclusions Targeted and relevant information and feedback, in addition to easy-to-use monitoring tools, were found to be important features of a mobile phone app to support a reduction in drinking. Future app development should consider tailoring all app aspects to the needs of young adults, considering broader well-being monitoring tools and online community functions. PMID:27220371

User Preferences for Content, Features, and Style for an App to Reduce Harmful Drinking in Young Adults: Analysis of User Feedback in App Stores and Focus Group Interviews.

PubMed

Milward, Joanna; Khadjesari, Zarnie; Fincham-Campbell, Stephanie; Deluca, Paolo; Watson, Rod; Drummond, Colin

2016-05-24

Electronic screening and brief intervention (eSBI) is effective in reducing weekly alcohol consumption when delivered by a computer. Mobile phone apps demonstrate promise in delivering eSBI; however, few have been designed with an evidence-based and user-informed approach. This study aims to explore from a user perspective, preferences for content, appearance, and operational features to inform the design of a mobile phone app for reducing quantity and frequency of drinking in young adults engaged in harmful drinking (18-30 year olds). Phase 1 included a review of user reviews of available mobile phone apps that support a reduction in alcohol consumption. Apps were identified on iTunes and Google Play and were categorized into alcohol reduction support, entertainment, blood alcohol content measurement (BAC), or other. eSBI apps with ≥18 user reviews were subject to a content analysis, which coded praise, criticism, and recommendations for app content, functionality, and esthetics. Phase 2 included four focus groups with young adults drinking at harmful levels and residing in South London to explore their views on existing eSBI apps and preferences for future content, functionality, and appearance. Detailed thematic analysis of the data was undertaken. In Phase 1, of the 1584 apps extracted, 201 were categorized as alcohol reduction, 154 as BAC calculators, 509 as entertainment, and 720 as other. We classified 32 apps as eSBI apps. Four apps had ≥18 user reviews: Change for Life Drinks Tracker, Drinksmeter, Drinkaware, and Alcohol Units Calculator. The highest proportion of content praises were for information and feedback provided in the apps (12/27, 44%), followed by praise for the monitoring features (5/27, 19%). Many (8/12, 67%) criticisms were for the drinking diary; all of these were related to difficulty entering drinks. Over half (18/32, 56%) of functionality criticisms were descriptions of software bugs, and over half of those (10/18, 56%) were for app crashing or freezing. Drinksmeter and Alcohol Units Calculator were the most highly praised apps overall (23/57 and 22/57; 39% of praise overall). In Phase 2, two main themes were identified. The meaningfulness theme reflected how young adults thought apps needed to be tailored to the interests and values of their age group, particularly emphasizing content and feedback around broader health and well-being factors such as exercise, diet, and image. The community theme suggested that young adults want to be able to engage with other app users, both in groups of friends and with online users for motivation and support. Targeted and relevant information and feedback, in addition to easy-to-use monitoring tools, were found to be important features of a mobile phone app to support a reduction in drinking. Future app development should consider tailoring all app aspects to the needs of young adults, considering broader well-being monitoring tools and online community functions.

Feedback-Based, System-Level Properties of Vertebrate-Microbial Interactions

PubMed Central

Rivas, Ariel L.; Jankowski, Mark D.; Piccinini, Renata; Leitner, Gabriel; Schwarz, Daniel; Anderson, Kevin L.; Fair, Jeanne M.; Hoogesteijn, Almira L.; Wolter, Wilfried; Chaffer, Marcelo; Blum, Shlomo; Were, Tom; Konah, Stephen N.; Kempaiah, Prakash; Ong’echa, John M.; Diesterbeck, Ulrike S.; Pilla, Rachel; Czerny, Claus-Peter; Hittner, James B.; Hyman, James M.; Perkins, Douglas J.

2013-01-01

Background Improved characterization of infectious disease dynamics is required. To that end, three-dimensional (3D) data analysis of feedback-like processes may be considered. Methods To detect infectious disease data patterns, a systems biology (SB) and evolutionary biology (EB) approach was evaluated, which utilizes leukocyte data structures designed to diminish data variability and enhance discrimination. Using data collected from one avian and two mammalian (human and bovine) species infected with viral, parasite, or bacterial agents (both sensitive and resistant to antimicrobials), four data structures were explored: (i) counts or percentages of a single leukocyte type, such as lymphocytes, neutrophils, or macrophages (the classic approach), and three levels of the SB/EB approach, which assessed (ii) 2D, (iii) 3D, and (iv) multi-dimensional (rotating 3D) host-microbial interactions. Results In all studies, no classic data structure discriminated disease-positive (D+, or observations in which a microbe was isolated) from disease-negative (D–, or microbial-negative) groups: D+ and D– data distributions overlapped. In contrast, multi-dimensional analysis of indicators designed to possess desirable features, such as a single line of observations, displayed a continuous, circular data structure, whose abrupt inflections facilitated partitioning into subsets statistically significantly different from one another. In all studies, the 3D, SB/EB approach distinguished three (steady, positive, and negative) feedback phases, in which D– data characterized the steady state phase, and D+ data were found in the positive and negative phases. In humans, spatial patterns revealed false-negative observations and three malaria-positive data classes. In both humans and bovines, methicillin-resistant Staphylococcus aureus (MRSA) infections were discriminated from non-MRSA infections. Conclusions More information can be extracted, from the same data, provided that data are structured, their 3D relationships are considered, and well-conserved (feedback-like) functions are estimated. Patterns emerging from such structures may distinguish well-conserved from recently developed host-microbial interactions. Applications include diagnosis, error detection, and modeling. PMID:23437039

Feedback-based, system-level properties of vertebrate-microbial interactions.

PubMed

Rivas, Ariel L; Jankowski, Mark D; Piccinini, Renata; Leitner, Gabriel; Schwarz, Daniel; Anderson, Kevin L; Fair, Jeanne M; Hoogesteijn, Almira L; Wolter, Wilfried; Chaffer, Marcelo; Blum, Shlomo; Were, Tom; Konah, Stephen N; Kempaiah, Prakash; Ong'echa, John M; Diesterbeck, Ulrike S; Pilla, Rachel; Czerny, Claus-Peter; Hittner, James B; Hyman, James M; Perkins, Douglas J

2013-01-01

Improved characterization of infectious disease dynamics is required. To that end, three-dimensional (3D) data analysis of feedback-like processes may be considered. To detect infectious disease data patterns, a systems biology (SB) and evolutionary biology (EB) approach was evaluated, which utilizes leukocyte data structures designed to diminish data variability and enhance discrimination. Using data collected from one avian and two mammalian (human and bovine) species infected with viral, parasite, or bacterial agents (both sensitive and resistant to antimicrobials), four data structures were explored: (i) counts or percentages of a single leukocyte type, such as lymphocytes, neutrophils, or macrophages (the classic approach), and three levels of the SB/EB approach, which assessed (ii) 2D, (iii) 3D, and (iv) multi-dimensional (rotating 3D) host-microbial interactions. In all studies, no classic data structure discriminated disease-positive (D+, or observations in which a microbe was isolated) from disease-negative (D-, or microbial-negative) groups: D+ and D- data distributions overlapped. In contrast, multi-dimensional analysis of indicators designed to possess desirable features, such as a single line of observations, displayed a continuous, circular data structure, whose abrupt inflections facilitated partitioning into subsets statistically significantly different from one another. In all studies, the 3D, SB/EB approach distinguished three (steady, positive, and negative) feedback phases, in which D- data characterized the steady state phase, and D+ data were found in the positive and negative phases. In humans, spatial patterns revealed false-negative observations and three malaria-positive data classes. In both humans and bovines, methicillin-resistant Staphylococcus aureus (MRSA) infections were discriminated from non-MRSA infections. More information can be extracted, from the same data, provided that data are structured, their 3D relationships are considered, and well-conserved (feedback-like) functions are estimated. Patterns emerging from such structures may distinguish well-conserved from recently developed host-microbial interactions. Applications include diagnosis, error detection, and modeling.

Integrating teaching into routine outpatient care: The design and evaluation of an ambulatory training concept (HeiSA).

PubMed

Hundertmark, Jan; Apondo, Sandra Karina; Schultz, Jobst-Hendrik

2018-01-01

Background: Direct patient contact is crucial in learning important interactional and examination skills. However, medical students have limited opportunity to self-responsibly practise these skills in authentic clinical settings and typically receive insufficient feedback on their performance. We developed a novel single-session ambulatory teaching concept (Heidelberg Student Ambulatory training, "HeiSA") to prepare students more adequately for clinical-practical responsibilities. Methods: To identify challenges and target group needs, we reviewed current literature and consulted an expert group of faculty lecturers and training researchers. The resulting course concept was put into practice at the University Hospital's general-internistic outpatient department and evaluated in a pilot phase (winter term 2010, ten participants) and a main project phase (summer and winter terms 2011, 14 and 21 participants, respectively). Third and fourth-year students autonomously take a new patient's medical history and conduct a complete physical examination in one hour under supervision, followed by extensive preceptor feedback. To assess learning achievements, participants and a control group self-rated their communication and examination skills before and (participants only) after the session on six-point Likert scales (1=completely able, 6=completely unable). The preceptor also evaluated the participants' performance. Finally, all stakeholders re-evaluated the course concept. Results: HeiSA is a feasible training concept and accepted by staff members and students. It provides opportunities to practise clinical skills in a relevant, authentic learning environment with extensive feedback. Participants report improved anamnesis (0.27±0.51, p =.003) and physical examination (0.25±0.41, p =.008) skills. The preceptor evaluated students' performance to be generally high, with ratings ranging from 1.40±0.55 (item: the student does not interrupt the patient) to 2.51±0.89 (item: psychosocial anamnesis). Conclusions: HeiSA is a viable course concept for teaching anamnesis and physical examination skills. It integrates student teaching into routine care and can potentially be adapted to other outpatient departments.

Integration of a Community Pharmacy Simulation Program into a Therapeutics Course.

PubMed

Shin, Jaekyu; Tabatabai, Daryush; Boscardin, Christy; Ferrone, Marcus; Brock, Tina

2018-02-01

Objective. To demonstrate the feasibility of integrating the computer simulation, MyDispense, into a therapeutics course and to measure its effects on student perception and learning. Methods. We conducted a prospective study with an experimental phase and an implementation phase. In the first phase, students were randomized to complete a therapeutics case using MyDispense or traditional paper methods in class. In the second phase, all students completed two therapeutic cases using MyDispense in class with the option to complete four additional outside-of-class cases using MyDispense. Students completed pre- and post-tests in class and three surveys. Results. In the experimental phase, mean test scores increased from pre- to post-test for both MyDispense and traditional paper groups, but the difference between the groups was not statistically significant. Students in the traditional paper group reported statistically significant gains in confidence compared to the MyDispense group. In the implementation phase, mean test scores again increased, however, student perception of the use of MyDispense for therapeutics was negative. Completing the optional outside-of-class cases, however, was positively and significantly correlated with the midterm and final examination scores. Conclusion. Implementation of MyDispense in therapeutics may be feasible and has positive effects (eg, correlation with exam scores, capacity for immediate feedback, and potential for effective self-study). With short-term use and in the absence of assessment methods that also require seeking information from patients, students prefer to learn via traditional paper cases.

Offset quadrature communications with decision-feedback carrier synchronization

NASA Technical Reports Server (NTRS)

Simon, M. K.; Smith, J. G.

1974-01-01

In order to accommodate a quadrature amplitude-shift-keyed (QASK) signal, Simon and Smith (1974) have modified the decision-feedback loop which tracks a quadrature phase-shift-keyed (QPSK). In the investigation reported approaches are considered to modify the loops in such a way that offset QASK signals can be tracked, giving attention to the special case of an offset QPSK. The development of the stochastic integro-differential equation of operation for a decision-feedback offset QASK loop is discussed along with the probability density function of the phase error process.

The Additive Impact of Group and Individual Publicly Displayed Feedback: Examining Individual Response Patterns and Response Generalization in a Safe-Driving Occupational Intervention

ERIC Educational Resources Information Center

Ludwig, Timothy D.; Geller, E. Scott; Clarke, Steven W.

2010-01-01

Additive effects of publicly posting individual feedback following group goal-setting and feedback were evaluated. The turn-signal use of pizza deliverers was studied in a multiple baseline design across two pizza stores. After baseline observations, pizza deliverers voted on a group turn-signal goal and then received 4 weeks of group feedback on…

Remote video auditing with real-time feedback in an academic surgical suite improves safety and efficiency metrics: a cluster randomised study

PubMed Central

Overdyk, Frank J; Dowling, Oonagh; Newman, Sheldon; Glatt, David; Chester, Michelle; Armellino, Donna; Cole, Brandon; Landis, Gregg S; Schoenfeld, David; DiCapua, John F

2016-01-01

Importance Compliance with the surgical safety checklist during operative procedures has been shown to reduce inhospital mortality and complications but proper execution by the surgical team remains elusive. Objective We evaluated the impact of remote video auditing with real-time provider feedback on checklist compliance during sign-in, time-out and sign-out and case turnover times. Design, setting Prospective, cluster randomised study in a 23-operating room (OR) suite. Participants Surgeons, anaesthesia providers, nurses and support staff. Exposure ORs were randomised to receive, or not receive, real-time feedback on safety checklist compliance and efficiency metrics via display boards and text messages, followed by a period during which all ORs received feedback. Main outcome(s) and measure(s) Checklist compliance (Pass/Fail) during sign-in, time-out and sign-out demonstrated by (1) use of checklist, (2) team attentiveness, (3) required duration, (4) proper sequence and duration of case turnover times. Results Sign-in, time-out and sign-out PASS rates increased from 25%, 16% and 32% during baseline phase (n=1886) to 64%, 84% and 68% for feedback ORs versus 40%, 77% and 51% for no-feedback ORs (p<0.004) during the intervention phase (n=2693). Pass rates were 91%, 95% and 84% during the all-feedback phase (n=2001). For scheduled cases (n=1406, 71%), feedback reduced mean turnover times by 14% (41.4 min vs 48.1 min, p<0.004), and the improvement was sustained during the all-feedback period. Feedback had no effect on turnover time for unscheduled cases (n=587, 29%). Conclusions and relevance Our data indicate that remote video auditing with feedback improves surgical safety checklist compliance for all cases, and turnover time for scheduled cases, but not for unscheduled cases. PMID:26658775

Creating a performance appraisal template for pharmacy technicians using the method of equal-appearing intervals.

PubMed

Desselle, Shane P; Vaughan, Melissa; Faria, Thomas

2002-01-01

To design a highly quantitative template for the evaluation of community pharmacy technicians' job performance that enables managers to provide sufficient feedback and fairly allocate organizational rewards. Two rounds of interviews with two convenience samples of community pharmacists and pharmacy technicians were conducted. The interview in phase 1 was qualitative, and responses were used to design the second interview protocol. During the phase 2 interviews, a new group of respondents ranked technicians' job responsibilities, identified through the initial interviewees' responses, using scales the researchers had designed using an interval-level scaling technique called equal-appearing intervals. Chain and independent pharmacies. Phase 1-20 pharmacists and 20 technicians from chain and independent pharmacies; phase 2-20 pharmacists and 9 technicians from chain and independent pharmacies. Ratings of the importance of technician practice functions and corresponding responsibilities. Weights were calculated for each practice function. A weighted list of practice functions was developed, and this may serve as a performance evaluation template. Customer service-related activities were judged by pharmacists and technicians alike to be the most important technician functions. Many pharmacies either lack formal performance appraisal systems or fail to implement them properly. Technicians may desire more consistent feedback from pharmacists and value information that may lead to organizational rewards. Using a weighted, behaviorally anchored performance appraisal system may help pharmacists and pharmacy managers meet these demands.

Quantifying the Relative Contributions of Divisive and Subtractive Feedback to Rhythm Generation

PubMed Central

Tabak, Joël; Rinzel, John; Bertram, Richard

2011-01-01

Biological systems are characterized by a high number of interacting components. Determining the role of each component is difficult, addressed here in the context of biological oscillations. Rhythmic behavior can result from the interplay of positive feedback that promotes bistability between high and low activity, and slow negative feedback that switches the system between the high and low activity states. Many biological oscillators include two types of negative feedback processes: divisive (decreases the gain of the positive feedback loop) and subtractive (increases the input threshold) that both contribute to slowly move the system between the high- and low-activity states. Can we determine the relative contribution of each type of negative feedback process to the rhythmic activity? Does one dominate? Do they control the active and silent phase equally? To answer these questions we use a neural network model with excitatory coupling, regulated by synaptic depression (divisive) and cellular adaptation (subtractive feedback). We first attempt to apply standard experimental methodologies: either passive observation to correlate the variations of a variable of interest to system behavior, or deletion of a component to establish whether a component is critical for the system. We find that these two strategies can lead to contradictory conclusions, and at best their interpretive power is limited. We instead develop a computational measure of the contribution of a process, by evaluating the sensitivity of the active (high activity) and silent (low activity) phase durations to the time constant of the process. The measure shows that both processes control the active phase, in proportion to their speed and relative weight. However, only the subtractive process plays a major role in setting the duration of the silent phase. This computational method can be used to analyze the role of negative feedback processes in a wide range of biological rhythms. PMID:21533065

Initial development and psychometric testing of an instrument to measure the quality of children's end-of-life care.

PubMed

Widger, Kimberley; Tourangeau, Ann E; Steele, Rose; Streiner, David L

2015-01-01

The field of pediatric palliative care is hindered by the lack of a well-defined, reliable, and valid method for measuring the quality of end-of-life care. The study purpose was to develop and test an instrument to measure mothers' perspectives on the quality of care received before, at the time of, and following a child's death. In Phase 1, key components of quality end-of-life care for children were synthesized through a comprehensive review of research literature. These key components were validated in Phase 2 and then extended through focus groups with bereaved parents. In Phase 3, items were developed to assess structures, processes, and outcomes of quality end-of-life care then tested for content and face validity with health professionals. Cognitive testing was conducted through interviews with bereaved parents. In Phase 4, bereaved mothers were recruited through 10 children's hospitals/hospices in Canada to complete the instrument, and psychometric testing was conducted. Following review of 67 manuscripts and 3 focus groups with 10 parents, 141 items were initially developed. The overall content validity index for these items was 0.84 as rated by 7 health professionals. Based on feedback from health professionals and cognitive testing with 6 parents, a 144-item instrument was finalized for further testing. In Phase 4, 128 mothers completed the instrument, 31 of whom completed it twice. Test-retest reliability, internal consistency, and construct validity were demonstrated for six subscales: Connect With Families, Involve Parents, Share Information With Parents, Share Information Among Health Professionals, Support Parents, and Provide Care at Death. Additional items with content validity were grouped in four domains: Support the Child, Support Siblings, Provide Bereavement Follow-up, and Structures of Care. Forty-eight items were deleted through psychometric testing, leaving a 95-item instrument. There is good initial evidence for the reliability and validity of this new quality of end-of-life care instrument as a mechanism for evaluative feedback to health professionals, health systems, and policy makers to improve children's end-of-life care.

Counterintuitive effects of negative social feedback on attention.

PubMed

Anderson, Brian A

2017-04-01

Which stimuli we pay attention to is strongly influenced by learning. Stimuli previously associated with reward outcomes, such as money and food, and stimuli previously associated with aversive outcomes, such as monetary loss and electric shock, automatically capture attention. Social reward (happy expressions) can bias attention towards associated stimuli, but the role of negative social feedback in biasing attentional selection remains unexplored. On the one hand, negative social feedback often serves to discourage particular behaviours. If attentional selection can be curbed much like any other behavioural preference, we might expect stimuli associated with negative social feedback to be more readily ignored. On the other hand, if negative social feedback influences attention in the same way that other aversive outcomes do, such feedback might ironically bias attention towards the stimuli it is intended to discourage selection of. In the present study, participants first completed a training phase in which colour targets were associated with negative social feedback. Then, in a subsequent test phase, these same colour stimuli served as task-irrelevant distractors during a visual search task. The results strongly support the latter interpretation in that stimuli previously associated with negative social feedback impaired search performance.

Expert monitoring and verbal feedback as sources of performance pressure.

PubMed

Buchanan, John J; Park, Inchon; Chen, Jing; Mehta, Ranjana K; McCulloch, Austin; Rhee, Joohyun; Wright, David L

2018-05-01

The influence of monitoring-pressure and verbal feedback on the performance of the intrinsically stable bimanual coordination patterns of in-phase and anti-phase was examined. The two bimanual patterns were produced under three conditions: 1) no-monitoring, 2) monitoring-pressure (viewed by experts), and 3) monitoring-pressure (viewed by experts) combined with verbal feedback emphasizing poor performance. The bimanual patterns were produced at self-paced movement frequencies. Anti-phase coordination was always less stable than in-phase coordination across all three conditions. When performed under conditions 2 and 3, both bimanual patterns were performed with less variability in relative phase across a wide range of self-paced movement frequencies compared to the no-monitoring condition. Thus, monitoring-pressure resulted in performance stabilization rather than degradation and the presence of verbal feedback had no impact on the influence of monitoring pressure. The current findings are inconsistent with the predictions of explicit monitoring theory; however, the findings are consistent with studies that have revealed increased stability for the system's intrinsic dynamics as a result of attentional focus and intentional control. The results are discussed within the contexts of the dynamic pattern theory of coordination, explicit monitoring theory, and action-focused theories as explanations for choking under pressure. Copyright © 2018. Published by Elsevier B.V.

Security-enhanced chaos communication with time-delay signature suppression and phase encryption.

PubMed

Xue, Chenpeng; Jiang, Ning; Lv, Yunxin; Wang, Chao; Li, Guilan; Lin, Shuqing; Qiu, Kun

2016-08-15

A security-enhanced chaos communication scheme with time delay signature (TDS) suppression and phase-encrypted feedback light is proposed, in virtue of dual-loop feedback with independent high-speed phase modulation. We numerically investigate the property of TDS suppression in the intensity and phase space and quantitatively discuss security of the proposed system by calculating the bit error rate of eavesdroppers who try to crack the system by directly filtering the detected signal or by using a similar semiconductor laser to synchronize the link signal and extract the data. The results show that TDS embedded in the chaotic carrier can be well suppressed by properly setting the modulation frequency, which can keep the time delay a secret from the eavesdropper. Moreover, because the feedback light is encrypted, without the accurate time delay and key, the eavesdropper cannot reconstruct the symmetric operation conditions and decode the correct data.

Feedback mechanisms of change: How problem alerts reported by youth clients and their caregivers impact clinician-reported session content

PubMed Central

Douglas, Susan R.; Jonghyuk, Bae; de Andrade, Ana Regina Vides; Tomlinson, M. Michele; Hargraves, Ryan Pamela; Bickman, Leonard

2015-01-01

Objective This study explored how clinician-reported content addressed in treatment sessions was predicted by clinician feedback group and multi-informant cumulative problem alerts that appeared in computerized feedback reports for 299 clients aged 11 to 18 years receiving home-based community mental health treatment. Method Measures included a clinician-report of content addressed in sessions and additional measures of treatment progress and process (e.g., therapeutic alliance) completed by clinicians, clients, and their caregivers. Item responses in the top 25th percentile in severity from these measures appeared as ‘problem alerts’ on corresponding computerized feedback reports. Clinicians randomized to the feedback group received feedback weekly while the control group did not. Analyses were conducted using the Cox proportional hazards regression for recurrent events. Results For all content domains, the results of the survival analyses indicated a robust effect of the feedback group on addressing specific content in sessions, with feedback associated with shorter duration to first occurrence and increased likelihood of addressing or focusing on a topic compared to the non-feedback group. Conclusion There appears to be an important relationship between feedback and cumulative problem alerts reported by multiple informants as they influence session content. PMID:26337327

Information-reduced Carrier Synchronization of Iterative Decoded BPSK and QPSK using Soft Decision (Extrinsic) Feedback

NASA Technical Reports Server (NTRS)

Simon, Marvin; Valles, Esteban; Jones, Christopher

2008-01-01

This paper addresses the carrier-phase estimation problem under low SNR conditions as are typical of turbo- and LDPC-coded applications. In previous publications by the first author, closed-loop carrier synchronization schemes for error-correction coded BPSK and QPSK modulation were proposed that were based on feeding back hard data decisions at the input of the loop, the purpose being to remove the modulation prior to attempting to track the carrier phase as opposed to the more conventional decision-feedback schemes that incorporate such feedback inside the loop. In this paper, we consider an alternative approach wherein the extrinsic soft information from the iterative decoder of turbo or LDPC codes is instead used as the feedback.

Specific interpretation of augmented feedback changes motor performance and cortical processing.

PubMed

Lauber, Benedikt; Keller, Martin; Leukel, Christian; Gollhofer, Albert; Taube, Wolfgang

2013-05-01

It is well established that the presence of external feedback, also termed augmented feedback, can be used to improve performance of a motor task. The present study aimed to elucidate whether differential interpretation of the external feedback signal influences the time to task failure of a sustained submaximal contraction and modulates motor cortical activity. In Experiment 1, subjects had to maintain a submaximal contraction (30% of maximum force) performed with their thumb and index finger. Half of the tested subjects were always provided with feedback about joint position (pF-group), whereas the other half of the subjects were always provided with feedback about force (fF-group). Subjects in the pF-group were led to belief in half of their trials that they would receive feedback about the applied force, and subjects in the fF-group to receive feedback about the position. In both groups (fF and pF), the time to task failure was increased when subjects thought to receive feedback about the force. In Experiment 2, subthreshold transcranial magnetic stimulation was applied over the right motor cortex and revealed an increased motor cortical activity when subjects thought to receive feedback about the joint position. The results showed that the interpretation of feedback influences motor behavior and alters motor cortical activity. The current results support previous studies suggesting a distinct neural control of force and position.

Depression screening with patient-targeted feedback in cardiology: DEPSCREEN-INFO randomised clinical trial.

PubMed

Löwe, Bernd; Blankenberg, Stefan; Wegscheider, Karl; König, Hans-Helmut; Walter, Dirk; Murray, Alexandra M; Gierk, Benjamin; Kohlmann, Sebastian

2017-02-01

International guidelines advocate depression screening in patients with coronary heart disease (CHD) and other chronic illnesses, but evidence is lacking. To test the differential efficacy of written patient-targeted feedback v. no written patient feedback after depression screening. Patients with CHD or hypertension from three cardiology settings were randomised and screened for depression (ClinicalTrials.gov Identifier: NCT01879111). Compared with the control group, where only cardiologists received written feedback, in the intervention group both cardiologists and patients received written feedback regarding depression status. Depression severity was measured 1 month (primary outcome) and 6 months after screening. The control group (n = 220) and the patient-feedback group (n = 155) did not differ in depression severity 1 month after screening. Six months after screening, the patient-feedback group showed significantly greater improvements in depression severity and was twice as likely to seek information about depression compared with the control group. Patient-targeted feedback in addition to screening has a significant but small effect on depression severity after 6 months and may encourage patients to take an active role in the self-management of depression. © The Royal College of Psychiatrists 2017.

Three nested randomized controlled trials of peer-only or multiple stakeholder group feedback within Delphi surveys during core outcome and information set development.

PubMed

Brookes, Sara T; Macefield, Rhiannon C; Williamson, Paula R; McNair, Angus G; Potter, Shelley; Blencowe, Natalie S; Strong, Sean; Blazeby, Jane M

2016-08-17

Methods for developing a core outcome or information set require involvement of key stakeholders to prioritise many items and achieve agreement as to the core set. The Delphi technique requires participants to rate the importance of items in sequential questionnaires (or rounds) with feedback provided in each subsequent round such that participants are able to consider the views of others. This study examines the impact of receiving feedback from different stakeholder groups, on the subsequent rating of items and the level of agreement between stakeholders. Randomized controlled trials were nested within the development of three core sets each including a Delphi process with two rounds of questionnaires, completed by patients and health professionals. Participants rated items from 1 (not essential) to 9 (absolutely essential). For round 2, participants were randomized to receive feedback from their peer stakeholder group only (peer) or both stakeholder groups separately (multiple). Decisions as to which items to retain following each round were determined by pre-specified criteria. Whilst type of feedback did not impact on the percentage of items for which a participant subsequently changed their rating, or the magnitude of change, it did impact on items retained at the end of round 2. Each core set contained discordant items retained by one feedback group but not the other (3-22 % discordant items). Consensus between patients and professionals in items to retain was greater amongst those receiving multiple group feedback in each core set (65-82 % agreement for peer-only feedback versus 74-94 % for multiple feedback). In addition, differences in round 2 scores were smaller between stakeholder groups receiving multiple feedback than between those receiving peer group feedback only. Variability in item scores across stakeholders was reduced following any feedback but this reduction was consistently greater amongst the multiple feedback group. In the development of a core outcome or information set, providing feedback within Delphi questionnaires from all stakeholder groups separately may influence the final core set and improve consensus between the groups. Further work is needed to better understand how participants rate and re-rate items within a Delphi process. The three randomized controlled trials reported here were each nested within the development of a core information or outcome set to investigate processes in core outcome and information set development. Outcomes were not health-related and therefore trial registration was not applicable.

A study on M/G/1 retrial G - queue with two phases of service, immediate feedback and working vacations

NASA Astrophysics Data System (ADS)

Varalakshmi, M.; Chandrasekaran, V. M.; Saravanarajan, M. C.

2017-11-01

In this paper, we discuss about the steady state behaviour of M/G/1 retrial queueing system with two phases of services and immediate feedbacks under working vacation policy where the regular busy server is affected due to the arrival of negative customers. Upon arrival if the customer finds the server busy, breakdown or on working vacation it enters an orbit; otherwise the customer enters into the service area immediately. After service completion, the customer is allowed to make finite number of immediate feedback. The feedback service also consists of two phases. At the service completion epoch of a positive customer, if the orbit is empty the server goes for a working vacation. The server works at a lower service rate during working vacation (WV) period. Using the supplementary variable technique, we found out the steady state probability generating function for the system and in orbit. System performance measures and reliability measures are discussed. Finally, some numerical examples are presented to validate the analyticalresults.

The impact of immediate or delayed feedback on driving behaviour in a simulated Pay-As-You-Drive system.

PubMed

Dijksterhuis, Chris; Lewis-Evans, Ben; Jelijs, Bart; de Waard, Dick; Brookhuis, Karel; Tucha, Oliver

2015-02-01

Pay-As-You-Drive (PAYD) insurance links an individual's driving behaviour to the insurance fee that they pay, making car insurance more actuarially accurate. The best known PAYD insurance format is purely mileage based and is estimated to reduce accidents by about 15% (Litman, 2011). However, these benefits could be further enhanced by incorporating a wider range of driving behaviours, such as lateral and longitudinal accelerations and speeding behaviour, thereby stimulating not only a safe but also an eco-friendly driving style. Currently, feedback on rewards and driver behaviour is mostly provided through a web-based interface, which is presented temporally separated from driving. However, providing immediate feedback within the vehicle itself could elicit more effect. To investigate this hypothesis, two groups of 20 participants drove with a behavioural based PAYD system in a driving simulator and were provided with either delayed feedback through a website, or immediate feedback through an in-car interface, allowing them to earn up to €6 extra. To be clear, every participant in the web group did actually view their feedback during the one week between sessions. Results indicate clear driving behaviour improvements for both PAYD groups as compared to baseline rides and an equal sized control group. After both PAYD groups had received feedback, the initial advantage of the in-car group was reduced substantially. Taken together with usability ratings and driving behaviours in specific situations these results show a moderate advantage of using immediate in-car feedback. However, the study also showed that under conditions of feedback certainty, the effectiveness of delayed feedback approaches that of immediate feedback as compared to a naïve control group. Copyright © 2014 Elsevier Ltd. All rights reserved.

Control of follicle-stimulating hormone by estradiol and the inhibins: critical role of estradiol at the hypothalamus during the luteal-follicular transition.

PubMed

Welt, Corrine K; Pagan, Yanira L; Smith, Patricia C; Rado, Kimberly B; Hall, Janet E

2003-04-01

To test the hypothesis that estradiol, inhibin A, and inhibin B contribute differentially to FSH negative feedback in specific phases of the menstrual cycle, daily blood samples were obtained across a control cycle and after selective estrogen blockade with tamoxifen. To examine the site of estradiol-negative feedback in control and tamoxifen treatment cycles, early follicular phase GnRH (free alpha-subunit) pulse frequency was assessed in normal women, and FSH levels were examined in GnRH-deficient women in whom hypothalamic output was fixed with GnRH administration. FSH was higher in the early follicular phase in the presence of estrogen receptor blockade (15.7 +/- 3.1 vs. 13.2 +/- 1.9 IU/liter; P < 0.05) but was not increased in the late follicular phase. In the luteal phase, FSH was elevated (10.1 +/- 0.7 vs. 7.3 +/- 0.6 IU/liter; P < 0.01). In normal women, free alpha-subunit pulse frequency increased (7.3 +/- 0.4 vs. 4.8 +/- 0.4 pulses per 8 h; P < 0.003), but in GnRH-deficient women, there was no FSH increase (11.1 +/- 1.6 vs. 12.5 +/- 3.6 IU/liter) in the early follicular phase in the presence of estrogen blockade. In conclusion, estradiol exerts a greater role over inhibin in FSH-negative feedback regulation during the luteal phase and the luteal-follicular transition. In contrast, inhibin A and/or B plays a more critical role as the follicular phase progresses. In addition, these studies support a primary if not exclusive hypothalamic site of estrogen-negative feedback in the early follicular phase.

Developmental Programming: Contribution of Prenatal Androgen and Estrogen to Estradiol Feedback Systems and Periovulatory Hormonal Dynamics in Sheep1

PubMed Central

Veiga-Lopez, Almudena; Astapova, Olga I.; Aizenberg, Esther F.; Lee, James S.; Padmanabhan, Vasantha

2009-01-01

Prenatal testosterone excess leads to neuroendocrine and periovulatory disruptions in the offspring culminating in progressive loss of cyclicity. It is unknown whether the mediary of these disruptions is androgen or estrogen, because testosterone can be aromatized to estrogen. Taking a reproductive life span approach of studying control, prenatal testosterone, and dihydrotestosterone-treated offspring, this study tested the hypothesis that disruptions in estradiol-negative but not -positive feedback effects are programmed by androgenic actions of testosterone and that these disruptions in turn will have an impact on the periovulatory hormonal dynamics. The approach was to test estradiol-negative and -positive feedback responses of all three groups of ovary-intact females during prepubertal age and then compare the periovulatory dynamics of luteinizing hormone, follicle-stimulating hormone, estradiol, and progesterone during the first breeding season. The findings show that estradiol-negative but not estradiol-positive feedback disruptions in prenatal testosterone-treated females are programmed by androgenic actions of prenatal testosterone excess and that follicular phase estradiol and gonadotropins surge disruptions during reproductive life are consistent with estrogenic programming. Additional studies carried out testing estradiol-positive feedback response over time found progressive deterioration of estradiol-positive feedback in prenatal testosterone-treated sheep until the time of puberty. Together, these findings provide insight into the mechanisms by which prenatal testosterone disrupts the reproductive axis. The findings may be of translational relevance since daughters of mothers with hyperandrogenism are at risk of increased exposure to androgens. PMID:19122183

Developmental programming: contribution of prenatal androgen and estrogen to estradiol feedback systems and periovulatory hormonal dynamics in sheep.

PubMed

Veiga-Lopez, Almudena; Astapova, Olga I; Aizenberg, Esther F; Lee, James S; Padmanabhan, Vasantha

2009-04-01

Prenatal testosterone excess leads to neuroendocrine and periovulatory disruptions in the offspring culminating in progressive loss of cyclicity. It is unknown whether the mediary of these disruptions is androgen or estrogen, because testosterone can be aromatized to estrogen. Taking a reproductive life span approach of studying control, prenatal testosterone, and dihydrotestosterone-treated offspring, this study tested the hypothesis that disruptions in estradiol-negative but not -positive feedback effects are programmed by androgenic actions of testosterone and that these disruptions in turn will have an impact on the periovulatory hormonal dynamics. The approach was to test estradiol-negative and -positive feedback responses of all three groups of ovary-intact females during prepubertal age and then compare the periovulatory dynamics of luteinizing hormone, follicle-stimulating hormone, estradiol, and progesterone during the first breeding season. The findings show that estradiol-negative but not estradiol-positive feedback disruptions in prenatal testosterone-treated females are programmed by androgenic actions of prenatal testosterone excess and that follicular phase estradiol and gonadotropins surge disruptions during reproductive life are consistent with estrogenic programming. Additional studies carried out testing estradiol-positive feedback response over time found progressive deterioration of estradiol-positive feedback in prenatal testosterone-treated sheep until the time of puberty. Together, these findings provide insight into the mechanisms by which prenatal testosterone disrupts the reproductive axis. The findings may be of translational relevance since daughters of mothers with hyperandrogenism are at risk of increased exposure to androgens.

Randomised controlled trial of routine individual feedback to improve rationality and reduce numbers of test requests.

PubMed

Winkens, R A; Pop, P; Bugter-Maessen, A M; Grol, R P; Kester, A D; Beusmans, G H; Knottnerus, J A

1995-02-25

Feedback can be described as a way to provide information on doctors' performance to enable changes in future behaviour. Feedback is used with the aim of changing test-ordering behaviour. It can lead to reductions in test usage and cost savings. It is not sufficiently clear, however, whether feedback leads to more appropriate test use. Since 1985, the Diagnostic Coordinating Center Maastricht has been giving feedback on diagnostic tests as a routine health care activity to all family doctors in its region. Both quantity and quality of requests are discussed. In a randomised, controlled trial over 2.5 years, discussion of tests not included previously was added to the existing routine feedback. One group of family doctors (n = 39) received feedback on test-group A (electrocardiography, endoscopy, cervical smears, and allergy tests), the other (n = 40) on test-group B (radiographic and ultrasonographic tests). Thus, each group of doctors acted as a control group for the other. Changes in volume and rationality of requests were analysed. The number of requests decreased during the trial (p = 0.036). Request numbers decreased particularly for test-group A (p = 0.04). The proportion of requests that were non-rational decreased more in the intervention than in the control groups (p = 0.009). Rationality improved predominantly for test-group B (p = 0.043). Thus, routine feedback can change the quantity and quality of requests.

Cooperative Control for A Hybrid Rehabilitation System Combining Functional Electrical Stimulation and Robotic Exoskeleton

PubMed Central

Zhang, Dingguo; Ren, Yong; Gui, Kai; Jia, Jie; Xu, Wendong

2017-01-01

Functional electrical stimulation (FES) and robotic exoskeletons are two important technologies widely used for physical rehabilitation of paraplegic patients. We developed a hybrid rehabilitation system (FEXO Knee) that combined FES and an exoskeleton for swinging movement control of human knee joints. This study proposed a novel cooperative control strategy, which could realize arbitrary distribution of torque generated by FES and exoskeleton, and guarantee harmonic movements. The cooperative control adopted feedfoward control for FES and feedback control for exoskeleton. A parameter regulator was designed to update key parameters in real time to coordinate FES controller and exoskeleton controller. Two muscle groups (quadriceps and hamstrings) were stimulated to generate active torque for knee joint in synchronization with torque compensation from exoskeleton. The knee joint angle and the interactive torque between exoskeleton and shank were used as feedback signals for the control system. Central pattern generator (CPG) was adopted that acted as a phase predictor to deal with phase confliction of motor patterns, and realized synchronization between the two different bodies (shank and exoskeleton). Experimental evaluation of the hybrid FES-exoskeleton system was conducted on five healthy subjects and four paraplegic patients. Experimental results and statistical analysis showed good control performance of the cooperative control on torque distribution, trajectory tracking, and phase synchronization. PMID:29311798

Cooperative Control for A Hybrid Rehabilitation System Combining Functional Electrical Stimulation and Robotic Exoskeleton.

PubMed

Zhang, Dingguo; Ren, Yong; Gui, Kai; Jia, Jie; Xu, Wendong

2017-01-01

Functional electrical stimulation (FES) and robotic exoskeletons are two important technologies widely used for physical rehabilitation of paraplegic patients. We developed a hybrid rehabilitation system (FEXO Knee) that combined FES and an exoskeleton for swinging movement control of human knee joints. This study proposed a novel cooperative control strategy, which could realize arbitrary distribution of torque generated by FES and exoskeleton, and guarantee harmonic movements. The cooperative control adopted feedfoward control for FES and feedback control for exoskeleton. A parameter regulator was designed to update key parameters in real time to coordinate FES controller and exoskeleton controller. Two muscle groups (quadriceps and hamstrings) were stimulated to generate active torque for knee joint in synchronization with torque compensation from exoskeleton. The knee joint angle and the interactive torque between exoskeleton and shank were used as feedback signals for the control system. Central pattern generator (CPG) was adopted that acted as a phase predictor to deal with phase confliction of motor patterns, and realized synchronization between the two different bodies (shank and exoskeleton). Experimental evaluation of the hybrid FES-exoskeleton system was conducted on five healthy subjects and four paraplegic patients. Experimental results and statistical analysis showed good control performance of the cooperative control on torque distribution, trajectory tracking, and phase synchronization.

Primiparous women's preferences for care during a prolonged latent phase of labour.

PubMed

Ängeby, Karin; Wilde-Larsson, Bodil; Hildingsson, Ingegerd; Sandin-Bojö, Ann-Kristin

2015-10-01

To investigate primiparous women's preferences for care during a prolonged latent phase of labour. A qualitative study based on focus groups and individual interviews and analysed with inductive content analysis. Sixteen primiparous women with a prolonged latent phase of labour >18 hours were interviewed in five focus groups (n = 11) or individually (n = 5). One main category emerged "Beyond normality - a need of individual adapted guidance in order to understand and manage an extended latent phase of labour" which covers the women's preferences during the prolonged latent phase. Five categories were generated from the data: "A welcoming manner and not being rejected", "Individually adapted care", "Important information which prepares for reality and coping", "Participation and need for feedback" and "Staying nearby the labour ward or being admitted for midwifery support". Women with a prolonged latent phase of labour sought to use their own resources, but their needs for professional support increased as time passed. A welcoming attitude from an available midwife during the latent phase created a feeling of security, and personally adapted care was perceived positively. Women with a prolonged latent phase of labour preferred woman-centred care. Midwives play an important role in supporting these women. Women's need for midwifery-support increases as the time spent in latent phase increases. Copyright © 2015 Elsevier B.V. All rights reserved.

The use of real-time ultrasound feedback in teaching abdominal hollowing exercises to healthy subjects.

PubMed

Henry, Sharon M; Westervelt, Karen C

2005-06-01

Randomized controlled trial. To determine if supplementing typical clinical instruction with real-time ultrasound feedback facilitates performance and retention of the abdominal hollowing exercise (AHE). Increasingly clinicians are using real-time ultrasound imaging as a form of feedback when teaching patients trunk stabilization exercises; however, there has been no justification for this practice. Forty-eight subjects were divided randomly into 3 groups that received different types of feedback: group 1 received minimal verbal feedback, group 2 received verbal and palpatory feedback, and group 3 received real-time ultrasound, verbal, and palpatory feedback. If the subject performed 3 consecutive correct AHEs during the initial session, she/he returned for a retention test. The performance of 3 consecutive, correct AHEs was the criterion measure; the number of trials to criterion was also recorded during the initial and retention test sessions. The ability to perform the AHE differed among groups (P<.001). During the initial session, 12.5% of subjects in group 1, 50.0% of subjects in group 2, and 87.5% of subjects in group 3 were able to perform 3 consecutive AHEs. Group 3 subjects achieved the criterion in fewer trials than the other 2 groups (P = .0006). No differences among groups were found for the retention testing; however, low power due to fewer subjects precluded a strong interpretation of this finding. Real-time ultrasound feedback can decrease the number of trials needed to consistently perform the AHE; however, the data are inconclusive with regard to retention of this skill.

The Effects of a Local Negative Feedback Function between Choice and Relative Reinforcer Rate

ERIC Educational Resources Information Center

Davison, Michael; Elliffe, Douglas; Marr, M. Jackson

2010-01-01

Four pigeons were trained on two-key concurrent variable-interval schedules with no changeover delay. In Phase 1, relative reinforcers on the two alternatives were varied over five conditions from 0.1 to 0.9. In Phases 2 and 3, we instituted a molar feedback function between relative choice in an interreinforcer interval and the probability of…

In-situ high-resolution visualization of laser-induced periodic nanostructures driven by optical feedback.

PubMed

Aguilar, Alberto; Mauclair, Cyril; Faure, Nicolas; Colombier, Jean-Philippe; Stoian, Razvan

2017-11-28

Optical feedback is often evoked in laser-induced periodic nanostructures. Visualizing the coupling between surfaces and light requires highly-resolved imaging methods. We propose in-situ structured-illumination-microscopy to observe ultrafast-laser-induced nanostructures during fabrication on metallic glass surfaces. This resolves the pulse-to-pulse development of periodic structures on a single irradiation site and indicates the optical feedback on surface topographies. Firstly, the quasi-constancy of the ripples pattern and the reinforcement of the surface relief with the same spatial positioning indicates a phase-locking mechanism that stabilizes and amplifies the ordered corrugation. Secondly, on sites with uncorrelated initial corrugation, we observe ripple patterns spatially in-phase. These feedback aspects rely on the electromagnetic interplay between the laser pulse and the surface relief, stabilizing the pattern in period and position. They are critically dependent on the space-time coherence of the exciting pulse. This suggests a modulation of energy according to the topography of the surface with a pattern phase imposed by the driving pulse. A scattering and interference model for ripple formation on surfaces supports the experimental observations. This relies on self-phase-stabilized far-field interaction between surface scattered wavelets and the incoming pulse front.

The use of real-time ultrasound imaging for biofeedback of lumbar multifidus muscle contraction in healthy subjects.

PubMed

Van, Khai; Hides, Julie A; Richardson, Carolyn A

2006-12-01

Randomized controlled trial. To determine if the provision of visual biofeedback using real-time ultrasound imaging enhances the ability to activate the multifidus muscle. Increasingly clinicians are using real-time ultrasound as a form of biofeedback when re-educating muscle activation. The effectiveness of this form of biofeedback for the multifidus muscle has not been reported. Healthy subjects were randomly divided into groups that received different forms of biofeedback. All subjects received clinical instruction on how to activate the multifidus muscle isometrically prior to testing and verbal feedback regarding the amount of multifidus contraction, which occurred during 10 repetitions (acquisition phase). In addition, 1 group received visual biofeedback (watched the multifidus muscle contract) using real-time ultrasound imaging. All subjects were reassessed a week later (retention phase). Subjects from both groups improved their voluntary contraction of the multifidus muscle in the acquisition phase (P<.001) and the ability to recruit the multifidus muscle differed between groups (P<.05), with subjects in the group that received visual ultrasound biofeedback achieving greater improvements. In addition, the group that received visual ultrasound biofeedback retained their improvement in performance from week 1 to week 2 (P>.90), whereas the performance of the other group decreased (P<.05). Real-time ultrasound imaging can be used to provide visual biofeedback and improve performance and retention in the ability to activate the multifidus muscle in healthy subjects.

Feedback Model to Support Designers of Blended-Learning Courses

ERIC Educational Resources Information Center

Hummel, Hans G. K.

2006-01-01

Although extensive research has been carried out, describing the role of feedback in education, and many theoretical models are yet available, procedures and guidelines for actually designing and implementing feedback in practice have remained scarce so far. This explorative study presents a preliminary six-phase design model for feedback…

Quiet eye training improves surgical knot tying more than traditional technical training: a randomized controlled study.

PubMed

Causer, Joe; Harvey, Adrian; Snelgrove, Ryan; Arsenault, Gina; Vickers, Joan N

2014-08-01

We examined the effectiveness of technical training (TT) and quiet eye training (QE) on the performance of one-handed square knot tying in surgical residents. Twenty surgical residents were randomly assigned to the 2 groups and completed pretest, training, retention, and transfer tests. Participants wore a mobile eye tracker that simultaneously recorded their gaze and hand movements. Dependent variables were knot tying performance (%), QE duration (%), number of fixations, total movement time (s), and hand movement phase time (s). The QE training group had significantly higher performance scores, a longer QE duration, fewer fixations, faster total knot tying times, and faster movement phase times compared with the TT group. The QE group maintained performance in the transfer test, whereas the TT group significantly decreased performance from retention to transfer. QE training significantly improved learning, retention, and transfer of surgical knot tying compared with a traditional technical approach. Both performance effectiveness (performance outcome) and movement efficiency (hand movement times) were improved using QE modeling, instruction, and feedback. Copyright © 2014 Elsevier Inc. All rights reserved.

Phase I to II cross-induction of xenobiotic metabolizing enzymes: a feedforward control mechanism for potential hormetic responses.

PubMed

Zhang, Qiang; Pi, Jingbo; Woods, Courtney G; Andersen, Melvin E

2009-06-15

Hormetic responses to xenobiotic exposure likely occur as a result of overcompensation by the homeostatic control systems operating in biological organisms. However, the mechanisms underlying overcompensation that leads to hormesis are still unclear. A well-known homeostatic circuit in the cell is the gene induction network comprising phase I, II and III metabolizing enzymes, which are responsible for xenobiotic detoxification, and in many cases, bioactivation. By formulating a differential equation-based computational model, we investigated in this study whether hormesis can arise from the operation of this gene/enzyme network. The model consists of two feedback and one feedforward controls. With the phase I negative feedback control, xenobiotic X activates nuclear receptors to induce cytochrome P450 enzyme, which bioactivates X into a reactive metabolite X'. With the phase II negative feedback control, X' activates transcription factor Nrf2 to induce phase II enzymes such as glutathione S-transferase and glutamate cysteine ligase, etc., which participate in a set of reactions that lead to the metabolism of X' into a less toxic conjugate X''. The feedforward control involves phase I to II cross-induction, in which the parent chemical X can also induce phase II enzymes directly through the nuclear receptor and indirectly through transcriptionally upregulating Nrf2. As a result of the active feedforward control, a steady-state hormetic relationship readily arises between the concentrations of the reactive metabolite X' and the extracellular parent chemical X to which the cell is exposed. The shape of dose-response evolves over time from initially monotonically increasing to J-shaped at the final steady state-a temporal sequence consistent with adaptation-mediated hormesis. The magnitude of the hormetic response is enhanced by increases in the feedforward gain, but attenuated by increases in the bioactivation or phase II feedback loop gains. Our study suggests a possibly common mechanism for the hormetic responses observed with many mutagens/carcinogens whose activities require bioactivation by phase I enzymes. Feedforward control, often operating in combination with negative feedback regulation in a homeostatic system, may be a general control theme responsible for steady-state hormesis.

Chaos crisis and bistability of self-pulsing dynamics in a laser diode with phase-conjugate feedback

DOE Office of Scientific and Technical Information (OSTI.GOV)

Virte, Martin; Karsaklian Dal Bosco, Andreas; Wolfersberger, Delphine

2011-10-15

A laser diode subject to a phase-conjugate optical feedback can exhibit rich nonlinear dynamics and chaos. We report here on two bifurcation mechanisms that appear when increasing the amount of light being fed back to the laser. First, we report on a full suppression of chaos from a crisis induced by a saddle-node bifurcation on self-pulsing, so-called external-cavity-mode solutions (ECMs). Second, the feedback-dependent torus and saddle-node bifurcations on ECMs may be responsible for large regions of bistability between ECMs of different and high (beyond gigahertz) frequencies.

Using Technological Advances to Improve Surgery Curriculum: Experience With a Mobile Application.

PubMed

Green, Courtney A; Kim, Edward H; O'Sullivan, Patricia S; Chern, Hueylan

2018-01-31

Our previous home-video basic surgical skills curriculum required substantial faculty time and resources, and was limited by delayed feedback and technical difficulties. Consequently, we integrated that curriculum with a mobile application platform. Our purpose is to describe this application and learner satisfaction. The mobile platform incorporates a patented pedagogical design based on Ericsson's deliberate practice and Bandura's social learning theory. Instructors built step-wise skills modules. During the challenge phase, learners watched a video of surgical tasks completed by experts and uploaded a video of themselves performing the same task. In the Peer Review phase, they used a grading rubric to provide feedback. In the Recap stage, learners received individual feedback and could review their own videos. Two groups of learners, graduating medical students and matriculating surgical residents, participated in this independent learning platform, along with 2 to 4 laboratory sessions, and completed a survey about their experience. Survey responses were summarized descriptively and comments analyzed using content analysis. Fifty learners submitted videos of assigned tasks and completed peer reviews. Learners reported positive experiences specifically for the Peer Review Stage, structured home practice, ease of mobile access to submit and review videos, and ongoing immediate feedback. Over half of the learners reported spending at least 10 to 30 minute practicing skills before recording their videos and over 80% rerecorded at least 2 times before submission. Content analysis revealed learners engaged with the educational concepts designed into the platform. Learners easily used and were satisfied with a mobile-technology teaching platform that maintained the fundamental content, educational theories, and organizational structure of our previously effective surgical skills curriculum. Prior challenges were directly addressed through the mobile application's ease of use, support of deliberate practice, and improved timeliness of feedback. Copyright © 2018 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Instructor feedback versus no instructor feedback on performance in a laparoscopic virtual reality simulator: a randomized trial.

PubMed

Strandbygaard, Jeanett; Bjerrum, Flemming; Maagaard, Mathilde; Winkel, Per; Larsen, Christian Rifbjerg; Ringsted, Charlotte; Gluud, Christian; Grantcharov, Teodor; Ottesen, Bent; Sorensen, Jette Led

2013-05-01

To investigate the impact of instructor feedback versus no instructor feedback when training a complex operational task on a laparoscopic virtual reality simulator. : Simulators are now widely accepted as a training tool, but there is insufficient knowledge about how much feedback is necessary, which is useful for sustainable implementation. A randomized trial complying with CONSORT Statement. All participants had to reach a predefined proficiency level for a complex operational task on a virtual reality simulator. The intervention group received standardized instructor feedback a maximum of 3 times. The control group did not receive instructor feedback. Participants were senior medical students without prior laparoscopic experience (n = 99). Outcome measures were time, repetitions, and performance score to reach a predefined proficiency level. Furthermore, influence of sex and perception of own surgical skills were examined. Time (in minutes) and repetitions were reduced in the intervention group (162 vs 342 minutes; P < 0.005) and (29 vs 65 repetitions; P < 0.005). The control group achieved a higher performance score than the intervention group (57% vs 49%; P = 0.004). Men used less time (in minutes) than women (P = 0.037), but no sex difference was observed for repetitions (P = 0.20). Participants in the intervention group had higher self-perception regarding surgical skills after the trial (P = 0.011). Instructor feedback increases the efficiency when training a complex operational task on a virtual reality simulator; time and repetitions used to achieve a predefined proficiency level were significantly reduced in the group that received instructor feedback compared with the control group. NCT01497782.

Feedback process responsible for the suppression of ENSO activity during the mid-Holocene

NASA Astrophysics Data System (ADS)

An, Soon-Il; Bong, Hayoung

2018-05-01

Using the output of 12 models from the Paleoclimate Modeling Intercomparison Project Phase 3, we investigate the feedback process responsible for changes in El Niño-Southern Oscillation activity during the mid-Holocene based on a linear stability index (Bjerknes stability index; BJ index) analysis. The multi-model ensemble mean (MME) variance of the Niño-3.4 index (sea surface temperature anomalies averaged over 5°S-5°N, 170°-120°W) simulated for 6000 years ago (6 kya) was 13% lower than that for the pre-industrial era (0 kya), while changes in the MME BJ index were negligible. This is due to a balance between enhanced damping by anomalous thermal advection by mean currents (MA) and enhanced positive thermocline feedback (TH). Seven of the models show that MME variance of the Niño-3.4 and BJ indexes for the 6 kya run is 21 and 70% lower, respectively, than the 0 kya run. However, two models show the opposite change. Interestingly, MA in both model groups increases, especially due to the mean meridional current associated with enhanced trade winds, indicating a robust mechanism. The opposite tendency between the two groups is mainly due to large TH in the second group 6 kya, as a result of enhanced air-sea coupling and strongly reduced ocean stratification due to subsurface warming, which led to increased sensitivity of the zonal thermocline contrast to surface zonal wind stress.

Preventing back injuries in hospital settings: the effects of video modeling on safe patient lifting by nurses.

PubMed

Nielsen, Don; Sigurdsson, Sigurdur O; Austin, John

2009-01-01

This study evaluated video scoring and feedback about scoring as a safety intervention among 6 nursing staff. The dependent variable was safety behavior on one-person transfers. Following baseline, 5 nursing staff participated in an information phase. A video scoring phase was then introduced for all 6. A feedback phase was added for 2 participants. All participants experienced treatment withdrawal. Information resulted in improvements for all 5 participants who received it. Further improvements were observed during video scoring for the 5 participants who improved following information. No improvements were observed for the participant who received only video scoring. Safety feedback further improved safety for the 2 participants who received it. However, participants' behavior returned to video scoring levels during withdrawal.

PREVENTING BACK INJURIES IN HOSPITAL SETTINGS: THE EFFECTS OF VIDEO MODELING ON SAFE PATIENT LIFTING BY NURSES

PubMed Central

Nielsen, Don; Sigurdsson, Sigurdur O; Austin, John

2009-01-01

This study evaluated video scoring and feedback about scoring as a safety intervention among 6 nursing staff. The dependent variable was safety behavior on one-person transfers. Following baseline, 5 nursing staff participated in an information phase. A video scoring phase was then introduced for all 6. A feedback phase was added for 2 participants. All participants experienced treatment withdrawal. Information resulted in improvements for all 5 participants who received it. Further improvements were observed during video scoring for the 5 participants who improved following information. No improvements were observed for the participant who received only video scoring. Safety feedback further improved safety for the 2 participants who received it. However, participants' behavior returned to video scoring levels during withdrawal. PMID:20190918

Developing a theory of the societal lifecycle of cigarette smoking : explaining and anticipating trends using information feedback.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodsky, Nancy S.; Glass, Robert John, Jr.; Zagonel, Aldo A.

Cigarette smoking presented the most significant public health challenge in the United States in the 20th Century and remains the single most preventable cause of morbidity and mortality in this country. A number of System Dynamics models exist that inform tobacco control policies. We reviewed them and discuss their contributions. We developed a theory of the societal lifecycle of smoking, using a parsimonious set of feedback loops to capture historical trends and explore future scenarios. Previous work did not explain the long-term historical patterns of smoking behaviors. Much of it used stock-and-flow to represent the decline in prevalence in themore » recent past. With noted exceptions, information feedbacks were not embedded in these models. We present and discuss our feedback-rich conceptual model and illustrate the results of a series of simulations. A formal analysis shows phenomena composed of different phases of behavior with specific dominant feedbacks associated with each phase. We discuss the implications of our society's current phase, and conclude with simulations of what-if scenarios. Because System Dynamics models must contain information feedback to be able to anticipate tipping points and to help identify policies that exploit leverage in a complex system, we expanded this body of work to provide an endogenous representation of the century-long societal lifecycle of smoking.« less

Active Nonlinear Feedback Control for Aerospace Systems. Processor

DTIC Science & Technology

1990-12-01

relating to the role of nonlinearities in feedback control. These area include Lyapunov function theory, chaotic controllers, statistical energy analysis , phase robustness, and optimal nonlinear control theory.

The System-Wide Effect of Real-Time Audiovisual Feedback and Postevent Debriefing for In-Hospital Cardiac Arrest: The Cardiopulmonary Resuscitation Quality Improvement Initiative*

PubMed Central

Couper, Keith; Kimani, Peter K.; Abella, Benjamin S.; Chilwan, Mehboob; Cooke, Matthew W.; Davies, Robin P.; Field, Richard A.; Gao, Fang; Quinton, Sarah; Stallard, Nigel; Woolley, Sarah

2015-01-01

Objective: To evaluate the effect of implementing real-time audiovisual feedback with and without postevent debriefing on survival and quality of cardiopulmonary resuscitation quality at in-hospital cardiac arrest. Design: A two-phase, multicentre prospective cohort study. Setting: Three UK hospitals, all part of one National Health Service Acute Trust. Patients: One thousand three hundred and ninety-five adult patients who sustained an in-hospital cardiac arrest at the study hospitals and were treated by hospital emergency teams between November 2009 and May 2013. Interventions: During phase 1, quality of cardiopulmonary resuscitation and patient outcomes were measured with no intervention implemented. During phase 2, staff at hospital 1 received real-time audiovisual feedback, whereas staff at hospital 2 received real-time audiovisual feedback supplemented by postevent debriefing. No intervention was implemented at hospital 3 during phase 2. Measurements and Main Results: The primary outcome was return of spontaneous circulation. Secondary endpoints included other patient-focused outcomes, such as survival to hospital discharge, and process-focused outcomes, such as chest compression depth. Random-effect logistic and linear regression models, adjusted for baseline patient characteristics, were used to analyze the effect of the interventions on study outcomes. In comparison with no intervention, neither real-time audiovisual feedback (adjusted odds ratio, 0.62; 95% CI, 0.31–1.22; p = 0.17) nor real-time audiovisual feedback supplemented by postevent debriefing (adjusted odds ratio, 0.65; 95% CI, 0.35–1.21; p = 0.17) was associated with a statistically significant improvement in return of spontaneous circulation or any process-focused outcome. Despite this, there was evidence of a system-wide improvement in phase 2, leading to improvements in return of spontaneous circulation (adjusted odds ratio, 1.87; 95% CI, 1.06–3.30; p = 0.03) and process-focused outcomes. Conclusions: Implementation of real-time audiovisual feedback with or without postevent debriefing did not lead to a measured improvement in patient or process-focused outcomes at individual hospital sites. However, there was an unexplained system-wide improvement in return of spontaneous circulation and process-focused outcomes during the second phase of the study. PMID:26186567

Rotation in a reversed field pinch with active feedback stabilization of resistive wall modes

NASA Astrophysics Data System (ADS)

Cecconello, M.; Menmuir, S.; Brunsell, P. R.; Kuldkepp, M.

2006-09-01

Active feedback stabilization of multiple resistive wall modes (RWMs) has been successfully proven in the EXTRAP T2R reversed field pinch. One of the features of plasma discharges operated with active feedback stabilization, in addition to the prolongation of the plasma discharge, is the sustainment of the plasma rotation. Sustained rotation is observed both for the internally resonant tearing modes (TMs) and the intrinsic impurity oxygen ions. Good quantitative agreement between the toroidal rotation velocities of both is found: the toroidal rotation is characterized by an acceleration phase followed, after one wall time, by a deceleration phase that is slower than in standard discharges. The TMs and the impurity ions rotate in the same poloidal direction with also similar velocities. Poloidal and toroidal velocities have comparable amplitudes and a simple model of their radial profile reproduces the main features of the helical angular phase velocity. RWMs feedback does not qualitatively change the TMs behaviour and typical phenomena such as the dynamo and the 'slinky' are still observed. The improved sustainment of the plasma and TMs rotation occurs also when feedback only acts on internally non-resonant RWMs. This may be due to an indirect positive effect, through non-linear coupling between TMs and RWMs, of feedback on the TMs or to a reduced plasma-wall interaction affecting the plasma flow rotation. Electromagnetic torque calculations show that with active feedback stabilization the TMs amplitude remains well below the locking threshold condition for a thick shell. Finally, it is suggested that active feedback stabilization of RWMs and current profile control techniques can be employed simultaneously thus improving both the plasma duration and its confinement properties.

Reduced sensitivity to neutral feedback versus negative feedback in subjects with mild depression: Evidence from event-related potentials study.

PubMed

Li, Peng; Song, Xinxin; Wang, Jing; Zhou, Xiaoran; Li, Jiayi; Lin, Fengtong; Hu, Zhonghua; Zhang, Xinxin; Cui, Hewei; Wang, Wenmiao; Li, Hong; Cong, Fengyu; Roberson, Debi

2015-11-01

Many previous event-related potential (ERP) studies have linked the feedback related negativity (FRN) component with medial frontal cortex processing and associated this component with depression. Few if any studies have investigated the processing of neutral feedback in mildly depressive subjects in the normal population. Two experiments compared brain responses to neutral feedback with behavioral performance in mildly depressed subjects who scored highly on the Beck Depression Inventory (high BDI) and a control group with lower BDI scores (low BDI). In the first study, the FRN component was recorded when neutral, negative or positive feedback was pseudo-randomly delivered to the two groups in a time estimation task. In the second study, real feedback was provided to the two groups in the same task in order to measure their actual accuracy of performance. The results of experiment one (Exp. 1) revealed that a larger FRN effect was elicited by neutral feedback than by negative feedback in the low BDI group, but no significant difference was found between neutral condition and negative condition in the High BDI group. The present findings demonstrated that depressive tendencies influence the processing of neutral feedback in medial frontal cortex. The FRN effect may work as a helpful index for investigating cognitive bias in depression in future studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Phase difference in modulated signals of two orthogonally polarized outputs of a Nd:YAG microchip laser with anisotropic optical feedback.

PubMed

Zhang, Peng; Tan, Yi-Dong; Liu, Ning; Wu, Yun; Zhang, Shu-Lian

2013-11-01

We present an experimental observation of the output responses of a Nd:YAG microchip laser with an anisotropic external cavity under weak optical feedback. The feedback mirror is stationary during the experiments. A pair of acousto-optic modulators is used to produce a frequency shift in the feedback light with respect to the initial light. The laser output is a beat signal with 40 kHz modulation frequency and is separated into two orthogonal directions by a Wollaston prism. Phase differences between the two intensity curves are observed as the laser works in two orthogonal modes, and vary with the external birefringence element and the pump power. Theoretical analyses are given, and the simulated results are consistent with the experimental phenomena.

Post-license education for novice drivers: evaluation of a training programme implemented in Spain.

PubMed

Molina, J Gabriel; Sanmartín, Jaime; Keskinen, Esko; Sanders, Nick

2007-01-01

This study evaluated the implementation of a second phase training program for novice drivers in Spain, which puts the primary focus of the training on the higher hierarchical levels of driver behavior. Two hundred and sixty-three participants took part throughout the study, which was implemented as an experimental design with the test and control groups assessed before and after the one day safety training. Measurement of the impact of the training program focused on the participants' self-evaluation and self-reporting of some driving behavior indicators related to accident risk. Data analysis showed a change in the expected direction in the scale related to the skills for careful driving, but not for the other four scales considered. A feedback survey about the training course offered some important input for evaluating the organization, contents, tuition, and results of the three parts of the training program (discussion group, on-road and track training) as reported by the participants in the test group. The results of the experiment show that using a one day driver safety course, it is possible to change some of the drivers' evaluations connected to safe driving style into safe direction. The follow-up period was exceptionally long (9 months) and the design (randomly divided experimental and control groups with before and after measurements) was reliable. More effort should be devoted to improving the on-road part of the training, which was often perceived as a typical driving lesson rather than a feedback drive. The findings suggest consideration of a mandatory 2nd phase driver training programme as a means to raise awareness of the full range of risks encountered by novice drivers, and as already introduced in 5 EU countries: Austria, Estonia, Finland, Luxembourg and Switzerland.

Normative Feedback Effects on Learning a Timing Task

ERIC Educational Resources Information Center

Wulf, Gabriele; Chiviacowsky, Suzete; Lewthwaite, Rebecca

2010-01-01

This study investigated the influence of normative feedback on learning a sequential timing task. In addition to feedback about their performance per trial, two groups of participants received bogus normative feedback about a peer group's average block-to-block improvement after each block of 10 trials. Scores indicated either greater (better…

Peer Feedback Content and Sender's Competence Level in Academic Writing Revision Tasks: Are They Critical for Feedback Perceptions and Efficiency?

ERIC Educational Resources Information Center

Strijbos, Jan-Willem; Narciss, Susanne; Dunnebier, Katrin

2010-01-01

Peer-feedback content is a core component of peer assessment, but the impact of various contents of feedback is hardly studied. Participants in the study were 89 graduate students who were assigned to four experimental and a control group. Experimental groups received a scenario with concise general (CGF) or elaborated specific (ESF) feedback by a…

A qualitative study on feedback provided by students in nurse education.

PubMed

Chan, Zenobia C Y; Stanley, David John; Meadus, Robert J; Chien, Wai Tong

2017-08-01

This study aims to help nurse educators/academics understand the perspectives and expectations of students providing their feedback to educators about teaching performance and subject quality. The aim of this study is to reveal students' voices regarding their feedback in nurse education in order to shed light on how the current student feedback practice may be modified. A qualitative study using focus group inquiry. Convenience sampling was adopted and participants recruited from one school of nursing in Hong Kong. A total of 66 nursing students from two pre-registration programs were recruited for seven focus group interviews: one group of Year 1 students (n=21), two groups of Year 3 students (n=27), and four groups of Final Year students (n=18). The interviews were guided by a semi-structured interview guideline and the interview narratives were processed through content analysis. The trustworthiness of this study was guaranteed through peer checking, research meetings, and an audit trail. The participants' privacy was protected throughout the study. Four core themes were discerned based on the narratives of the focus group interviews: (1) "timing of collecting feedback at more than one time point"; (2) "modify the questions being asked in collecting student feedback"; (3) "are electronic means of collecting feedback good enough?; and (4) "what will be next for student feedback?". This study is significant in the following three domains: 1) it contributed to student feedback because it examined the issue from a student's perspective; 2) it explored the timing and channels for collecting feedback from the students' point of view; and 3) it showed the preferred uses of student feedback. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerns, Q.A.; Jackson, G.; Kerns, C.R.

This paper describes the damper design for 6 proton on 6 pbar bunches in the Tevatron collider. Signal pickup, transient phase detection, derivative networks, and phase correction via the high-level rf are covered. Each rf station is controlled by a slow feedback loop. In addition, global feedback loops control each set of four cavities, one set for protons and one set for antiprotons. Operational experience with these systems is discussed. 7 refs., 9 figs.

A hospital-site controlled intervention using audit and feedback to implement guidelines concerning inappropriate treatment of catheter-associated asymptomatic bacteriuria

PubMed Central

2011-01-01

Background Catheter-associated urinary tract infection (CAUTI) is one of the most common hospital-acquired infections. However, many cases treated as hospital-acquired CAUTI are actually asymptomatic bacteriuria (ABU). Evidence-based guidelines recommend that providers neither screen for nor treat ABU in most catheterized patients, but there is a significant gap between these guidelines and clinical practice. Our objectives are (1) to evaluate the effectiveness of an audit and feedback intervention for increasing guideline-concordant care concerning catheter-associated ABU and (2) to measure improvements in healthcare providers' knowledge of and attitudes toward the practice guidelines associated with the intervention. Methods/Design The study uses a controlled pre/post design to test an intervention using audit and feedback of healthcare providers to improve their compliance with ABU guidelines. The intervention and the control sites are two VA hospitals. For objective 1 we will review medical records to measure the clinical outcomes of inappropriate screening for and treatment of catheter-associated ABU. For objective 2 we will survey providers' knowledge and attitudes. Three phases of our protocol are proposed: the first 12-month phase will involve observation of the baseline incidence of inappropriate screening for and treatment of ABU at both sites. This surveillance for clinical outcomes will continue at both sites throughout the study. Phase 2 consists of 12 months of individualized audit and feedback at the intervention site and guidelines distribution at both sites. The third phase, also over 12 months, will provide unit-level feedback at the intervention site to assess sustainability. Healthcare providers at the intervention site during phase 2 and at both sites during phase 3 will complete pre/post surveys of awareness and familiarity (knowledge), as well as of acceptance and outcome expectancy (attitudes) regarding the relevant practice guidelines. Discussion Our proposal to bring clinical practice in line with published guidelines has significant potential to decrease overdiagnosis of CAUTI and associated inappropriate antibiotic use. Our study will also provide information about how to maximize effectiveness of audit and feedback to achieve guideline adherence in the inpatient setting. Trial Registration NCT01052545 PMID:21513539

A hospital-site controlled intervention using audit and feedback to implement guidelines concerning inappropriate treatment of catheter-associated asymptomatic bacteriuria.

PubMed

Trautner, Barbara W; Kelly, P Adam; Petersen, Nancy; Hysong, Sylvia; Kell, Harrison; Liao, Kershena S; Patterson, Jan E; Naik, Aanand D

2011-04-22

Catheter-associated urinary tract infection (CAUTI) is one of the most common hospital-acquired infections. However, many cases treated as hospital-acquired CAUTI are actually asymptomatic bacteriuria (ABU). Evidence-based guidelines recommend that providers neither screen for nor treat ABU in most catheterized patients, but there is a significant gap between these guidelines and clinical practice. Our objectives are (1) to evaluate the effectiveness of an audit and feedback intervention for increasing guideline-concordant care concerning catheter-associated ABU and (2) to measure improvements in healthcare providers' knowledge of and attitudes toward the practice guidelines associated with the intervention. The study uses a controlled pre/post design to test an intervention using audit and feedback of healthcare providers to improve their compliance with ABU guidelines. The intervention and the control sites are two VA hospitals. For objective 1 we will review medical records to measure the clinical outcomes of inappropriate screening for and treatment of catheter-associated ABU. For objective 2 we will survey providers' knowledge and attitudes. Three phases of our protocol are proposed: the first 12-month phase will involve observation of the baseline incidence of inappropriate screening for and treatment of ABU at both sites. This surveillance for clinical outcomes will continue at both sites throughout the study. Phase 2 consists of 12 months of individualized audit and feedback at the intervention site and guidelines distribution at both sites. The third phase, also over 12 months, will provide unit-level feedback at the intervention site to assess sustainability. Healthcare providers at the intervention site during phase 2 and at both sites during phase 3 will complete pre/post surveys of awareness and familiarity (knowledge), as well as of acceptance and outcome expectancy (attitudes) regarding the relevant practice guidelines. Our proposal to bring clinical practice in line with published guidelines has significant potential to decrease overdiagnosis of CAUTI and associated inappropriate antibiotic use. Our study will also provide information about how to maximize effectiveness of audit and feedback to achieve guideline adherence in the inpatient setting. NCT01052545.

The influence of extratropical cloud phase and amount feedbacks on climate sensitivity

NASA Astrophysics Data System (ADS)

Frey, William R.; Kay, Jennifer E.

2018-04-01

Global coupled climate models have large long-standing cloud and radiation biases, calling into question their ability to simulate climate and climate change. This study assesses the impact of reducing shortwave radiation biases on climate sensitivity within the Community Earth System Model (CESM). The model is modified by increasing supercooled cloud liquid to better match absorbed shortwave radiation observations over the Southern Ocean while tuning to reduce a compensating tropical shortwave bias. With a thermodynamic mixed-layer ocean, equilibrium warming in response to doubled CO2 increases from 4.1 K in the control to 5.6 K in the modified model. This 1.5 K increase in equilibrium climate sensitivity is caused by changes in two extratropical shortwave cloud feedbacks. First, reduced conversion of cloud ice to liquid at high southern latitudes decreases the magnitude of a negative cloud phase feedback. Second, warming is amplified in the mid-latitudes by a larger positive shortwave cloud feedback. The positive cloud feedback, usually associated with the subtropics, arises when sea surface warming increases the moisture gradient between the boundary layer and free troposphere. The increased moisture gradient enhances the effectiveness of mixing to dry the boundary layer, which decreases cloud amount and optical depth. When a full-depth ocean with dynamics and thermodynamics is included, ocean heat uptake preferentially cools the mid-latitude Southern Ocean, partially inhibiting the positive cloud feedback and slowing warming. Overall, the results highlight strong connections between Southern Ocean mixed-phase cloud partitioning, cloud feedbacks, and ocean heat uptake in a climate forced by greenhouse gas changes.

Altering length and velocity feedback during a neuro-musculoskeletal simulation of normal gait contributes to hemiparetic gait characteristics.

PubMed

Jansen, Karen; De Groote, Friedl; Aerts, Wouter; De Schutter, Joris; Duysens, Jacques; Jonkers, Ilse

2014-04-30

Spasticity is an important complication after stroke, especially in the anti-gravity muscles, i.e. lower limb extensors. However the contribution of hyperexcitable muscle spindle reflex loops to gait impairments after stroke is often disputed. In this study a neuro-musculoskeletal model was developed to investigate the contribution of an increased length and velocity feedback and altered reflex modulation patterns to hemiparetic gait deficits. A musculoskeletal model was extended with a muscle spindle model providing real-time length and velocity feedback of gastrocnemius, soleus, vasti and rectus femoris during a forward dynamic simulation (neural control model). By using a healthy subject's base muscle excitations, in combination with increased feedback gains and altered reflex modulation patterns, the effect on kinematics was simulated. A foot-ground contact model was added to account for the interaction effect between the changed kinematics and the ground. The qualitative effect i.e. the directional effect and the specific gait phases where the effect is present, on the joint kinematics was then compared with hemiparetic gait deviations reported in the literature. Our results show that increased feedback in combination with altered reflex modulation patterns of soleus, vasti and rectus femoris muscle can contribute to excessive ankle plantarflexion/inadequate dorsiflexion, knee hyperextension/inadequate flexion and increased hip extension/inadequate flexion during dedicated gait cycle phases. Increased feedback of gastrocnemius can also contribute to excessive plantarflexion/inadequate dorsiflexion, however in combination with excessive knee and hip flexion. Increased length/velocity feedback can therefore contribute to two types of gait deviations, which are both in accordance with previously reported gait deviations in hemiparetic patients. Furthermore altered modulation patterns, in particular the reduced suppression of the muscle spindle feedback during swing, can contribute largely to an increased plantarflexion and knee extension during the swing phase and consequently to hampered toe clearance. Our results support the idea that hyperexcitability of length and velocity feedback pathways, especially in combination with altered reflex modulation patterns, can contribute to deviations in hemiparetic gait. Surprisingly, our results showed only subtle temporal differences between length and velocity feedback. Therefore, we cannot attribute the effects seen in kinematics to one specific type of feedback.

Roles of participation and feedback in group potency.

PubMed

Gamero, Nuria; Peiró, José M; Zornoza, Ana; Picazo, Carmen

2009-08-01

The roles of group participation and group performance feedback were examined as antecedents of group potency, i.e., beliefs shared among a work group's members about the general effectiveness of the work group. Also examined were how group participation and the congruence of the feedback received from different sources about performance predicted convergence in members' beliefs about group effectiveness. The sample comprised 61 work groups of professionals involved in Master in Business Administration (MBA) programs (284 participants). Mean group size was 4.6 members (SD = .58). 65% of participants were male, and 51% were between 30 and 40 years of age. Data were gathered at two measurement times. Increases in group participation were positively related to increases in group potency and the convergence in beliefs about group effectiveness among group members over time. Results supported the premise that group performance feedback is an antecedent of changes in group potency over time.

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR CLEANING QUESTIONNAIRE FEEDBACK FORM (UA-D-47.0)

EPA Science Inventory

The purpose of this SOP is to describe the steps involved in cleaning the electronic data generated from data entry of the Questionnaire Feedback form. It applies to electronic data corresponding to the Questionnaire Feedback form that was scanned and verified by the data staff ...

Measurement technology based on laser internal/external cavity tuning

NASA Astrophysics Data System (ADS)

Zhang, Shulian

2011-08-01

For an ordinary laser with two cavity mirrors, if the length of laser cavity changes half wavelength the laser frequency changes one longitudinal mode separation. For a laser with three cavity mirrors, in which a feedback mirror is used to feed part of the laser output beam back into the laser cavity, the external cavity length changes half wavelength the laser intensity fluctuates one period. This presentation gives some research results in measurement field based on changing (tuning) the length of laser internal/external cavity, including 1) HeNe laser cavity-tuning nanometer displacement measurement instruments (laser nanometer rulers), 2) HeNe laser feedback displacement measurement, 3) Nd:YAG laser feedback nanometer displacement measurement, 4) benchmark of waveplate phase retardation measurement based on laser frequency splitting, 5) in-site waveplate phase retardation measurement instruments based on laser feedback and polarization hopping, 6) quasi-common-path microchip Nd:YAG laser feedback interferometer, 7) non-contact Nd:YAG laser feedback surface profile measurement. Some of these instruments have been put into application and display some irreplaceable advantages.

A Sensitivity Analysis of an Inverted Pendulum Balance Control Model.

PubMed

Pasma, Jantsje H; Boonstra, Tjitske A; van Kordelaar, Joost; Spyropoulou, Vasiliki V; Schouten, Alfred C

2017-01-01

Balance control models are used to describe balance behavior in health and disease. We identified the unique contribution and relative importance of each parameter of a commonly used balance control model, the Independent Channel (IC) model, to identify which parameters are crucial to describe balance behavior. The balance behavior was expressed by transfer functions (TFs), representing the relationship between sensory perturbations and body sway as a function of frequency, in terms of amplitude (i.e., magnitude) and timing (i.e., phase). The model included an inverted pendulum controlled by a neuromuscular system, described by several parameters. Local sensitivity of each parameter was determined for both the magnitude and phase using partial derivatives. Both the intrinsic stiffness and proportional gain shape the magnitude at low frequencies (0.1-1 Hz). The derivative gain shapes the peak and slope of the magnitude between 0.5 and 0.9 Hz. The sensory weight influences the overall magnitude, and does not have any effect on the phase. The effect of the time delay becomes apparent in the phase above 0.6 Hz. The force feedback parameters and intrinsic stiffness have a small effect compared with the other parameters. All parameters shape the TF magnitude and phase and therefore play a role in the balance behavior. The sensory weight, time delay, derivative gain, and the proportional gain have a unique effect on the TFs, while the force feedback parameters and intrinsic stiffness contribute less. More insight in the unique contribution and relative importance of all parameters shows which parameters are crucial and critical to identify underlying differences in balance behavior between different patient groups.

Voluntarily controlled but not merely observed visual feedback affects postural sway

PubMed Central

Asai, Tomohisa; Hiromitsu, Kentaro; Imamizu, Hiroshi

2018-01-01

Online stabilization of human standing posture utilizes multisensory afferences (e.g., vision). Whereas visual feedback of spontaneous postural sway can stabilize postural control especially when observers concentrate on their body and intend to minimize postural sway, the effect of intentional control of visual feedback on postural sway itself remains unclear. This study assessed quiet standing posture in healthy adults voluntarily controlling or merely observing visual feedback. The visual feedback (moving square) had either low or high gain and was either horizontally flipped or not. Participants in the voluntary-control group were instructed to minimize their postural sway while voluntarily controlling visual feedback, whereas those in the observation group were instructed to minimize their postural sway while merely observing visual feedback. As a result, magnified and flipped visual feedback increased postural sway only in the voluntary-control group. Furthermore, regardless of the instructions and feedback manipulations, the experienced sense of control over visual feedback positively correlated with the magnitude of postural sway. We suggest that voluntarily controlled, but not merely observed, visual feedback is incorporated into the feedback control system for posture and begins to affect postural sway. PMID:29682421

Performance drifts in two-finger cyclical force production tasks performed by one and two actors.

PubMed

Hasanbarani, Fariba; Reschechtko, Sasha; Latash, Mark L

2018-03-01

We explored changes in the cyclical two-finger force performance task caused by turning visual feedback off performed either by the index and middle fingers of the dominant hand or by two index fingers of two persons. Based on an earlier study, we expected drifts in finger force amplitude and midpoint without a drift in relative phase. The subjects performed two rhythmical tasks at 1 Hz while paced by an auditory metronome. One of the tasks required cyclical changes in total force magnitude without changes in the sharing of the force between the two fingers. The other task required cyclical changes in the force sharing without changing total force magnitude. Subjects were provided with visual feedback, which showed total force magnitude and force sharing via cursor motion along the vertical and horizontal axes, respectively. Further, visual feedback was turned off, first on the variable that was not required to change and then on both variables. Turning visual feedback off led to a mean force drift toward lower magnitudes while force amplitude increased. There was a consistent drift in the relative phase in the one-hand task with the index finger leading the middle finger. No consistent relative phase drift was seen in the two-person tasks. The shape of the force cycle changed without visual feedback reflected in the lower similarity to a perfect cosine shape and in the higher time spent at lower force magnitudes. The data confirm findings of earlier studies regarding force amplitude and midpoint changes, but falsify predictions of an earlier proposed model with respect to the relative phase changes. We discuss factors that could contribute to the observed relative phase drift in the one-hand tasks including the leader-follower pattern generalized for two-effector tasks performed by one person.

An Analysis of Peer Feedback Exchanged in Group Supervision

ERIC Educational Resources Information Center

Wahesh, Edward; Kemer, Gulsah; Willis, Ben T.; Schmidt, Christopher D.

2017-01-01

The authors examined the peer feedback exchanged in 2 supervision groups of counselors-in-training (CITs). CITs generated 169 statements grouped into 10 clusters representing 5 regions of peer feedback: counselor focus and engagement, insight-oriented skills, exploratory skills, therapeutic alliance, and intervention activities. Both positive and…

Social deviance activates the brain's error-monitoring system.

PubMed

Kim, Bo-Rin; Liss, Alison; Rao, Monica; Singer, Zachary; Compton, Rebecca J

2012-03-01

Social psychologists have long noted the tendency for human behavior to conform to social group norms. This study examined whether feedback indicating that participants had deviated from group norms would elicit a neural signal previously shown to be elicited by errors and monetary losses. While electroencephalograms were recorded, participants (N = 30) rated the attractiveness of 120 faces and received feedback giving the purported average rating made by a group of peers. The feedback was manipulated so that group ratings either were the same as a participant's rating or deviated by 1, 2, or 3 points. Feedback indicating deviance from the group norm elicited a feedback-related negativity, a brainwave signal known to be elicited by objective performance errors and losses. The results imply that the brain treats deviance from social norms as an error.

Processing of Continuously Provided Punishment and Reward in Children with ADHD and the Modulating Effects of Stimulant Medication: An ERP Study

PubMed Central

Groen, Yvonne; Tucha, Oliver; Wijers, Albertus A.; Althaus, Monika

2013-01-01

Objectives Current models of ADHD suggest abnormal reward and punishment sensitivity, but the exact mechanisms are unclear. This study aims to investigate effects of continuous reward and punishment on the processing of performance feedback in children with ADHD and the modulating effects of stimulant medication. Methods 15 Methylphenidate (Mph)-treated and 15 Mph-free children of the ADHD-combined type and 17 control children performed a selective attention task with three feedback conditions: no-feedback, gain and loss. Event Related Potentials (ERPs) time-locked to feedback and errors were computed. Results All groups performed more accurately with gain and loss than without feedback. Feedback-related ERPs demonstrated no group differences in the feedback P2, but an enhanced late positive potential (LPP) to feedback stimuli (both gains and losses) for Mph-free children with ADHD compared to controls. Feedback-related ERPs in Mph-treated children with ADHD were similar to controls. Correlational analyses in the ADHD groups revealed that the severity of inattention problems correlated negatively with the feedback P2 amplitude and positively with the LPP to losses and omitted gains. Conclusions The early selective attention for rewarding and punishing feedback was relatively intact in children with ADHD, but the late feedback processing was deviant (increased feedback LPP). This may explain the often observed positive effects of continuous reinforcement on performance and behaviour in children with ADHD. However, these group findings cannot be generalised to all individuals with the ADHD, because the feedback-related ERPs were associated with the severity of the inattention problems. Children with ADHD-combined type with more inattention problems showed both deviant early attentional selection of feedback stimuli, and deviant late processing of non-reward and punishment. PMID:23555639

Processing of continuously provided punishment and reward in children with ADHD and the modulating effects of stimulant medication: an ERP study.

PubMed

Groen, Yvonne; Tucha, Oliver; Wijers, Albertus A; Althaus, Monika

2013-01-01

Current models of ADHD suggest abnormal reward and punishment sensitivity, but the exact mechanisms are unclear. This study aims to investigate effects of continuous reward and punishment on the processing of performance feedback in children with ADHD and the modulating effects of stimulant medication. 15 Methylphenidate (Mph)-treated and 15 Mph-free children of the ADHD-combined type and 17 control children performed a selective attention task with three feedback conditions: no-feedback, gain and loss. Event Related Potentials (ERPs) time-locked to feedback and errors were computed. All groups performed more accurately with gain and loss than without feedback. Feedback-related ERPs demonstrated no group differences in the feedback P2, but an enhanced late positive potential (LPP) to feedback stimuli (both gains and losses) for Mph-free children with ADHD compared to controls. Feedback-related ERPs in Mph-treated children with ADHD were similar to controls. Correlational analyses in the ADHD groups revealed that the severity of inattention problems correlated negatively with the feedback P2 amplitude and positively with the LPP to losses and omitted gains. The early selective attention for rewarding and punishing feedback was relatively intact in children with ADHD, but the late feedback processing was deviant (increased feedback LPP). This may explain the often observed positive effects of continuous reinforcement on performance and behaviour in children with ADHD. However, these group findings cannot be generalised to all individuals with the ADHD, because the feedback-related ERPs were associated with the severity of the inattention problems. Children with ADHD-combined type with more inattention problems showed both deviant early attentional selection of feedback stimuli, and deviant late processing of non-reward and punishment.

Proprioceptive feedback and brain computer interface (BCI) based neuroprostheses.

PubMed

Ramos-Murguialday, Ander; Schürholz, Markus; Caggiano, Vittorio; Wildgruber, Moritz; Caria, Andrea; Hammer, Eva Maria; Halder, Sebastian; Birbaumer, Niels

2012-01-01

Brain computer interface (BCI) technology has been proposed for motor neurorehabilitation, motor replacement and assistive technologies. It is an open question whether proprioceptive feedback affects the regulation of brain oscillations and therefore BCI control. We developed a BCI coupled on-line with a robotic hand exoskeleton for flexing and extending the fingers. 24 healthy participants performed five different tasks of closing and opening the hand: (1) motor imagery of the hand movement without any overt movement and without feedback, (2) motor imagery with movement as online feedback (participants see and feel their hand, with the exoskeleton moving according to their brain signals, (3) passive (the orthosis passively opens and closes the hand without imagery) and (4) active (overt) movement of the hand and rest. Performance was defined as the difference in power of the sensorimotor rhythm during motor task and rest and calculated offline for different tasks. Participants were divided in three groups depending on the feedback receiving during task 2 (the other tasks were the same for all participants). Group 1 (n = 9) received contingent positive feedback (participants' sensorimotor rhythm (SMR) desynchronization was directly linked to hand orthosis movements), group 2 (n = 8) contingent "negative" feedback (participants' sensorimotor rhythm synchronization was directly linked to hand orthosis movements) and group 3 (n = 7) sham feedback (no link between brain oscillations and orthosis movements). We observed that proprioceptive feedback (feeling and seeing hand movements) improved BCI performance significantly. Furthermore, in the contingent positive group only a significant motor learning effect was observed enhancing SMR desynchronization during motor imagery without feedback in time. Furthermore, we observed a significantly stronger SMR desynchronization in the contingent positive group compared to the other groups during active and passive movements. To summarize, we demonstrated that the use of contingent positive proprioceptive feedback BCI enhanced SMR desynchronization during motor tasks.

Group Projects in Interior Design Studio Classes: Peer Feedback Benefits

ERIC Educational Resources Information Center

Jurado, Juan A.

2011-01-01

Group projects have been shown to be effective for providing peer feedback in classrooms. While students in regular enrollment classes benefit from peer feedback, low-enrollment classes face many challenges. This study compares peer feedback effectiveness between two interior design studio classes with different design projects. In one class,…

Vega roll and attitude control system algorithms trade-off study

NASA Astrophysics Data System (ADS)

Paulino, N.; Cuciniello, G.; Cruciani, I.; Corraro, F.; Spallotta, D.; Nebula, F.

2013-12-01

This paper describes the trade-off study for the selection of the most suitable algorithms for the Roll and Attitude Control System (RACS) within the FPS-A program, aimed at developing the new Flight Program Software of VEGA Launcher. Two algorithms were analyzed: Switching Lines (SL) and Quaternion Feedback Regulation. Using a development simulation tool that models two critical flight phases (Long Coasting Phase (LCP) and Payload Release (PLR) Phase), both algorithms were assessed with Monte Carlo batch simulations for both of the phases. The statistical outcomes of the results demonstrate a 100 percent success rate for Quaternion Feedback Regulation, and support the choice of this method.

Effects of structured written feedback by cards on medical students' performance at Mini Clinical Evaluation Exercise (Mini-CEX) in an outpatient clinic.

PubMed

Haghani, Fariba; Hatef Khorami, Mohammad; Fakhari, Mohammad

2016-07-01

Feedback cards are recommended as a feasible tool for structured written feedback delivery in clinical education while effectiveness of this tool on the medical students' performance is still questionable.  The purpose of this study was to compare the effects of structured written feedback by cards as well as verbal feedback versus verbal feedback alone on the clinical performance of medical students at the Mini Clinical Evaluation Exercise (Mini-CEX) test in an outpatient clinic. This is a quasi-experimental study with pre- and post-test comprising four groups in two terms of medical students' externship. The students' performance was assessed through the Mini-Clinical Evaluation Exercise (Mini-CEX) as a clinical performance evaluation tool. Structured written feedbacks were given to two experimental groups by designed feedback cards as well as verbal feedback, while in the two control groups feedback was delivered verbally as a routine approach in clinical education. By consecutive sampling method, 62 externship students were enrolled in this study and seven students were excluded from the final analysis due to their absence for three days. According to the ANOVA analysis and Post Hoc Tukey test,  no statistically significant difference was observed among the four groups at the pre-test, whereas a statistically significant difference was observed between the experimental and control groups at the post-test  (F = 4.023, p =0.012). The effect size of the structured written feedbacks on clinical performance was 0.19. Structured written feedback by cards could improve the performance of medical students in a statistical sense. Further studies must be conducted in other clinical courses with longer durations.

Self-controlled video feedback on tactical skills for soccer teams results in more active involvement of players.

PubMed

van Maarseveen, Mariëtte J J; Oudejans, Raôul R D; Savelsbergh, Geert J P

2018-02-01

Many studies have shown that self-controlled feedback is beneficial for learning motor tasks, and that learners prefer to receive feedback after supposedly good trials. However, to date all studies conducted on self-controlled learning have used individual tasks and mainly relatively simple skills. Therefore, the aim of this study was to examine self-controlled feedback on tactical skills in small-sided soccer games. Highly talented youth soccer players were assigned to a self-control or yoked group and received video feedback on their offensive performance in 3 vs. 2 small-sided games. The results showed that the self-control group requested feedback mostly after good trials, that is, after they scored a goal. In addition, the perceived performance of the self-control group was higher on feedback than on no-feedback trials. Analyses of the conversations around the video feedback revealed that the players and coach discussed good and poor elements of performance and how to improve it. Although the coach had a major role in these conversations, the players of the self-control group spoke more and showed more initiative compared to the yoked group. The results revealed no significant beneficial effect of self-controlled feedback on performance as judged by the coach. Overall, the findings suggest that in such a complex situation as small-sided soccer games, self-controlled feedback is used both to confirm correct performance elements and to determine and correct errors, and that self-controlled learning stimulates the involvement of the learner in the learning process. Copyright © 2017 Elsevier B.V. All rights reserved.

How Residents Learn From Patient Feedback: A Multi-Institutional Qualitative Study of Pediatrics Residents' Perspectives.

PubMed

Bogetz, Alyssa L; Orlov, Nicola; Blankenburg, Rebecca; Bhavaraju, Vasudha; McQueen, Alisa; Rassbach, Caroline

2018-04-01

Residents may view feedback from patients and their families with greater skepticism than feedback from supervisors and peers. While discussing patient and family feedback with faculty may improve residents' acceptance of feedback and learning, specific strategies have not been identified. We explored pediatrics residents' perspectives of patient feedback and identified strategies that promote residents' reflection on and learning from feedback. In this multi-institutional, qualitative study conducted in June and July 2016, we conducted focus groups with a purposive sample of pediatrics residents after their participation in a randomized controlled trial in which they received written patient feedback and either discussed it with faculty or reviewed it independently. Focus group transcripts were audiorecorded, transcribed, and analyzed for themes using the constant comparative approach associated with grounded theory. Thirty-six of 92 (39%) residents participated in 7 focus groups. Four themes emerged: (1) residents valued patient feedback but felt it may lack the specificity they desire; (2) discussing feedback with a trusted faculty member was helpful for self-reflection; (3) residents identified 5 strategies faculty used to facilitate their openness to and acceptance of patient feedback (eg, help resident overcome emotional responses to feedback and situate feedback in the context of lifelong learning); and (4) residents' perceptions of feedback credibility improved when faculty observed patient encounters and solicited feedback on the resident's behalf prior to discussions. Discussing patient feedback with faculty provided important scaffolding to enhance residents' openness to and reflection on patient feedback.

Common-signal-induced synchronization in photonic integrated circuits and its application to secure key distribution.

PubMed

Sasaki, Takuma; Kakesu, Izumi; Mitsui, Yusuke; Rontani, Damien; Uchida, Atsushi; Sunada, Satoshi; Yoshimura, Kazuyuki; Inubushi, Masanobu

2017-10-16

We experimentally achieve common-signal-induced synchronization in two photonic integrated circuits with short external cavities driven by a constant-amplitude random-phase light. The degree of synchronization can be controlled by changing the optical feedback phase of the two photonic integrated circuits. The change in the optical feedback phase leads to a significant redistribution of the spectral energy of optical and RF spectra, which is a unique characteristic of PICs with the short external cavity. The matching of the RF and optical spectra is necessary to achieve synchronization between the two PICs, and stable synchronization can be obtained over an hour in the presence of optical feedback. We succeed in generating information-theoretic secure keys and achieving the final key generation rate of 184 kb/s using the PICs.

A feedback control for the advanced launch system

NASA Technical Reports Server (NTRS)

Seywald, Hans; Cliff, Eugene M.

1991-01-01

A robust feedback algorithm is presented for a near-minimum-fuel ascent of a two-stage launch vehicle operating in the equatorial plane. The development of the algorithm is based on the ideas of neighboring optimal control and can be derived into three phases. In phase 1, the formalism of optimal control is employed to calculate fuel-optimal ascent trajectories for a simple point-mass model. In phase 2, these trajectories are used to numerically calculate gain functions of time for the control(s), the total flight time, and possibly, for other variables of interest. In phase 3, these gains are used to determine feedback expressions for the controls associated with a more realistic model of a launch vehicle. With the Advanced Launch System in mind, all calculations are performed on a two-stage vehicle with fixed thrust history, but this restriction is by no means important for the approach taken. Performance and robustness of the algorithm is found to be excellent.

Synchronization of tunable asymmetric square-wave pulses in delay-coupled optoelectronic oscillators.

PubMed

Martínez-Llinàs, Jade; Colet, Pere; Erneux, Thomas

2015-03-01

We consider a model for two delay-coupled optoelectronic oscillators under positive delayed feedback as prototypical to study the conditions for synchronization of asymmetric square-wave oscillations, for which the duty cycle is not half of the period. We show that the scenario arising for positive feedback is much richer than with negative feedback. First, it allows for the coexistence of multiple in- and out-of-phase asymmetric periodic square waves for the same parameter values. Second, it is tunable: The period of all the square-wave periodic pulses can be tuned with the ratio of the delays, and the duty cycle of the asymmetric square waves can be changed with the offset phase while the total period remains constant. Finally, in addition to the multiple in- and out-of-phase periodic square waves, low-frequency periodic asymmetric solutions oscillating in phase may coexist for the same values of the parameters. Our analytical results are in agreement with numerical simulations and bifurcation diagrams obtained by using continuation techniques.

Eye-Hand Coordination during Visuomotor Adaptation with Different Rotation Angles

PubMed Central

Rentsch, Sebastian; Rand, Miya K.

2014-01-01

This study examined adaptive changes of eye-hand coordination during a visuomotor rotation task. Young adults made aiming movements to targets on a horizontal plane, while looking at the rotated feedback (cursor) of hand movements on a monitor. To vary the task difficulty, three rotation angles (30°, 75°, and 150°) were tested in three groups. All groups shortened hand movement time and trajectory length with practice. However, control strategies used were different among groups. The 30° group used proportionately more implicit adjustments of hand movements than other groups. The 75° group used more on-line feedback control, whereas the 150° group used explicit strategic adjustments. Regarding eye-hand coordination, timing of gaze shift to the target was gradually changed with practice from the late to early phase of hand movements in all groups, indicating an emerging gaze-anchoring behavior. Gaze locations prior to the gaze anchoring were also modified with practice from the cursor vicinity to an area between the starting position and the target. Reflecting various task difficulties, these changes occurred fastest in the 30° group, followed by the 75° group. The 150° group persisted in gazing at the cursor vicinity. These results suggest that the function of gaze control during visuomotor adaptation changes from a reactive control for exploring the relation between cursor and hand movements to a predictive control for guiding the hand to the task goal. That gaze-anchoring behavior emerged in all groups despite various control strategies indicates a generality of this adaptive pattern for eye-hand coordination in goal-directed actions. PMID:25333942

Effects of Training and Feedback on Accuracy of Predicting Rectosigmoid Neoplastic Lesions and Selection of Surveillance Intervals by Endoscopists Performing Optical Diagnosis of Diminutive Polyps.

PubMed

Vleugels, Jasper L A; Dijkgraaf, Marcel G W; Hazewinkel, Yark; Wanders, Linda K; Fockens, Paul; Dekker, Evelien

2018-05-01

Real-time differentiation of diminutive polyps (1-5 mm) during endoscopy could replace histopathology analysis. According to guidelines, implementation of optical diagnosis into routine practice would require it to identify rectosigmoid neoplastic lesions with a negative predictive value (NPV) of more than 90%, using histologic findings as a reference, and agreement with histology-based surveillance intervals for more than 90% of cases. We performed a prospective study with 39 endoscopists accredited to perform colonoscopies on participants with positive results from fecal immunochemical tests in the Bowel Cancer Screening Program at 13 centers in the Netherlands. Endoscopists were trained in optical diagnosis using a validated module (Workgroup serrAted polypS and Polyposis). After meeting predefined performance thresholds in the training program, the endoscopists started a 1-year program (continuation phase) in which they performed narrow band imaging analyses during colonoscopies of participants in the screening program and predicted histological findings with confidence levels. The endoscopists were randomly assigned to groups that received feedback or no feedback on the accuracy of their predictions. Primary outcome measures were endoscopists' abilities to identify rectosigmoid neoplastic lesions (using histology as a reference) with NPVs of 90% or more, and selecting surveillance intervals that agreed with those determined by histology for at least 90% of cases. Of 39 endoscopists initially trained, 27 (69%) completed the training program. During the continuation phase, these 27 endoscopists performed 3144 colonoscopies in which 4504 diminutive polyps were removed. The endoscopists identified neoplastic lesions with a pooled NPV of 90.8% (95% confidence interval 88.6-92.6); their proposed surveillance intervals agreed with those determined by histologic analysis for 95.4% of cases (95% confidence interval 94.0-96.6). Findings did not differ between the group that did vs did not receive feedback. Sixteen endoscopists (59%) identified rectosigmoid neoplastic lesions with NPVs greater than 90% and selected surveillance intervals in agreement with those determined from histology for more than 90% of patients. In a prospective study following a validated training module, we found that a selected group of endoscopists identified rectosigmoid neoplastic lesions with pooled NPVs greater than 90% and accurately selected surveillance intervals for more than 90% of patients over the course of 1 year. Providing regular interim feedback on the accuracy of neoplastic lesion prediction and surveillance interval selection did not lead to differences in those endpoints. Monitoring is suggested, as individual performance varied. ClinicalTrials.gov no: NCT02516748; Netherland Trial Register: NTR4635. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

The impact of constructive feedback on training in gastrointestinal endoscopy using high-fidelity Virtual-Reality simulation: a randomised controlled trial.

PubMed

Kruglikova, Irina; Grantcharov, Teodor P; Drewes, Asbjorn M; Funch-Jensen, Peter

2010-02-01

Recently, virtual reality computer simulators have been used to enhance traditional endoscopy teaching. Previous studies have demonstrated construct validity of these systems and transfer of virtual skills to the operating room. However, to date no simulator-training curricula have been designed and there is very little evidence on the impact of external feedback on acquisition of endoscopic skills. The aim of the present study was to assess the impact of external feedback on the learning curves on a VR colonoscopy simulator using inexperienced trainees. 22 trainees, without colonoscopy experience were randomised to a group which received structured feedback provided by an experienced supervisor and a controlled group. All participants performed 15 repetitions of task 3 from the Introduction colonoscopy module of the Accu Touch Endoscopy simulator. Retention/transfer tests on simulator were performed 4-6 weeks after the last repetition. The proficiency levels were based on the performance of eight experienced colonoscopists. All subjects were able to complete the procedure on the simulator. There were no perforations in the feedback group versus seven in the non-feedback group. Subjects in the feedback group reached expert proficiency levels in percentage of mucosa visualised and time to reach the caecum significantly faster compared with the control group. None of the groups demonstrated significant degradation of performance in simulator retention/transfer tests. Concurrent feedback given by supervisor concur an advantage in acquisition of basic colonoscopy skills and achieving of proficiency level as compared to independent training.

On wave-CISK and the evaporation-wind feedback for the Madden-Julian oscillation

NASA Technical Reports Server (NTRS)

Kirtman, B.; Vernekar, A.

1993-01-01

The combined effects of Kelvin wave-CISK and the evaporation-wind (E-W) feedback are proposed as a possible mechanism for the Madden-Julian oscillation. A very simple single vertical mode model has been employed to examine the effects of both these processes on moist Kelvin waves. The effects of wave-induced moisture convergence is parameterized by reducing the moist static stability, and CISK occurs when the moist static stability becomes negative. The E-W feedback in the presence of mean easterlies leads to unstable Kelvin modes. The presence of mean westerlies leads to decaying Kelvin modes. When CISK and the E-W feedback work in concert, an unstable Kelvin mode develops that has phase speeds of propagation between 5 m/s and 10 m/s for a large range of parameter values. On the other hand, the E-W feedback mechanism alone, in the case when CISK is not operating, produces the phase speeds of the observed Madden-Julian oscillation for only a very limited range of parameter values.

Pre-training evaluation and feedback improve medical students' skills in basic life support.

PubMed

Li, Qi; Ma, Er-Li; Liu, Jin; Fang, Li-Qun; Xia, Tian

2011-01-01

Evaluation and feedback are two factors that could influence simulation-based medical education and the time when they were delivered contributes their different effects. To investigate the impact of pre-training evaluation and feedback on medical students' performance in basic life support (BLS). Forty 3rd-year undergraduate medical students were randomly divided into two groups, C group (the control) and pre-training evaluation and feedback group (E&F group), each of 20. After BLS theoretical lecture, the C group received 45 min BLS training and the E&F group was individually evaluated (video-taped) in a mock cardiac arrest (pre-training evaluation). Fifteen minutes of group feedback related with the students' BLS performance in pre-training evaluation was given in the E&F group, followed by a 30-min BLS training. After BLS training, both groups were evaluated with one-rescuer BLS skills in a 3-min mock cardiac arrest scenario (post-training evaluation). The score from the post-training evaluation was converted to a percentage and was compared between the two groups. The score from the post-training evaluation was higher in the E&F group (82.9 ± 3.2% vs. 63.9 ± 13.4% in C group). In undergraduate medical students without previous BLS training, pre-training evaluation and feedback improve their performance in followed BLS training.

Phase-Shifted Laser Feedback Interferometry

NASA Technical Reports Server (NTRS)

Ovryn, Benjie

1999-01-01

Phase-shifted, laser feedback interferometry is a new diagnostic tool developed at the NASA Lewis Research Center under the Advanced Technology Development (ATD) Program directed by NASA Headquarters Microgravity Research Division. It combines the principles of phase-shifting interferometry (PSI) and laser-feedback interferometry (LFI) to produce an instrument that can quantify both optical path length changes and sample reflectivity variations. In a homogenous medium, the optical path length between two points is the product of the index of refraction and the geometric distance between the two points. LFI differs from other forms of interferometry by using the laser as both the source and the phase detector. In LFI, coherent feedback of the incident light either reflected directly from a surface or reflected after transmission through a region of interest will modulate the output intensity of the laser. The combination of PSI and LFI has produced a robust instrument, based on a low-power helium-neon (HeNe) gas laser, with a high dynamic range that can be used to measure either static or oscillatory changes of the optical path length. Small changes in optical path length are limited by the fraction of a fringe that can be measured; we can measure nonoscillatory changes with a root mean square (rms) error of the wavelength/1000 without averaging.

The Effect Of Different Corrective Feedback Methods on the Outcome and Self Confidence of Young Athletes

PubMed Central

Tzetzis, George; Votsis, Evandros; Kourtessis, Thomas

2008-01-01

This experiment investigated the effects of three corrective feedback methods, using different combinations of correction, or error cues and positive feedback for learning two badminton skills with different difficulty (forehand clear - low difficulty, backhand clear - high difficulty). Outcome and self-confidence scores were used as dependent variables. The 48 participants were randomly assigned into four groups. Group A received correction cues and positive feedback. Group B received cues on errors of execution. Group C received positive feedback, correction cues and error cues. Group D was the control group. A pre, post and a retention test was conducted. A three way analysis of variance ANOVA (4 groups X 2 task difficulty X 3 measures) with repeated measures on the last factor revealed significant interactions for each depended variable. All the corrective feedback methods groups, increased their outcome scores over time for the easy skill, but only groups A and C for the difficult skill. Groups A and B had significantly better outcome scores than group C and the control group for the easy skill on the retention test. However, for the difficult skill, group C was better than groups A, B and D. The self confidence scores of groups A and C improved over time for the easy skill but not for group B and D. Again, for the difficult skill, only group C improved over time. Finally a regression analysis depicted that the improvement in performance predicted a proportion of the improvement in self confidence for both the easy and the difficult skill. It was concluded that when young athletes are taught skills of different difficulty, different type of instruction, might be more appropriate in order to improve outcome and self confidence. A more integrated approach on teaching will assist coaches or physical education teachers to be more efficient and effective. Key pointsThe type of the skill is a critical factor in determining the effectiveness of the feedback types.Different instructional methods of corrective feedback could have beneficial effects in the outcome and self-confidence of young athletesInstructions focusing on the correct cues or errors increase performance of easy skills.Positive feedback or correction cues increase self-confidence of easy skills but only the combination of error and correction cues increase self confidence and outcome scores of difficult skills. PMID:24149905

Immediate Web-Based Essay Critiquing System Feedback and Teacher Follow-Up Feedback on Young Second Language Learners' Writings: An Experimental Study in a Hong Kong Secondary School

ERIC Educational Resources Information Center

Lee, Cynthia; Cheung, William Kwok Wai; Wong, Kelvin Chi Kuen; Lee, Fion Sau Ling

2013-01-01

This article is an effort to add to computer-assisted language learning by extending a study on an essay critiquing system (ECS) feedback to secondary school language learners' writing. The study compared two groups of participants' performance, namely the treatment group which received both the system feedback and teacher feedback (i.e., blended…

Barriers and Facilitators to Effective Feedback: A Qualitative Analysis of Data From Multispecialty Resident Focus Groups.

PubMed

Reddy, Shalini T; Zegarek, Matthew H; Fromme, H Barrett; Ryan, Michael S; Schumann, Sarah-Anne; Harris, Ilene B

2015-06-01

Despite the importance of feedback, the literature suggests that there is inadequate feedback in graduate medical education. We explored barriers and facilitators that residents in anesthesiology, emergency medicine, obstetrics and gynecology, and surgery experience with giving and receiving feedback during their clinical training. Residents from 3 geographically diverse teaching institutions were recruited to participate in focus groups in 2012. Open-ended questions prompted residents to describe their experiences with giving and receiving feedback, and discuss facilitators and barriers. Data were transcribed and analyzed using the constant comparative method associated with a grounded theory approach. A total of 19 residents participated in 1 of 3 focus groups. Five major themes related to feedback were identified: teacher factors, learner factors, feedback process, feedback content, and educational context. Unapproachable attendings, time pressures due to clinical work, and discomfort with giving negative feedback were cited as major barriers in the feedback process. Learner engagement in the process was a major facilitator in the feedback process. Residents provided insights for improving the feedback process based on their dual roles as teachers and learners. Time pressures in the learning environment may be mitigated by efforts to improve the quality of teacher-learner relationships. Forms for collecting written feedback should be augmented by faculty development to ensure meaningful use. Efforts to improve residents' comfort with giving feedback and encouraging learners to engage in the feedback process may foster an environment conducive to increasing feedback.

About Politeness, Face, and Feedback: Exploring Resident and Faculty Perceptions of How Institutional Feedback Culture Influences Feedback Practices.

PubMed

Ramani, Subha; Könings, Karen D; Mann, Karen V; Pisarski, Emily E; van der Vleuten, Cees P M

2018-03-06

To explore resident and faculty perspectives on what constitutes feedback culture, their perceptions of how institutional feedback culture (including politeness concepts) might influence the quality and impact of feedback, feedback seeking, receptivity, and readiness to engage in bidirectional feedback. Using a constructivist grounded theory approach, five focus group discussions with internal medicine residents, three focus group discussions with general medicine faculty, and eight individual interviews with subspecialist faculty were conducted at Brigham and Women's Hospital between April and December 2016. Discussions and interviews were audiotaped and transcribed verbatim; concurrent data collection and analysis were performed using the constant comparative approach. Analysis was considered through the lens of politeness theory and organizational culture. Twenty-nine residents and twenty-two general medicine faculty participated in focus group discussions, and eight subspecialty faculty participated in interviews. The institutional feedback culture was described by participants as: (1) a culture of politeness, in which language potentially damaging to residents' self-esteem was discouraged, and (2) a culture of excellence, in which the institution's outstanding reputation and pedigree of trainees inhibited constructive feedback. Three key themes situated within this broader cultural context were discovered: normalizing constructive feedback to promote a culture of growth, overcoming the mental block to feedback seeking, and hierarchical culture impeding bidirectional feedback. An institutional feedback culture of excellence and politeness may impede honest, meaningful feedback and may impact feedback seeking, receptivity, and bidirectional feedback exchanges. It is essential to understand the institutional feedback culture before it can be successfully changed.

The spectral details of observed and simulated short-term water vapor feedbacks of El Niño-Southern Oscillation

NASA Astrophysics Data System (ADS)

Pan, F.; Huang, X.; Chen, X.

2015-12-01

Radiative kernel method has been validated and widely used in the study of climate feedbacks. This study uses spectrally resolved longwave radiative kernels to examine the short-term water vapor feedbacks associated with the ENSO cycles. Using a 500-year GFDL CM3 and a 100-year NCAR CCSM4 pre-industry control simulation, we have constructed two sets of longwave spectral radiative kernels. We then composite El Niño, La Niña and ENSO-neutral states and estimate the water vapor feedbacks associated with the El Niño and La Niña phases of ENSO cycles in both simulations. Similar analysis is also applied to 35-year (1979-2014) ECMWF ERA-interim reanalysis data, which is deemed as observational results here. When modeled and observed broadband feedbacks are compared to each other, they show similar geographic patterns but with noticeable discrepancies in the contrast between the tropics and extra-tropics. Especially, in El Niño phase, the feedback estimated from reanalysis is much greater than those from the model simulations. Considering the observational data span, we carry out a sensitivity test to explore the variability of feedback-deriving using 35-year data. To do so, we calculate the water vapor feedback within every 35-year segment of the GFDL CM3 control run by two methods: one is to composite El Nino or La Nina phases as mentioned above and the other is to regressing the TOA flux perturbation caused by water vapor change (δR_H­2O) against the global-mean surface temperature a­­­­nomaly. We find that the short-term feedback strengths derived from composite method can change considerably from one segment to another segment, while the feedbacks by regression method are less sensitive to the choice of segment and their strengths are also much smaller than those from composite analysis. This study suggests that caution is warranted in order to infer long-term feedbacks from a few decades of observations. When spectral details of the global-mean feedbacks are examined, more inconsistencies can be revealed in many spectral bands, especially H2O continuum absorption bands and window regions. These discrepancies can be attributed back to differences in observed and modeled water vapor profiles in responses to tropical SST.

Prefrontal Neural Activity When Feedback Is Not Relevant to Adjust Performance

PubMed Central

Özyurt, Jale; Rietze, Mareike; Thiel, Christiane M.

2012-01-01

It has been shown that the rostral cingulate zone (RCZ) in humans uses both positive and negative feedback to evaluate performance and to flexibly adjust behaviour. Less is known on how the feedback types are processed by the RCZ and other prefrontal brain areas, when feedback can only be used to evaluate performance, but cannot be used to adjust behaviour. The present fMRI study aimed at investigating feedback that can only be used to evaluate performance in a word-learning paradigm. One group of volunteers (N = 17) received informative, performance-dependent positive or negative feedback after each trial. Since new words had to be learnt in each trial, the feedback could not be used for task-specific adaptations. The other group (N = 17) always received non-informative feedback, providing neither information about performance nor about possible task-specific adaptations. Effects of the informational value of feedback were assessed between-subjects, comparing trials with positive and negative informative feedback to non-informative feedback. Effects of feedback valence were assessed by comparing neural activity to positive and negative feedback within the informative-feedback group. Our results show that several prefrontal regions, including the pre-SMA, the inferior frontal cortex and the insula were sensitive to both, the informational value and the valence aspect of the feedback with stronger activations to informative as compared to non-informative feedback and to informative negative compared to informative positive feedback. The only exception was RCZ which was sensitive to the informational value of the feedback, but not to feedback valence. The findings indicate that outcome information per se is sufficient to activate prefrontal brain regions, with the RCZ being the only prefrontal brain region which is equally sensitive to positive and negative feedback. PMID:22615774

Outcomes of biomarker feedback on physical activity, eating habits, and emotional health: from the Americans in Motion-Healthy Intervention (AIM-HI) study.

PubMed

Mitchell, Nia S; Manning, Brian K; Staton, Elizabeth W; Emsermann, Caroline D; Dickinson, L Miriam; Pace, Wilson D

2014-01-01

The purpose of this article was to test whether physical activity, healthy eating, and emotional well-being would improve if patients received feedback about biomarkers that have been shown to be responsive to changes in weight and fitness. Patients were randomized to limited feedback (weight, body mass index [BMI], and blood pressure at 4 and 10 months) or enhanced feedback (weight, BMI, blood pressure, homeostatic insulin resistance, and nuclear magnetic resonance lipoprotein profiles at 2, 4, 7, and 10 months). Repeated measures mixed effects multivariate regression models were used to determine whether BMI, fitness, diet, and quality of life changed over time. Major parameters were similar in both groups at baseline. BMI, measures of fitness, healthy eating, quality of life, and health state improved in both patient groups, but there was no difference between patient groups at 4 or 10 months. Systolic blood pressure improved in the enhanced feedback group, and there was a difference between the enhanced and limited feedback groups at 10 months (95% confidence interval, -6.011 to -0.5113). Providing patients with enhanced feedback did not dramatically change outcomes. However, across groups, many patients maintained or lost weight, suggesting the need for more study of nondiet interventions.

Gambling behavior in Parkinson's Disease: Impulsivity, reward mechanism and cortical brain oscillations.

PubMed

Balconi, Michela; Angioletti, Laura; Siri, Chiara; Meucci, Nicoletta; Pezzoli, Gianni

2018-03-20

Psychopathological components, such as reward sensitivity and impulsivity, and dopaminergic treatment are crucial characteristics related to the development of Pathological Gambling (PG) in Parkinson's Disease (PD). The aim of the present study is to investigate the differences in decision-making in PD patients with or without PG considering both neurophysiological and behavioral aspects. The IOWA Gambling Task (IGT) and electroencephalographic (EEG) activity were considered to elucidate the decision and post-feedback processes in PG. The sample included fifty-two PD patients, divided in three groups: 17 PD patients with active gambling behavior (PD Gamblers, PDG); 15 PD patients who remitted from PG (PD Non-Gamblers, PDNG); and a Control Group (CG) composed by 20 patients with PD only. EEG and IGT performance were recorded during decision and post-feedback phase. Results showed worse performance and an increase of the low frequency bands in the frontal area for the PDG group compared to the other two groups. In addition, higher BAS (Behavioral Activation System) and BIS-11 (Barratt Impulsiveness Scale) personality components were correlated to groups' behavioral response. These results show an anomalous behavioral (IGT) and cortical response of PDG patients related to their inability to use adequate control mechanisms during a decision-making task where reward mechanisms (BAS) and impulsivity (BIS-11) are relevant. Copyright © 2018 Elsevier B.V. All rights reserved.

Integrated Knowledge Translation and Grant Development: Addressing the Research Practice Gap through Stakeholder-informed Research.

PubMed

Henderson, Joanna; Brownlie, Elizabeth; Rosenkranz, Susan; Chaim, Gloria; Beitchman, Joseph

2013-11-01

We describe our stakeholder engagement process for grant application development that occurred as part of our integrated knowledge translation plan and make recommendations for researchers. In phase 1, a stakeholder consultation group was developed. In phase 2, surveys regarding knowledge gathering, research agenda, and research collaboration preferences were sent to 333 cross-sectoral youth-serving organizations in Ontario, including family and consumer organizations. In phase 1, 28 stakeholders from six sectors participated in the consultation group and provided input on multiple aspects of the proposal. Through this process, 19 stakeholders adopted formal roles within the project. In phase 2, 206 surveys were received (response rate = 62%). Survey responses supported the grant focus (concurrent youth mental health and substance use problems). Respondents also prioritized project goals and provided specific feedback on research and knowledge translation. Finally, although some stakeholders chose greater involvement, most survey respondents indicated a preference for a moderate level of participation in research rather than full team membership. Despite short timelines and feasibility challenges, stakeholders can be meaningfully engaged in and contribute to the grant proposal development process. Consideration is needed for the practical challenges that stakeholder organizations face in supporting and participating in research.

The effect of feedback-assisted reduction in heart rate reactivity on videogame performance.

PubMed

Larkin, K T; Manuck, S B; Kasprowicz, A L

1990-12-01

In 67 male volunteers, we examined the reduction of cardiovascular responsivity to a psychomotor challenge (videogame) achieved by use of heart rate (HR) feedback and effects of these procedures on concomitant behavioral performance. Each subject participated in a pretraining assessment of his cardiovascular responses to the videogame, a training condition, and a posttraining assessment identical to the initial evaluation. During training, subjects were assigned to one of four conditions: (a) a habituation control group receiving no instructions to alter HR (HC); (b) an instructions-only control group receiving instructions to maintain a low or unchanged HR during videogame presentations (IC); (c) a feedback group receiving instructions to reduce HR using ongoing HR feedback (FB-); or (d) a feedback group receiving instructions to lower HR and given HR feedback plus a score contingency in which total game score was jointly determined by subjects' game performance and success at HR control (FB+). Subjects receiving feedback (FB+, FB-) exhibited greater reductions in HR response to the videogame in the posttraining assessment than control (HC, IC) subjects; FB+ subjects showed greater HR reductions than subjects in any other group. FB+ and FB- subjects showed a lower SBP at posttraining relative to the two control groups, but no reduction in task-induced blood pressure reactivity. There were no group differences in videogame performance, either before or following training.

The Impact of Different Degrees of Feedback on Physical Activity Levels: A 4-Week Intervention Study

PubMed Central

Van Hoye, Karen; Boen, Filip; Lefevre, Johan

2015-01-01

Assessing levels of physical activity (PA) and providing feedback about these levels might have an effect on participant’s PA behavior. This study discusses the effect of different levels of feedback—from minimal to use of a feedback display and coach—on PA over a 4-week intervention period. PA was measured at baseline, during and immediately after the intervention. Participants (n = 227) were randomly assigned to a Minimal Intervention Group (MIG-no feedback), Pedometer Group (PG-feedback on steps taken), Display Group (DG-feedback on steps, minutes of moderate to vigorous physical activity and energy expenditure) or Coaching Group (CoachG-same as DG with need-supportive coaching). Two-way ANCOVA showed no significant Group × Time interaction effect for the different PA variables between the MIG and PG. Also no differences emerged between PG and DG. As hypothesized, CoachG had higher PA values throughout the intervention compared with DG. Self-monitoring using a pedometer resulted in more steps compared with a no-feedback condition at the start of the intervention. However, adding individualized coaching seems necessary to increase the PA level until the end of the intervention. PMID:26067990

The development and evaluation of a community attachment scheme for first-year medical students.

PubMed

Hannay, David; Mitchell, Caroline; Chung, Man Cheung

2003-03-01

This paper describes the development over 14 years of a Community Attachment Scheme for First Year Medical Students in Sheffield, together with feedback from tutors and students. The scheme involves pairs of students visiting families expecting a baby or experiencing an illness. The families are identified by general practitioners who act as tutors together with a behavioural scientist for groups of eight to 10 students. The scheme provides first-year students with practical experience of sociology and psychology in terms of family dynamics and illness behaviour. Assessment is part of the degree examination, and involves a written assignment on the family, together with tutors' assessments. The development of the attachment scheme took place in three phases, which are described together with feedback from tutors and students, as well as changes in methods of assessment. The basis of the Community Attachment Scheme has been self-directed problem-based learning in small groups with continuous assessment, and these principles have now extended to the rest of the medical curriculum in Sheffield, of which the Community Attachment Scheme is an integral part.

Unexpected Acceptance? Patients with Social Anxiety Disorder Manifest their Social Expectancy in ERPs During Social Feedback Processing.

PubMed

Cao, Jianqin; Gu, Ruolei; Bi, Xuejing; Zhu, Xiangru; Wu, Haiyan

2015-01-01

Previous studies on social anxiety have demonstrated negative-expectancy bias in social contexts. In this study, we used a paradigm that employed self-relevant positive or negative social feedback, in order to test whether this negative expectancy manifests in event-related potentials (ERPs) during social evaluation among socially anxious individuals. Behavioral data revealed that individuals with social anxiety disorder (SAD) showed more negative expectancy of peer acceptance both in the experiment and in daily life than did the healthy control participants. Regarding ERP results, we found a overally larger P2 for positive social feedback and also a group main effect, such that the P2 was smaller in SAD group. SAD participants demonstrated a larger feedback-related negativity (FRN) to positive feedback than to negative feedback. In addition, SAD participants showed a more positive ΔFRN (ΔFRN = negative - positive). Furthermore, acceptance expectancy in daily life correlated negatively with ΔFRN amplitude, while the Interaction Anxiousness Scale (IAS) score correlated positively with the ΔFRN amplitude. Finally, the acceptance expectancy in daily life fully mediated the relationship between the IAS and ΔFRN. These results indicated that both groups could differentiate between positive and negative social feedback in the early stage of social feedback processing (reflected on the P2). However, the SAD group exhibited a larger FRN to positive social feedback than to negative social feedback, demonstrating their dysfunction in the late stage of social feedback processing. In our opinion, such dysfunction is due to their greater negative social feedback expectancy.

Unexpected Acceptance? Patients with Social Anxiety Disorder Manifest their Social Expectancy in ERPs During Social Feedback Processing

PubMed Central

Cao, Jianqin; Gu, Ruolei; Bi, Xuejing; Zhu, Xiangru; Wu, Haiyan

2015-01-01

Previous studies on social anxiety have demonstrated negative-expectancy bias in social contexts. In this study, we used a paradigm that employed self-relevant positive or negative social feedback, in order to test whether this negative expectancy manifests in event-related potentials (ERPs) during social evaluation among socially anxious individuals. Behavioral data revealed that individuals with social anxiety disorder (SAD) showed more negative expectancy of peer acceptance both in the experiment and in daily life than did the healthy control participants. Regarding ERP results, we found a overally larger P2 for positive social feedback and also a group main effect, such that the P2 was smaller in SAD group. SAD participants demonstrated a larger feedback-related negativity (FRN) to positive feedback than to negative feedback. In addition, SAD participants showed a more positive ΔFRN (ΔFRN = negative – positive). Furthermore, acceptance expectancy in daily life correlated negatively with ΔFRN amplitude, while the Interaction Anxiousness Scale (IAS) score correlated positively with the ΔFRN amplitude. Finally, the acceptance expectancy in daily life fully mediated the relationship between the IAS and ΔFRN. These results indicated that both groups could differentiate between positive and negative social feedback in the early stage of social feedback processing (reflected on the P2). However, the SAD group exhibited a larger FRN to positive social feedback than to negative social feedback, demonstrating their dysfunction in the late stage of social feedback processing. In our opinion, such dysfunction is due to their greater negative social feedback expectancy. PMID:26635659

Effects of head movement and proprioceptive feedback in training of sound localization

PubMed Central

Honda, Akio; Shibata, Hiroshi; Hidaka, Souta; Gyoba, Jiro; Iwaya, Yukio; Suzuki, Yôiti

2013-01-01

We investigated the effects of listeners' head movements and proprioceptive feedback during sound localization practice on the subsequent accuracy of sound localization performance. The effects were examined under both restricted and unrestricted head movement conditions in the practice stage. In both cases, the participants were divided into two groups: a feedback group performed a sound localization drill with accurate proprioceptive feedback; a control group conducted it without the feedback. Results showed that (1) sound localization practice, while allowing for free head movement, led to improvement in sound localization performance and decreased actual angular errors along the horizontal plane, and that (2) proprioceptive feedback during practice decreased actual angular errors in the vertical plane. Our findings suggest that unrestricted head movement and proprioceptive feedback during sound localization training enhance perceptual motor learning by enabling listeners to use variable auditory cues and proprioceptive information. PMID:24349686

Diurnal suppression of EGFR signalling by glucocorticoids and implications for tumour progression and treatment.

PubMed

Lauriola, Mattia; Enuka, Yehoshua; Zeisel, Amit; D'Uva, Gabriele; Roth, Lee; Sharon-Sevilla, Michal; Lindzen, Moshit; Sharma, Kirti; Nevo, Nava; Feldman, Morris; Carvalho, Silvia; Cohen-Dvashi, Hadas; Kedmi, Merav; Ben-Chetrit, Nir; Chen, Alon; Solmi, Rossella; Wiemann, Stefan; Schmitt, Fernando; Domany, Eytan; Yarden, Yosef

2014-10-03

Signal transduction by receptor tyrosine kinases (RTKs) and nuclear receptors for steroid hormones is essential for body homeostasis, but the cross-talk between these receptor families is poorly understood. We observed that glucocorticoids inhibit signalling downstream of EGFR, an RTK. The underlying mechanism entails suppression of EGFR's positive feedback loops and simultaneous triggering of negative feedback loops that normally restrain EGFR. Our studies in mice reveal that the regulation of EGFR's feedback loops by glucocorticoids translates to circadian control of EGFR signalling: EGFR signals are suppressed by high glucocorticoids during the active phase (night-time in rodents), while EGFR signals are enhanced during the resting phase. Consistent with this pattern, treatment of animals bearing EGFR-driven tumours with a specific kinase inhibitor was more effective if administered during the resting phase of the day, when glucocorticoids are low. These findings support a circadian clock-based paradigm in cancer therapy.

Aspheric figure generation using feedback from an infrared phase-shifting interferometer

NASA Astrophysics Data System (ADS)

Stahl, H. P.; Ketelsen, D.

An infrared phase-shifting interferometric system has been integrated with a novel optical figure generator at the University of Arizona Optical Sciences Center. This unique generator facility can produce generalized axially symmetric surface figures in a timely and cost-effective manner. The success of this facility depends on both its ability to efficiently remove material while forming the surface figure, and its ability to monitor the surface figure during the generation process to provide feedback to the optician. The facility has been used on several occasions to custom-generate off-axis parabolic segments. Figures to within 0.30 microns rms of the desired figure have been obtained. This paper discusses the usefulness of the infrared phase-shifting interferometric system for providing figure correcting feedback to the optician during the generation of the off-axis parabolic segments, and how it is affected by the surface roughness produced by each generator tool.

A qualitative study of the variable effects of audit and feedback in the ICU.

PubMed

Sinuff, Tasnim; Muscedere, John; Rozmovits, Linda; Dale, Craig M; Scales, Damon C

2015-06-01

Audit and feedback is integral to performance improvement and behaviour change in the intensive care unit (ICU). However, there remain large gaps in our understanding of the social experience of audit and feedback and the mechanisms whereby it can be optimised as a quality improvement strategy in the ICU setting. We conducted a modified grounded theory qualitative study. Seventy-two clinicians from five academic and five community ICUs in Ontario, Canada, were interviewed. Team members reviewed interview transcripts independently. Data analysis used constant comparative methods. Clinicians interviewed experienced audit and feedback as fragmented and variable in its effectiveness. Moreover, clinicians felt disconnected from the process. The audit process was perceived as being insufficiently transparent. Feedback was often untimely, incomplete and not actionable. Specific groups such as respiratory therapists and night-shift clinicians felt marginalised. Suggestions for improvement included improving information sharing about the rationale for change and the audit process, tools and metrics; implementing peer-to-peer quality discussions to avoid a top-down approach (eg, incorporating feedback into discussions at daily rounds); providing effective feedback which contains specific, transparent and actionable information; delivering timely feedback (ie, balancing feedback proximate to events with trends over time) and increasing engagement by senior management. ICU clinicians experience audit and feedback as fragmented communication with feedback being especially problematic. Attention to improving communication, integration of the process into daily clinical activities and making feedback timely, specific and actionable may increase the effectiveness of audit and feedback to affect desired change. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Common mode frequency instability in internally phase-locked terahertz quantum cascade lasers.

PubMed

Wanke, M C; Grine, A D; Fuller, C T; Nordquist, C D; Cich, M J; Reno, J L; Lee, Mark

2011-11-21

Feedback from a diode mixer integrated into a 2.8 THz quantum cascade laser (QCL) was used to phase lock the difference frequencies (DFs) among the Fabry-Perot (F-P) longitudinal modes of a QCL. Approximately 40% of the DF power was phase locked, consistent with feedback loop bandwidth of 10 kHz and phase noise bandwidth ~0.5 MHz. While the locked DF signal has ≤ 1 Hz linewidth and negligible drift over ~30 min, mixing measurements between two QCLs and between a QCL and molecular gas laser show that the common mode frequency stability is no better than a free-running QCL. © 2011 Optical Society of America

Ocular and visual status among children in special schools in Wales: the burden of unrecognised visual impairment.

PubMed

Woodhouse, J Margaret; Davies, Nathan; McAvinchey, Aideen; Ryan, Barbara

2014-06-01

The high prevalence of visual defects among children with special needs is well reported and guidelines for vision screening are in place. However, recent research has suggested that vision care for such children is neglected. This study set out to evaluate the current status of vision screening and eye care in special schools in Wales. In phase 1, all 44 special schools in Wales received a questionnaire on current vision screening practices. In phase 2, full eye examinations were conducted with 173 pupils of five schools with no screening service; the pupils were aged 2-21 years. In phase 3, feedback about the service was obtained from all schools and from 15 parents whose children took part. In phase 1, vision screening was patchy and inconsistent among the 39 schools responding. In phase 2, there is a high proportion of pupils (42%) reporting no previous eye examination. Overall, 17% of the pupils in the five schools presented with low vision (WHO definition, poorer than 0.3 LogMAR), 50% needed a first-time or updated spectacle prescription and 51% had some ocular abnormality that was either sight-limiting or warranted action to prevent risk to sight. In phase 3, school staff and parents reported that school-based eye examinations were valuable and, for those children with previous experience, likely to be more successful than clinic-based or practice-based examinations for this particular population. There is an urgent need for a school-based optometric service for this vulnerable group of children and young people. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Linear systems with structure group and their feedback invariants

NASA Technical Reports Server (NTRS)

Martin, C.; Hermann, R.

1977-01-01

A general method described by Hermann and Martin (1976) for the study of the feedback invariants of linear systems is considered. It is shown that this method, which makes use of ideas of topology and algebraic geometry, is very useful in the investigation of feedback problems for which the classical methods are not suitable. The transfer function as a curve in the Grassmanian is examined. The general concepts studied in the context of specific systems and applications are organized in terms of the theory of Lie groups and algebraic geometry. Attention is given to linear systems which have a structure group, linear mechanical systems, and feedback invariants. The investigation shows that Lie group techniques are powerful and useful tools for analysis of the feedback structure of linear systems.

An Assessment of Feedback Procedures and Information Provided to Instructors within Computer Managed Learning Environments--Implications for Instruction and Software Redesign.

ERIC Educational Resources Information Center

Kotesky, Arturo A.

Feedback procedures and information provided to instructors within computer managed learning environments were assessed to determine current usefulness and meaningfulness to users, and to present the design of a different instructor feedback instrument. Kaufman's system model was applied to accomplish the needs assessment phase of the study; and…

Providing time-discrete gait information by wearable feedback apparatus for lower-limb amputees: usability and functional validation.

PubMed

Crea, Simona; Cipriani, Christian; Donati, Marco; Carrozza, Maria Chiara; Vitiello, Nicola

2015-03-01

Here we describe a novel wearable feedback apparatus for lower-limb amputees. The system is based on three modules: a pressure-sensitive insole for the measurement of the plantar pressure distribution under the prosthetic foot during gait, a computing unit for data processing and gait segmentation, and a set of vibrating elements placed on the thigh skin. The feedback strategy relies on the detection of specific gait-phase transitions of the amputated leg. Vibrating elements are activated in a time-discrete manner, simultaneously with the occurrence of the detected gait-phase transitions. Usability and effectiveness of the apparatus were successfully assessed through an experimental validation involving ten healthy volunteers.

The Role of the Interplay between Stimulus Type and Timing in Explaining BCI-Illiteracy for Visual P300-Based Brain-Computer Interfaces

PubMed Central

Carabalona, Roberta

2017-01-01

Visual P300-based Brain-Computer Interface (BCI) spellers enable communication or interaction with the environment by flashing elements in a matrix and exploiting consequent changes in end-user's brain activity. Despite research efforts, performance variability and BCI-illiteracy still are critical issues for real world applications. Moreover, there is a quite unaddressed kind of BCI-illiteracy, which becomes apparent when the same end-user operates BCI-spellers intended for different applications: our aim is to understand why some well performers can become BCI-illiterate depending on speller type. We manipulated stimulus type (factor STIM: either characters or icons), color (factor COLOR: white, green) and timing (factor SPEED: fast, slow). Each BCI session consisted of training (without feedback) and performance phase (with feedback), both in copy-spelling. For fast flashing spellers, we observed a performance worsening for white icon-speller. Our findings are consistent with existing results reported on end-users using identical white×fast spellers, indicating independence of worsening trend from users' group. The use of slow stimulation timing shed a new light on the perceptual and cognitive phenomena related to the use of a BCI-speller during both the training and the performance phase. We found a significant STIM main effect for the N1 component on Pz and PO7 during the training phase and on PO8 during the performance phase, whereas in both phases neither the STIM×COLOR interaction nor the COLOR main effect was statistically significant. After collapsing data for factor COLOR, it emerged a statistically significant modulation of N1 amplitude depending to the phase of BCI session: N1 was more negative for icons than for characters both on Pz and PO7 (training), whereas the opposite modulation was observed for PO8 (performance). Results indicate that both feedback and expertise with respect to the stimulus type can modulate the N1 component and that icons require more perceptual analysis. Therefore, fast flashing is likely to be more detrimental for end-users' performance in case of icon-spellers. In conclusion, the interplay between stimulus type and timing seems relevant for a satisfactory and efficient end-user's BCI-experience. PMID:28713233

The Role of the Interplay between Stimulus Type and Timing in Explaining BCI-Illiteracy for Visual P300-Based Brain-Computer Interfaces.

PubMed

Carabalona, Roberta

2017-01-01

Visual P300-based Brain-Computer Interface (BCI) spellers enable communication or interaction with the environment by flashing elements in a matrix and exploiting consequent changes in end-user's brain activity. Despite research efforts, performance variability and BCI-illiteracy still are critical issues for real world applications. Moreover, there is a quite unaddressed kind of BCI-illiteracy, which becomes apparent when the same end-user operates BCI-spellers intended for different applications: our aim is to understand why some well performers can become BCI-illiterate depending on speller type. We manipulated stimulus type (factor STIM: either characters or icons), color (factor COLOR: white, green) and timing (factor SPEED: fast, slow). Each BCI session consisted of training (without feedback) and performance phase (with feedback), both in copy-spelling. For fast flashing spellers, we observed a performance worsening for white icon-speller. Our findings are consistent with existing results reported on end-users using identical white×fast spellers, indicating independence of worsening trend from users' group. The use of slow stimulation timing shed a new light on the perceptual and cognitive phenomena related to the use of a BCI-speller during both the training and the performance phase. We found a significant STIM main effect for the N1 component on P z and PO 7 during the training phase and on PO 8 during the performance phase, whereas in both phases neither the STIM×COLOR interaction nor the COLOR main effect was statistically significant. After collapsing data for factor COLOR, it emerged a statistically significant modulation of N1 amplitude depending to the phase of BCI session: N1 was more negative for icons than for characters both on P z and PO 7 (training), whereas the opposite modulation was observed for PO 8 (performance). Results indicate that both feedback and expertise with respect to the stimulus type can modulate the N1 component and that icons require more perceptual analysis. Therefore, fast flashing is likely to be more detrimental for end-users' performance in case of icon-spellers. In conclusion, the interplay between stimulus type and timing seems relevant for a satisfactory and efficient end-user's BCI-experience.

The importance of expert feedback during endovascular simulator training.

PubMed

Boyle, Emily; O'Keeffe, Dara A; Naughton, Peter A; Hill, Arnold D K; McDonnell, Ciaran O; Moneley, Daragh

2011-07-01

Complex endovascular skills are difficult to obtain in the clinical environment. Virtual reality (VR) simulator training is a valuable addition to current training curricula, but is there a benefit in the absence of expert trainers? Eighteen endovascular novices performed a renal artery angioplasty/stenting (RAS) on the Vascular Interventional Surgical Trainer simulator. They were randomized into three groups: Group A (n = 6, control), no performance feedback; Group B (n = 6, nonexpert feedback), feedback after every procedure from a nonexpert facilitator; and Group C (n = 6, expert feedback), feedback after every procedure from a consultant vascular surgeon. Each trainee completed RAS six times. Simulator-measured performance metrics included procedural and fluoroscopy time, contrast volume, accuracy of balloon placement, and handling errors. Clinical errors were also measured by blinded video assessment. Data were analyzed using SPSS version 15. A clear learning curve was observed across the six trials. There were no significant differences between the three groups for the general performance metrics, but Group C made fewer errors than Groups A (P = .009) or B (P = .004). Video-based error assessment showed that Groups B and C performed better than Group A (P = .002 and P = .000, respectively). VR simulator training for novices can significantly improve general performance in the absence of expert trainers. Procedure-specific qualitative metrics are improved with expert feedback, but nonexpert facilitators can also enhance the quality of training and may represent a valuable alternative to expert clinical faculty. Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

The effect of force feedback on student reasoning about gravity, mass, force and motion

NASA Astrophysics Data System (ADS)

Bussell, Linda

The purpose of this study was to examine whether force feedback within a computer simulation had an effect on reasoning by fifth grade students about gravity, mass, force, and motion, concepts which can be difficult for learners to grasp. Few studies have been done on cognitive learning and haptic feedback, particularly with young learners, but there is an extensive base of literature on children's conceptions of science and a number of studies focus specifically on children's conceptions of force and motion. This case study used a computer-based paddleball simulation with guided inquiry as the primary stimulus. Within the simulation, the learner could adjust the mass of the ball and the gravitational force. The experimental group used the simulation with visual and force feedback; the control group used the simulation with visual feedback but without force feedback. The proposition was that there would be differences in reasoning between the experimental and control groups, with force feedback being helpful with concepts that are more obvious when felt. Participants were 34 fifth-grade students from three schools. Students completed a modal (visual, auditory, and haptic) learning preference assessment and a pretest. The sessions, including participant experimentation and interviews, were audio recorded and observed. The interviews were followed by a written posttest. These data were analyzed to determine whether there were differences based on treatment, learning style, demographics, prior gaming experience, force feedback experience, or prior knowledge. Work with the simulation, regardless of group, was found to increase students' understanding of key concepts. The experimental group appeared to benefit from the supplementary help that force feedback provided. Those in the experimental group scored higher on the posttest than those in the control group. The greatest difference between mean group scores was on a question concerning the effects of increased gravitational force.

Biophysical network modeling of the dLGN circuit: Effects of cortical feedback on spatial response properties of relay cells

PubMed Central

Martínez-Cañada, Pablo; Halnes, Geir; Fyhn, Marianne

2018-01-01

Despite half-a-century of research since the seminal work of Hubel and Wiesel, the role of the dorsal lateral geniculate nucleus (dLGN) in shaping the visual signals is not properly understood. Placed on route from retina to primary visual cortex in the early visual pathway, a striking feature of the dLGN circuit is that both the relay cells (RCs) and interneurons (INs) not only receive feedforward input from retinal ganglion cells, but also a prominent feedback from cells in layer 6 of visual cortex. This feedback has been proposed to affect synchronicity and other temporal properties of the RC firing. It has also been seen to affect spatial properties such as the center-surround antagonism of thalamic receptive fields, i.e., the suppression of the response to very large stimuli compared to smaller, more optimal stimuli. Here we explore the spatial effects of cortical feedback on the RC response by means of a a comprehensive network model with biophysically detailed, single-compartment and multicompartment neuron models of RCs, INs and a population of orientation-selective layer 6 simple cells, consisting of pyramidal cells (PY). We have considered two different arrangements of synaptic feedback from the ON and OFF zones in the visual cortex to the dLGN: phase-reversed (‘push-pull’) and phase-matched (‘push-push’), as well as different spatial extents of the corticothalamic projection pattern. Our simulation results support that a phase-reversed arrangement provides a more effective way for cortical feedback to provide the increased center-surround antagonism seen in experiments both for flashing spots and, even more prominently, for patch gratings. This implies that ON-center RCs receive direct excitation from OFF-dominated cortical cells and indirect inhibitory feedback from ON-dominated cortical cells. The increased center-surround antagonism in the model is accompanied by spatial focusing, i.e., the maximum RC response occurs for smaller stimuli when feedback is present. PMID:29377888

Responses to false physiological feedback in individuals with panic attacks and elevated anxiety sensitivity.

PubMed

Story, Tyler J; Craske, Michelle G

2008-09-01

Participants with elevated anxiety sensitivity and a history of panic attacks were compared to a low anxiety comparison group with respect to physiological and subjective reactivity to false heart-rate feedback and reactivity to a priming procedure. Whereas accurate heart-rate feedback elicited minimal responses, participants across groups showed significant physiological and subjective responses to false feedback. High risk and low risk participants did not differ in heart-rate responses to false feedback, though panic attack frequency did predict physiological and subjective reactions to false feedback in the high risk group. Self-reported nonspecific anxiety was significantly higher in high risk female participants than in low risk female participants, while males did not different in general subjective anxiety. However, high risk participants reported more panic-specific symptoms during the false feedback task than low risk participants, regardless of the sex of the participant. Therefore, although the experimental paradigm appeared to trigger nonspecific anxiety in high risk female participants, panic attack symptoms in reaction to the task were specific to risk group, not sex, and consistent with hypotheses. Surprisingly, the priming procedure did not influence physiological or subjective responses to false feedback in either group. These results raise additional questions regarding the process and impact of interception in individuals with panic attacks, and suggest that false perception of internal changes may contribute to risk for panic disorder when exposed to believable cues.

Electrocardiographic anxiety profiles improve speech anxiety.

PubMed

Kim, Pyoung Won; Kim, Seung Ae; Jung, Keun-Hwa

2012-12-01

The present study was to set out in efforts to determine the effect of electrocardiographic (ECG) feedback on the performance in speech anxiety. Forty-six high school students participated in a speech performance educational program. They were randomly divided into two groups, an experimental group with ECG feedback (N = 21) and a control group (N = 25). Feedback was given with video recording in the control, whereas in the experimental group, an additional ECG feedback was provided. Speech performance was evaluated by the Korean Broadcasting System (KBS) speech ability test, which determines the 10 different speaking categories. ECG was recorded during rest and speech, together with a video recording of the speech performance. Changes in R-R intervals were used to reflect anxiety profiles. Three trials were performed for 3-week program. Results showed that the subjects with ECG feedback revealed a significant improvement in speech performance and anxiety states, which compared to those in the control group. These findings suggest that visualization of the anxiety profile feedback with ECG can be a better cognitive therapeutic strategy in speech anxiety.

A target sample of adolescents and reward processing: same neural and behavioral correlates engaged in common paradigms?

PubMed

Nees, Frauke; Vollstädt-Klein, Sabine; Fauth-Bühler, Mira; Steiner, Sabina; Mann, Karl; Poustka, Luise; Banaschewski, Tobias; Büchel, Christian; Conrod, Patricia J; Garavan, Hugh; Heinz, Andreas; Ittermann, Bernd; Artiges, Eric; Paus, Tomas; Pausova, Zdenka; Rietschel, Marcella; Smolka, Michael N; Struve, Maren; Loth, Eva; Schumann, Gunter; Flor, Herta

2012-11-01

Adolescence is a transition period that is assumed to be characterized by increased sensitivity to reward. While there is growing research on reward processing in adolescents, investigations into the engagement of brain regions under different reward-related conditions in one sample of healthy adolescents, especially in a target age group, are missing. We aimed to identify brain regions preferentially activated in a reaction time task (monetary incentive delay (MID) task) and a simple guessing task (SGT) in a sample of 14-year-old adolescents (N = 54) using two commonly used reward paradigms. Functional magnetic resonance imaging was employed during the MID with big versus small versus no win conditions and the SGT with big versus small win and big versus small loss conditions. Analyses focused on changes in blood oxygen level-dependent contrasts during reward and punishment processing in anticipation and feedback phases. We found clear magnitude-sensitive response in reward-related brain regions such as the ventral striatum during anticipation in the MID task, but not in the SGT. This was also true for reaction times. The feedback phase showed clear reward-related, but magnitude-independent, response patterns, for example in the anterior cingulate cortex, in both tasks. Our findings highlight neural and behavioral response patterns engaged in two different reward paradigms in one sample of 14-year-old healthy adolescents and might be important for reference in future studies investigating reward and punishment processing in a target age group.

Shaping with Visual Feedback and Token Reinforcement: Effects on Voice Volume Changes in Mentally Retarded Adults.

ERIC Educational Resources Information Center

Bieber, Carrie; Gurski, John C.

In an attempt to confirm earlier results with a group of mentally retarded females, 12 mentally retarded institutionalized adults (8 male, 4 female) were trained to either reduce (Loud group) or increase (Soft group) their voice volumes with a combination of visual feedback and token reinforcement. The feedback unit provided a binary light on-off…

Use of Accelerometer-Based Feedback of Walking Activity for Appraising Progress With Walking-Related Goals in Inpatient Stroke Rehabilitation: A Randomized Controlled Trial.

PubMed

Mansfield, Avril; Wong, Jennifer S; Bryce, Jessica; Brunton, Karen; Inness, Elizabeth L; Knorr, Svetlana; Jones, Simon; Taati, Babak; McIlroy, William E

2015-10-01

Regaining independent ambulation is important to those with stroke. Increased walking practice during "down time" in rehabilitation could improve walking function for individuals with stroke. To determine the effect of providing physiotherapists with accelerometer-based feedback on patient activity and walking-related goals during inpatient stroke rehabilitation. Participants with stroke wore accelerometers around both ankles every weekday during inpatient rehabilitation. Participants were randomly assigned to receive daily feedback about walking activity via their physiotherapists (n = 29) or to receive no feedback (n = 28). Changes in measures of daily walking (walking time, number of steps, average cadence, longest bout duration, and number of "long" walking bouts) and changes in gait control and function assessed in-laboratory were compared between groups. There was no significant increase in walking time, number of steps, longest bout duration, or number of long walking bouts for the feedback group compared with the control group (P values > .20). However, individuals who received feedback significantly increased cadence of daily walking more than the control group (P = .013). From the in-laboratory gait assessment, individuals who received feedback had a greater increase in walking speed and decrease in step time variability than the control group (P values < .030). Feedback did not increase the amount of walking completed by individuals with stroke. However, there was a significant increase in cadence, indicating that intensity of daily walking was greater for those who received feedback than the control group. Additionally, more intense daily walking activity appeared to translate to greater improvements in walking speed. © The Author(s) 2015.

Participative versus assigned production standard setting in a repetitive industrial task: a strategy for improving worker productivity.

PubMed

Das, B; Shikdar, A A

1999-01-01

The participative standard with feedback condition was superior to the assigned difficult (140% of normal) standard with feedback condition in terms of worker productivity. The percentage increase in worker productivity with the participative standard and feedback condition was 46%, whereas the increase in the assigned difficult standard with feedback was 23%, compared to the control group (no standard, no feedback). Worker productivity also improved significantly as a result of assigning a normal (100%) production standard with feedback, compared to the control group, and the increase was 12%. The participative standard with feedback condition emerges as the optimum strategy for improving worker productivity in a repetitive industrial production task.

The effect of learning on feedback-related potentials in adolescents with dyslexia: an EEG-ERP study.

PubMed

Kraus, Dror; Horowitz-Kraus, Tzipi

2014-01-01

Individuals with dyslexia exhibit associated learning deficits and impaired executive functions. The Wisconsin Card Sorting Test (WCST) is a learning-based task that relies heavily on executive functioning, in particular, attention shift and working memory. Performance during early and late phases of a series within the task represents learning and implementation of a newly learned rule. Here, we aimed to examine two event-related potentials associated with learning, feedback-related negativity (FRN)-P300 complex, in individuals with dyslexia performing the WCST. Adolescents with dyslexia and age-matched typical readers performed the Madrid card sorting test (MCST), a computerized version of the WCST. Task performance, reading measures, and cognitive measures were collected. FRN and the P300 complex were acquired using the event-related potentials methodology and were compared in early vs late errors within a series. While performing the MCST, both groups showed a significant reduction in average reaction times and a trend toward decreased error rates. Typical readers performed consistently better than individuals with dyslexia. FRN amplitudes in early phases were significantly smaller in dyslexic readers, but were essentially equivalent to typical readers in the late phase. P300 amplitudes were initially smaller among readers with dyslexia and tended to decrease further in late phases. Differences in FRN amplitudes for early vs late phases were positively correlated with those of P300 amplitudes in the entire sample. Individuals with dyslexia demonstrate a behavioral and electrophysiological change within single series of the MCST. However, learning patterns seem to differ between individuals with dyslexia and typical readers. We attribute these differences to the lower baseline performance of individuals with dyslexia. We suggest that these changes represent a fast compensatory mechanism, demonstrating the importance of learning strategies on reading among individuals with dyslexia.

On the Representation of Cloud Phase in Global Climate Models, and its Importance for Simulations of Climate Forcings and Feedbacks

NASA Astrophysics Data System (ADS)

Storelvmo, Trude; Sagoo, Navjit; Tan, Ivy

2016-04-01

Despite the growing effort in improving the cloud microphysical schemes in GCMs, most of this effort has not focused on improving the ability of GCMs to accurately simulate phase partitioning in mixed-phase clouds. Getting the relative proportion of liquid droplets and ice crystals in clouds right in GCMs is critical for the representation of cloud radiative forcings and cloud-climate feedbacks. Here, we first present satellite observations of cloud phase obtained by NASA's CALIOP instrument, and report on robust statistical relationships between cloud phase and several aerosols species that have been demonstrated to act as ice nuclei (IN) in laboratory studies. We then report on results from model intercomparison projects that reveal that GCMs generally underestimate the amount of supercooled liquid in clouds. For a selected GCM (NCAR 's CAM5), we thereafter show that the underestimate can be attributed to two main factors: i) the presence of IN in the mixed-phase temperature range, and ii) the Wegener-Bergeron-Findeisen process, which converts liquid to ice once ice crystals have formed. Finally, we show that adjusting these two processes such that the GCM's cloud phase is in agreement with the observed has a substantial impact on the simulated radiative forcing due to IN perturbations, as well as on the cloud-climate feedbacks and ultimately climate sensitivity simulated by the GCM.

Motivation in vigilance - A test of the goal-setting hypothesis of the effectiveness of knowledge of results.

NASA Technical Reports Server (NTRS)

Warm, J. S.; Riechmann, S. W.; Grasha, A. F.; Seibel, B.

1973-01-01

This study tested the prediction, derived from the goal-setting hypothesis, that the facilitating effects of knowledge of results (KR) in a simple vigilance task should be related directly to the level of the performance standard used to regulate KR. Two groups of Ss received dichotomous KR in terms of whether Ss response times (RTs) to signal detections exceeded a high or low standard of performance. The aperiodic offset of a visual signal was the critical event for detection. The vigil was divided into a training phase followed by testing, during which KR was withdrawn. Knowledge of results enhanced performance in both phases. However, the two standards used to regulate feedback contributed little to these effects.

Artificial redirection of sensation from prosthetic fingers to the phantom hand map on transradial amputees: vibrotactile versus mechanotactile sensory feedback.

PubMed

Antfolk, Christian; D'Alonzo, Marco; Controzzi, Marco; Lundborg, Göran; Rosén, Birgitta; Sebelius, Fredrik; Cipriani, Christian

2013-01-01

This work assesses the ability of transradial amputees to discriminate multi-site tactile stimuli in sensory discrimination tasks. It compares different sensory feedback modalities using an artificial hand prosthesis in: 1) a modality matched paradigm where pressure recorded on the five fingertips of the hand was fed back as pressure stimulation on five target points on the residual limb; and 2) a modality mismatched paradigm where the pressures were transformed into mechanical vibrations and fed back. Eight transradial amputees took part in the study and were divided in two groups based on the integrity of their phantom map; group A had a complete phantom map on the residual limb whereas group B had an incomplete or nonexisting map. The ability in localizing stimuli was compared with that of 10 healthy subjects using the vibration feedback and 11 healthy subjects using the pressure feedback (in a previous study), on their forearms, in similar experiments. Results demonstrate that pressure stimulation surpassed vibrotactile stimulation in multi-site sensory feedback discrimination. Furthermore, we demonstrate that subjects with a detailed phantom map had the best discrimination performance and even surpassed healthy participants for both feedback paradigms whereas group B had the worst performance overall. Finally, we show that placement of feedback devices on a complete phantom map improves multi-site sensory feedback discrimination, independently of the feedback modality.

Learning feedback and feedforward control in a mirror-reversed visual environment.

PubMed

Kasuga, Shoko; Telgen, Sebastian; Ushiba, Junichi; Nozaki, Daichi; Diedrichsen, Jörn

2015-10-01

When we learn a novel task, the motor system needs to acquire both feedforward and feedback control. Currently, little is known about how the learning of these two mechanisms relate to each other. In the present study, we tested whether feedforward and feedback control need to be learned separately, or whether they are learned as common mechanism when a new control policy is acquired. Participants were trained to reach to two lateral and one central target in an environment with mirror (left-right)-reversed visual feedback. One group was allowed to make online movement corrections, whereas the other group only received visual information after the end of the movement. Learning of feedforward control was assessed by measuring the accuracy of the initial movement direction to lateral targets. Feedback control was measured in the responses to sudden visual perturbations of the cursor when reaching to the central target. Although feedforward control improved in both groups, it was significantly better when online corrections were not allowed. In contrast, feedback control only adaptively changed in participants who received online feedback and remained unchanged in the group without online corrections. Our findings suggest that when a new control policy is acquired, feedforward and feedback control are learned separately, and that there may be a trade-off in learning between feedback and feedforward controllers. Copyright © 2015 the American Physiological Society.

Learning feedback and feedforward control in a mirror-reversed visual environment

PubMed Central

Kasuga, Shoko; Telgen, Sebastian; Ushiba, Junichi; Nozaki, Daichi

2015-01-01

When we learn a novel task, the motor system needs to acquire both feedforward and feedback control. Currently, little is known about how the learning of these two mechanisms relate to each other. In the present study, we tested whether feedforward and feedback control need to be learned separately, or whether they are learned as common mechanism when a new control policy is acquired. Participants were trained to reach to two lateral and one central target in an environment with mirror (left-right)-reversed visual feedback. One group was allowed to make online movement corrections, whereas the other group only received visual information after the end of the movement. Learning of feedforward control was assessed by measuring the accuracy of the initial movement direction to lateral targets. Feedback control was measured in the responses to sudden visual perturbations of the cursor when reaching to the central target. Although feedforward control improved in both groups, it was significantly better when online corrections were not allowed. In contrast, feedback control only adaptively changed in participants who received online feedback and remained unchanged in the group without online corrections. Our findings suggest that when a new control policy is acquired, feedforward and feedback control are learned separately, and that there may be a trade-off in learning between feedback and feedforward controllers. PMID:26245313

Aerosol-cloud interactions in Arctic mixed-phase stratocumulus

NASA Astrophysics Data System (ADS)

Solomon, A.

2017-12-01

Reliable climate projections require realistic simulations of Arctic cloud feedbacks. Of particular importance is accurately simulating Arctic mixed-phase stratocumuli (AMPS), which are ubiquitous and play an important role in regional climate due to their impact on the surface energy budget and atmospheric boundary layer structure through cloud-driven turbulence, radiative forcing, and precipitation. AMPS are challenging to model due to uncertainties in ice microphysical processes that determine phase partitioning between ice and radiatively important cloud liquid water. Since temperatures in AMPS are too warm for homogenous ice nucleation, ice must form through heterogeneous nucleation. In this presentation we discuss a relatively unexplored source of ice production-recycling of ice nuclei in regions of ice subsaturation. AMPS frequently have ice-subsaturated air near the cloud-driven mixed-layer base where falling ice crystals can sublimate, leaving behind IN. This study provides an idealized framework to understand feedbacks between dynamics and microphysics that maintain phase-partitioning in AMPS. In addition, the results of this study provide insight into the mechanisms and feedbacks that may maintain cloud ice in AMPS even when entrainment of IN at the mixed-layer boundaries is weak.

False feedback and beliefs influence name recall in younger and older adults.

PubMed

Strickland-Hughes, Carla M; West, Robin Lea; Smith, Kimberly A; Ebner, Natalie C

2017-09-01

Feedback is an important self-regulatory process that affects task effort and subsequent performance. Benefits of positive feedback for list recall have been explored in research on goals and feedback, but the effect of negative feedback on memory has rarely been studied. The current research extends knowledge of memory and feedback effects by investigating face-name association memory and by examining the potential mediation of feedback effects, in younger and older adults, through self-evaluative beliefs. Beliefs were assessed before and after name recognition and name recall testing. Repeated presentation of false positive feedback was compared to false negative feedback and a no feedback condition. Results showed that memory self-efficacy declined over time for participants in the negative and no feedback conditions but was sustained for those receiving positive feedback. Furthermore, participants who received negative feedback felt older after testing than before testing. For name recall, the positive feedback group outperformed the negative feedback and no feedback groups combined, with no age interactions. The observed feedback-related effects on memory were fully mediated by changes in memory self-efficacy. These findings advance our understanding of how beliefs are related to feedback in memory and inform future studies examining the importance of self-regulation in memory.

Designing for sustained adoption: A model of developing educational innovations for successful propagation

NASA Astrophysics Data System (ADS)

Khatri, Raina; Henderson, Charles; Cole, Renée; Froyd, Jeffrey E.; Friedrichsen, Debra; Stanford, Courtney

2016-06-01

[This paper is part of the Focused Collection on Preparing and Supporting University Physics Educators.] The physics education research community has produced a wealth of knowledge about effective teaching and learning of college level physics. Based on this knowledge, many research-proven instructional strategies and teaching materials have been developed and are currently available to instructors. Unfortunately, these intensive research and development activities have failed to influence the teaching practices of many physics instructors. This paper describes interim results of a larger study to develop a model of designing materials for successful propagation. The larger study includes three phases, the first two of which are reported here. The goal of the first phase was to characterize typical propagation practices of education developers, using data from a survey of 1284 National Science Foundation (NSF) principal investigators and focus group data from eight disciplinary groups of NSF program directors. The goal of the second phase was to develop an understanding of successful practice by studying three instructional strategies that have been well propagated. The result of the first two phases is a tentative model of designing for successful propagation, which will be further validated in the third phase through purposeful sampling of additional well-propagated instructional strategies along with typical education development projects. We found that interaction with potential adopters was one of the key missing ingredients in typical education development activities. Education developers often develop a polished product before getting feedback, rely on mass-market communication channels for dissemination, and do not plan for supporting adopters during implementation. The tentative model resulting from this study identifies three key propagation activities: interactive development, interactive dissemination, and support of adopters. Interactive development uses significant feedback from potential adopters to develop a strong product suitable for use in many settings. Interactive dissemination uses personal interactions to reach and motivate potential users. Support of adopters is missing from typical propagation practice and is important to reduce the burden of implementation and increases the likelihood of successful adoption.

Exploring the role of quantitative feedback in inhaler technique education: a cluster-randomised, two-arm, parallel-group, repeated-measures study.

PubMed

Toumas-Shehata, Mariam; Price, David; Basheti, Iman Amin; Bosnic-Anticevich, Sinthia

2014-11-13

Feedback is a critical component of any educational intervention. When it comes to feedback associated with inhaler technique education, there is a lack of knowledge on its role or its potential to solve the major issue of poor inhaler technique. This study aims to explore the role of feedback in inhaler technique education and its impact on the inhaler technique of patients over time. A parallel-group, repeated-measures study was conducted in the community pharmacy in which the effectiveness of current best practice inhaler technique education utilising qualitative visual feedback (Group 1) was compared with a combination of qualitative and quantitative visual feedback (Group 2). The impact of these two interventions on inhaler technique maintenance was evaluated. Community pharmacists were randomly allocated to recruit people with asthma who were using a dry powder inhaler. At Visit 1 their inhaler technique was evaluated and education delivered and they were followed up at Visit 2 (1 month later). Both educational interventions resulted in an increase in the proportion of patients with correct inhaler technique: from 4% to 51% in Group 1 and from 6% to 83% in Group 2 (Pearson's Chi-Squared, P=0.03, n=49, and Pearson's Chi-Squared, P=0.01, n=48, respectively). The magnitude of improvement was statistically significantly higher for Group 2 compared with Group 1 (n=97, P=0.02, Pearson's Chi-Square test). The nature of feedback has an impact on the effectiveness of inhaler technique education with regard to correct inhaler technique maintenance over time.

Pre-training evaluation and feedback improved skills retention of basic life support in medical students.

PubMed

Li, Qi; Zhou, Rong-hua; Liu, Jin; Lin, Jing; Ma, Er-Li; Liang, Peng; Shi, Ting-wei; Fang, Li-qun; Xiao, Hong

2013-09-01

Pre-training evaluation and feedback have been shown to improve medical students' skills acquisition of basic life support (BLS) immediately following training. The impact of such training on BLS skills retention is unknown. This study was conducted to investigate effects of pre-training evaluation and feedback on BLS skills retention in medical students. Three hundred and thirty 3rd year medical students were randomized to two groups, the control group (C group) and pre-training evaluation and feedback group (EF group). Each group was subdivided into four subgroups according to the time of retention-test (at 1-, 3-, 6-, 12-month following the initial training). After a 45-min BLS lecture, BLS skills were assessed (pre-training evaluation) in both groups before training. Following this, the C group received 45 min training. 15 min of group feedback corresponding to students' performance in pre-training evaluation was given only in the EF group that was followed by 30 min of BLS training. BLS skills were assessed immediately after training (post-test) and at follow up (retention-test). No skills difference was observed between the two groups in pre-training evaluation. Better skills acquisition was observed in the EF group (85.3 ± 7.3 vs. 68.1 ± 12.2 in C group) at post-test (p<0.001). In all retention-test, better skills retention was observed in each EF subgroup, compared with its paired C subgroup. Pre-training evaluation and feedback improved skills retention in the EF group for 12 months after the initial training, compared with the control group. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

‘Much clearer with pictures’: using community-based participatory research to design and test a Picture Option Grid for underserved patients with breast cancer

PubMed Central

Durand, Marie-Anne; Alam, Shama; Grande, Stuart W; Elwyn, Glyn

2016-01-01

Objective Women of low socioeconomic status (SES) diagnosed with early stage breast cancer experience decision-making, treatment and outcome disparities. Evidence suggests that decision aids can benefit underserved patients, when tailored to their needs. Our aim was to develop and test the usability, acceptability and accessibility of a pictorial encounter decision aid targeted at women of low SES diagnosed with early stage breast cancer. Design Community-based participatory research (CBPR) using think-aloud protocols (phases 1 and 2) and semistructured interviews (phase 3). Setting Underserved community settings (eg, knitting groups, bingo halls, senior centres) and breast clinics. Participants In phase 1, we recruited a convenience sample of clinicians and academics. In phase 2, we targeted women over 40 years of age, of low SES, regardless of breast cancer history, and in phase 3, women of low SES, recently diagnosed with breast cancer. Intervention The pictorial encounter decision aid was derived from an evidence-based table comparing treatment options for breast cancer (http://www.optiongrid.org). Outcome measures We assessed the usability, acceptability and accessibility of the pictorial decision aid prototypes using the think-aloud protocol and semistructured interviews. Results After initial testing of the first prototype with 18 academics and health professionals, new versions were developed and tested with 53 lay individuals in community settings. Usability was high. In response to feedback indicating that the use of cartoon characters was considered insensitive, a picture-only version was developed and tested with 23 lay people in phase 2, and 10 target users in phase 3. Conclusions and relevance Using CBPR methods and iterative user testing cycles improved usability and accessibility, and led to the development of the Picture Option Grid, entirely guided by multiple stakeholder feedback. All women of low SES recently diagnosed with early stage breast cancer found the Picture Option Grid usable, acceptable and accessible. PMID:26839014

SIRRACT: An international randomized clinical trial of activity feedback during inpatient stroke rehabilitation enabled by wireless sensing

PubMed Central

Dorsch, Andrew K.; Thomas, Seth; Xu, Xiaoyu; Kaiser, William; Dobkin, Bruce H.

2014-01-01

Background Walking-related disability is the most frequent reason for inpatient stroke rehabilitation. Task-related practice is a critical component for improving patient outcomes. Objective To test the feasibility of providing quantitative feedback about daily walking performance and motivating greater skills practice via remote sensing. Methods In this phase III randomized, single blind clinical trial, patients participated in conventional therapies while wearing wireless sensors (tri-axial accelerometers) at both ankles. Activity-recognition algorithms calculated the speed, distance, and duration of walking bouts. Three times a week, therapists provided either feedback about performance on a 10-meter walk (speed-only) or walking speed feedback plus a review of walking activity recorded by the sensors (augmented). Primary outcomes at discharge included total daily walking time, derived from the sensors, and a timed 15-meter walk. Results Sixteen rehabilitation centers in 11 countries enrolled 135 participants over 15 months. Sensors recorded more than 1800 days of therapy, 37,000 individual walking bouts, and 2.5 million steps. No significant differences were found between the two feedback groups in daily walking time (15.1±13.1min vs. 16.6±14.3min, p=0.54) or 15-meter walking speed (0.93±0.47m/s vs. 0.91±0.53m/s, p=0.96). Remarkably, 30% of participants decreased their total daily walking time over their rehabilitation stay. Conclusions In this first trial of remote monitoring of inpatient stroke rehabilitation, augmented feedback beyond speed alone did not increase the time spent practicing or improve walking outcomes. Remarkably modest time was spent walking. Wireless sensing, however, allowed clinicians to audit skills practice and provided ground truth regarding changes in clinically important, mobility-related activities. PMID:25261154

Somatosensory cortex functional connectivity abnormalities in autism show opposite trends, depending on direction and spatial scale

PubMed Central

Khan, Sheraz; Michmizos, Konstantinos; Tommerdahl, Mark; Ganesan, Santosh; Kitzbichler, Manfred G.; Zetino, Manuel; Garel, Keri-Lee A.; Herbert, Martha R.; Hämäläinen, Matti S.

2015-01-01

Functional connectivity is abnormal in autism, but the nature of these abnormalities remains elusive. Different studies, mostly using functional magnetic resonance imaging, have found increased, decreased, or even mixed pattern functional connectivity abnormalities in autism, but no unifying framework has emerged to date. We measured functional connectivity in individuals with autism and in controls using magnetoencephalography, which allowed us to resolve both the directionality (feedforward versus feedback) and spatial scale (local or long-range) of functional connectivity. Specifically, we measured the cortical response and functional connectivity during a passive 25-Hz vibrotactile stimulation in the somatosensory cortex of 20 typically developing individuals and 15 individuals with autism, all males and right-handed, aged 8–18, and the mu-rhythm during resting state in a subset of these participants (12 per group, same age range). Two major significant group differences emerged in the response to the vibrotactile stimulus. First, the 50-Hz phase locking component of the cortical response, generated locally in the primary (S1) and secondary (S2) somatosensory cortex, was reduced in the autism group (P < 0.003, corrected). Second, feedforward functional connectivity between S1 and S2 was increased in the autism group (P < 0.004, corrected). During resting state, there was no group difference in the mu-α rhythm. In contrast, the mu-β rhythm, which has been associated with feedback connectivity, was significantly reduced in the autism group (P < 0.04, corrected). Furthermore, the strength of the mu-β was correlated to the relative strength of 50 Hz component of the response to the vibrotactile stimulus (r = 0.78, P < 0.00005), indicating a shared aetiology for these seemingly unrelated abnormalities. These magnetoencephalography-derived measures were correlated with two different behavioural sensory processing scores (P < 0.01 and P < 0.02 for the autism group, P < 0.01 and P < 0.0001 for the typical group), with autism severity (P < 0.03), and with diagnosis (89% accuracy). A biophysically realistic computational model using data driven feedforward and feedback parameters replicated the magnetoencephalography data faithfully. The direct observation of both abnormally increased and abnormally decreased functional connectivity in autism occurring simultaneously in different functional connectivity streams, offers a potential unifying framework for the unexplained discrepancies in current findings. Given that cortical feedback, whether local or long-range, is intrinsically non-linear, while cortical feedforward is generally linear relative to the stimulus, the present results suggest decreased non-linearity alongside an increased veridical component of the cortical response in autism. PMID:25765326

CPR feedback/prompt device improves the quality of hands-only CPR performed in manikin by laypersons following the 2015 AHA guidelines.

PubMed

Liu, Yuanshan; Huang, Zitong; Li, Heng; Zheng, Guanghui; Ling, Qin; Tang, Wanchun; Yang, Zhengfei

2018-03-06

We investigated the effects of a cardiopulmonary resuscitation (CPR) feedback/prompt device on the quality of chest compression (CC) during hands-only CPR following the 2015 AHA guidelines. A total of 124 laypersons were randomly assigned into three groups. The first (n=42) followed the 2010 guidelines, the second (n=42) followed the 2015 guidelines with no feedback/prompt device, the third (n=40) followed the 2015 guidelines with a feedback/prompt device (2015F). Participants underwent manual CPR training and took a written basic life support examination, then required to perform 2min of hands-only CPR monitored by a CPR feedback/prompt device. The quality of CPR was quantified as the percentage of correct CCs (mean CC depth and rate, complete recoil and chest compression fraction (CCF)) per 20s, as recorded by the CPR feedback/prompt device. Significantly higher correct ratios of CC, CC depth, and rate were achieved in the 2010 group in each minute vs the 2015 group. The greater mean CC depth and rate were observed in the 2015F group vs the 2015 group. The correct ratio of CC was significantly higher in the 2015F group vs the 2015 group. CCF was also significantly higher in the 2015F group vs the 2015 group in the last 20s of CPR. It is difficult for a large percentage of laypersons to achieve the targets of CC depth and rate following the 2015 AHA guidelines. CPR feedback/prompt devices significantly improve the quality of hands-only CPR performance by laypersons following the standards of the 2015 AHA guidelines. Copyright © 2017. Published by Elsevier Inc.

Adaptable healing patient room for stroke patients. A staff evaluation.

PubMed

Daemen, E M L; Flinsenberg, I C M; Van Loenen, E J; Cuppen, R P G; Rajae-Joordens, R J E

2014-01-01

This article is part of the focus theme of Methods of Information in Medicine on "Pervasive Intelligent Technologies for Health". This paper addresses the evaluation with hospital staff of an in-patient environment that supports patients, family, nursing staff and medical specialists during the recovery process of neurology patients and especially patients recovering from a stroke. We describe the methods that were used to evaluate the Adaptive Daily Rhythm Atmospheres (ADRA), Artificial Skylight (AS) and Adaptive Stimulus Dosage (ASD) concepts. The goal of this evaluation was to gather qualitative and quantitative feedback from hospital staff about the usefulness, the usability and desirability of the Adaptive Daily Rhythm Atmospheres (ADRA), Artificial Skylight (AS) and Adaptive Stimulus Dosage (ASD) concepts that were implemented as different phases of a novel healing patient room. This paper reports the effects of these concepts with regard to 1) the healing process of the patient and 2) the workflow of the staff. These results are part of a larger R&D project and provide the initial feedback in an iterative user-centered design methodology. After signing informed consents, the group of participants was taken to the laboratory environment where they were introduced to the Adaptive Healing Environment Patient Room and where they could also experience the room. Then, the participants were seated next to the patient bed so they had a similar viewing angle as the patients. The participants received a booklet with questionnaires. The items on this questionnaire addressed the influence on the healing process (i.e., the possible effect the concept/phase has on the healing process of the patient, meaning faster recovery, better sleep and enhanced well-being) and influence on the workflow (i.e., the possible effect of such a concept/phase on the working activities of the staff in the ward). We presented every concept (AS and ASD) and all the phases of ADRA. After every presentation of the concept or phase of the ADRA system the participants rated the concept or phase anonymously on a 7-point Likert scale. In addition to rating the phase in the therefore designed booklets, they were also asked to motivate their ratings in writing. Subsequently, a focus group discussion took place. During the discussion the two note takers wrote down all the comments. Afterwards the quantitative results were analyzed with the non-parametric Kruskal-Wallis test. Significant effects were further analyzed in a post-hoc Mann-Whitney test. The results show that hospital staff expects a positive effect on the healing process of the patient for the Artificial Skylight, the Adaptable Stimulus Dosage concept and the different ADRA phases that provide a clear daily rhythm structure during the day. In fact the staff members from different healthcare institutions and with different professional roles agreed on most aspects. In addition, the staff also expected a positive effect for almost all phases on the efficiency of the clinical workflow, also for the AS and ASD concepts. This is a very promising result as the phases were designed primarily with the healing effect of the patient in mind. The hospital staff evaluation in the laboratory setting gave us an indication of the likely impact of the Adaptive Healing Environment Patient Room on the healing progress of patients. Furthermore, this laboratory evaluation of the concepts was an important step that enabled to improve the shortcomings of the current concept before starting clinical trials. In addition, we generated feedback from different departments from different institutions, which suggest that they all see similar added values for the patient room.

Improving Timely Resident Follow-Up and Communication of Results in Ambulatory Clinics Utilizing a Web-Based Audit and Feedback Module.

PubMed

Boggan, Joel C; Swaminathan, Aparna; Thomas, Samantha; Simel, David L; Zaas, Aimee K; Bae, Jonathan G

2017-04-01

Failure to follow up and communicate test results to patients in outpatient settings may lead to diagnostic and therapeutic delays. Residents are less likely than attending physicians to report results to patients, and may face additional barriers to reporting, given competing clinical responsibilities. This study aimed to improve the rates of communicating test results to patients in resident ambulatory clinics. We performed an internal medicine, residency-wide, pre- and postintervention, quality improvement project using audit and feedback. Residents performed audits of ambulatory patients requiring laboratory or radiologic testing by means of a shared online interface. The intervention consisted of an educational module viewed with initial audits, development of a personalized improvement plan after Phase 1, and repeated real-time feedback of individual relative performance compared at clinic and program levels. Outcomes included results communicated within 14 days and prespecified "significant" results communicated within 72 hours. A total of 76 of 86 eligible residents (88%) reviewed 1713 individual ambulatory patients' charts in Phase 1, and 73 residents (85%) reviewed 1509 charts in Phase 2. Follow-up rates were higher in Phase 2 than Phase 1 for communicating results within 14 days and significant results within 72 hours (85% versus 78%, P  < .001; and 82% versus 70%, P  = .002, respectively). Communication of "significant" results was more likely to occur via telephone, compared with communication of nonsignificant results. Participation in a shared audit and feedback quality improvement project can improve rates of resident follow-up and communication of results, although communication gaps remained.

CEBAF Superconducting Cavity RF Drive System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fugitt, Jock; Moore, Thomas

1987-03-01

The CEBAR RF system consists of 418 individual RF amplifier chains. Each superconducting cavity is phase locked to the master drive reference line to within 1 degree, and the cavity field gradient is regulated to within 1 part in 10 by a state-of-the-art RF control module. Precision, continuously adjustable, modulo 360 phase shifters are used to generate the individual phase references, and a compensated RF detector is used for level feedback. The close coupled digital system enhances system accuracy, provides self-calibration, and continuously checks the system for malfunction. Calibration curves, the operating program, and system history are stored in anmore » on board EEPROM. The RF power is generated by a 5Kw, water cooled, permanent magnet focused klystorn. The klystons are clustered in groups of 8 and powered from a common supply. RF power is transmitted to the accelerator sections by semiflexible waveguide.« less

Effects of Immediate Instructor Feedback on Group Discussion Participants.

ERIC Educational Resources Information Center

Jurma, William E.; Froelich, Deidre L.

1984-01-01

Investigated the effects of immediate instructor feedback, via a video display system (ComET system), on the performance of group discussion participants. Found that receivers of immediate feedback were more satisfied with their performances, participated in discussions of higher quality, and were no more anxious than individuals not receiving…

Instruction of jump-landing technique using videotape feedback: altering lower extremity motion patterns.

PubMed

Oñate, James A; Guskiewicz, Kevin M; Marshall, Stephen W; Giuliani, Carol; Yu, Bing; Garrett, William E

2005-06-01

Anterior cruciate ligament injury prevention programs have used videotapes of jump-landing technique as a key instructional component to improve landing performance. All videotape feedback model groups will increase knee flexion angles at initial contact and overall knee flexion motion and decrease peak vertical ground reaction forces and peak proximal anterior tibial shear forces to a greater extent than will a nonfeedback group. The secondary hypothesis is that the videotape feedback using the combination of the expert and self models will create the greatest change in each variable. Controlled laboratory study. Knee kinematics and kinetics of college-aged recreational athletes randomly placed in 3 different videotape feedback model groups (expert only, self only, combination of expert and self) and a nonfeedback group were collected while participants performed a basketball jump-landing task on 3 testing occasions. All feedback groups significantly increased knee angular displacement flexion angles [F(6,70) = 8.03, P = .001] and decreased peak vertical ground reaction forces [F(6,78) = 2.68, P = .021] during performance and retention tests. The self and combination groups significantly increased knee angular displacement flexion angles more than the control group did; the expert model group did not change significantly more than the control group did. All feedback groups and the nonfeedback group significantly reduced peak vertical forces across performance and retention tests. There were no statistically significant changes in knee flexion angle at initial ground contact (P = .111) and peak proximal anterior tibial shear forces (P = .509) for both testing sessions for each group. The use of self or combination videotape feedback is most useful for increasing knee angular displacement flexion angles and reducing peak vertical forces during landing. The use of self or combination modeling is more effective than is expert-only modeling for the implementation of instructional programs aimed at reducing the risk of jump-landing anterior cruciate ligament injuries.

Potentiated processing of negative feedback in depression is attenuated by anhedonia

PubMed Central

Mueller, E. M.; Pechtel, P.; Cohen, A.L.; Douglas, S.R.; Pizzagalli, D.A.

2014-01-01

Background Although cognitive theories of depression have postulated enhanced processing of negatively valenced information, previous EEG studies have shown both increased and reduced sensitivity for negative performance feedback in MDD. To reconcile these paradoxical findings, it has been speculated that sensitivity for negative feedback is potentiated in moderate MDD but reduced in highly anhedonic subjects. The goal of this study was to test this hypothesis by analyzing the feedback-related negativity (FRN), frontomedial theta power (FMT), and source-localized anterior midcingulate cortex (aMCC) activity after negative feedback. Methods Fourteen unmedicated participants with MDD and 15 control participants performed a reinforcement learning task while 128-channel EEG was recorded. FRN, FMT and LORETA source-localized aMCC activity after negative and positive feedback were compared between groups. Results The MDD group showed higher FRN amplitudes and aMCC activation to negative feedback than controls. Moreover, aMCC activation to negative feedback was inversely related to self-reported anhedonia. In contrast, self-reported anxiety correlated with feedback-evoked frontomedial theta (FMT) within the depression group. Conclusions The present findings suggest that, among depressed and anxious individuals, enhanced processing of negative feedback occurs relatively early in the information processing stream. These results extend prior work and indicate that although moderate depression is associated with elevated sensitivity for negative feedback, high levels of anhedonia may attenuate this effect. PMID:25620272

Motivation and intelligence drive auditory perceptual learning.

PubMed

Amitay, Sygal; Halliday, Lorna; Taylor, Jenny; Sohoglu, Ediz; Moore, David R

2010-03-23

Although feedback on performance is generally thought to promote perceptual learning, the role and necessity of feedback remain unclear. We investigated the effect of providing varying amounts of positive feedback while listeners attempted to discriminate between three identical tones on learning frequency discrimination. Using this novel procedure, the feedback was meaningless and random in relation to the listeners' responses, but the amount of feedback provided (or lack thereof) affected learning. We found that a group of listeners who received positive feedback on 10% of the trials improved their performance on the task (learned), while other groups provided either with excess (90%) or with no feedback did not learn. Superimposed on these group data, however, individual listeners showed other systematic changes of performance. In particular, those with lower non-verbal IQ who trained in the no feedback condition performed more poorly after training. This pattern of results cannot be accounted for by learning models that ascribe an external teacher role to feedback. We suggest, instead, that feedback is used to monitor performance on the task in relation to its perceived difficulty, and that listeners who learn without the benefit of feedback are adept at self-monitoring of performance, a trait that also supports better performance on non-verbal IQ tests. These results show that 'perceptual' learning is strongly influenced by top-down processes of motivation and intelligence.

The effect of performance feedback on drivers' hazard perception ability and self-ratings.

PubMed

Horswill, Mark S; Garth, Megan; Hill, Andrew; Watson, Marcus O

2017-04-01

Drivers' hazard perception ability has been found to predict crash risk, and novice drivers appear to be particularly poor at this skill. This competency appears to develop only slowly with experience, and this could partially be a result of poor quality performance feedback. We report an experiment in which we provided high-quality artificial feedback on individual drivers' performance in a validated video-based hazard perception test via either: (1) a graph-based comparison of hazard perception response times between the test-taker, the average driver, and an expert driver; (2) a video-based comparison between the same groups; or (3) both. All three types of feedback resulted in both an improvement in hazard perception performance and a reduction in self-rated hazard perception skill, compared with a no-feedback control group. Video-based and graph-based feedback combined resulted in a greater improvement in hazard perception performance than either of the individual components, which did not differ from one another. All three types of feedback eliminated participants' self-enhancement bias for hazard perception skill. Participants judged both interventions involving video feedback to be significantly more likely to improve their real-world driving than the no feedback control group. While all three forms of feedback had some value, the combined video and graph feedback intervention appeared to be the most effective across all outcome measures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microwave oscillator with reduced phase noise by negative feedback incorporating microwave signals with suppressed carrier

NASA Technical Reports Server (NTRS)

Dick, G. J.; Saunders, J.

1989-01-01

Oscillator configurations which reduce the effect of 1/f noise sources for both direct feedback and stabilized local oscillator (STALO) circuits are developed and analyzed. By appropriate use of carrier suppression, a small signal is generated which suffers no loss of loop phase information or signal-to-noise ratio. This small signal can be amplified without degradation by multiplicative amplifier noise, and can be detected without saturation of the detector. Together with recent advances in microwave resonator Qs, these circuit improvements will make possible lower phase noise than can be presently achieved without the use of cryogenic devices.

Smartwatch feedback device for high-quality chest compressions by a single rescuer during infant cardiac arrest: a randomized, controlled simulation study.

PubMed

Lee, Juncheol; Song, Yeongtak; Oh, Jaehoon; Chee, Youngjoon; Ahn, Chiwon; Shin, Hyungoo; Kang, Hyunggoo; Lim, Tae Ho

2018-02-12

According to the guidelines, rescuers should provide chest compressions (CC) ∼1.5 inches (40 mm) for infants. Feedback devices could help rescuers perform CC with adequate rates (CCR) and depths (CCD). However, there is no CC feedback device for infant cardiopulmonary resuscitation (CPR). We suggest a smartwatch-based CC feedback application for infant CPR. We created a smartwatch-based CC feedback application. This application provides feedback on CCD and CCR by colour and text for infant CPR. To evaluate the application, 30 participants were divided randomly into two groups on the basis of whether CC was performed with or without the assistance of the smartwatch application. Both groups performed continuous CC-only CPR for 2 min on an infant mannequin placed on a firm table. We collected CC parameters from the mannequin, including the proportion of correct depth, CCR, CCD and the proportion of correct decompression depth. Demographics between the two groups were not significantly different. The median (interquartile range) proportion of correct depth was 99 (97-100) with feedback compared with 83 (58-97) without feedback (P=0.002). The CCR and proportion of correct decompression depth were not significantly different between the two groups (P=0.482 and 0.089). The CCD of the feedback group was significantly deeper than that of the control group [feedback vs. 41.2 (39.8-41.7) mm vs. 38.6 (36.1-39.6) mm; P=0.004]. Rescuers who receive feedback of CC parameters from a smartwatch could perform adequate CC during infant CPR.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0/.

Confidential conversations between supervisor and employee as a means for improving leadership: a quasi-experimental study in hospital wards.

PubMed

Kivimäki, M

1996-11-01

Although yearly confidential conversations between a supervisor and an employee have been recommended as a means for improving leadership, evidence on the actual effects of these conversations has been lacking. The present study therefore investigated whether confidential conversations improve perceptions of goal clarity, sufficiency of feedback and innovativeness, and elicit satisfaction with the supervisor's leadership style within the hospital setting. Nine wards were divided into one experimental group (3 wards) and two control groups (3 + 3 wards). A questionnaire on goal clarity, feedback, innovativeness and satisfaction was administered twice to every group (1st measurement: r = 186, 2nd measurement: n = 163). The experimental group began confidential conversations after the first measurement, control group 1 entered into conversations during both measurements, and control group 2 did not enter into conversations at the time of either measurement. Confidential conversations improved perceived feedback. In both measurements, the sufficiency of feedback was reported to be significantly better in the groups having conversations than in the other groups. In addition, there was a significant positive change in the perceived sufficiency of feedback in the experimental group but not in the other groups. Confidential conversations did not affect the perceptions of goal clarity and innovativeness or elicit satisfaction with the supervisor's management style.

Details and acceptability of a nutrition intervention programme designed to improve the contents of children's packed lunches.

PubMed

Cleghorn, Christine L; Evans, Charlotte El; Kitchen, Meaghan S; Cade, Janet E

2010-08-01

To describe the 'Smart Lunch Box' intervention and provide details on feedback from the participants on the acceptability and usability of the intervention materials. A cluster randomised controlled trial, randomised by school. English schools were stratified on percentage free-school-meals eligibility and attainment at Key Stage 2. A 'Smart Lunch Box' with supporting materials and activities on healthy eating was delivered to parents and children via schools in the intervention group. Feedback forms containing information on a total of fifteen intervention items were filled out by the parents and/or children participating in the intervention and were collected after each of the three phases of the intervention. Eighty-nine primary schools in England, Scotland, Wales and Northern Ireland, randomly selected; forty-four schools in the intervention arm. A total of 1294 children, aged 9-10 years, took part in the trial. Of the 604 children in the intervention arm, 343 provided feedback after at least one of the three phases. A median of twelve items out of a total of fifteen were used by responders. The two intervention items most likely to be used were the individual food boxes and the cooler bags. Whether a participant liked an item significantly affected whether they used it for all items except the cooler bag, fruity face and individual food boxes. Practical intervention items aimed at parents are likely to be used in the longer term and therefore may be appropriate for use in an intervention strategy to improve packed lunches.

Regimes of external optical feedback in 5.6 μm distributed feedback mid-infrared quantum cascade lasers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jumpertz, L., E-mail: louise.jumpertz@telecom-paristech.fr; Alcatel Thales III-V Lab, Campus de Polytechnique, 1 avenue Augustin Fresnel, 91767 Palaiseau; Carras, M.

2014-09-29

External optical feedback is studied experimentally in mid-infrared quantum cascade lasers. These structures exhibit a dynamical response close to that observed in interband lasers, with threshold reduction and optical power enhancement when increasing the feedback ratio. The study of the optical spectrum proves that the laser undergoes five distinct regimes depending on the phase and amplitude of the reinjected field. These regimes are mapped in the plane of external cavity length and feedback strength, revealing unstable behavior only for a very narrow range of operation, making quantum cascade lasers much more stable than their interband counterparts.

Environmental initiative prioritization with a Delphi approach: a case study.

PubMed

Gokhale, A A

2001-08-01

India is fast finding its place in the industrialized world and that is beginning to raise its environmental consciousness. The Delphi technique was used to prioritize specific needs and articulate a sustainable urban improvement strategy for the city of Mumbai (formerly Bombay). The Delphi technique is a means of achieving consensual validity among raters by providing them feedback regarding other raters' responses. Mumbai has several indigenous environmental groups that were tapped for activists and leaders; the study was conducted using ten environmentalists. In the initial phases the responses resulted in a range of possible program alternatives. The last two stages helped to seek out information that generated a consensus on the part of the respondent group. Statistical analysis methods included a hierarchical cluster analysis, mean, median, mode, and percent of agreement calculations using SPSS software. The face-to-face discussion in phase 4 clarified some issues and helped the group as a whole to outline the strategy for putting in place the essential elements of a framework to improve the quality of life in an urban environment.

Effects of video-feedback on the communication, clinical competence and motivational interviewing skills of practice nurses: a pre-test posttest control group study.

PubMed

Noordman, Janneke; van der Weijden, Trudy; van Dulmen, Sandra

2014-10-01

To examine the effects of individual video-feedback on the generic communication skills, clinical competence (i.e. adherence to practice guidelines) and motivational interviewing skills of experienced practice nurses working in primary care. Continuing professional education may be necessary to refresh and reflect on the communication and motivational interviewing skills of experienced primary care practice nurses. A video-feedback method was designed to improve these skills. Pre-test/posttest control group design. Seventeen Dutch practice nurses and 325 patients participated between June 2010-June 2011. Nurse-patient consultations were videotaped at two moments (T0 and T1), with an interval of 3-6 months. The videotaped consultations were rated using two protocols: the Maastrichtse Anamnese en Advies Scorelijst met globale items (MAAS-global) and the Behaviour Change Counselling Index. Before the recordings, nurses were allocated to a control or video-feedback group. Nurses allocated to the video-feedback group received video-feedback between T0 and T1. Data were analysed using multilevel linear or logistic regression. Nurses who received video-feedback appeared to pay significantly more attention to patients' request for help, their physical examination and gave significantly more understandable information. With respect to motivational interviewing, nurses who received video-feedback appeared to pay more attention to 'agenda setting and permission seeking' during their consultations. Video-feedback is a potentially effective method to improve practice nurses' generic communication skills. Although a single video-feedback session does not seem sufficient to increase all motivational interviewing skills, significant improvement in some specific skills was found. Nurses' clinical competences were not altered after feedback due to already high standards. © 2014 John Wiley & Sons Ltd.

Examining action effects in the execution of a skilled soccer kick by using erroneous feedback.

PubMed

Ford, Paul; Hodges, Nicola J; Williams, A Mark

2007-11-01

The authors examined the role of action effects (i.e., ball trajectory) during the performance of a soccer kick. Participants were 20 expert players who kicked a ball over a height barrier toward a ground-level target. The authors occluded participants' vision of the ball trajectory after foot-to-ball contact. Participants in a 1st group received erroneous feedback from a video that showed a ball-trajectory apex approximately 75 cm lower than that of their actual kick, although the ball's landing position was unaltered. Participants in a 2nd group received correct video feedback of both the ball trajectory and the landing position. The erroneous-feedback group showed a significant bias toward higher ball trajectories than did the correct-feedback group. The authors conclude that performers at high levels of skill use the visual consequences of the action to plan and execute an action.

Next-generation audit and feedback for inpatient quality improvement using electronic health record data: a cluster randomised controlled trial.

PubMed

Patel, Sajan; Rajkomar, Alvin; Harrison, James D; Prasad, Priya A; Valencia, Victoria; Ranji, Sumant R; Mourad, Michelle

2018-03-05

Audit and feedback improves clinical care by highlighting the gap between current and ideal practice. We combined best practices of audit and feedback with continuously generated electronic health record data to improve performance on quality metrics in an inpatient setting. We conducted a cluster randomised control trial comparing intensive audit and feedback with usual audit and feedback from February 2016 to June 2016. The study subjects were internal medicine teams on the teaching service at an urban tertiary care hospital. Teams in the intensive feedback arm received access to a daily-updated team-based data dashboard as well as weekly inperson review of performance data ('STAT rounds'). The usual feedback arm received ongoing twice-monthly emails with graphical depictions of team performance on selected quality metrics. The primary outcome was performance on a composite discharge metric (Discharge Mix Index, 'DMI'). A washout period occurred at the end of the trial (from May through June 2016) during which STAT rounds were removed from the intensive feedback arm. A total of 40 medicine teams participated in the trial. During the intervention period, the primary outcome of completion of the DMI was achieved on 79.3% (426/537) of patients in the intervention group compared with 63.2% (326/516) in the control group (P<0.0001). During the washout period, there was no significant difference in performance between the intensive and usual feedback groups. Intensive audit and feedback using timely data and STAT rounds significantly increased performance on a composite discharge metric compared with usual feedback. With the cessation of STAT rounds, performance between the intensive and usual feedback groups did not differ significantly, highlighting the importance of feedback delivery on effecting change. The trial was registered with ClinicalTrials.gov (NCT02593253). © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Computer-Aided Modeling and Analysis of Power Processing Systems (CAMAPPS). Phase 1: Users handbook

NASA Technical Reports Server (NTRS)

Kim, S.; Lee, J.; Cho, B. H.; Lee, F. C.

1986-01-01

The EASY5 macro component models developed for the spacecraft power system simulation are described. A brief explanation about how to use the macro components with the EASY5 Standard Components to build a specific system is given through an example. The macro components are ordered according to the following functional group: converter power stage models, compensator models, current-feedback models, constant frequency control models, load models, solar array models, and shunt regulator models. Major equations, a circuit model, and a program listing are provided for each macro component.

Proceedings of the Meeting of the Coordinating Group on Modern Control Theory (4th) Held at Rochester, Michigan on 27-28 October 1982. Part 1

DTIC Science & Technology

1982-10-01

and time-to-go (T60) are provided from the Estimation Algorithm. The gimbal angle commands used in the first two phases are applied to the gimbal...lighting techniques are also used to simplify image understanding or to extract additional information about position, range, or shape of objects in the...motion or firing dis- turbances. Since useful muzzle position and rate information is difficult to obtain, conventional feedback techniques 447 cannot

Performance changes in lung nodule detection following perceptual feedback of eye movements

NASA Astrophysics Data System (ADS)

Donovan, T.; Manning, D. J.; Crawford, T.

2008-03-01

In a previously reported study we demonstrated that expert performance can decline following perceptual feedback of eye movements in the relatively simple radiological task of wrist fracture detection. This study was carried out to determine if the same effect could be observed using a more complicated radiological task of identifying lung nodules on chest radiographs. Four groups (n=10 in each group) of observers with different levels of expertise were tested. The groups were naÃve observers, level 1 radiography students, level 2 radiography students and experts. Feedback was presented to the observers in the form of their scan paths and fixations. Half the observers had feedback and half had no perceptual feedback. JAFROC analysis was used to measure observer performance. A repeated measures ANOVA was carried out. There was no significant effect between the pre and post "no feedback" condition. There was a significant difference between the pre and post "feedback" condition with a significant improvement following feedback (F(1,16)=6.6,p = 0.021). Overall the mean percentage improvement was small of 3.3%, with most of the improvement due to the level 1 group where the percentage increase in the figure of merit (FOM) was 8.4% and this was significant (p<0.05). Eye tracking metrics indicate that the expert and naÃve observers were less affected by feedback or a second look whereas there were mixed results between the level 1 and level 2 students possibly reflecting the different search strategies used. Perceptual feedback may be beneficial for those early in their training.

Peer video review and feedback improve performance in basic surgical skills.

PubMed

Vaughn, Carolyn J; Kim, Edward; O'Sullivan, Patricia; Huang, Emily; Lin, Matthew Y C; Wyles, Susannah; Palmer, Barnard J A; Pierce, Jonathan L; Chern, Hueylan

2016-02-01

Incorporation of home-video assessments allows flexibility in feedback but requires faculty time. Peer feedback (PF) may provide additional benefits while avoiding these constraints. Twenty-four surgical interns completed a 12-week skills curriculum with home-video assignments focused on knot tying and suturing. Interns were randomized into 2 groups: PF or faculty feedback (FF). Peers and faculty provided feedback on home videos with checklists, global rating, and comments. Learners' skills were assessed at baseline, during, and at the conclusion of the curriculum. Performance of the 2 groups as rated by experts was compared. FF and PF were compared. Both groups improved from baseline, and the highest rated scores were seen on their home-video assessments. The PF group performed better at the final assessment than the FF group (effect size, .84). When using a checklist, there was no significant difference between scores given by peers and faculty. The PF group performed better at the final assessment, suggesting reviewing and analyzing another's performance may improve one's own performance. With checklists as guidance, peers can serve as raters comparable to faculty. Copyright © 2016 Elsevier Inc. All rights reserved.

Proprioceptive feedback determines visuomotor gain in Drosophila

PubMed Central

Bartussek, Jan; Lehmann, Fritz-Olaf

2016-01-01

Multisensory integration is a prerequisite for effective locomotor control in most animals. Especially, the impressive aerial performance of insects relies on rapid and precise integration of multiple sensory modalities that provide feedback on different time scales. In flies, continuous visual signalling from the compound eyes is fused with phasic proprioceptive feedback to ensure precise neural activation of wing steering muscles (WSM) within narrow temporal phase bands of the stroke cycle. This phase-locked activation relies on mechanoreceptors distributed over wings and gyroscopic halteres. Here we investigate visual steering performance of tethered flying fruit flies with reduced haltere and wing feedback signalling. Using a flight simulator, we evaluated visual object fixation behaviour, optomotor altitude control and saccadic escape reflexes. The behavioural assays show an antagonistic effect of wing and haltere signalling on visuomotor gain during flight. Compared with controls, suppression of haltere feedback attenuates while suppression of wing feedback enhances the animal’s wing steering range. Our results suggest that the generation of motor commands owing to visual perception is dynamically controlled by proprioception. We outline a potential physiological mechanism based on the biomechanical properties of WSM and sensory integration processes at the level of motoneurons. Collectively, the findings contribute to our general understanding how moving animals integrate sensory information with dynamically changing temporal structure. PMID:26909184

ERD-based online brain-machine interfaces (BMI) in the context of neurorehabilitation: optimizing BMI learning and performance.

PubMed

Soekadar, Surjo R; Witkowski, Matthias; Mellinger, Jürgen; Ramos, Ander; Birbaumer, Niels; Cohen, Leonardo G

2011-10-01

Event-related desynchronization (ERD) of sensori-motor rhythms (SMR) can be used for online brain-machine interface (BMI) control, but yields challenges related to the stability of ERD and feedback strategy to optimize BMI learning.Here, we compared two approaches to this challenge in 20 right-handed healthy subjects (HS, five sessions each, S1-S5) and four stroke patients (SP, 15 sessions each, S1-S15). ERD was recorded from a 275-sensor MEG system. During daily training,motor imagery-induced ERD led to visual and proprioceptive feedback delivered through an orthotic device attached to the subjects' hand and fingers. Group A trained with a heterogeneous reference value (RV) for ERD detection with binary feedback and Group B with a homogenous RV and graded feedback (10 HS and 2 SP in each group). HS in Group B showed better BMI performance than Group A (p < 0.001) and improved BMI control from S1 to S5 (p = 0.012) while Group A did not. In spite of the small n, SP in Group B showed a trend for a higher BMI performance (p = 0.06) and learning was significantly better (p < 0.05). Using a homogeneous RV and graded feedback led to improved modulation of ipsilesional activity resulting in superior BMI learning relative to use of a heterogeneous RV and binary feedback.

Feedback on end-of-life care in dementia: the study protocol of the FOLlow-up project.

PubMed

Boogaard, Jannie A; van Soest-Poortvliet, Mirjam C; Anema, Johannes R; Achterberg, Wilco P; Hertogh, Cees M P M; de Vet, Henrica C W; van der Steen, Jenny T

2013-08-07

End-of-life care in dementia in nursing homes is often found to be suboptimal. The Feedback on End-of-Life care in dementia (FOLlow-up) project tests the effectiveness of audit- and feedback to improve the quality of end-of-life care in dementia. Nursing homes systematically invite the family after death of a resident with dementia to provide feedback using the End-of-Life in Dementia (EOLD) - instruments. Two audit- and feedback strategies are designed and tested in a three-armed Randomized Controlled Trial (RCT): a generic feedback strategy using cumulative EOLD-scores of a group of patients and a patient specific feedback strategy using EOLD-scores on a patient level. A total of 18 nursing homes, three groups of six homes matched on size, geographic location, religious affiliation and availability of a palliative care unit were randomly assigned to an intervention group or the control group. The effect on quality of care and quality of dying and the barriers and facilitators of audit- and feedback in the nursing home setting are evaluated using mixed-method analyses. The FOLlow-up project is the first study to assess and compare the effect of two audit- and feedback strategies to improve quality of care and quality of dying in dementia. The results contribute to the development of practice guidelines for nursing homes to monitor and improve care outcomes in the realm of end-of-life care in dementia. The Netherlands National Trial Register (NTR). NTR3942.

Cognitive flexibility: A distinct element of performance impairment due to sleep deprivation.

PubMed

Honn, K A; Hinson, J M; Whitney, P; Van Dongen, H P A

2018-03-14

In around-the-clock operations, reduced alertness due to circadian misalignment and sleep loss causes performance impairment, which can lead to catastrophic errors and accidents. There is mounting evidence that performance on different tasks is differentially affected, but the general principles underlying this differentiation are not well understood. One factor that may be particularly relevant is the degree to which tasks require executive control, that is, control over the initiation, monitoring, and termination of actions in order to achieve goals. A key aspect of this is cognitive flexibility, i.e., the deployment of cognitive control resources to adapt to changes in events. Loss of cognitive flexibility due to sleep deprivation has been attributed to "feedback blunting," meaning that feedback on behavioral outcomes has reduced salience - and that feedback is therefore less effective at driving behavior modification under changing circumstances. The cognitive mechanisms underlying feedback blunting are as yet unknown. Here we present data from an experiment that investigated the effects of sleep deprivation on performance after an unexpected reversal of stimulus-response mappings, requiring cognitive flexibility to maintain good performance. Nineteen healthy young adults completed a 4-day in-laboratory study. Subjects were randomized to either a total sleep deprivation condition (n = 11) or a control condition (n = 8). Athree-phase reversal learning decision task was administered at baseline, and again after 30.5 h of sleep deprivation, or matching well-rested control. The task was based on a go/no go task paradigm, in which stimuli were assigned to either a go (response) set or a no go (no response) set. Each phase of the task included four stimuli (two in the go set and two in the no go set). After each stimulus presentation, subjects could make a response within 750 ms or withhold their response. They were then shown feedback on the accuracy of their response. In phase 1 of the task, subjects were explicitly told which stimuli were assigned to the go and no go sets. In phases 2 and 3, new stimuli were used that were different from those used in phase 1. Subjects were not explicitly told the go/no go mappings and were instead required to use accuracy feedback to learn which stimuli were in the go and nogo sets. Phase 3 continued directly from phase 2 and retained the same stimuli as in phase 2, but there was an unannounced reversal of the stimulus-response mappings. Task results confirmed that sleep deprivation resulted in loss of cognitive flexibility through feedback blunting, and that this effect was not produced solely by (1) general performance impairment because of overwhelming sleep drive; (2) reduced working memory resources available to perform the task; (3) incomplete learning of stimulus-response mappings before the unannounced reversal; or (4) interference with stimulus identification through lapses in vigilant attention. Overall, the results suggest that sleep deprivation causes a fundamental problem with dynamic attentional control. This element of performance impairment due to sleep deprivation appears to be distinct from vigilant attention deficits, and represents a particularly significant challenge for fatigue risk management. Copyright © 2018. Published by Elsevier Ltd.

Effects of generic versus non-generic feedback on motor learning in children.

PubMed

Chiviacowsky, Suzete; Drews, Ricardo

2014-01-01

Non-generic feedback refers to a specific event and implies that performance is malleable, while generic feedback implies that task performance reflects an inherent ability. The present study examined the influences of generic versus non-generic feedback on motor performance and learning in 10-year-old children. In the first experiment, using soccer ball kicking at a target as a task, providing participants with generic feedback resulted in worse performance than providing non-generic feedback, after both groups received negative feedback. The second experiment measured more permanent effects. Results of a retention test, performed one day after practicing a throwing task, showed that participants who received non-generic feedback during practice outperformed the generic feedback group, after receiving a negative feedback statement. The findings demonstrate the importance of the wording of feedback. Even though different positive feedback statements may not have an immediate influence on performance, they can affect performance, and presumably individuals' motivation, when performance is (purportedly) poor. Feedback implying that performance is malleable, rather than due to an inherent ability, seems to have the potential to inoculate learners against setbacks--a situation frequently encountered in the context of motor performance and learning.

Effects of Generic versus Non-Generic Feedback on Motor Learning in Children

PubMed Central

Chiviacowsky, Suzete; Drews, Ricardo

2014-01-01

Non-generic feedback refers to a specific event and implies that performance is malleable, while generic feedback implies that task performance reflects an inherent ability. The present study examined the influences of generic versus non-generic feedback on motor performance and learning in 10-year-old children. In the first experiment, using soccer ball kicking at a target as a task, providing participants with generic feedback resulted in worse performance than providing non-generic feedback, after both groups received negative feedback. The second experiment measured more permanent effects. Results of a retention test, performed one day after practicing a throwing task, showed that participants who received non-generic feedback during practice outperformed the generic feedback group, after receiving a negative feedback statement. The findings demonstrate the importance of the wording of feedback. Even though different positive feedback statements may not have an immediate influence on performance, they can affect performance, and presumably individuals' motivation, when performance is (purportedly) poor. Feedback implying that performance is malleable, rather than due to an inherent ability, seems to have the potential to inoculate learners against setbacks – a situation frequently encountered in the context of motor performance and learning. PMID:24523947

Factors affecting feeling-of-knowing in a medical intelligent tutoring system: the role of immediate feedback as a metacognitive scaffold.

PubMed

El Saadawi, Gilan M; Azevedo, Roger; Castine, Melissa; Payne, Velma; Medvedeva, Olga; Tseytlin, Eugene; Legowski, Elizabeth; Jukic, Drazen; Crowley, Rebecca S

2010-03-01

Previous studies in our laboratory have shown the benefits of immediate feedback on cognitive performance for pathology residents using an intelligent tutoring system (ITS) in pathology. In this study, we examined the effect of immediate feedback on metacognitive performance, and investigated whether other metacognitive scaffolds will support metacognitive gains when immediate feedback is faded. Twenty-three participants were randomized into intervention and control groups. For both groups, periods working with the ITS under varying conditions were alternated with independent computer-based assessments. On day 1, a within-subjects design was used to evaluate the effect of immediate feedback on cognitive and metacognitive performance. On day 2, a between-subjects design was used to compare the use of other metacognitive scaffolds (intervention group) against no metacognitive scaffolds (control group) on cognitive and metacognitive performance, as immediate feedback was faded. Measurements included learning gains (a measure of cognitive performance), as well as several measures of metacognitive performance, including Goodman-Kruskal gamma correlation (G), bias, and discrimination. For the intervention group, we also computed metacognitive measures during tutoring sessions. Results showed that immediate feedback in an intelligent tutoring system had a statistically significant positive effect on learning gains, G and discrimination. Removal of immediate feedback was associated with decreasing metacognitive performance, and this decline was not prevented when students used a version of the tutoring system that provided other metacognitive scaffolds. Results obtained directly from the ITS suggest that other metacognitive scaffolds do have a positive effect on G and discrimination, as immediate feedback is faded. We conclude that immediate feedback had a positive effect on both metacognitive and cognitive gains in a medical tutoring system. Other metacognitive scaffolds were not sufficient to replace immediate feedback in this study. However, results obtained directly from the tutoring system are not consistent with results obtained from assessments. In order to facilitate transfer to real-world tasks, further research will be needed to determine the optimum methods for supporting metacognition as immediate feedback is faded.

Factors Affecting Feeling-of-knowing in a Medical Intelligent Tutoring System – the role of Immediate Feedback as a Metacognitive Scaffold

PubMed Central

El Saadawi, Gilan M.; Azevedo, Roger; Castine, Melissa; Payne, Velma; Medvedeva, Olga; Tseytlin, Eugene; Legowski, Elizabeth; Jukic, Drazen; Crowley, Rebecca S.

2009-01-01

Objective Previous studies in our laboratory have shown the benefits of immediate feedback on cognitive performance for pathology residents using an Intelligent Tutoring System in Pathology. In this study, we examined the effect of immediate feedback on metacognitive performance, and investigated whether other metacognitive scaffolds will support metacognitive gains when immediate feedback is faded. Methods Twenty-three (23) participants were randomized into intervention and control groups. For both groups, periods working with the ITS under varying conditions were alternated with independent computer-based assessments. On day 1, a within-subjects design was used to evaluate the effect of immediate feedback on cognitive and metacognitive performance. On day 2, a between-subjects design was used to compare the use of other metacognitive scaffolds (intervention group) against no metacognitive scaffolds (control group) on cognitive and metacognitive performance, as immediate feedback was faded. Measurements included learning gains (a measure of cognitive performance), as well as several measures of metacognitive performance, including Goodman-Kruskal Gamma correlation (G), Bias, and Discrimination. For the intervention group, we also computed metacognitive measures during tutoring sessions. Results Results showed that immediate feedback in an intelligent tutoring system had a statistically significant positive effect on learning gains, G and discrimination. Removal of immediate feedback was associated with decreasing metacognitive performance, and this decline was not prevented when students used a version of the tutoring system that provided other metacognitive scaffolds. Results obtained directly from the ITS suggest that other metacognitive scaffolds do have a positive effect on G and Discrimination, as immediate feedback is faded. Conclusions Immediate feedback had a positive effect on both metacognitive and cognitive gains in a medical tutoring system. Other metacognitive scaffolds were not sufficient to replace immediate feedback in this study. However, results obtained directly from the tutoring system are not consistent with results obtained from assessments. In order to facilitate transfer to real-world tasks, further research will be needed to determine the optimum methods for supporting metacognition as immediate feedback is faded. PMID:19434508

Adaptive restoration of a partially coherent blurred image using an all-optical feedback interferometer with a liquid-crystal device.

PubMed

Shirai, Tomohiro; Barnes, Thomas H

2002-02-01

A liquid-crystal adaptive optics system using all-optical feedback interferometry is applied to partially coherent imaging through a phase disturbance. A theoretical analysis based on the propagation of the cross-spectral density shows that the blurred image due to the phase disturbance can be restored, in principle, irrespective of the state of coherence of the light illuminating the object. Experimental verification of the theory has been performed for two cases when the object to be imaged is illuminated by spatially coherent light originating from a He-Ne laser and by spatially incoherent white light from a halogen lamp. We observed in both cases that images blurred by the phase disturbance were successfully restored, in agreement with the theory, immediately after the adaptive optics system was activated. The origin of the deviation of the experimental results from the theory, together with the effect of the feedback misalignment inherent in our optical arrangement, is also discussed.

"I Really Need Feedback to Learn:" Students' Perspectives on the Effectiveness of the Differential Feedback Messages

ERIC Educational Resources Information Center

Lipnevich, Anastasiya A.; Smith, Jeffrey K.

2009-01-01

The current study examined students' perceptions of the effects of different forms of instructional feedback on their performance, motivation, and emotion. Forty-nine students attending an eastern US university participated in focus group discussions. The groups explored students' reactions to grades, praise, and computer versus instructor…

Show and Tell: Video Modeling and Instruction Without Feedback Improves Performance but Is Not Sufficient for Retention of a Complex Voice Motor Skill.

PubMed

Look, Clarisse; McCabe, Patricia; Heard, Robert; Madill, Catherine J

2018-02-02

Modeling and instruction are frequent components of both traditional and technology-assisted voice therapy. This study investigated the value of video modeling and instruction in the early acquisition and short-term retention of a complex voice task without external feedback. Thirty participants were randomized to two conditions and trained to produce a vocal siren over 40 trials. One group received a model and verbal instructions, the other group received a model only. Sirens were analyzed for phonation time, vocal intensity, cepstral peak prominence, peak-to-peak time, and root-mean-square error at five time points. The model and instruction group showed significant improvement on more outcome measures than the model-only group. There was an interaction effect for vocal intensity, which showed that instructions facilitated greater improvement when they were first introduced. However, neither group reproduced the model's siren performance across all parameters or retained the skill 1 day later. Providing verbal instruction with a model appears more beneficial than providing a model only in the prepractice phase of acquiring a complex voice skill. Improved performance was observed; however, the higher level of performance was not retained after 40 trials in both conditions. Other prepractice variables may need to be considered. Findings have implications for traditional and technology-assisted voice therapy. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Learning to trust: social feedback normalizes trust behavior in first-episode psychosis and clinical high risk.

PubMed

Lemmers-Jansen, Imke L J; Fett, Anne-Kathrin J; Hanssen, Esther; Veltman, Dick J; Krabbendam, Lydia

2018-06-13

Psychosis is characterized by problems in social functioning that exist well before illness onset, and in individuals at clinical high risk (CHR) for psychosis. Trust is an essential element for social interactions that is impaired in psychosis. In the trust game, chronic patients showed reduced baseline trust, impaired response to positive social feedback, and attenuated brain activation in reward and mentalizing areas. We investigated whether first-episode psychosis patients (FEP) and CHR show similar abnormalities in the neural and behavioral mechanisms underlying trust. Twenty-two FEP, 17 CHR, and 43 healthy controls performed two trust games, with a cooperative and an unfair partner in the fMRI scanner. Region of interest analyses were performed on mentalizing and reward processing areas, during the investment and outcome phases of the games. Compared with healthy controls, FEP and CHR showed reduced baseline trust, but like controls, learned to trust in response to cooperative and unfair feedback. Symptom severity was not associated with baseline trust, however in FEP associated with reduced response to feedback. The only group differences in brain activation were that CHR recruited the temporo-parietal junction (TPJ) more than FEP and controls during investment in the unfair condition. This hyper-activation in CHR was associated with greater symptom severity. Reduced baseline trust may be associated with risk for psychotic illness, or generally with poor mental health. Feedback learning is still intact in CHR and FEP, as opposed to chronic patients. CHR however show distinct neural activation patterns of hyper-activation of the TPJ.

Vectorized and multitasked solution of the few-group neutron diffusion equations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zee, S.K.; Turinsky, P.J.; Shayer, Z.

1989-03-01

A numerical algorithm with parallelism was used to solve the two-group, multidimensional neutron diffusion equations on computers characterized by shared memory, vector pipeline, and multi-CPU architecture features. Specifically, solutions were obtained on the Cray X/MP-48, the IBM-3090 with vector facilities, and the FPS-164. The material-centered mesh finite difference method approximation and outer-inner iteration method were employed. Parallelism was introduced in the inner iterations using the cyclic line successive overrelaxation iterative method and solving in parallel across lines. The outer iterations were completed using the Chebyshev semi-iterative method that allows parallelism to be introduced in both space and energy groups. Formore » the three-dimensional model, power, soluble boron, and transient fission product feedbacks were included. Concentrating on the pressurized water reactor (PWR), the thermal-hydraulic calculation of moderator density assumed single-phase flow and a closed flow channel, allowing parallelism to be introduced in the solution across the radial plane. Using a pinwise detail, quarter-core model of a typical PWR in cycle 1, for the two-dimensional model without feedback the measured million floating point operations per second (MFLOPS)/vector speedups were 83/11.7. 18/2.2, and 2.4/5.6 on the Cray, IBM, and FPS without multitasking, respectively. Lower performance was observed with a coarser mesh, i.e., shorter vector length, due to vector pipeline start-up. For an 18 x 18 x 30 (x-y-z) three-dimensional model with feedback of the same core, MFLOPS/vector speedups of --61/6.7 and an execution time of 0.8 CPU seconds on the Cray without multitasking were measured. Finally, using two CPUs and the vector pipelines of the Cray, a multitasking efficiency of 81% was noted for the three-dimensional model.« less

Using Task Clarification, Graphic Feedback, And Verbal Feedback To Increase Closing-Task Completion In A Privately Owned Restaurant

PubMed Central

Weatherly, Nic L; Gravina, Nicole E

2005-01-01

An informant functional assessment was used to evaluate closing-task completion by servers and dishwashers at a restaurant. Based on the functional assessment results, an intervention consisting of task clarification, posted graphic feedback, and verbal feedback was implemented and evaluated with a multiple baseline design across two groups of employees. Results showed an increase of 15% and 38% in task completion for the two groups. PMID:15898481

The effect on teenage risky driving of feedback from a safety monitoring system: a randomized controlled trial.

PubMed

Simons-Morton, Bruce G; Bingham, C Raymond; Ouimet, Marie Claude; Pradhan, Anuj K; Chen, Rusan; Barretto, Andrea; Shope, Jean T

2013-07-01

Teenage risky driving may be due to teenagers not knowing what is risky, preferring risk, or the lack of consequences. Elevated gravitational-force (g-force) events, caused mainly by hard braking and sharp turns, provide a valid measure of risky driving and are the target of interventions using in-vehicle data recording and feedback devices. The effect of two forms of feedback about risky driving events to teenagers only or to teenagers and their parents was tested in a randomized controlled trial. Ninety parent-teen dyads were randomized to one of two groups: (1) immediate feedback to teens (Lights Only); or (2) immediate feedback to teens plus family access to event videos and ranking of the teen relative to other teenage drivers (Lights Plus). Participants' vehicles were instrumented with data recording devices and events exceeding .5 g were assessed for 2 weeks of baseline and 13 weeks of feedback. Growth curve analysis with random slopes yielded a significant decrease in event rates for the Lights Plus group (slope = -.11, p < .01), but no change for the Lights Only group (slope = .05, p = .67) across the 15 weeks. A large effect size of 1.67 favored the Lights Plus group. Provision of feedback with possible consequences associated with parents being informed reduced risky driving, whereas immediate feedback only to teenagers did not. Published by Elsevier Inc.

Study protocol: identifying and delivering point-of-care information to improve care coordination.

PubMed

Hysong, Sylvia J; Che, Xinxuan; Weaver, Sallie J; Petersen, Laura A

2015-10-19

The need for deliberately coordinated care is noted by many national-level organizations. The Department of Veterans Affairs (VA) recently transitioned primary care clinics nationwide into Patient Aligned Care Teams (PACTs) to provide more accessible, coordinated, comprehensive, and patient-centered care. To better serve this purpose, PACTs must be able to successfully sequence and route interdependent tasks to appropriate team members while also maintaining collective situational awareness (coordination). Although conceptual frameworks of care coordination exist, few explicitly articulate core behavioral markers of coordination or the related information needs of team members attempting to synchronize complex care processes across time for a shared patient population. Given this gap, we partnered with a group of frontline primary care personnel at ambulatory care sites to identify the specific information needs of PACT members that will enable them to coordinate their efforts to provide effective, coordinated care. The study has three objectives: (1) development of measurable, prioritized point-of-care criteria for effective PACT coordination; (2) identifying the specific information needed at the point of care to optimize coordination; and (3) assessing the effect of adopting the aforementioned coordination standards on PACT clinicians' coordination behaviors. The study consists of three phases. In phase 1, we will employ the Productivity Measurement and Enhancement System (ProMES), a structured approach to performance measure creation from industrial/organizational psychology, to develop coordination measures with a design team of 6-10 primary care personnel; in phase 2, we will conduct focus groups with the phase 1 design team to identify point-of-care information needs. Phase 3 is a two-arm field experiment (n PACT = 28/arm); intervention arm PACTs will receive monthly feedback reports using the measures developed in phase 1 and attend brief monthly feedback sessions. Control arm PACTs will receive no intervention. PACTs will be followed prospectively for up to 1 year. This project combines both action research and implementation science methods to address important gaps in the existing care coordination literature using a partnership-based research design. It will provide an evidence-based framework for care coordination by employing a structured methodology for a systematic approach to care coordination in PACT settings and identifying the information needs that produce the most successful coordination of care. ISRCTN15412521.

Real-time computer-based visual feedback improves visual acuity in downbeat nystagmus - a pilot study.

PubMed

Teufel, Julian; Bardins, S; Spiegel, Rainer; Kremmyda, O; Schneider, E; Strupp, M; Kalla, R

2016-01-04

Patients with downbeat nystagmus syndrome suffer from oscillopsia, which leads to an unstable visual perception and therefore impaired visual acuity. The aim of this study was to use real-time computer-based visual feedback to compensate for the destabilizing slow phase eye movements. The patients were sitting in front of a computer screen with the head fixed on a chin rest. The eye movements were recorded by an eye tracking system (EyeSeeCam®). We tested the visual acuity with a fixed Landolt C (static) and during real-time feedback driven condition (dynamic) in gaze straight ahead and (20°) sideward gaze. In the dynamic condition, the Landolt C moved according to the slow phase eye velocity of the downbeat nystagmus. The Shapiro-Wilk test was used to test for normal distribution and one-way ANOVA for comparison. Ten patients with downbeat nystagmus were included in the study. Median age was 76 years and the median duration of symptoms was 6.3 years (SD +/- 3.1y). The mean slow phase velocity was moderate during gaze straight ahead (1.44°/s, SD +/- 1.18°/s) and increased significantly in sideward gaze (mean left 3.36°/s; right 3.58°/s). In gaze straight ahead, we found no difference between the static and feedback driven condition. In sideward gaze, visual acuity improved in five out of ten subjects during the feedback-driven condition (p = 0.043). This study provides proof of concept that non-invasive real-time computer-based visual feedback compensates for the SPV in DBN. Therefore, real-time visual feedback may be a promising aid for patients suffering from oscillopsia and impaired text reading on screen. Recent technological advances in the area of virtual reality displays might soon render this approach feasible in fully mobile settings.

Hip proprioceptive feedback influences the control of mediolateral stability during human walking

PubMed Central

Roden-Reynolds, Devin C.; Walker, Megan H.; Wasserman, Camille R.

2015-01-01

Active control of the mediolateral location of the feet is an important component of a stable bipedal walking pattern, although the roles of sensory feedback in this process are unclear. In the present experiments, we tested whether hip abductor proprioception influenced the control of mediolateral gait motion. Participants performed a series of quiet standing and treadmill walking trials. In some trials, 80-Hz vibration was applied intermittently over the right gluteus medius (GM) to evoke artificial proprioceptive feedback. During walking, the GM was vibrated during either right leg stance (to elicit a perception that the pelvis was closer mediolaterally to the stance foot) or swing (to elicit a perception that the swing leg was more adducted). Vibration during quiet standing evoked leftward sway in most participants (13 of 16), as expected from its predicted perceptual effects. Across the 13 participants sensitive to vibration, stance phase vibration caused the contralateral leg to be placed significantly closer to the midline (by ∼2 mm) at the end of the ongoing step. In contrast, swing phase vibration caused the vibrated leg to be placed significantly farther mediolaterally from the midline (by ∼2 mm), whereas the pelvis was held closer to the stance foot (by ∼1 mm). The estimated mediolateral margin of stability was thus decreased by stance phase vibration but increased by swing phase vibration. Although the observed effects of vibration were small, they were consistent with humans monitoring hip proprioceptive feedback while walking to maintain stable mediolateral gait motion. PMID:26289467

Distributed Wireless Power Transfer With Energy Feedback

NASA Astrophysics Data System (ADS)

Lee, Seunghyun; Zhang, Rui

2017-04-01

Energy beamforming (EB) is a key technique for achieving efficient radio-frequency (RF) transmission enabled wireless energy transfer (WET). By optimally designing the waveforms from multiple energy transmitters (ETs) over the wireless channels, they can be constructively combined at the energy receiver (ER) to achieve an EB gain that scales with the number of ETs. However, the optimal design of EB waveforms requires accurate channel state information (CSI) at the ETs, which is challenging to obtain practically, especially in a distributed system with ETs at separate locations. In this paper, we study practical and efficient channel training methods to achieve optimal EB in a distributed WET system. We propose two protocols with and without centralized coordination, respectively, where distributed ETs either sequentially or in parallel adapt their transmit phases based on a low-complexity energy feedback from the ER. The energy feedback only depends on the received power level at the ER, where each feedback indicates one particular transmit phase that results in the maximum harvested power over a set of previously used phases. Simulation results show that the two proposed training protocols converge very fast in practical WET systems even with a large number of distributed ETs, while the protocol with sequential ET phase adaptation is also analytically shown to converge to the optimal EB design with perfect CSI by increasing the training time. Numerical results are also provided to evaluate the performance of the proposed distributed EB and training designs as compared to other benchmark schemes.

Automated feedback to foster safe driving in young drivers : Phase 2.

DOT National Transportation Integrated Search

2015-12-01

Intelligent Speed Adaptation (ISA) represents a promising approach to reduce speeding. A core principle for ISA systems is that they provide real-time feedback to drivers, prompting them to reduce speed when some threshold at or above the limit is re...

Distinct Feedforward and Feedback Effects of Microstimulation in Visual Cortex Reveal Neural Mechanisms of Texture Segregation.

PubMed

Klink, P Christiaan; Dagnino, Bruno; Gariel-Mathis, Marie-Alice; Roelfsema, Pieter R

2017-07-05

The visual cortex is hierarchically organized, with low-level areas coding for simple features and higher areas for complex ones. Feedforward and feedback connections propagate information between areas in opposite directions, but their functional roles are only partially understood. We used electrical microstimulation to perturb the propagation of neuronal activity between areas V1 and V4 in monkeys performing a texture-segregation task. In both areas, microstimulation locally caused a brief phase of excitation, followed by inhibition. Both these effects propagated faithfully in the feedforward direction from V1 to V4. Stimulation of V4, however, caused little V1 excitation, but it did yield a delayed suppression during the late phase of visually driven activity. This suppression was pronounced for the V1 figure representation and weaker for background representations. Our results reveal functional differences between feedforward and feedback processing in texture segregation and suggest a specific modulating role for feedback connections in perceptual organization. Copyright © 2017 Elsevier Inc. All rights reserved.

An Iterative Information-Reduced Quadriphase-Shift-Keyed Carrier Synchronization Scheme Using Decision Feedback for Low Signal-to-Noise Ratio Applications

NASA Technical Reports Server (NTRS)

Simon, M.; Tkacenko, A.

2006-01-01

In a previous publication [1], an iterative closed-loop carrier synchronization scheme for binary phase-shift keyed (BPSK) modulation was proposed that was based on feeding back data decisions to the input of the loop, the purpose being to remove the modulation prior to carrier synchronization as opposed to the more conventional decision-feedback schemes that incorporate such feedback inside the loop. The idea there was that, with sufficient independence between the received data and the decisions on it that are fed back (as would occur in an error-correction coding environment with sufficient decoding delay), a pure tone in the presence of noise would ultimately be produced (after sufficient iteration and low enough error probability) and thus could be tracked without any squaring loss. This article demonstrates that, with some modification, the same idea of iterative information reduction through decision feedback can be applied to quadrature phase-shift keyed (QPSK) modulation, something that was mentioned in the previous publication but never pursued.

VLF wave growth and discrete emission triggering in the magnetosphere - A feedback model

NASA Technical Reports Server (NTRS)

Helliwell, R. A.; Inan, U. S.

1982-01-01

A simple nonlinear feedback model is presented to explain VLF wave growth and emission triggering observed in VLF transmission experiments. The model is formulated in terms of the interaction of electrons with a slowly varying wave in an inhomogeneous medium as in an unstable feedback amplifier with a delay line; constant frequency oscillations are generated on the magnetic equator, while risers and fallers are generated on the downstream and upstream sides of the equator, respectively. Quantitative expressions are obtained for the stimulated radiation produced by energy exchanged between energetic electrons and waves by Doppler-shifted cyclotron resonance, and feedback between the stimulated radiation and the phase bunched currents is incorporated in terms of a two-port discrete time model. The resulting model is capable of explaining the observed temporal growth and saturation effects, phase advance, retardation or frequency shift during growth in the context of a single parameter depending on the energetic particle distribution function, as well as pretermination triggering.

Positive Feedback Keeps Duration of Mitosis Temporally Insulated from Upstream Cell-Cycle Events.

PubMed

Araujo, Ana Rita; Gelens, Lendert; Sheriff, Rahuman S M; Santos, Silvia D M

2016-10-20

Cell division is characterized by a sequence of events by which a cell gives rise to two daughter cells. Quantitative measurements of cell-cycle dynamics in single cells showed that despite variability in G1-, S-, and G2 phases, duration of mitosis is short and remarkably constant. Surprisingly, there is no correlation between cell-cycle length and mitotic duration, suggesting that mitosis is temporally insulated from variability in earlier cell-cycle phases. By combining live cell imaging and computational modeling, we showed that positive feedback is the molecular mechanism underlying the temporal insulation of mitosis. Perturbing positive feedback gave rise to a sluggish, variable entry and progression through mitosis and uncoupled duration of mitosis from variability in cell cycle length. We show that positive feedback is important to keep mitosis short, constant, and temporally insulated and anticipate it might be a commonly used regulatory strategy to create modularity in other biological systems. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Sustainable childhood obesity prevention through community engagement (SCOPE) program: evaluation of the implementation phase.

PubMed

McIntosh, Bonnie; Daly, Amelia; Mâsse, Louise C; Collet, Jean-Paul; Higgins, Joan Wharf; Naylor, Patti-Jean; Amed, Shazhan

2015-10-01

Childhood obesity rates are steadily rising. Sustainable Childhood Obesity Prevention Through Community Engagement (SCOPE) is a community-based participatory action research (PAR) program aimed at preventing childhood obesity. This study aimed to describe community perspectives on, and elicit feedback about, SCOPE's first phase of implementation in two pilot cities in British Columbia, Canada. A case study was implemented using interviews and questionnaires to obtain feedback about SCOPE from two groups: SCOPE coordinators and stakeholders (i.e., individuals and organizations that were a member of the community and engaged with SCOPE coordinators). Participants were recruited via email and (or) by telephone. Coordinators completed a telephone interview. Stakeholders completed a questionnaire and (or) a telephone interview. Thematic analysis was conducted. Participants included 2 coordinators and 15 stakeholders. Participants similarly interpreted SCOPE as a program focused on raising awareness about childhood obesity prevention, while engaging multiple community sectors. Overall, participants valued the program's role in facilitating networking and partnership development, providing evidence-based resources, technical expertise, and contributing funding. Participants felt that SCOPE is sustainable. However, participants felt that barriers to achieving healthy weights among children included those related to the built environment, and social, behavioral, and economic obstacles. Perspectives on factors that facilitated and acted as barriers to SCOPE's first phase of implementation were obtained from the SCOPE communities and may be used to enhance the sustainability of SCOPE and its applicability to other BC communities.

Effects of interactive visual feedback training on post-stroke pusher syndrome: a pilot randomized controlled study.

PubMed

Yang, Yea-Ru; Chen, Yi-Hua; Chang, Heng-Chih; Chan, Rai-Chi; Wei, Shun-Hwa; Wang, Ray-Yau

2015-10-01

We investigated the effects of a computer-generated interactive visual feedback training program on the recovery from pusher syndrome in stroke patients. Assessor-blinded, pilot randomized controlled study. A total of 12 stroke patients with pusher syndrome were randomly assigned to either the experimental group (N = 7, computer-generated interactive visual feedback training) or control group (N = 5, mirror visual feedback training). The scale for contraversive pushing for severity of pusher syndrome, the Berg Balance Scale for balance performance, and the Fugl-Meyer assessment scale for motor control were the outcome measures. Patients were assessed pre- and posttraining. A comparison of pre- and posttraining assessment results revealed that both training programs led to the following significant changes: decreased severity of pusher syndrome scores (decreases of 4.0 ± 1.1 and 1.4 ± 1.0 in the experimental and control groups, respectively); improved balance scores (increases of 14.7 ± 4.3 and 7.2 ± 1.6 in the experimental and control groups, respectively); and higher scores for lower extremity motor control (increases of 8.4 ± 2.2 and 5.6 ± 3.3 in the experimental and control groups, respectively). Furthermore, the computer-generated interactive visual feedback training program produced significantly better outcomes in the improvement of pusher syndrome (p < 0.01) and balance (p < 0.05) compared with the mirror visual feedback training program. Although both training programs were beneficial, the computer-generated interactive visual feedback training program more effectively aided recovery from pusher syndrome compared with mirror visual feedback training. © The Author(s) 2014.

Numerical investigation of multichannel laser beam phase locking in turbulent atmosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Volkov, V A; Volkov, M V; Garanin, S G

2015-12-31

The efficiency of coherent multichannel beam combining under focusing through a turbulent medium on a target in the cases of phase conjugation and target irradiation in the feedback loop is investigated numerically in various approximations. The conditions of efficient focusing of multichannel radiation on the target are found. It is shown that the coherent beam combining with target irradiation in the feedback loop, which does not require a reference beam and wavefront measurements, is as good as the phase conjugation approach in the efficiency of focusing. It is found that the main effect of focusing is provided by properly chosenmore » phase shifts in the channels, whereas taking into account local wavefront tip tilts weakly affects the result. (control of laser radiation parameters)« less

Analysis of dental students' written peer feedback from a prospective peer assessment protocol.

PubMed

Tricio, J; Woolford, M; Escudier, M

2016-11-01

Peer assessment and feedback is encouraged to enhance students' learning. The aim of this study was to quantitatively and qualitatively analyse pre-clinical and clinical dental students' written peer feedback provided as part of a continuous, formative and structured peer assessment protocol. A total of 309 Year-2 and Year-5 dental students were invited to participate in a peer assessment and peer feedback protocol. Consenting volunteer students were trained to observe each other whilst working in the skills laboratory (Year-2) and in the dental clinic (Year-5). Subsequently, they followed a structured protocol of peer assessment and peer feedback using specially designed work-based forms during a complete academic year. The content of their written feedback was coded according to the UK General Dental Council domain, sign (positive or negative), specificity (task specific or general), and grouped into themes. A total of 108 participants (40 Year-2 and 68 Year-5) completed 1169 peer assessment work-based forms (516 pre-clinical and 653 clinical); 94% contained written feedback. The large majority (82%) of Year-2 feedback represented the clinical domain, 89% were positive, 77% were task specific, and they were grouped into 14 themes. Year-5 feedback was related mostly to Management and Leadership (37%) and Communication (32%), 64% were positive, 75% task specific, and they were clustered into 24 themes. The content of the feedback showed notable differences between Year-2 and Year-5 students. Senior students focused more on Communication and Management and Leadership skills, whilst juniors were more concerned with clinical skills. Year-5 students provided 13% negative feedback compared to only 2% from Year-2. Regulatory focus theory is discussed to explain these differences. Both groups provided peer feedback on a wide and different range of themes. However, four themes emerged in both groups: efficiency, infection control, time management and working speed. A structured peer assessment framework can be used to guide pre-clinical and clinical students to provide peer feedback focused on different domains, and on contrasting signs and specificities. It can also present an opportunity to complement tutors' feedback. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

How does feedback in mini-CEX affect students' learning response?

PubMed

Sudarso, Sulistiawati; Rahayu, Gandes Retno; Suhoyo, Yoyo

2016-12-19

This study was aimed to explore students' learning response toward feedback during mini-CEX encounter. This study used a phenomenological approach to identify the students' experiences toward feedback during mini-CEX encounter. Data was collected using Focus Group Discussion (FGD) for all students who were in their final week of clerkship in the internal medicine rotation. There were 4 FGD groups (6 students for each group). All FGD were audio-taped and transcribed verbatim. The FGD transcripts were analyzed thematically and managed using Atlas-ti (version 7.0). Feedback content and the way of providing feedback on mini-CEX stimulated students' internal process, including self-reflection, emotional response, and motivation. These internal processes encouraged the students to take action or do a follow-up on the feedback to improve their learning process. In addition, there was also an external factor, namely consequences, which also influenced the students' reaction to the follow-up on feedback. In the end, this action caused several learning effects that resulted in the students' increased self-efficacy, attitude, knowledge and clinical skill. Feedback content and the way of providing feedback on mini-CEX stimulates the students' internal processes to do a follow-up on feedback. However, another external factor also affects the students' decision on the follow-up actions. The follow-ups result in various learning effects on the students. Feedback given along with summative assessment enhances learning effects on students, as well. It is suggested that supervisors of clinical education are prepared to comprehend every factor influencing feedback on mini CEX to improve the students' learning response.

MQW Optical Feedback Modulators And Phase Shifters

NASA Technical Reports Server (NTRS)

Jackson, Deborah J.

1995-01-01

Laser diodes equipped with proposed multiple-quantum-well (MQW) optical feedback modulators prove useful in variety of analog and digital optical-communication applications, including fiber-optic signal-distribution networks and high-speed, low-crosstalk interconnections among super computers or very-high-speed integrated circuits. Development exploits accompanying electro-optical aspect of QCSE - variation in index of refraction with applied electric field. Also exploits sensitivity of laser diodes to optical feedback. Approach is reverse of prior approach.

Cardiac arrhythmias and degradation into chaotic behavior prevention using feedback control

NASA Astrophysics Data System (ADS)

Uzelac, Ilija; Sidorov, Veniamin; Wikswo, John; Gray, Richard

2012-02-01

During normal heart rhythm, cardiac cells behave as a set of oscillators with a distribution of phases but with the same frequency. The heart as a dynamical system in a phase space representation can be modeled as a set of oscillators that have closed overlapping orbits with the same period. These orbits are not stable and in the case of disruption of the cardiac rhythm, such as due to premature beats, the system will have a tendency to leave its periodic unstable orbits. If these orbits become attracted to phase singularities, their disruption may lead to chaotic behavior, which appears as a life-threating ventricular fibrillation. By using closed-loop feedback in the form of an adjustable defibrillation shock, any drift from orbits corresponding to the normal rhythm can be corrected by forcing the system to maintain its orbits. The delay through the feedback network coincides with the period of normal heart beats. To implement this approach we developed a 1 kW arbitrary waveform voltage-to-current converter with a 1 kHz bandwidth driven by a photodiode system that records an optical electrocardiogram and provides a feedback signal in real time. Our goal is to determine whether our novel method to defibrillate the heart will require much lower energies than are currently utilized in single shock defibrillators.

Improving Written Communication Through Minimal Feedback

PubMed Central

Traxler, Matthew J.; Gernsbacher, Morton Ann

2014-01-01

We propose that writers must form accurate representations of how their readers will interpret their texts to convey their ideas successfully. In two experiments, we investigated whether getting feedback from their readers helps writers form better representations of how their texts are interpreted. In our first experiment, one group of subjects (writers) wrote descriptions of a set of geometric figures; another group of subjects (readers) read those descriptions and used them to select the figures from sets of similar looking distractor figures. Half the writers received feedback on how well their readers selected the figures, and half the writers did not receive this feedback. Those writers who received feedback improved their descriptions more than those writers who did not receive feedback. In our second experiment, half the writers received two treatments of feedback on their descriptions of one set of figures, whereas the other half of the writers did not receive feedback. Then, all the writers described a new set of figures. Those writers who had previously received feedback wrote better new descriptions than did those writers who had never received feedback. We concluded that feedback – even this minimal form of feedback – helps writers to envision how readers interpret their texts. PMID:25520535

Collective irrationality and positive feedback.

PubMed

Nicolis, Stamatios C; Zabzina, Natalia; Latty, Tanya; Sumpter, David J T

2011-04-26

Recent experiments on ants and slime moulds have assessed the degree to which they make rational decisions when presented with a number of alternative food sources or shelter. Ants and slime moulds are just two examples of a wide range of species and biological processes that use positive feedback mechanisms to reach decisions. Here we use a generic, experimentally validated model of positive feedback between group members to show that the probability of taking the best of options depends crucially on the strength of feedback. We show how the probability of choosing the best option can be maximized by applying an optimal feedback strength. Importantly, this optimal value depends on the number of options, so that when we change the number of options the preference of the group changes, producing apparent "irrationalities". We thus reinterpret the idea that collectives show "rational" or "irrational" preferences as being a necessary consequence of the use of positive feedback. We argue that positive feedback is a heuristic which often produces fast and accurate group decision-making, but is always susceptible to apparent irrationality when studied under particular experimental conditions.

Laser confocal feedback tomography and nano-step height measurement

PubMed Central

Tan, Yidong; Wang, Weiping; Xu, Chunxin; Zhang, Shulian

2013-01-01

A promising method for tomography and step height measurement is proposed, which combines the high sensitivity of the frequency-shifted feedback laser and the axial positioning ability of confocal microscopy. By demodulating the feedback-induced intensity modulation signals, the obtained amplitude and phase information are used to respectively determine the coarse and fine measurement of the samples. Imaging the micro devices and biological samples by the demodulated amplitude, this approach is proved to be able to achieve the cross-sectional image in highly scattered mediums. And then the successful height measurement of nano-step on a glass-substrate grating by combination of both amplitude and phase information indicates its axial high resolution (better than 2 nm) in a non-ambiguous range of about ten microns. PMID:24145717

Augmented kinematic feedback from haptic virtual reality for dental skill acquisition.

PubMed

Suebnukarn, Siriwan; Haddawy, Peter; Rhienmora, Phattanapon; Jittimanee, Pannapa; Viratket, Piyanuch

2010-12-01

We have developed a haptic virtual reality system for dental skill training. In this study we examined several kinds of kinematic information about the movement provided by the system supplement knowledge of results (KR) in dental skill acquisition. The kinematic variables examined involved force utilization (F) and mirror view (M). This created three experimental conditions that received augmented kinematic feedback (F, M, FM) and one control condition that did not (KR-only). Thirty-two dental students were randomly assigned to four groups. Their task was to perform access opening on the upper first molar with the haptic virtual reality system. An acquisition session consisted of two days of ten trials of practice in which augmented kinematic feedback was provided for the appropriate experimental conditions after each trial. One week after, a retention test consisting of two trials without augmented feedback was completed. The results showed that the augmented kinematic feedback groups had larger mean performance scores than the KR-only group in Day 1 of the acquisition and retention sessions (ANOVA, p<0.05). The apparent differences among feedback groups were not significant in Day 2 of the acquisition session (ANOVA, p>0.05). The trends in acquisition and retention sessions suggest that the augmented kinematic feedback can enhance the performance earlier in the skill acquisition and retention sessions.

The Effect on Teenage Risky Driving of Feedback From a Safety Monitoring System: A Randomized Controlled Trial

PubMed Central

Bingham, C. Raymond; Ouimet, Marie Claude; Pradhan, Anuj; Chen, Rusan; Barretto, Andrea; Shope, Jean

2012-01-01

Purpose Teenage risky driving may be due to teenagers not knowing what is risky, preferring risk, or the lack of consequences. Elevated gravitational-force (g-force) events, caused mainly by hard braking and sharp turns, provide a valid measure of risky driving and are the target of interventions using in-vehicle data recording and feedback devices. The effect of two forms of feedback about risky driving events to teenagers only or to teenagers and their parents was tested in a randomized controlled trial. Methods Ninety parent-teen dyads were randomized to one of two groups: (1) immediate feedback to teens (Lights Only); or (2) immediate feedback to teens plus family access to event videos and ranking of the teen relative to other teenage drivers (Lights Plus). Participants’ vehicles were instrumented with data recording devices and events exceeding 0.5 g were assessed for two weeks of baseline and 13 weeks of feedback. Results Growth analysis with random slopes yielded a significant decrease in event rates for the Lights Plus group (slope = −.11, p < 0.01), but no change for the Lights Only group (slope = 0.05, p = 0.67) across the 15 weeks. A large effect size of 1.67 favored the Lights Plus group. Conclusions Provision of feedback with possible consequences associated with parents being informed reduced risky driving, while immediate feedback only to teenagers did not. Implications and Contribution Reducing elevated g-force events due to hard stops and sharp turns could reduce crash rates among novice teenage drivers. Using materials from the DriveCam For Families Program we found that feedback to both teens and parents significantly reduced rates, while feedback only to teens did not. PMID:23375825

Development of a Digital Control for the Phase Contrast Imaging Alignment Feedback System

NASA Astrophysics Data System (ADS)

Hirata, M.; Marinoni, A.; Rost, J. C.; Davis, E. M.; Porkolab, M.

2016-10-01

The Phase Contrast Imaging diagnostic is an internal reference interferometer that images density fluctuations on a 32-element linear detector array. Since proper operation of the system requires accurate alignment of a CO2 laser beam on a phase plate, beam motion due to vibrations of the DIII-D vessel need to be compensated up to 1 kHz. The feedback network controlling the steering mirrors currently uses a linear analog controller, but a digital controller can provide improved stability performance and flexibility. A prototype was developed using an Arduino Due, a low-cost microcontroller, to assess performance capabilities. Digital control parameters will be developed based on the measured frequency and phase response of the physical components. Finally, testing of the digital feedback system and the required revisions will be done to achieve successful performance. This upgrade to the linear analog controller is expected to be used routinely on similar diagnostics in fusion devices, especially in view of restricted access to the machine hall. Work supported in part by the US Department of Energy under DE-FG02-94ER54235, DE-FC02-04ER54698, and the Science Undergraduate Laboratory Internships Program (SULI).

Comparative Efficacy of Group and Individual Feedback in Gross Anatomy for Promoting Medical Student Professionalism

ERIC Educational Resources Information Center

Camp, Christopher L.; Gregory, Jeremy K.; Lachman, Nirusha; Chen, Laura P.; Juskewitch, Justin E.; Pawlina, Wojciech

2010-01-01

Professionalism is a core competency of medical training that requires students to develop the skills of providing and receiving feedback. Our study evaluated the effectiveness of delivering feedback in a group setting compared with an individual setting. The first-year class of Mayo medical students (n = 49) enrolled in gross anatomy (in…

Observational constraints on mixed-phase clouds imply higher climate sensitivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan, Ivy; Storelvmo, Trude; Zelinka, Mark D.

Global climate model (GCM) estimates of the equilibrium global mean surface temperature response to a doubling of atmospheric CO 2, measured by the equilibrium climate sensitivity (ECS), range from 2.0° to 4.6°C. Clouds are among the leading causes of this uncertainty. Here, in this paper, we show that the ECS can be up to 1.3°C higher in simulations where mixed-phase clouds consisting of ice crystals and supercooled liquid droplets are constrained by global satellite observations. The higher ECS estimates are directly linked to a weakened cloud-phase feedback arising from a decreased cloud glaciation rate in a warmer climate. Finally, wemore » point out the need for realistic representations of the supercooled liquid fraction in mixed-phase clouds in GCMs, given the sensitivity of the ECS to the cloud-phase feedback.« less

Observational constraints on mixed-phase clouds imply higher climate sensitivity

DOE PAGES

Tan, Ivy; Storelvmo, Trude; Zelinka, Mark D.

2016-04-08

Global climate model (GCM) estimates of the equilibrium global mean surface temperature response to a doubling of atmospheric CO 2, measured by the equilibrium climate sensitivity (ECS), range from 2.0° to 4.6°C. Clouds are among the leading causes of this uncertainty. Here, in this paper, we show that the ECS can be up to 1.3°C higher in simulations where mixed-phase clouds consisting of ice crystals and supercooled liquid droplets are constrained by global satellite observations. The higher ECS estimates are directly linked to a weakened cloud-phase feedback arising from a decreased cloud glaciation rate in a warmer climate. Finally, wemore » point out the need for realistic representations of the supercooled liquid fraction in mixed-phase clouds in GCMs, given the sensitivity of the ECS to the cloud-phase feedback.« less

Observational constraints on mixed-phase clouds imply higher climate sensitivity.

PubMed

Tan, Ivy; Storelvmo, Trude; Zelinka, Mark D

2016-04-08

Global climate model (GCM) estimates of the equilibrium global mean surface temperature response to a doubling of atmospheric CO2, measured by the equilibrium climate sensitivity (ECS), range from 2.0° to 4.6°C. Clouds are among the leading causes of this uncertainty. Here we show that the ECS can be up to 1.3°C higher in simulations where mixed-phase clouds consisting of ice crystals and supercooled liquid droplets are constrained by global satellite observations. The higher ECS estimates are directly linked to a weakened cloud-phase feedback arising from a decreased cloud glaciation rate in a warmer climate. We point out the need for realistic representations of the supercooled liquid fraction in mixed-phase clouds in GCMs, given the sensitivity of the ECS to the cloud-phase feedback. Copyright © 2016, American Association for the Advancement of Science.

Coherent addition of high power broad-area laser diodes with a compact VBG V-shaped external Talbot cavity

DOE PAGES

Liu, Bo; Braiman, Yehuda

2018-02-06

In this paper, we introduced a compact V-shaped external Talbot cavity for phase locking of high power broad-area laser diodes. The length of compact cavity is ~25 mm. Near diffraction-limit coherent addition of 10 broad-area laser diodes indicated that high quality phase locking was achieved. We measured the near-field emission mode of each individual broad-area laser diode with different feedback, such as a volume Bragg grating and a high reflection mirror. Finally, we found out that the best result of phase locking broad-area laser diodes was achieved by the compact V-shaped external Talbot cavity with volume Bragg grating feedback.

Coherent addition of high power broad-area laser diodes with a compact VBG V-shaped external Talbot cavity

NASA Astrophysics Data System (ADS)

Liu, Bo; Braiman, Yehuda

2018-05-01

We introduced a compact V-shaped external Talbot cavity for phase locking of high power broad-area laser diodes. The length of compact cavity is ∼25 mm. Near diffraction-limit coherent addition of 10 broad-area laser diodes indicated that high quality phase locking was achieved. We measured the near-field emission mode of each individual broad-area laser diode with different feedback, such as a volume Bragg grating and a high reflection mirror. We found out that the best result of phase locking broad-area laser diodes was achieved by the compact V-shaped external Talbot cavity with volume Bragg grating feedback.

Coherent addition of high power broad-area laser diodes with a compact VBG V-shaped external Talbot cavity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Bo; Braiman, Yehuda

In this paper, we introduced a compact V-shaped external Talbot cavity for phase locking of high power broad-area laser diodes. The length of compact cavity is ~25 mm. Near diffraction-limit coherent addition of 10 broad-area laser diodes indicated that high quality phase locking was achieved. We measured the near-field emission mode of each individual broad-area laser diode with different feedback, such as a volume Bragg grating and a high reflection mirror. Finally, we found out that the best result of phase locking broad-area laser diodes was achieved by the compact V-shaped external Talbot cavity with volume Bragg grating feedback.

Region grouping in natural foliage scenes: image statistics and human performance.

PubMed

Ing, Almon D; Wilson, J Anthony; Geisler, Wilson S

2010-04-27

This study investigated the mechanisms of grouping and segregation in natural scenes of close-up foliage, an important class of scenes for human and non-human primates. Close-up foliage images were collected with a digital camera calibrated to match the responses of human L, M, and S cones at each pixel. The images were used to construct a database of hand-segmented leaves and branches that correctly localizes the image region subtended by each object. We considered a task where a visual system is presented with two image patches and is asked to assign a category label (either same or different) depending on whether the patches appear to lie on the same surface or different surfaces. We estimated several approximately ideal classifiers for the task, each of which used a unique set of image properties. Of the image properties considered, we found that ideal classifiers rely primarily on the difference in average intensity and color between patches, and secondarily on the differences in the contrasts between patches. In psychophysical experiments, human performance mirrored the trends predicted by the ideal classifiers. In an initial phase without corrective feedback, human accuracy was slightly below ideal. After practice with feedback, human accuracy was approximately ideal.

Feedbacks between Air Pollution and Weather, Part 1: Effects on Weather

EPA Science Inventory

The meteorological predictions of fully coupled air-quality models running in “feedback” versus “nofeedback” simulations were compared against each other as part of Phase 2 of the Air Quality Model Evaluation International Initiative. The model simulations included a “no-feedback...

Automated feedback to foster safe driving in young drivers: phase 2 : traffic tech.

DOT National Transportation Integrated Search

2015-12-01

Intelligent Speed Adaptation (ISA) provides a promising approach to reduce speeding. A core principle of ISA is real-time feedback that lets drivers know when they are driving over the speed limit. The overall goal of the study was to provide insight...

Learning to Obtain Reward, but Not Avoid Punishment, Is Affected by Presence of PTSD Symptoms in Male Veterans: Empirical Data and Computational Model

PubMed Central

Myers, Catherine E.; Moustafa, Ahmed A.; Sheynin, Jony; VanMeenen, Kirsten M.; Gilbertson, Mark W.; Orr, Scott P.; Beck, Kevin D.; Pang, Kevin C. H.; Servatius, Richard J.

2013-01-01

Post-traumatic stress disorder (PTSD) symptoms include behavioral avoidance which is acquired and tends to increase with time. This avoidance may represent a general learning bias; indeed, individuals with PTSD are often faster than controls on acquiring conditioned responses based on physiologically-aversive feedback. However, it is not clear whether this learning bias extends to cognitive feedback, or to learning from both reward and punishment. Here, male veterans with self-reported current, severe PTSD symptoms (PTSS group) or with few or no PTSD symptoms (control group) completed a probabilistic classification task that included both reward-based and punishment-based trials, where feedback could take the form of reward, punishment, or an ambiguous “no-feedback” outcome that could signal either successful avoidance of punishment or failure to obtain reward. The PTSS group outperformed the control group in total points obtained; the PTSS group specifically performed better than the control group on reward-based trials, with no difference on punishment-based trials. To better understand possible mechanisms underlying observed performance, we used a reinforcement learning model of the task, and applied maximum likelihood estimation techniques to derive estimated parameters describing individual participants’ behavior. Estimations of the reinforcement value of the no-feedback outcome were significantly greater in the control group than the PTSS group, suggesting that the control group was more likely to value this outcome as positively reinforcing (i.e., signaling successful avoidance of punishment). This is consistent with the control group’s generally poorer performance on reward trials, where reward feedback was to be obtained in preference to the no-feedback outcome. Differences in the interpretation of ambiguous feedback may contribute to the facilitated reinforcement learning often observed in PTSD patients, and may in turn provide new insight into how pathological behaviors are acquired and maintained in PTSD. PMID:24015254

Attributions of the "causes" of group performance as an alternative explanation of the relationship between organizational citizenship behavior and organizational performance.

PubMed

Bachrach, D G; Bendoly, E; Podsakoff, P M

2001-12-01

The purpose of this study was to examine the possibility that feedback regarding team performance may influence team members' reports of organizational citizenship behaviors. Ninety-five teams of business students (N = 412) participated in a labor-scheduling simulation over a local area network. Teams were provided with false negative, false positive, or neutral feedback regarding their performance. Results support the hypothesis that the perception of 2 forms of organizational citizenship behavior (helping behavior and civic virtue) in work groups may, in part. be a function of the nature of the performance feedback that group members receive. However, negative feedback appears to play a more critical role than positive feedback in this attributional process. Possible reasons for these findings, as well as their implications, are discussed.

A randomised controlled trial of combined EEG feedback and methylphenidate therapy for the treatment of ADHD.

PubMed

Li, Li; Yang, Li; Zhuo, Chuan-jun; Wang, Yu-Feng

2013-08-22

To evaluate the efficacy of combined methylphenidate and EEG feedback treatment for children with ADHD. Forty patients with ADHD were randomly assigned to the combination group (methylphenidate therapy and EEG feedback training) or control group (methylphenidate therapy and non-feedback attention training) in a 1:1 ratio using the double-blind method. These patients, who met the DSM-IV diagnostic criteria and were aged between 7 and 16 years, had obtained optimal therapeutic effects by titrating the methylphenidate dose prior to the trial. The patients were assessed using multiple parameters at baseline, after 20 treatment sessions, after 40 treatment sessions, and in 6-month follow-up studies. Compared to the control group, patients in the combination group had reduced ADHD symptoms and improved in related behavioural and brain functions. The combination of EEG feedback and methylphenidate treatment is more effective than methylphenidate alone. The combined therapy is especially suitable for children and adolescents with ADHD who insufficiently respond to single drug treatment or experience drug side effects.

Performance feedback, self-esteem, and cardiovascular adaptation to recurring stressors.

PubMed

Brown, Eoin G; Creaven, Ann-Marie

2017-05-01

This study sought to examine the effects of performance feedback and individual differences in self-esteem on cardiovascular habituation to repeat stress exposure. Sixty-six university students (n = 39 female) completed a self-esteem measure and completed a cardiovascular stress-testing protocol involving repeated exposure to a mental arithmetic task. Cardiovascular functioning was sampled across four phases: resting baseline, initial stress exposure, a recovery period, and repeated stress exposure. Participants were randomly assigned to receive fictional positive feedback, negative feedback, or no feedback following the recovery period. Negative feedback was associated with a sensitized blood pressure response to a second exposure of the stress task. Positive feedback was associated with decreased cardiovascular and psychological responses to a second exposure. Self-esteem was also found to predict reactivity and this interacted with the type of feedback received. These findings suggest that negative performance feedback sensitizes cardiovascular reactivity to stress, whereas positive performance feedback increases both cardiovascular and psychological habituation to repeat exposure to stressors. Furthermore, an individual's self-esteem also appears to influence this process.

The relationship between interannual and long-term cloud feedbacks

DOE PAGES

Zhou, Chen; Zelinka, Mark D.; Dessler, Andrew E.; ...

2015-12-11

The analyses of Coupled Model Intercomparison Project phase 5 simulations suggest that climate models with more positive cloud feedback in response to interannual climate fluctuations also have more positive cloud feedback in response to long-term global warming. Ensemble mean vertical profiles of cloud change in response to interannual and long-term surface warming are similar, and the ensemble mean cloud feedback is positive on both timescales. However, the average long-term cloud feedback is smaller than the interannual cloud feedback, likely due to differences in surface warming pattern on the two timescales. Low cloud cover (LCC) change in response to interannual andmore » long-term global surface warming is found to be well correlated across models and explains over half of the covariance between interannual and long-term cloud feedback. In conclusion, the intermodel correlation of LCC across timescales likely results from model-specific sensitivities of LCC to sea surface warming.« less

Immediate vs. Delayed Feedback in a Computer-Managed Test: Effects on Long-Term Retention. Technical Report, March 1976-August 1976.

ERIC Educational Resources Information Center

Sturges, Persis T.

This experiment was designed to test the effect of immediate and delayed feedback on retention of learning in an educational situation. Four groups of college undergraduates took a multiple-choice computer-managed test. Three of these groups received informative feedback (the entire item with the correct answer identified) either: (1) immediately…

Meta-analysis: audit and feedback features impact effectiveness on care quality.

PubMed

Hysong, Sylvia J

2009-03-01

Audit and feedback (A&F) has long been used to improve quality of care, albeit with variable results. This meta-analytic study tested whether Feedback Intervention Theory, a framework from industrial/organizational psychology, explains the observed variability in health care A&F research. studies cited by Jamtvedt's 2006 Cochrane systematic review of A&F, followed by database searches using the Cochrane review's search strategy to identify more recent studies. Cochrane review criteria, plus: presence of a treatment group receiving only A & F; a control group receiving no intervention; a quantitatively measurable outcome; minimum n of 10 per arm; sufficient statistics for effect size calculations. Moderators: presence of discouragement and praise; correct solution, attainment level, velocity, frequency, and normative information; feedback format (verbal, textual, graphic, public, computerized, group vs. individual); goal setting activity. meta-analytic procedures using the Hedges-Olkin method. Of 519 studies initially identified, 19 met all inclusion criteria. Studies were most often excluded due to the lack of a feedback-only arm. A&F has a modest, though significant positive effect on quality outcomes (d = 0.40, 95% confidence interval = +/-0.20); providing specific suggestions for improvement, written, and more frequent feedback strengthened this effect, whereas graphical and verbal feedback attenuated this effect. A&F effectiveness is improved when feedback is delivered with specific suggestions for improvement, in writing, and frequently. Other feedback characteristics could also potentially improve effectiveness; however, research with stricter experimental controls is needed to identify the specific feedback characteristics that maximize its effectiveness.

Effects of Task-Specific Augmented Feedback on Deficit Modification During Performance of the Tuck-Jump Exercise

PubMed Central

Stroube, Benjamin W.; Myer, Gregory D.; Brent, Jensen L.; Ford, Kevin R.; Heidt, Robert S.; Hewett, Timothy E.

2014-01-01

Context Anterior cruciate ligament (ACL) injuries are prevalent in female athletes. Specific factors have possible links to increasing a female athlete’s chances of suffering an ACL injury. However, it is unclear if augmented feedback may be able to decrease possible risk factors. Objective To compare the effects of task-Specific feedback on a repeated tuck-jump maneuver. Design Double-blind randomized controlled trial. Setting Sports-medicine biodynamics center. Patients 37 female subjects (14.7 ± 1.5 y, 160.9 ± 6.8 cm, 54.5 ± 7.2 kg). Intervention All athletes received standard off-season training consisting of strength training, plyometrics, and conditioning. They were also videotaped during each session while running on a treadmill at a standardized speed (8 miles/h) and while performing a repeated tuck-jump maneuver for 10 s. The augmented feedback group (AF) received feedback on deficiencies present in a 10-s tuck jump, while the control group (CTRL) received feedback on 10-s treadmill running. Main Outcome Measures Outcome measurements of tuck-jump deficits were scored by a blinded rater to determine the effects of group (CTRL vs AF) and time (pre- vs posttesting) on changes in measured deficits. Results A significant interaction of time by group was noted with the task-Specific feedback training (P = .03). The AF group reduced deficits measured during the tuck-jump assessment by 23.6%, while the CTRL training reduced deficits by 10.6%. Conclusions The results of the current study indicate that task-Specific feedback is effective for reducing biomechanical risk factors associated with ACL injury. The data also indicate that Specific components of the tuck-jump assessment are potentially more modifiable than others. PMID:23238301

Brain-computer interface: changes in performance using virtual reality techniques.

PubMed

Ron-Angevin, Ricardo; Díaz-Estrella, Antonio

2009-01-09

The ability to control electroencephalographic (EEG) signals when different mental tasks are carried out would provide a method of communication for people with serious motor function problems. This system is known as a brain-computer interface (BCI). Due to the difficulty of controlling one's own EEG signals, a suitable training protocol is required to motivate subjects, as it is necessary to provide some type of visual feedback allowing subjects to see their progress. Conventional systems of feedback are based on simple visual presentations, such as a horizontal bar extension. However, virtual reality is a powerful tool with graphical possibilities to improve BCI-feedback presentation. The objective of the study is to explore the advantages of the use of feedback based on virtual reality techniques compared to conventional systems of feedback. Sixteen untrained subjects, divided into two groups, participated in the experiment. A group of subjects was trained using a BCI system, which uses conventional feedback (bar extension), and another group was trained using a BCI system, which submits subjects to a more familiar environment, such as controlling a car to avoid obstacles. The obtained results suggest that EEG behaviour can be modified via feedback presentation. Significant differences in classification error rates between both interfaces were obtained during the feedback period, confirming that an interface based on virtual reality techniques can improve the feedback control, specifically for untrained subjects.

Developing Non-Somatotopic Phantom Finger Sensation to Comparable Levels of Somatotopic Sensation through User Training With Electrotactile Stimulation.

PubMed

Chai, Guohong; Zhang, Dingguo; Zhu, Xiangyang

2017-05-01

Cutaneous electrical stimulation can provide tactile feedback for upper-limb amputees through somatotopic feedback (SF) or non-somatotopic feedback (NF). The SF delivers electrotactile stimulus to projection finger maps (PFMs) on the stumps of amputees, which outperforms NF that transfers stimulus to other human intact skin areas in general. However, the SF areas on stumps are very limited and often occupied by electromyography (EMG) sensors in application of myoelectric prosthesis. This work aims at improving NF performance on human upper arms through user training with electrotactile stimulation. The experiments were conducted over seven consecutive days on nine able-bodied subjects and two forearm amputees. The performance measures of NF/SF included the correct identification rates (CIR s ), the response time and the NASA-TLX questionnaire. The between-day CIR s on NF sites increased logarithmically with a mean course of 3-day rapid-improving phase and plateaued in the relative-steady phase. The response time and NASA-TLX scores could also rapidly reduce to the comparable levels of the SF areas during the same mean period of 3-day rapid-improving phase, respectively. These results indicated that the performance of NF could be highly improved to the equivalent level as that of SF through 3-day electrotactile training, which we named as "3-day effect". It provides important insights that intact skin areas without phantom sensations can effectively replace SF sites to transfer tactile feedback after continuous user training, which validates effectiveness of non-invasive interfaces of tactile feedback for upper-limb amputees in practice.

Feedback to Managers, Volume II: A Review and Comparison of Sixteen Multi-Rater Feedback Instruments.

ERIC Educational Resources Information Center

Van Velsor, Ellen; Leslie, Jean Brittain

"Feedback to Managers" is a two-volume report. Volume 2 compares 16 of the better feedback instruments available. The following are the instruments: (1) ACUMEN Group Feedback; (2) BENCHMARKS; (3) the Campbell Leadership Index; (4) COMPASS: the Managerial Practices Survey; (5) the Executive Success Profile; (6) Leader Behavior Analysis…

The impact of expert- and peer feedback on communication skills of undergraduate dental students - a single-blinded, randomized, controlled clinical trial.

PubMed

Krause, Felix; Schmalz, Gerhard; Haak, Rainer; Rockenbauch, Katrin

2017-12-01

To evaluate the effect of peer- and expert feedback on communication skills of undergraduate dental students. All students of the first clinical treatment course (n=46) were randomly assigned into two groups. For three times a medical-dental interview/consultation of each student with a real patient was videotaped. After every consultation the videos were assessed either by a person experienced in communication (expert group) or by a fellow student (peer group), giving the students feedback regarding their chairside performed communication skills. Before and after the feedback-interventions all students conducted an interview with simulated patients, which was rated using a validated global rating and analyzed statistically. Global ratings mean scores after feedback-intervention were significantly improved (p<0.05). Thereby, no significant differences in the overall assessment could be observed between expert and peer feedback (p>0.05). During this study students improved their communication skills in dentist-patient interactions. The communication experience of the feedback provider seems not to have any impact on the communication skills in undergraduate dental students. The clinical courses in dentistry offer the opportunity to implement peer-feedback interventions in real treatment situation as part of communication training to longitudinally improve communication skills. Copyright © 2017 Elsevier B.V. All rights reserved.

Four quadrant control circuit for a brushless three-phase dc motor

NASA Technical Reports Server (NTRS)

Nola, Frank J. (Inventor)

1987-01-01

A control circuit is provided for a brushless three-phase dc motor which affords four quadrant control from a single command. The control circuit probes acceleration of the motor in both clockwise and counterclockwise directions and braking and generation in both clockwise and counterclockwise directions. In addition to turning on individual transistors of the transistor pairs connected to the phase windings of the motor for 120 deg periods while the other transistor of that pair is off, the control circuit also provides, in a future mode of operation, turning the two transistors of each pair on and off alternately at a phase modulation frequency during such a 120 deg period. A feedback signal is derived which is proportional to the motor current and which has a polarity consistent with the command signal, such that negative feedback results.

The effects of feedback format, and egocentric & allocentric relative phase on coordination stability.

PubMed

Pickavance, John; Azmoodeh, Arianne; Wilson, Andrew D

2018-06-01

The stability of coordinated rhythmic movement is primarily affected by the required mean relative phase. In general, symmetrical coordination is more stable than asymmetrical coordination; however, there are two ways to define relative phase and the associated symmetries. The first is in an egocentric frame of reference, with symmetry defined relative to the sagittal plane down the midline of the body. The second is in an allocentric frame of reference, with symmetry defined in terms of the relative direction of motion. Experiments designed to separate these constraints have shown that both egocentric and allocentric constraints contribute to overall coordination stability, with the former typically showing larger effects. However, separating these constraints has meant comparing movements made either in different planes of motion, or by limbs in different postures. In addition, allocentric information about the coordination is either in the form of the actual limb motion, or a transformed, Lissajous feedback display. These factors limit both the comparisons that can be made and the interpretations of these comparisons. The current study examined the effects of egocentric relative phase, allocentric relative phase, and allocentric feedback format on coordination stability in a single task. We found that while all three independently contributed to stability, the egocentric constraint dominated. This supports previous work. We examine the evidence underpinning theoretical explanations for the egocentric constraint, and describe how it may reflect the haptic perception of relative phase. Copyright © 2018 Elsevier B.V. All rights reserved.

The benefits of a simplified method for CPR training of medical professionals: a randomized controlled study.

PubMed

Allan, Katherine S; Wong, Natalie; Aves, Theresa; Dorian, Paul

2013-08-01

We developed and tested a training method for basic life support incorporating defibrillator feedback during simulated cardiac arrest (CA) to determine the impact on the quality and retention of CPR skills. 298 subjects were randomized into 3 groups. All groups received a 2h training session followed by a simulated CA test scenario, immediately after training and at 3 months. Controls used a non-feedback defibrillator during training and testing. Group 1 was trained and tested with an audiovisual feedback defibrillator. During training, Group 1 reviewed quantitative CPR data from the defibrillator. Group 2 was trained as per Group 1, but was tested using the non-feedback defibrillator. The primary outcome was difference in compression depth between groups at initial testing. Secondary outcomes included differences in rate, depth at retesting, compression fraction, and self-assessment. Groups 1 and 2 had significantly deeper compressions than the controls (35.3 ± 7.6 mm, 43.7 ± 5.8 mm, 42.2 ± 6.6 mm for controls, Groups 1 and 2, P=0.001 for Group 1 vs. controls; P=0.001 for Group 2 vs. controls). At three months, CPR depth was maintained in all groups but remained significantly higher in Group 1 (39.1 ± 9.9 mm, 47.0 ± 7.4 mm, 42.2 ± 8.4 mm for controls, Groups 1 and 2, P=0.001 for Group 1 vs. control). No significant differences were noted between groups in compression rate or fraction. A simplified 2h training method using audiovisual feedback combined with quantitative review of CPR performance improved CPR quality and retention of these skills. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Effect of delayed auditory feedback on stuttering with and without central auditory processing disorders.

PubMed

Picoloto, Luana Altran; Cardoso, Ana Cláudia Vieira; Cerqueira, Amanda Venuti; Oliveira, Cristiane Moço Canhetti de

2017-12-07

To verify the effect of delayed auditory feedback on speech fluency of individuals who stutter with and without central auditory processing disorders. The participants were twenty individuals with stuttering from 7 to 17 years old and were divided into two groups: Stuttering Group with Auditory Processing Disorders (SGAPD): 10 individuals with central auditory processing disorders, and Stuttering Group (SG): 10 individuals without central auditory processing disorders. Procedures were: fluency assessment with non-altered auditory feedback (NAF) and delayed auditory feedback (DAF), assessment of the stuttering severity and central auditory processing (CAP). Phono Tools software was used to cause a delay of 100 milliseconds in the auditory feedback. The "Wilcoxon Signal Post" test was used in the intragroup analysis and "Mann-Whitney" test in the intergroup analysis. The DAF caused a statistically significant reduction in SG: in the frequency score of stuttering-like disfluencies in the analysis of the Stuttering Severity Instrument, in the amount of blocks and repetitions of monosyllabic words, and in the frequency of stuttering-like disfluencies of duration. Delayed auditory feedback did not cause statistically significant effects on SGAPD fluency, individuals with stuttering with auditory processing disorders. The effect of delayed auditory feedback in speech fluency of individuals who stutter was different in individuals of both groups, because there was an improvement in fluency only in individuals without auditory processing disorder.

The use of mHealth to deliver tailored messages reduces reported energy and fat intake

PubMed Central

Ambeba, Erica J.; Ye, Lei; Sereika, Susan M.; Styn, Mindi A.; Acharya, Sushama D.; Sevick, Mary Ann; Ewing, Linda J.; Conroy, Molly B.; Glanz, Karen; Zheng, Yaguang; Goode, Rachel W.; Mattos, Meghan; Burke, Lora E.

2016-01-01

Background Evidence supports the role of feedback in reinforcing motivation for behavior change. Feedback that provides reinforcement has the potential to increase dietary self-monitoring and enhance attainment of recommended dietary intake. Objective To examine the impact of daily feedback (DFB) messages, delivered remotely, on changes in dietary intake. Methods A secondary analysis of the SMART trial, a single-center, 24-month randomized clinical trial of behavioral treatment for weight loss. Participants included 210 obese adults (mean body mass index=34.0 kg/m2) who were randomized to either a paper diary (PD), personal digital assistant (PDA), or PDA plus daily, tailored feedback messages (PDA+FB). To determine the role of daily tailored feedback in dietary intake, we compared the self-monitoring with daily feedback group (DFB, n=70) to the self-monitoring without daily feedback group (No-DFB, n=140). All participants received a standard behavioral intervention for weight loss. Self-reported changes in dietary intake were compared between the DFB and No-DFB groups and were measured at baseline, 6, 12, 18, and 24 months. Linear mixed modeling was used to examine percent changes in dietary intake from baseline. Results Compared to the No-DFB group, the DFB group achieved a larger reduction in energy (−22.8% vs. −14.0%, p=0.02) and saturated fat (−11.3% vs. −0.5%, p=0.03) intake, and a trend toward a greater decrease in total fat intake (−10.4% vs. −4.7%, p=0.09). There were significant improvements over time in carbohydrate intake and total fat intake for both groups (p’s<0.05). Conclusion Daily, tailored feedback messages, designed to target energy and fat intake and delivered remotely in real-time using mobile devices, may play an important role in the reduction of energy and fat intake. PMID:24434827

Coexisting synchronous and asynchronous states in locally coupled array of oscillators by partial self-feedback control

NASA Astrophysics Data System (ADS)

Bera, Bidesh K.; Ghosh, Dibakar; Parmananda, Punit; Osipov, G. V.; Dana, Syamal K.

2017-07-01

We report the emergence of coexisting synchronous and asynchronous subpopulations of oscillators in one dimensional arrays of identical oscillators by applying a self-feedback control. When a self-feedback is applied to a subpopulation of the array, similar to chimera states, it splits into two/more sub-subpopulations coexisting in coherent and incoherent states for a range of self-feedback strength. By tuning the coupling between the nearest neighbors and the amount of self-feedback in the perturbed subpopulation, the size of the coherent and the incoherent sub-subpopulations in the array can be controlled, although the exact size of them is unpredictable. We present numerical evidence using the Landau-Stuart system and the Kuramoto-Sakaguchi phase model.

Feedback Driven Chemical Evolution in Simulations of Low Mass Dwarf Galaxies

NASA Astrophysics Data System (ADS)

Emerick, Andrew; Bryan, Greg; Mac Low, Mordecai-Mark

2018-06-01

Galaxy chemical properties place some of the best constraints on models of galaxy evolution. Both gas and stellar metal abundances in galaxies depend upon the integrated star formation history of the galaxy, gas accretion, outflows, and the effectiveness of metal mixing within the interstellar medium (ISM). Capturing the physics that governs these processes in detail, however, is challenging, in part due to the difficulty in self-consistently modelling stellar feedback physics that impacts each of these processes. Using high resolution hydrodynamics simulations of isolated dwarf galaxies where we follow stars as individual star particles, we examine the role of feedback in driving dwarf galaxy chemical evolution. This star-by-star method allows us to directly follow feedback from stellar winds from massive and AGB stars, stellar ionizing radiation and photoelectric heating, and supernovae. Additionally, we track 15 individual metal species yields from these stars as they pollute the ISM and enrich new stellar populations. I will present initial results from these simulations in the context of observational constraints on the retention/ejection of metals from Local Group dwarf galaxies. In addition, I will discuss the variations with which individual elements evolve in the various phases of the ISM, as they progress from hot, ionized gas down to cold, star forming regions. I will conclude by outlining the implications of these results on interpretations of observed chemical abundances in dwarf galaxies and on standard assumptions made in semi-analytic chemical evolution models of these galaxies.

What would you do? The effect of verbal persuasion on task choice.

PubMed

Lamarche, Larkin; Gionfriddo, Alicia M; Cline, Lindsay E; Gammage, Kimberley L; Adkin, Allan L

2014-01-01

Verbal persuasion has been shown to influence psychological and behavioral outcomes. The present study had two objectives: (1) to examine the effect of verbal persuasion on task choice in a balance setting and (2) to evaluate the use of verbal persuasion as an approach to experimentally induce mismatches between perceived and actual balance. Healthy young adults (N=68) completed an 8-m tandem walk task without vision and then were randomly assigned to a feedback group (good, control, or poor), regardless of actual balance. Following the feedback, participants chose to perform the task in one of three conditions differing in level of challenge and also were required to perform the task under the same pre-feedback conditions. Balance efficacy and perceived stability were rated before and after each pre- and post-feedback task, respectively. Balance performance measures were also collected. Following the feedback, participants in the good group were more likely to choose the most challenging task while those in the poor group were more likely to choose the least challenging task. Following the feedback, all groups showed improved balance performance. However, balance efficacy and perceived stability increased for the good and control groups but balance efficacy decreased and perceived stability was unchanged for the poor group. Thus, these findings demonstrate that verbal persuasion can influence task choice and may be used as an approach to experimentally create mismatches between perceived and actual balance. Copyright © 2013 Elsevier B.V. All rights reserved.

Inertial sensors as real-time feedback improve learning posterior-anterior thoracic manipulation: a randomized controlled trial.

PubMed

Cuesta-Vargas, Antonio I; González-Sánchez, Manuel; Lenfant, Yves

2015-01-01

The purpose of this study was to analyze the effect of real-time feedback on the learning process for posterior-anterior thoracic manipulation (PATM) comparing 2 undergraduate physiotherapy student groups. The study design was a randomized controlled trial in an educational setting. Sixty-one undergraduate physiotherapy students were divided randomly into 2 groups, G1 (n = 31; group without feedback in real time) and G2 (n = 30; group with real-time feedback) participated in this randomized controlled trial. Two groups of physiotherapy students learned PATM, one using a traditional method and the other using real-time feedback (inertial sensor). Measures were obtained preintervention and postintervention. Intragroup preintervention and postintervention and intergroup postintervention scores were calculated. An analysis of the measures' stability was developed through an interclass correlation index. Time, displacement and velocity, and improvement (only between groups) to reach maximum peak and to reach minimum peak from maximum peak, total manipulation time, and stability of all outcome measures were the outcome measures. Statistically significant differences were found in all variables analyzed (intragroup and intergroup) in favor of G2. The values of interclass correlation ranged from 0.627 to 0.706 (G1) and between 0.881 and 0.997 (G2). This study found that the learning process for PATM is facilitated when the student receives real-time feedback. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

Simple analytical model reveals the functional role of embodied sensorimotor interaction in hexapod gaits

PubMed Central

Aoi, Shinya; Nachstedt, Timo; Manoonpong, Poramate; Wörgötter, Florentin; Matsuno, Fumitoshi

2018-01-01

Insects have various gaits with specific characteristics and can change their gaits smoothly in accordance with their speed. These gaits emerge from the embodied sensorimotor interactions that occur between the insect’s neural control and body dynamic systems through sensory feedback. Sensory feedback plays a critical role in coordinated movements such as locomotion, particularly in stick insects. While many previously developed insect models can generate different insect gaits, the functional role of embodied sensorimotor interactions in the interlimb coordination of insects remains unclear because of their complexity. In this study, we propose a simple physical model that is amenable to mathematical analysis to explain the functional role of these interactions clearly. We focus on a foot contact sensory feedback called phase resetting, which regulates leg retraction timing based on touchdown information. First, we used a hexapod robot to determine whether the distributed decoupled oscillators used for legs with the sensory feedback generate insect-like gaits through embodied sensorimotor interactions. The robot generated two different gaits and one had similar characteristics to insect gaits. Next, we proposed the simple model as a minimal model that allowed us to analyze and explain the gait mechanism through the embodied sensorimotor interactions. The simple model consists of a rigid body with massless springs acting as legs, where the legs are controlled using oscillator phases with phase resetting, and the governed equations are reduced such that they can be explained using only the oscillator phases with some approximations. This simplicity leads to analytical solutions for the hexapod gaits via perturbation analysis, despite the complexity of the embodied sensorimotor interactions. This is the first study to provide an analytical model for insect gaits under these interaction conditions. Our results clarified how this specific foot contact sensory feedback contributes to generation of insect-like ipsilateral interlimb coordination during hexapod locomotion. PMID:29489831

The effect of feedback on attitudes toward cellular phone use while driving: a comparison between novice and experienced drivers.

PubMed

Wang, Ying; Zhang, Wei; Reimer, Bryan; Lavallière, Martin; Lesch, Mary F; Horrey, William J; Wu, Su

2010-10-01

To assess and compare the effectiveness of a simulation-based approach to change drivers' attitudes toward cellular phone use while driving for younger novice and older experienced drivers. Thirty young novice drivers were tested on a driving simulator in this study. Their performance in dealing with driving tasks was measured for a single task and dual tasks (driving while using a cellular phone) and compared to 30 older experienced drivers tested previously in another study. Half of the younger drivers received video-based feedback regarding their performance in the two conditions, with an emphasis on the contribution of dual-tasking to degraded performance. The other half did not receive any performance feedback. Drivers' perceptions and attitudes toward cellular phone use while driving were investigated by a questionnaire before, immediately after, and again one month following the simulation-based testing for both groups of drivers (feedback; no feedback). All drivers (including the novice and experienced) reported willingness to engage in driving and talking on a cellular phone in some situations. The simulated driving test showed that a secondary cellular phone task significantly degraded driving performance for both the novice and the experienced drivers. The feedback treatment group (both the novice and the experienced) showed significant attitude change toward cellular phone use while driving (toward being less favorable), whereas the control group had no attitude change. At the one-month follow-up, the benefit of feedback was sustained more so in the experienced driver group than the novice driver group, although both groups still benefited relative to the control conditions. Simulation-based feedback training is promising for short-term education in novice drivers but may be more effective in the long-term for drivers with higher levels of experience. Drivers with more experience appear to have a greater, more sustained benefit from the training than novices. Additional research is needed to better tailor this education method toward novice drivers. Simulation-based participative education approach through feedback needs to be better tailored toward novice drivers.

Real-time augmented feedback benefits robotic laparoscopic training.

PubMed

Judkins, Timothy N; Oleynikov, Dmitry; Stergiou, Nick

2006-01-01

Robotic laparoscopic surgery has revolutionized minimally invasive surgery for treatment of abdominal pathologies. However, current training techniques rely on subjective evaluation. There is a lack of research on the type of tasks that should be used for training. Robotic surgical systems also do not currently have the ability to provide feedback to the surgeon regarding success of performing tasks. We trained medical students on three laparoscopic tasks and provided real-time feedback of performance during training. We found that real-time feedback can benefit training if the feedback provides information that is not available through other means (grip force). Subjects that received grip force feedback applied less force when the feedback was removed. Other forms of feedback (speed and relative phase) did not aid or impede training. Secondly, a relatively short training period (10 trials for each task) significantly improved most objective measures of performance. We also showed that robotic surgical performance can be quantitatively measured and evaluated. Providing grip force feedback can make the surgeon more aware of the forces being applied to delicate tissue during surgery.

Reward Expectation Modulates Feedback-Related Negativity and EEG Spectra

PubMed Central

Cohen, Michael X; Elger, Christian E.; Ranganath, Charan

2007-01-01

The ability to evaluate outcomes of previous decisions is critical to adaptive decision-making. The feedback-related negativity (FRN) is an event-related potential (ERP) modulation that distinguishes losses from wins, but little is known about the effects of outcome probability on these ERP responses. Further, little is known about the frequency characteristics of feedback processing, for example, event-related oscillations and phase synchronizations. Here, we report an EEG experiment designed to address these issues. Subjects engaged in a probabilistic reinforcement learning task in which we manipulated, across blocks, the probability of winning and losing to each of two possible decision options. Behaviorally, all subjects quickly adapted their decision-making to maximize rewards. ERP analyses revealed that the probability of reward modulated neural responses to wins, but not to losses. This was seen both across blocks as well as within blocks, as learning progressed. Frequency decomposition via complex wavelets revealed that EEG responses to losses, compared to wins, were associated with enhanced power and phase coherence in the theta frequency band. As in the ERP analyses, power and phase coherence values following wins but not losses were modulated by reward probability. Some findings between ERP and frequency analyses diverged, suggesting that these analytic approaches provide complementary insights into neural processing. These findings suggest that the neural mechanisms of feedback processing may differ between wins and losses. PMID:17257860

Enhancing Productivity Through Feedback and Goal Setting. Final Report.

ERIC Educational Resources Information Center

Pritchard, Robert D.; And Others

A field test was conducted to research the effects of feedback and goal-setting techniques on increasing productivity. Subjects were regular employees of two autonomous clerical-type units in a credit card and payment processing center of a Southwestern oil company. The study desiqn had three phases--baseline period and two experimental conditions…

The Effects of Physical Activity Feedback on Behavior and Awareness in Employees: Study Protocol for a Randomized Controlled Trial

PubMed Central

Van Hoye, Karen; Boen, Filip; Lefevre, Johan

2012-01-01

Purpose. The SenseWear Armband (SWA) is a multisensor activity monitor that can be used in daily life to assess an individual's physical activity level (PAL). The primary goal of this study was to analyze the impact of different types of feedback on the PAL of Flemish employees. Methods/Design. We recruited 320 sedentary employees (age, 41.0 ± 10.7 years; BMI, 26.2 ± 4.2 kg/m2) to participate in the 12-month study. Participants were randomized into one of four intervention groups after being measured for 7 days and nights by means of the SWA: (1) a minimal intervention group received no feedback (MIG, n = 56); (2) a pedometer group was provided only information on their daily step count (PG, n = 57); (3) a display group received feedback on calories burned, steps taken, and minutes of physical activity by means of the SWA display (DG, n = 57); (4) a coaching group also received the display and had weekly meetings with a Personal Coach (CoachG, n = 57). We hypothesize that participants receiving feedback (SG, DG, and CoachG) will have a greater increase in physical activity outcome variables compared to participants of the minimal intervention group. PMID:23056040

Chaos synchronization in vertical-cavity surface-emitting laser based on rotated polarization-preserved optical feedback.

PubMed

Nazhan, Salam; Ghassemlooy, Zabih; Busawon, Krishna

2016-01-01

In this paper, the influence of the rotating polarization-preserved optical feedback on the chaos synchronization of a vertical-cavity surface-emitting laser (VCSEL) is investigated experimentally. Two VCSELs' polarization modes (XP) and (YP) are gradually rotated and re-injected back into the VCSEL. The anti-phase dynamics synchronization of the two polarization modes is evaluated using the cross-correlation function. For a fixed optical feedback, a clear relationship is found between the cross-correlation coefficient and the polarization angle θp. It is shown that high-quality anti-phase polarization-resolved chaos synchronization is achieved at higher values of θp. The maximum value of the cross-correlation coefficient achieved is -0.99 with a zero time delay over a wide range of θp beyond 65° with a poor synchronization dynamic at θp less than 65°. Furthermore, it is observed that the antiphase irregular oscillation of the XP and YP modes changes with θp. VCSEL under the rotating polarization optical feedback can be a good candidate as a chaotic synchronization source for a secure communication system.

Lack of transfer of skills after virtual reality simulator training with haptic feedback.

PubMed

Våpenstad, Cecilie; Hofstad, Erlend Fagertun; Bø, Lars Eirik; Kuhry, Esther; Johnsen, Gjermund; Mårvik, Ronald; Langø, Thomas; Hernes, Toril Nagelhus

2017-12-01

Virtual reality (VR) simulators enrich surgical training and offer training possibilities outside of the operating room (OR). In this study, we created a criterion-based training program on a VR simulator with haptic feedback and tested it by comparing the performances of a simulator group against a control group. Medical students with no experience in laparoscopy were randomly assigned to a simulator group or a control group. In the simulator group, the candidates trained until they reached predefined criteria on the LapSim ® VR simulator (Surgical Science AB, Göteborg, Sweden) with haptic feedback (Xitact TM IHP, Mentice AB, Göteborg, Sweden). All candidates performed a cholecystectomy on a porcine organ model in a box trainer (the clinical setting). The performances were video rated by two surgeons blinded to subject training status. In total, 30 students performed the cholecystectomy and had their videos rated (N = 16 simulator group, N = 14 control group). The control group achieved better video rating scores than the simulator group (p < .05). The criterion-based training program did not transfer skills to the clinical setting. Poor mechanical performance of the simulated haptic feedback is believed to have resulted in a negative training effect.

Comparing Learning Gains: Audio Versus Text-based Instructor Communication in a Blended Online Learning Environment

NASA Astrophysics Data System (ADS)

Shimizu, Dominique

Though blended course audio feedback has been associated with several measures of course satisfaction at the postsecondary and graduate levels compared to text feedback, it may take longer to prepare and positive results are largely unverified in K-12 literature. The purpose of this quantitative study was to investigate the time investment and learning impact of audio communications with 228 secondary students in a blended online learning biology unit at a central Florida public high school. A short, individualized audio message regarding the student's progress was given to each student in the audio group; similar text-based messages were given to each student in the text-based group on the same schedule; a control got no feedback. A pretest and posttest were employed to measure learning gains in the three groups. To compare the learning gains in two types of feedback with each other and to no feedback, a controlled, randomized, experimental design was implemented. In addition, the creation and posting of audio and text feedback communications were timed in order to assess whether audio feedback took longer to produce than text only feedback. While audio feedback communications did take longer to create and post, there was no difference between learning gains as measured by posttest scores when student received audio, text-based, or no feedback. Future studies using a similar randomized, controlled experimental design are recommended to verify these results and test whether the trend holds in a broader range of subjects, over different time frames, and using a variety of assessment types to measure student learning.

Effects of Feeding Back the Motivation of a Collaboratively Learning Group

ERIC Educational Resources Information Center

Schoor, Cornelia; Kownatzki, Salome; Narciss, Susanne; Körndle, Hermann

2014-01-01

Introduction: Motivation is an important issue in both face-to-face and computer-supported collaborative learning. There are several approaches for enhancing motivation, including group awareness tools that provide feedback on the group's motivation. However, this feedback was rarely unconfounded with other constructs. Additionally, it is…

Videotape Self-Confrontation in Human Relations Training

ERIC Educational Resources Information Center

Martin, Roger D.

1971-01-01

Results indicate that the effects of videotape feedback are not necessarily predictable, and may cause either beneficial or detrimental group behavior change. Videotape feedback also seems to have markedly different effects on different groups. Conclusions are presented regarding the appropriateness of time-series research designs with T groups.…

North American Wood Waste Forum: Summary of Group Feedback, 2-3, 2012

Treesearch

Bob Falk

2012-01-01

This report summarizes the feedback and recommendations of the North American Wood Recovery Group. This report summarizes the barriers and opportunities in wood recovery, reuse, and recycling as identified by this group of stakeholders from the wood industry, waste industry, and relevant government agencies.

The Contextualized Technology Adaptation Process (CTAP): Optimizing Health Information Technology to Improve Mental Health Systems.

PubMed

Lyon, Aaron R; Wasse, Jessica Knaster; Ludwig, Kristy; Zachry, Mark; Bruns, Eric J; Unützer, Jürgen; McCauley, Elizabeth

2016-05-01

Health information technologies have become a central fixture in the mental healthcare landscape, but few frameworks exist to guide their adaptation to novel settings. This paper introduces the contextualized technology adaptation process (CTAP) and presents data collected during Phase 1 of its application to measurement feedback system development in school mental health. The CTAP is built on models of human-centered design and implementation science and incorporates repeated mixed methods assessments to guide the design of technologies to ensure high compatibility with a destination setting. CTAP phases include: (1) Contextual evaluation, (2) Evaluation of the unadapted technology, (3) Trialing and evaluation of the adapted technology, (4) Refinement and larger-scale implementation, and (5) Sustainment through ongoing evaluation and system revision. Qualitative findings from school-based practitioner focus groups are presented, which provided information for CTAP Phase 1, contextual evaluation, surrounding education sector clinicians' workflows, types of technologies currently available, and influences on technology use. Discussion focuses on how findings will inform subsequent CTAP phases, as well as their implications for future technology adaptation across content domains and service sectors.

Parity-time–symmetric optoelectronic oscillator

PubMed Central

2018-01-01

An optoelectronic oscillator (OEO) is a hybrid microwave and photonic system incorporating an amplified positive feedback loop to enable microwave oscillation to generate a high-frequency and low–phase noise microwave signal. The low phase noise is ensured by the high Q factor of the feedback loop enabled by the use of a long and low-loss optical fiber. However, an OEO with a long fiber loop would have a small free spectral range, leading to a large number of closely spaced oscillation modes. To ensure single-mode oscillation, an ultranarrowband optical filter must be used, but such an optical filter is hard to implement and the stability is poor. Here, we use a novel concept to achieve single-mode oscillation without using an ultranarrowband optical filter. The single-mode operation is achieved based on parity-time (PT) symmetry by using two identical feedback loops, with one having a gain and the other having a loss of the same magnitude. The operation is analyzed theoretically and verified by an experiment. Stable single-mode oscillation at an ultralow phase noise is achieved without the use of an ultranarrowband optical filter. The use of PT symmetry in an OEO overcomes the long-existing mode-selection challenge that would greatly simplify the implementation of OEOs for ultralow–phase noise microwave generation. PMID:29888325

The effects of driver identity on driving safety in a retrospective feedback system.

PubMed

Zhao, Guozhen; Wu, Changxu

2012-03-01

Retrospective feedback that provides detailed information on a driver's performance in critical driving situations at the end of a trip enhances his/her driving behaviors and safe driving habits. Although this has been demonstrated by a previous study, retrospective feedback can be further improved and applied to non-critical driving situations, which is needed for transportation safety. To propose a new retrospective feedback system that uses driver identity (i.e., a driver's name) and to experimentally study its effects on measures of driving performance and safety in a driving simulator. We conducted a behavioral experimental study with 30 participants. "Feedback type" was a between-subject variable with three conditions: no feedback (control group), feedback without driver identity, and feedback with driver identity. We measured multiple aspects of participants' driving behavior. To control for potential confounds, factors that were significantly correlated with driving behavior (e.g., age and driving experience) were all entered as covariates into a multivariate analysis of variance. To examine the effects of speeding on collision severity in driving simulation studies, we also developed a new index - momentum of potential collision - with a set of equations. Subjects who used a feedback system with driver identity had the fewest speeding violations and central-line crossings, spent the least amount of time speeding and crossing the central line, had the lowest speeding and central-line crossing magnitude, ran the fewest red lights, and had the smallest momentum of potential collision compared to the groups with feedback without driver identity and without feedback (control group). The new retrospective feedback system with driver identity has the potential to enhance a person's driving safety (e.g., speeding, central-line crossing, momentum of potential collision), which is an indication of the valence of one's name in a feedback system design. Copyright © 2011 Elsevier Ltd. All rights reserved.

Amount of kinematic feedback affects learning of speech motor skills.

PubMed

Ballard, Kirrie J; Smith, Heather D; Paramatmuni, Divija; McCabe, Patricia; Theodoros, Deborah G; Murdoch, Bruce E

2012-01-01

Knowledge of Performance (KP) feedback, such as biofeedback or kinematic feedback, is used to provide information on the nature and quality of movement responses for the purpose of guiding active learning or rehabilitation of motor skills. It has been proposed that KP feedback may interfere with long-term learning when provided throughout training. Here, twelve healthy English-speaking adults were trained to produce a trilled Russian [r] in words with KP kinematic feedback using electropalatography (EPG) and without KP (noKP). Five one-hour training sessions were provided over one week with testing pretraining and one day and one week posttraining. No group differences were found at pretraining or one day post training for production accuracy. A group by time interaction supported the hypothesis that providing kinematic feedback continually during skill acquisition interferes with retention.

Using electronic patient records to inform strategic decision making in primary care.

PubMed

Mitchell, Elizabeth; Sullivan, Frank; Watt, Graham; Grimshaw, Jeremy M; Donnan, Peter T

2004-01-01

Although absolute risk of death associated with raised blood pressure increases with age, the benefits of treatment are greater in elderly patients. Despite this, the 'rule of halves' particularly applies to this group. We conducted a randomised controlled trial to evaluate different levels of feedback designed to improve identification, treatment and control of elderly hypertensives. Fifty-two general practices were randomly allocated to either: Control (n=19), Audit only feedback (n=16) or Audit plus Strategic feedback, prioritising patients by absolute risk (n=17). Feedback was based on electronic data, annually extracted from practice computer systems. Data were collected for 265,572 patients, 30,345 aged 65-79. The proportion of known hypertensives in each group with BP recorded increased over the study period and the numbers of untreated and uncontrolled patients reduced. There was a significant difference in mean systolic pressure between the Audit plus Strategic and Audit only groups and significantly greater control in the Audit plus Strategic group. Providing patient-specific practice feedback can impact on identification and management of hypertension in the elderly and produce a significant increase in control.

The role of intelligence and feedback in children's strategy competence.

PubMed

Luwel, Koen; Foustana, Ageliki; Papadatos, Yiannis; Verschaffel, Lieven

2011-01-01

A test-intervention-test study was conducted investigating the role of intelligence on four parameters of strategy competence in the context of a numerosity judgment task. Moreover, the effectiveness of two feedback types on these four parameters was tested. In the two test sessions, the choice/no-choice method was used to assess the strategy repertoire, frequency, efficiency, and adaptivity of a group of low-, average-, and high-intelligence children. During the intervention, half of the participants from each intelligence group were given outcome feedback (OFB), whereas the other half received strategy feedback (SFB). The pretest data showed large differences among the three intelligence groups on all four strategy parameters. These differences had disappeared at the posttest due to a particularly strong improvement on all strategy parameters in the low-intelligence group. Furthermore, it was found that SFB was more beneficial than OFB for all parameters involving strategy selection. These results indicate that intelligence plays an important role in children's strategy use and suggest that strategy feedback can be a powerful instructional tool, especially for low-intelligence children. Copyright © 2010 Elsevier Inc. All rights reserved.

Chaotic oscillations and noise transformations in a simple dissipative system with delayed feedback

NASA Astrophysics Data System (ADS)

Zverev, V. V.; Rubinstein, B. Ya.

1991-04-01

We analyze the statistical behavior of signals in nonlinear circuits with delayed feedback in the presence of external Markovian noise. For the special class of circuits with intense phase mixing we develop an approach for the computation of the probability distributions and multitime correlation functions based on the random phase approximation. Both Gaussian and Kubo-Andersen models of external noise statistics are analyzed and the existence of the stationary (asymptotic) random process in the long-time limit is shown. We demonstrate that a nonlinear system with chaotic behavior becomes a noise amplifier with specific statistical transformation properties.

Assessing Affective and Deliberative Decision-Making: Adaptation of the Columbia Card Task to Brazilian Portuguese.

PubMed

Kluwe-Schiavon, Bruno; Sanvicente-Vieira, Breno; Viola, Thiago W; Veiga, Eduardo; Bortolotto, Vanessa; Grassi-Oliveira, Rodrigo

2015-11-20

The ability to predict reward and punishment is essential for decision-making and the ability to learn about an ever-changing environment. Therefore, efforts have been made in understanding the mechanisms underlying decision-making, especially regarding how affective and deliberative processes interact with risk behavior. To adapt to Brazilian Portuguese the Columbia Card Task (CCT) and investigate affective and deliberative processes involved in decision-making. This study had two main phases: (1) a transcultural adaptation and (2) a pilot study. The feedback manipulation among the three conditions of CCT had an effect on the risk-taking level (p < .005, ES = .201). In addition, the feedback manipulation among the three conditions of CCT had an effect on the information use at both the individual and group levels. Further, a linear regression suggested that the use of information, indicated by the advantageous level of the scenarios, predict the number of cards chosen R 2 = .029, p < .001, accounting for 17% of the variance. The Brazilian CCT performs well and is a versatile method for the assessment of affective and deliberative decision-making under risk according to different feedback manipulation scenarios. This study goes further, comparing electrodermal activity during hot and warm conditions and addressing an advantageous level index analysis to asses deliberative processing.

Adaptation effects in static postural control by providing simultaneous visual feedback of center of pressure and center of gravity.

PubMed

Takeda, Kenta; Mani, Hiroki; Hasegawa, Naoya; Sato, Yuki; Tanaka, Shintaro; Maejima, Hiroshi; Asaka, Tadayoshi

2017-07-19

The benefit of visual feedback of the center of pressure (COP) on quiet standing is still debatable. This study aimed to investigate the adaptation effects of visual feedback training using both the COP and center of gravity (COG) during quiet standing. Thirty-four healthy young adults were divided into three groups randomly (COP + COG, COP, and control groups). A force plate was used to calculate the coordinates of the COP in the anteroposterior (COP AP ) and mediolateral (COP ML ) directions. A motion analysis system was used to calculate the coordinates of the center of mass (COM) in both directions (COM AP and COM ML ). The coordinates of the COG in the AP direction (COG AP ) were obtained from the force plate signals. Augmented visual feedback was presented on a screen in the form of fluctuation circles in the vertical direction that moved upward as the COP AP and/or COG AP moved forward and vice versa. The COP + COG group received the real-time COP AP and COG AP feedback simultaneously, whereas the COP group received the real-time COP AP feedback only. The control group received no visual feedback. In the training session, the COP + COG group was required to maintain an even distance between the COP AP and COG AP and reduce the COG AP fluctuation, whereas the COP group was required to reduce the COP AP fluctuation while standing on a foam pad. In test sessions, participants were instructed to keep their standing posture as quiet as possible on the foam pad before (pre-session) and after (post-session) the training sessions. In the post-session, the velocity and root mean square of COM AP in the COP + COG group were lower than those in the control group. In addition, the absolute value of the sum of the COP - COM distances in the COP + COG group was lower than that in the COP group. Furthermore, positive correlations were found between the COM AP velocity and COP - COM parameters. The results suggest that the novel visual feedback training that incorporates the COP AP -COG AP interaction reduces postural sway better than the training using the COP AP alone during quiet standing. That is, even COP AP fluctuation around the COG AP would be effective in reducing the COM AP velocity.

Method and apparatus for controlling carrier envelope phase

DOEpatents

Chang, Zenghu [Manhattan, KS; Li, Chengquan [Sunnyvale, CA; Moon, Eric [Manhattan, KS

2011-12-06

A chirped pulse amplification laser system. The system generally comprises a laser source, a pulse modification apparatus including first and second pulse modification elements separated by a separation distance, a positioning element, a measurement device, and a feedback controller. The laser source is operable to generate a laser pulse and the pulse modification apparatus operable to modify at least a portion of the laser pulse. The positioning element is operable to reposition at least a portion of the pulse modification apparatus to vary the separation distance. The measurement device is operable to measure the carrier envelope phase of the generated laser pulse and the feedback controller is operable to control the positioning element based on the measured carrier envelope phase to vary the separation distance of the pulse modification elements and control the carrier envelope phase of laser pulses generated by the laser source.

Motivational and metacognitive feedback in SQL-Tutor*

NASA Astrophysics Data System (ADS)

Hull, Alison; du Boulay, Benedict

2015-04-01

Motivation and metacognition are strongly intertwined, with learners high in self-efficacy more likely to use a variety of self-regulatory learning strategies, as well as to persist longer on challenging tasks. The aim of the research was to improve the learner's focus on the process and experience of problem-solving while using an Intelligent Tutoring System (ITS) and including motivational and metacognitive feedback based on the learner's past states and experiences. An existing ITS, SQL-Tutor, was used with first-year undergraduates studying a database module. The study used two versions of SQL-Tutor: the Control group used a base version providing domain feedback and the Study group used an extended version that also provided motivational and metacognitive feedback. This paper summarises the pre- and post-process results. Comparisons between groups showed some differing trends both in learning outcomes and behaviour in favour of the Study group.

Visual crowding illustrates the inadequacy of local vs. global and feedforward vs. feedback distinctions in modeling visual perception

PubMed Central

Clarke, Aaron M.; Herzog, Michael H.; Francis, Gregory

2014-01-01

Experimentalists tend to classify models of visual perception as being either local or global, and involving either feedforward or feedback processing. We argue that these distinctions are not as helpful as they might appear, and we illustrate these issues by analyzing models of visual crowding as an example. Recent studies have argued that crowding cannot be explained by purely local processing, but that instead, global factors such as perceptual grouping are crucial. Theories of perceptual grouping, in turn, often invoke feedback connections as a way to account for their global properties. We examined three types of crowding models that are representative of global processing models, and two of which employ feedback processing: a model based on Fourier filtering, a feedback neural network, and a specific feedback neural architecture that explicitly models perceptual grouping. Simulations demonstrate that crucial empirical findings are not accounted for by any of the models. We conclude that empirical investigations that reject a local or feedforward architecture offer almost no constraints for model construction, as there are an uncountable number of global and feedback systems. We propose that the identification of a system as being local or global and feedforward or feedback is less important than the identification of a system's computational details. Only the latter information can provide constraints on model development and promote quantitative explanations of complex phenomena. PMID:25374554

Distinct processing of social and monetary rewards in late adolescents with trait anhedonia.

PubMed

Chan, Raymond C K; Li, Zhi; Li, Ke; Zeng, Ya-Wei; Xie, Wei-Zhen; Yan, Chao; Cheung, Eric F C; Jin, Zhen

2016-03-01

Anticipatory and consummatory dissociation of hedonic experience may manifest as trait anhedonia in healthy and clinical populations. It is still unclear whether the underlying neural mechanisms of the monetary-based and affect-based incentive delay paradigms are distinct from each other. The present study aimed to examine the similarities and differences between the Affect Incentive Delay (AID) and the Monetary Incentive Delay (MID) imaging paradigms in relation to brain activations. We administered the AID and the MID imaging tasks to 28 adolescent participants. A cue signaling the type of forthcoming feedback (reward or punishment) was displayed to the participants, followed by a target-hit task with corresponding reward or punishment. The striatal and limbic regions were activated during the anticipatory phase of MID, while there was no brain activation during the anticipatory phase of AID. In the consummatory phase, the MID task activated the medial frontal cortex, while the AID task activated the frontal and dorsal limbic regions. We further found that the anhedonic group exhibited significant hypoactivation than the nonanhedonic group at the left pulvinar, the left claustrum and the left insula to positive cues in the anticipatory phase of the AID task. The results suggest that the AID and the MID tasks have unique activation patterns. Our findings also suggest that the AID task may be more sensitive in detecting anhedonia in people with trait anhedonia. (c) 2016 APA, all rights reserved).

Primary and submovement control of aiming in C6 tetraplegics following posterior deltoid transfer

PubMed Central

2014-01-01

Background Upper limb motor control in fast, goal-directed aiming is altered in tetraplegics following posterior-deltoid musculotendinous transfer. Specifically, movements have similar end-point accuracy but longer duration and lower peak velocity than those of age-matched, neurotypical controls. Here, we examine in detail the interplay between primary movement and submovement phases in five C6 tetraplegic and five control participants. Methods Aiming movements were performed in two directions (20 cm away or toward), with or without vision. Trials that contained a submovement phase (i.e., discontinuity in velocity, acceleration or jerk) were identified. Discrete kinematic variables were then extracted on the primary and submovements phases. Results The presence of submovements did not differ between the tetraplegic (68%) and control (57%) groups, and almost all submovements resulted from acceleration and jerk discontinuities. Tetraplegics tended to make a smaller amplitude primary movement, which had lower peak velocity and greater spatial variability at peak velocity. This was followed by a larger amplitude and longer duration secondary submovement. Peak velocity of primary movement was not related to submovement incidence. Together, the primary and submovement phases of both groups were equally effective in reducing end-point error. Conclusions C6 tetraplegic participants exhibit some subtle differences in measures of motor behaviour compared to control participants, but importantly feedforward and feedback processes work effectively in combination to achieve accurate goal-directed aiming. PMID:25055852

Performance monitoring during associative learning and its relation to obsessive-compulsive characteristics.

PubMed

Doñamayor, Nuria; Dinani, Jakob; Römisch, Manuel; Ye, Zheng; Münte, Thomas F

2014-10-01

Neural responses to performance errors and external feedback have been suggested to be altered in obsessive-compulsive disorder. In the current study, an associative learning task was used in healthy participants assessed for obsessive-compulsive symptoms by the OCI-R questionnaire. The task included a condition with equivocal feedback that did not inform about the participants' performance. Following incorrect responses, an error-related negativity and an error positivity were observed. In the feedback phase, the largest feedback-related negativity was observed following equivocal feedback. Theta and beta oscillatory components were found following incorrect and correct responses, respectively, and an increase in theta power was associated with negative and equivocal feedback. Changes over time were also explored as an indicator for possible learning effects. Finally, event-related potentials and oscillatory components were found to be uncorrelated with OCI-R scores in the current non-clinical sample. Copyright © 2014 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Chen; Zelinka, Mark D.; Dessler, Andrew E.

The analyses of Coupled Model Intercomparison Project phase 5 simulations suggest that climate models with more positive cloud feedback in response to interannual climate fluctuations also have more positive cloud feedback in response to long-term global warming. Ensemble mean vertical profiles of cloud change in response to interannual and long-term surface warming are similar, and the ensemble mean cloud feedback is positive on both timescales. However, the average long-term cloud feedback is smaller than the interannual cloud feedback, likely due to differences in surface warming pattern on the two timescales. Low cloud cover (LCC) change in response to interannual andmore » long-term global surface warming is found to be well correlated across models and explains over half of the covariance between interannual and long-term cloud feedback. In conclusion, the intermodel correlation of LCC across timescales likely results from model-specific sensitivities of LCC to sea surface warming.« less

Feedback on prescribing errors to junior doctors: exploring views, problems and preferred methods.

PubMed

Bertels, Jeroen; Almoudaris, Alex M; Cortoos, Pieter-Jan; Jacklin, Ann; Franklin, Bryony Dean

2013-06-01

Prescribing errors are common in hospital inpatients. However, the literature suggests that doctors are often unaware of their errors as they are not always informed of them. It has been suggested that providing more feedback to prescribers may reduce subsequent error rates. Only few studies have investigated the views of prescribers towards receiving such feedback, or the views of hospital pharmacists as potential feedback providers. Our aim was to explore the views of junior doctors and hospital pharmacists regarding feedback on individual doctors' prescribing errors. Objectives were to determine how feedback was currently provided and any associated problems, to explore views on other approaches to feedback, and to make recommendations for designing suitable feedback systems. A large London NHS hospital trust. To explore views on current and possible feedback mechanisms, self-administered questionnaires were given to all junior doctors and pharmacists, combining both 5-point Likert scale statements and open-ended questions. Agreement scores for statements regarding perceived prescribing error rates, opinions on feedback, barriers to feedback, and preferences for future practice. Response rates were 49% (37/75) for junior doctors and 57% (57/100) for pharmacists. In general, doctors did not feel threatened by feedback on their prescribing errors. They felt that feedback currently provided was constructive but often irregular and insufficient. Most pharmacists provided feedback in various ways; however some did not or were inconsistent. They were willing to provide more feedback, but did not feel it was always effective or feasible due to barriers such as communication problems and time constraints. Both professional groups preferred individual feedback with additional regular generic feedback on common or serious errors. Feedback on prescribing errors was valued and acceptable to both professional groups. From the results, several suggested methods of providing feedback on prescribing errors emerged. Addressing barriers such as the identification of individual prescribers would facilitate feedback in practice. Research investigating whether or not feedback reduces the subsequent error rate is now needed.

Types of Feedback in Competency-Based Predoctoral Orthodontics: Effects on Students' Attitudes and Confidence.

PubMed

Lipp, Mitchell J; Cho, Kiyoung; Kim, Han Suk

2017-05-01

Feedback can exert a powerful influence on learning and achievement although its effect varies. The aim of this study was to investigate the effects of three types of feedback on dental students' attitudes and confidence in a competency-based course in predoctoral orthodontics at New York University College of Dentistry. In 2013-14, all 253 third-year students in a course using test-enhanced instructional methods received written feedback on formative assessments. The type of feedback varied across three groups: pass/fail grades (PF) N=77, emoticons (EM) N=90, or written comments (WC) N=86. At the end of the course, students completed surveys that included four statements addressing their attitudes toward course instruction and confidence in their abilities. The survey response rate ranged from 75% to 100% among groups. The lowest response rate (75%) was in the PF group. In attitudes toward course instruction and confidence in their abilities, the WC group trended to more positive responses than the other groups, while the PF group trended to negative responses. On two of the four statements, the trend for the WC group was significant (95% CI). In both statements concerning attitudes toward instruction, the PF group trended to negative responses that were significant (95% CI). These results support the effectiveness of descriptive written comments over pass/fail grades or emoticons in improving dental students' confidence in their abilities and their attitudes toward instruction.

Individualized In-Service Teacher Education. (Project IN-STEP). Evaluation Report, Phase II.

ERIC Educational Resources Information Center

Thurber, John C.

Phase 2 of Project IN-STEP was conducted to revise, refine, and conduct further field testing of a new inservice teacher education model. The method developed (in Phase 1--see ED 003 905 for report) is an individualized, multi-media approach. Revision activities, based on feedback provided for Phase 1, include the remaking of six videotape…

Can providing feedback on driving behavior and training on parental vigilant care affect male teen drivers and their parents?

PubMed

Farah, Haneen; Musicant, Oren; Shimshoni, Yaara; Toledo, Tomer; Grimberg, Einat; Omer, Haim; Lotan, Tsippy

2014-08-01

This study focuses on investigating the driving behavior of young novice male drivers during the first year of driving (three months of accompanied driving and the following nine months of solo driving). The study's objective is to examine the potential of various feedback forms on driving to affect young drivers' behavior and to mitigate the transition from accompanied to solo driving. The study examines also the utility of providing parents with guidance on how to exercise vigilant care regarding their teens' driving. Driving behavior was evaluated using data collected by In-Vehicle Data Recorders (IVDR), which document events of extreme g-forces measured in the vehicles. IVDR systems were installed in 242 cars of the families of young male drivers, however, only 217 families of young drivers aged 17-22 (M=17.5; SD=0.8) completed the one year period. The families were randomly allocated into 4 groups: (1) Family feedback: In which all the members of the family were exposed to feedback on their own driving and on that of the other family members; (2) Parental training: in which in addition to the family feedback, parents received personal guidance on ways to enhance vigilant care regarding their sons' driving; (3) Individual feedback: In which family members received feedback only on their own driving behavior (and were not exposed to the data on other family members); (4) CONTROL: Group that received no feedback at all. The feedback was provided to the different groups starting from the solo period, thus, the feedback was not provided during the supervised period. The data collected by the IVDRs was first analyzed using analysis of variance in order to compare the groups with respect to their monthly event rates. Events' rates are defined as the number of events in a trip divided by its duration. This was followed by the development and estimation of random effect negative binomial models that explain the monthly event rates of young drivers and their parents. The study showed that: (1) the Parental training group recorded significantly lower events rates (-29%) compared to the CONTROL group during the solo period; (2) although directed mainly at the novice drivers, the intervention positively affected also the behavior of parents, with both fathers and mothers in the Parental training group improving their driving (by -23% for both fathers and mothers) and mothers improving it also in the Family feedback group (by -30%). Thus, the intervention has broader impact effect beside the targeted population. It can be concluded that providing feedback on driving behavior and parental training in vigilant care significantly improves the driving behavior of young novice male drivers. Future research directions could include applying the intervention to a broader population, with larger diversity with respect to their driving records, culture, and behaviors. The challenge is to reach wide dissemination of IVDR for young drivers accompanied by parents' involvement, and to find the suitable incentives for its sustainability. Copyright © 2013 Elsevier Ltd. All rights reserved.

Do Southern Ocean Cloud Feedbacks Matter for 21st Century Warming?

NASA Astrophysics Data System (ADS)

Frey, W. R.; Maroon, E. A.; Pendergrass, A. G.; Kay, J. E.

2017-12-01

Cloud phase improvements in a state-of-the-art climate model produce a large 1.5 K increase in equilibrium climate sensitivity (ECS, the surface warming in response to instantaneously doubled CO2) via extratropical shortwave cloud feedbacks. Here we show that the same model improvements produce only a small surface warming increase in a realistic 21st century emissions scenario. The small 21st century warming increase is attributed to extratropical ocean heat uptake. Southern Ocean mean-state circulation takes up heat while a slowdown in North Atlantic circulation acts as a feedback to slow surface warming. Persistent heat uptake by extratropical oceans implies that extratropical cloud biases may not be as important to 21st century warming as biases in other regions. Observational constraints on cloud phase and shortwave radiation that produce a large ECS increase do not imply large changes in 21st century warming.

Skill learning from kinesthetic feedback.

PubMed

Pinzon, David; Vega, Roberto; Sanchez, Yerly Paola; Zheng, Bin

2017-10-01

It is important for a surgeon to perform surgical tasks under appropriate guidance from visual and kinesthetic feedback. However, our knowledge on kinesthetic (muscle) memory and its role in learning motor skills remains elementary. To discover the effect of exclusive kinesthetic training on kinesthetic memory in both performance and learning. In Phase 1, a total of twenty participants duplicated five 2 dimensional movements of increasing complexity via passive kinesthetic guidance, without visual or auditory stimuli. Five participants were asked to repeat the task in the Phase 2 over a period of three weeks, for a total of nine sessions. Subjects accurately recalled movement direction using kinesthetic memory, but recalling movement length was less precise. Over the nine training sessions, error occurrence dropped after the sixth session. Muscle memory constructs the foundation for kinesthetic training. Knowledge gained helps surgeons learn skills from kinesthetic information in the condition where visual feedback is limited. Copyright © 2016 Elsevier Inc. All rights reserved.

Swept-frequency feedback interferometry using terahertz frequency QCLs: a method for imaging and materials analysis.

PubMed

Rakić, Aleksandar D; Taimre, Thomas; Bertling, Karl; Lim, Yah Leng; Dean, Paul; Indjin, Dragan; Ikonić, Zoran; Harrison, Paul; Valavanis, Alexander; Khanna, Suraj P; Lachab, Mohammad; Wilson, Stephen J; Linfield, Edmund H; Davies, A Giles

2013-09-23

The terahertz (THz) frequency quantum cascade laser (QCL) is a compact source of high-power radiation with a narrow intrinsic linewidth. As such, THz QCLs are extremely promising sources for applications including high-resolution spectroscopy, heterodyne detection, and coherent imaging. We exploit the remarkable phase-stability of THz QCLs to create a coherent swept-frequency delayed self-homodyning method for both imaging and materials analysis, using laser feedback interferometry. Using our scheme we obtain amplitude-like and phase-like images with minimal signal processing. We determine the physical relationship between the operating parameters of the laser under feedback and the complex refractive index of the target and demonstrate that this coherent detection method enables extraction of complex refractive indices with high accuracy. This establishes an ultimately compact and easy-to-implement THz imaging and materials analysis system, in which the local oscillator, mixer, and detector are all combined into a single laser.

Development and Piloting of a Classroom-focused Measurement Feedback System

PubMed Central

Nadeem, Erum; Cappella, Elise; Holland, Sibyl; Coccaro, Candace; Crisonino, Gerard

2015-01-01

The present study used a community partnered research method to develop and pilot a classroom-focused measurement feedback system (MFS) for school mental health providers to support teachers’ use of effective universal and target classroom practices related to student emotional and behavioral issues. School personnel from seven urban elementary and middle school classrooms participated. Phase I involved development and refinement of the system through a baseline needs assessment and rapid-cycle feedback. Phase II involved detailed case study analysis of pre-to-post quantitative and implementation process data. Results suggest that teachers who used the dashboard along with consultation showed improvement in observed classroom organization and emotional support. Results also suggest that MFS use was tied closely to consultation dose, and that broader support at the school level was critical. Classroom-focused MFSs are a promising tool to support classroom improvement, and warrant future research focused on their effectiveness and broad applicability. PMID:25894312

On the Stability of Collocated Controllers in the Presence or Uncertain Nonlinearities and Other Perils

NASA Technical Reports Server (NTRS)

Joshi, S. M.

1985-01-01

Robustness properties are investigated for two types of controllers for large flexible space structures, which use collocated sensors and actuators. The first type is an attitude controller which uses negative definite feedback of measured attitude and rate, while the second type is a damping enhancement controller which uses only velocity (rate) feedback. It is proved that collocated attitude controllers preserve closed loop global asymptotic stability when linear actuator/sensor dynamics satisfying certain phase conditions are present, or monotonic increasing nonlinearities are present. For velocity feedback controllers, the global asymptotic stability is proved under much weaker conditions. In particular, they have 90 phase margin and can tolerate nonlinearities belonging to the (0,infinity) sector in the actuator/sensor characteristics. The results significantly enhance the viability of both types of collocated controllers, especially when the available information about the large space structure (LSS) parameters is inadequate or inaccurate.

The use of objective structured self-assessment and peer-feedback (OSSP) for learning communication skills: evaluation using a controlled trial.

PubMed

Perera, Jennifer; Mohamadou, Galy; Kaur, Satpal

2010-05-01

Feedback is essential to guide students towards expected performance goals. The usefulness of teacher feedback on improving communication skills (CS) has been well documented. It has been proposed that self-assessment and peer-feedback has an equally important role to play in enhancing learning. This is the focus of this study. Objectively structured self-assessment and peer feedback (OSSP) was incorporated into small group CS teaching sessions of a group of semester one medical students who were learning CS for the first time, to minimise the influence of previous educational interventions. A control group matched for academic performance, gender and age was used to enable parallel evaluation of the innovation. A reflective log containing closed and open ended questions was used for OSSP. Facilitators and simulated patients provided feedback to students in both groups during CS learning as per routine practice. Student perceptions on OSSP and acceptability as a learning method were explored using a questionnaire. CS were assessed in both groups using objective structured clinical examination (OSCE) as per routine practice and assessors were blinded as to which group the student belonged. Mean total score and scores for specific areas of interview skills were significantly higher in the experimental group. Analysis of the questionnaire data showed that students gained fresh insights into specific areas such as empathy, addressing patients' concerns and interview style during OSSP which clearly corroborated the specific differences in scores. The free text comments were highly encouraging as to acceptability of OSSP, in spite of 67% being never exposed to formal self- and peer-assessment during pre-university studies. OSSP promotes effective CS learning and learner acceptability is high.

Instructor feedback versus no instructor feedback on performance in a laparoscopic virtual reality simulator: a randomized educational trial.

PubMed

Oestergaard, Jeanett; Bjerrum, Flemming; Maagaard, Mathilde; Winkel, Per; Larsen, Christian Rifbjerg; Ringsted, Charlotte; Gluud, Christian; Grantcharov, Teodor; Ottesen, Bent; Soerensen, Jette Led

2012-02-28

Several studies have found a positive effect on the learning curve as well as the improvement of basic psychomotor skills in the operating room after virtual reality training. Despite this, the majority of surgical and gynecological departments encounter hurdles when implementing this form of training. This is mainly due to lack of knowledge concerning the time and human resources needed to train novice surgeons to an adequate level. The purpose of this trial is to investigate the impact of instructor feedback regarding time, repetitions and self-perception when training complex operational tasks on a virtual reality simulator. The study population consists of medical students on their 4th to 6th year without prior laparoscopic experience. The study is conducted in a skills laboratory at a centralized university hospital. Based on a sample size estimation 98 participants will be randomized to an intervention group or a control group. Both groups have to achieve a predefined proficiency level when conducting a laparoscopic salpingectomy using a surgical virtual reality simulator. The intervention group receives standardized instructor feedback of 10 to 12 min a maximum of three times. The control group receives no instructor feedback. Both groups receive the automated feedback generated by the virtual reality simulator. The study follows the CONSORT Statement for randomized trials. Main outcome measures are time and repetitions to reach the predefined proficiency level on the simulator. We include focus on potential sex differences, computer gaming experience and self-perception. The findings will contribute to a better understanding of optimal training methods in surgical education. NCT01497782.

Conceptual development and retention within the learning cycle

NASA Astrophysics Data System (ADS)

McWhirter, Lisa Jo

1998-12-01

This research was designed to achieve two goals: (1) examine concept development and retention within the learning cycle and (2) examine how students' concept development is mediated by classroom discussions and the students' small cooperative learning group. Forty-eight sixth-grade students and one teacher at an urban middle school participated in the study. The research utilized both quantitative and qualitative analyses. Quantitative assessments included a concept mapping technique as well as teacher generated multiple choice tests. Preliminary quantitative analysis found that students' reading levels had an effect on students' pretest scores in both the concept mapping and the multiple-choice assessment. Therefore, a covariant design was implemented for the quantitative analyses. Quantitative analysis techniques were used to examine concept development and retention, it was discovered that the students' concept knowledge increased significantly from the time of the conclusion of the term introduction phase to the conclusion of the expansion phase. These findings would indicate that all three phases of the learning cycle are necessary for conceptual development. However, quantitative analyses of concept maps indicated that this is not true for all students. Individual students showed evidence of concept development and integration at each phase. Therefore, concept development is individualized and all phases of the learning cycle are not necessary for all students. As a result, individual's assimilation, disequilibration, accommodation and organization may not correlate with the phases of the learning cycle. Quantitative analysis also indicated a significant decrease in the retention of concepts over time. Qualitative analyses were used to examine how students' concept development is mediated by classroom discussions and the students' small cooperative learning group. It was discovered that there was a correlation between teacher-student interaction and small-group interaction and concept mediation. Therefore, students who had a high level of teacher-student dialogue which utilized teacher led discussions with integrated scaffolding techniques where the same students who mediated the ideas within the small group discussions. Those students whose teacher-student interactions consisted of dialogue with little positive teacher feedback made no contributions within the small group regardless of their level of concept development.

My action lasts longer: Potential link between subjective time and agency during voluntary action.

PubMed

Imaizumi, Shu; Asai, Tomohisa

2017-05-01

Time perception distorts across different phases of bodily movement. During motor execution, sensory feedback matching an internal sensorimotor prediction is perceived to last longer. The sensorimotor prediction also underlies sense of agency. We investigated association between subjective time and agency during voluntary action. Participants performed hand action while watching a video feedback of their hand with various delays to manipulate agency. The perceived duration and agency over the video feedback were judged. Minimal delay of the video feedback resulted in longer perceived duration than the actual duration and stronger agency, while substantial feedback delay resulted in shorter perceived duration and weaker agency. These fluctuations of perceived duration and agency were nullified by the feedback of other's hand instead of their own, but not by inverted feedback from a third-person perspective. Subjective time during action might be associated with agency stemming from sensorimotor prediction, and self-other distinction based on bodily appearance. Copyright © 2017 Elsevier Inc. All rights reserved.

Assessment Certitude as a Feedback Strategy for Learners' Constructed Responses

ERIC Educational Resources Information Center

Kealy, W. A.; Ritzhaupt, A. D.

2010-01-01

Educational researchers have "rarely" addressed the problem of how to provide feedback on constructed responses. All participants (N = 76) read a story and completed short-answer questions based on the text, with some receiving feedback consisting of the exact material on which the questions were based. During feedback, two groups receiving…

Teamwork and Feedback: Broadening the Base of Collaborative Writing.

ERIC Educational Resources Information Center

Gebhardt, Richard

Many advocates of collaborative writing place too little emphasis on the emotional benefits of feedback to the writer by restricting group feedback to relatively late points in the writing process. Collaboration is as appropriate during the early stages of writing as it is after the completion of a draft. Students can receive feedback from…

Sample-Clock Phase-Control Feedback

NASA Technical Reports Server (NTRS)

Quirk, Kevin J.; Gin, Jonathan W.; Nguyen, Danh H.; Nguyen, Huy

2012-01-01

To demodulate a communication signal, a receiver must recover and synchronize to the symbol timing of a received waveform. In a system that utilizes digital sampling, the fidelity of synchronization is limited by the time between the symbol boundary and closest sample time location. To reduce this error, one typically uses a sample clock in excess of the symbol rate in order to provide multiple samples per symbol, thereby lowering the error limit to a fraction of a symbol time. For systems with a large modulation bandwidth, the required sample clock rate is prohibitive due to current technological barriers and processing complexity. With precise control of the phase of the sample clock, one can sample the received signal at times arbitrarily close to the symbol boundary, thus obviating the need, from a synchronization perspective, for multiple samples per symbol. Sample-clock phase-control feedback was developed for use in the demodulation of an optical communication signal, where multi-GHz modulation bandwidths would require prohibitively large sample clock frequencies for rates in excess of the symbol rate. A custom mixedsignal (RF/digital) offset phase-locked loop circuit was developed to control the phase of the 6.4-GHz clock that samples the photon-counting detector output. The offset phase-locked loop is driven by a feedback mechanism that continuously corrects for variation in the symbol time due to motion between the transmitter and receiver as well as oscillator instability. This innovation will allow significant improvements in receiver throughput; for example, the throughput of a pulse-position modulation (PPM) with 16 slots can increase from 188 Mb/s to 1.5 Gb/s.

On the Representation of Ice Nucleation in Global Climate Models, and its Importance for Simulations of Climate Forcings and Feedbacks

NASA Astrophysics Data System (ADS)

Storelvmo, T.

2015-12-01

Substantial improvements have been made to the cloud microphysical schemes used in the latest generation of global climate models (GCMs), however, an outstanding weakness of these schemes lies in the arbitrariness of their tuning parameters. Despite the growing effort in improving the cloud microphysical schemes in GCMs, most of this effort has not focused on improving the ability of GCMs to accurately simulate phase partitioning in mixed-phase clouds. Getting the relative proportion of liquid droplets and ice crystals in clouds right in GCMs is critical for the representation of cloud radiative forcings and cloud-climate feedbacks. Here, we first present satellite observations of cloud phase obtained by NASA's CALIOP instrument, and report on robust statistical relationships between cloud phase and several aerosols species that have been demonstrated to act as ice nuclei (IN) in laboratory studies. We then report on results from model intercomparison projects that reveal that GCMs generally underestimate the amount of supercooled liquid in clouds. For a selected GCM (NCAR 's CAM5), we thereafter show that the underestimate can be attributed to two main factors: i) the presence of IN in the mixed-phase temperature range, and ii) the Wegener-Bergeron-Findeisen process, which converts liquid to ice once ice crystals have formed. Finally, we show that adjusting these two processes such that the GCM's cloud phase is in agreement with the observed has a substantial impact on the simulated radiative forcing due to IN perturbations, as well as on the cloud-climate feedbacks and ultimately climate sensitivity simulated by the GCM.

Application of Phase Shifted, Laser Feedback Interferometry to Fluid Physics

NASA Technical Reports Server (NTRS)

Ovryn, Ben; Eppell, Steven J.; Andrews, James H.; Khaydarov, John

1996-01-01

We have combined the principles of phase-shifting interferometry (PSI) and laser-feedback interferometry (LFI) to produce a new instrument that can measure both optical path length (OPL) changes and discern sample reflectivity variations. In LFI, coherent feedback of the incident light either reflected directly from a surface or reflected after transmission through a region of interest will modulate the output intensity of the laser. LFI can yield a high signal-to-noise ratio even for low reflectivity samples. By combining PSI and LFI, we have produced a robust instrument, based upon a HeNe laser, with high dynamic range that can be used to measure either static (dc) or oscillatory changes along the optical path. As with other forms of interferometry, large changes in OPL require phase unwrapping. Conversely, small phase changes are limited by the fraction of a fringe that can be measured. We introduce the phase shifts with an electro-optic modulator (EOM) and use either the Carre or Hariharan algorithms to determine the phase and visibility. We have determined the accuracy and precision of our technique by measuring both the bending of a cantilevered piezoelectric bimorph and linear ramps to the EOM. Using PSI, sub-nanometer displacements can be measured. We have combined our interferometer with a commercial microscope and scanning piezoelectric stage and have measured the variation in OPL and visibility for drops of PDMS (silicone oil) on coated single crystal silicon. Our measurement of the static contact angle agrees with the value of 68 deg stated in the literature.

Video-augmented feedback for procedural performance.

PubMed

Wittler, Mary; Hartman, Nicholas; Manthey, David; Hiestand, Brian; Askew, Kim

2016-06-01

Resident programs must assess residents' achievement of core competencies for clinical and procedural skills. Video-augmented feedback may facilitate procedural skill acquisition and promote more accurate self-assessment. A randomized controlled study to investigate whether video-augmented verbal feedback leads to increased procedural skill and improved accuracy of self-assessment compared to verbal only feedback. Participants were evaluated during procedural training for ultrasound guided internal jugular central venous catheter (US IJ CVC) placement. All participants received feedback based on a validated 30-point checklist for US IJ CVC placement and validated 6-point procedural global rating scale. Scores in both groups improved by a mean of 9.6 points (95% CI: 7.8-11.4) on the 30-point checklist, with no difference between groups in mean score improvement on the global rating scale. In regards to self-assessment, participant self-rating diverged from faculty scoring, increasingly so after receiving feedback. Residents rated highly by faculty underestimated their skill, while those rated more poorly demonstrated increasing overestimation. Accuracy of self-assessment was not improved by addition of video. While feedback advanced the skill of the resident, video-augmented feedback did not enhance skill acquisition or improve accuracy of resident self-assessment compared to standard feedback.

The connecting health and technology study: a 6-month randomized controlled trial to improve nutrition behaviours using a mobile food record and text messaging support in young adults.

PubMed

Kerr, Deborah A; Harray, Amelia J; Pollard, Christina M; Dhaliwal, Satvinder S; Delp, Edward J; Howat, Peter A; Pickering, Mark R; Ahmad, Ziad; Meng, Xingqiong; Pratt, Iain S; Wright, Janine L; Kerr, Katherine R; Boushey, Carol J

2016-04-21

Early adulthood represents the transition to independent living which is a period when changes in diet and body weight are likely to occur. This presents an ideal time for health interventions to reduce the effect of health problems and risk factors for chronic disease in later life. As young adults are high users of mobile devices, interventions that use this technology may improve engagement. The Connecting Health and Technology study aimed to evaluate the effectiveness of tailored dietary feedback and weekly text messaging to improve dietary intake of fruit, vegetables and junk food over 6 months among a population-based sample of men and women (aged 18-30 years). A three-arm, parallel, randomized control trial was conducted. After baseline assessments, participants were randomized to one of three groups: A) dietary feedback and weekly text messages, B) dietary feedback only or C) control group. Dietary intake was assessed using a mobile food record App (mFR) where participants captured images of foods and beverages consumed over 4-days at baseline and post-intervention. The primary outcomes were changes in serves of fruits, vegetables, energy-dense nutrient-poor (EDNP) foods and sugar-sweetened beverages (SSB). The intervention effects were assessed using linear mixed effect models for change in food group serves. Young adults (n = 247) were randomized to group A (n = 82), group B (n = 83), or group C (n = 82). Overall, no changes in food group serves for either intervention groups were observed. An unanticipated outcome was a mean weight reduction of 1.7 kg (P = .02) among the dietary feedback only. Men who received dietary feedback only, significantly reduced their serves of EDNP foods by a mean of 1.4 serves/day (P = .02). Women who received dietary feedback only significantly reduced their intake of SSB (P = .04) by an average of 0.2 serves/day compared with controls. Tailored dietary feedback only resulted in a decrease in EDNP foods in men and SSB in women, together with a reduction in body weight. Using a mobile food record for dietary assessment and tailored feedback has great potential for future health promotion interventions targeting diet and weight in young adults. Australian Clinical Trials Registry Registration number: ACTRN12612000250831 .

TREAT Modeling and Simulation Strategy

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeHart, Mark David

2015-09-01

This report summarizes a four-phase process used to describe the strategy in developing modeling and simulation software for the Transient Reactor Test Facility. The four phases of this research and development task are identified as (1) full core transient calculations with feedback, (2) experiment modeling, (3) full core plus experiment simulation and (4) quality assurance. The document describes the four phases, the relationship between these research phases, and anticipated needs within each phase.

Evaluation of an in-vehicle monitoring system (IVMS) to reduce risky driving behaviors in commercial drivers: Comparison of in-cab warning lights and supervisory coaching with videos of driving behavior.

PubMed

Bell, Jennifer L; Taylor, Matthew A; Chen, Guang-Xiang; Kirk, Rachel D; Leatherman, Erin R

2017-02-01

Roadway incidents are the leading cause of work-related death in the United States. The objective of this research was to evaluate whether two types of feedback from a commercially available in-vehicle monitoring system (IVMS) would reduce the incidence of risky driving behaviors in drivers from two companies. IVMS were installed in 315 vehicles representing the industries of local truck transportation and oil and gas support operations, and data were collected over an approximate two-year period in intervention and control groups. In one period, intervention group drivers were given feedback from in-cab warning lights from an IVMS that indicated occurrence of harsh vehicle maneuvers. In another period, intervention group drivers viewed video recordings of their risky driving behaviors with supervisors, and were coached by supervisors on safe driving practices. Risky driving behaviors declined significantly more during the period with coaching plus instant feedback with lights in comparison to the period with lights-only feedback (ORadj=0.61 95% CI 0.43-0.86; Holm-adjusted p=0.035) and the control group (ORadj=0.52 95% CI 0.33-0.82; Holm-adjusted p=0.032). Lights-only feedback was not found to be significantly different than the control group's decline from baseline (ORadj=0.86 95% CI 0.51-1.43; Holm-adjusted p>0.05). The largest decline in the rate of risky driving behaviors occurred when feedback included both supervisory coaching and lights. Supervisory coaching is an effective form of feedback to improve driving habits in the workplace. The potential advantages and limitations of this IVMS-based intervention program are discussed. Published by Elsevier Ltd.

Sensing interstitial glucose to nudge active lifestyles (SIGNAL): feasibility of combining novel self-monitoring technologies for persuasive behaviour change

PubMed Central

Kingsnorth, Andrew P; Orme, Mark W; Sherar, Lauren B; Esliger, Dale W

2017-01-01

Introduction Increasing physical activity (PA) reduces the risk of developing diabetes, highlighting the role of preventive medicine approaches. Changing lifestyle behaviours is difficult and is often predicated on the assumption that individuals are willing to change their lifestyles today to reduce the risk of developing disease years or even decades later. The self-monitoring technologies tested in this study will present PA feedback in real time, parallel with acute physiological data. Presenting the immediate health benefits of being more physically active may help enact change by observing the immediate consequences of that behaviour. The present study aims to assess user engagement with the self-monitoring technologies in individuals at moderate-to-high risk of developing type 2 diabetes. Methods and analysis 45 individuals with a moderate-to-high risk, aged ≥40 years old and using a compatible smartphone, will be invited to take part in a 7-week protocol. Following 1 week of baseline measurements, participants will be randomised into one of three groups: group 1— glucose feedback followed by biobehavioural feedback (glucose plus PA); group 2—PA feedback followed by biobehavioural feedback; group 3—biobehavioural feedback. A PA monitor and a flash glucose monitor will be deployed during the intervention. Participants will wear both devices throughout the intervention but blinded to feedback depending on group allocation. The primary outcome is the level of participant engagement and will be assessed by device use and smartphone usage. Feasibility will be assessed by the practicality of the technology and screening for diabetes risk. Semistructured interviews will be conducted to explore participant experiences using the technologies. Trial registration number ISRCTN17545949. Registered on 15/05/2017. PMID:28993396

Evaluation of an in-vehicle monitoring system (IVMS) to reduce risky driving behaviors in commercial drivers: Comparison of in-cab warning lights and supervisory coaching with videos of driving behavior

PubMed Central

Bell, Jennifer L.; Taylor, Matthew A.; Chen, Guang-Xiang; Kirk, Rachel D.; Leatherman, Erin R.

2017-01-01

Problem Roadway incidents are the leading cause of work-related death in the United States. Methods The objective of this research was to evaluate whether two types of feedback from a commercially available in-vehicle monitoring system (IVMS) would reduce the incidence of risky driving behaviors in drivers from two companies. IVMS were installed in 315 vehicles representing the industries of local truck transportation and oil and gas support operations, and data were collected over an approximate two-year period in intervention and control groups. In one period, intervention group drivers were given feedback from in-cab warning lights from an IVMS that indicated occurrence of harsh vehicle maneuvers. In another period, intervention group drivers viewed video recordings of their risky driving behaviors with supervisors, and were coached by supervisors on safe driving practices. Results Risky driving behaviors declined significantly more during the period with coaching plus instant feedback with lights in comparison to the period with lights-only feedback (ORadj = 0.61 95% CI 0.43–0.86; Holm-adjusted p = 0.035) and the control group (ORadj = 0.52 95% CI 0.33–0.82; Holm-adjusted p = 0.032). Lights-only feedback was not found to be significantly different than the control group's decline from baseline (ORadj = 0.86 95% CI 0.51–1.43; Holm-adjusted p > 0.05). Conclusions The largest decline in the rate of risky driving behaviors occurred when feedback included both supervisory coaching and lights. Practical applications Supervisory coaching is an effective form of feedback to improve driving habits in the workplace. The potential advantages and limitations of this IVMS-based intervention program are discussed. PMID:28160807

Stabilization of self-mode-locked quantum dash lasers by symmetric dual-loop optical feedback

NASA Astrophysics Data System (ADS)

Asghar, Haroon; Wei, Wei; Kumar, Pramod; Sooudi, Ehsan; McInerney, John. G.

2018-02-01

We report experimental studies of the influence of symmetric dual-loop optical feedback on the RF linewidth and timing jitter of self-mode-locked two-section quantum dash lasers emitting at 1550 nm. Various feedback schemes were investigated and optimum levels determined for narrowest RF linewidth and low timing jitter, for single-loop and symmetric dual-loop feedback. Two symmetric dual-loop configurations, with balanced and unbalanced feedback ratios, were studied. We demonstrate that unbalanced symmetric dual loop feedback, with the inner cavity resonant and fine delay tuning of the outer loop, gives narrowest RF linewidth and reduced timing jitter over a wide range of delay, unlike single and balanced symmetric dual-loop configurations. This configuration with feedback lengths 80 and 140 m narrows the RF linewidth by 4-67x and 10-100x, respectively, across the widest delay range, compared to free-running. For symmetric dual-loop feedback, the influence of different power split ratios through the feedback loops was determined. Our results show that symmetric dual-loop feedback is markedly more effective than single-loop feedback in reducing RF linewidth and timing jitter, and is much less sensitive to delay phase, making this technique ideal for applications where robustness and alignment tolerance are essential.

The Effect of Tailored Web-Based Feedback and Optional Telephone Coaching on Health Improvements: A Randomized Intervention Among Employees in the Transport Service Industry.

PubMed

Solenhill, Madeleine; Grotta, Alessandra; Pasquali, Elena; Bakkman, Linda; Bellocco, Rino; Trolle Lagerros, Ylva

2016-08-11

Lifestyle-related health problems are an important health concern in the transport service industry. Web- and telephone-based interventions could be suitable for this target group requiring tailored approaches. To evaluate the effect of tailored Web-based health feedback and optional telephone coaching to improve lifestyle factors (body mass index-BMI, dietary intake, physical activity, stress, sleep, tobacco and alcohol consumption, disease history, self-perceived health, and motivation to change health habits), in comparison to no health feedback or telephone coaching. Overall, 3,876 employees in the Swedish transport services were emailed a Web-based questionnaire. They were randomized into: control group (group A, 498 of 1238 answered, 40.23%), or intervention Web (group B, 482 of 1305 answered, 36.93%), or intervention Web + telephone (group C, 493 of 1333 answered, 36.98%). All groups received an identical questionnaire, only the interventions differed. Group B received tailored Web-based health feedback, and group C received tailored Web-based health feedback + optional telephone coaching if the participants' reported health habits did not meet the national guidelines, or if they expressed motivation to change health habits. The Web-based feedback was fully automated. Telephone coaching was performed by trained health counselors. Nine months later, all participants received a follow-up questionnaire and intervention Web + telephone. Descriptive statistics, the chi-square test, analysis of variance, and generalized estimating equation (GEE) models were used. Overall, 981 of 1473 (66.60%) employees participated at baseline (men: 66.7%, mean age: 44 years, mean BMI: 26.4 kg/m(2)) and follow-up. No significant differences were found in reported health habits between the 3 groups over time. However, significant changes were found in motivation to change. The intervention groups reported higher motivation to improve dietary habits (144 of 301 participants, 47.8%, and 165 of 324 participants, 50.9%, for groups B and C, respectively) and physical activity habits (181 of 301 participants, 60.1%, and 207 of 324 participants, 63.9%, for B and C, respectively) compared with the control group A (122 of 356 participants, 34.3%, for diet and 177 of 356 participants, 49.7%, for physical activity). At follow-up, the intervention groups had significantly decreased motivation (group B: P<.001 for change in diet; P<.001 for change in physical activity; group C: P=.007 for change in diet; P<.001 for change in physical activity), whereas the control group reported significantly increased motivation to change diet and physical activity (P<.001 for change in diet; P<.001 for change in physical activity). Tailored Web-based health feedback and the offering of optional telephone coaching did not have a positive health effect on employees in the transport services. However, our findings suggest an increased short-term motivation to change health behaviors related to diet and physical activity among those receiving tailored Web-based health feedback.

Sports Institute for Research/Change Agent Research (SIR/CAR) Windsor Minor Hockey.

ERIC Educational Resources Information Center

Moriarty, Dick; Duthie, James

This organizational analysis of Windsor minor hockey was conducted as a pilot study into the policy decision making process in a sports organization. The study was divided into three phases. In the first phase the organization was audited and provided with information about various feedback channels. In phase two observations, available…

The strength of negative plant-soil feedback increases from the intraspecific to the interspecific and the functional group level.

PubMed

Bukowski, Alexandra R; Schittko, Conrad; Petermann, Jana S

2018-02-01

One of the processes that may play a key role in plant species coexistence and ecosystem functioning is plant-soil feedback, the effect of plants on associated soil communities and the resulting feedback on plant performance. Plant-soil feedback at the interspecific level (comparing growth on own soil with growth on soil from different species) has been studied extensively, while plant-soil feedback at the intraspecific level (comparing growth on own soil with growth on soil from different accessions within a species) has only recently gained attention. Very few studies have investigated the direction and strength of feedback among different taxonomic levels, and initial results have been inconclusive, discussing phylogeny, and morphology as possible determinants. To test our hypotheses that the strength of negative feedback on plant performance increases with increasing taxonomic level and that this relationship is explained by morphological similarities, we conducted a greenhouse experiment using species assigned to three taxonomic levels (intraspecific, interspecific, and functional group level). We measured certain fitness-related aboveground traits and used them along literature-derived traits to determine the influence of morphological similarities on the strength and direction of the feedback. We found that the average strength of negative feedback increased from the intraspecific over the interspecific to the functional group level. However, individual accessions and species differed in the direction and strength of the feedback. None of our results could be explained by morphological dissimilarities or individual traits. Synthesis . Our results indicate that negative plant-soil feedback is stronger if the involved plants belong to more distantly related species. We conclude that the taxonomic level is an important factor in the maintenance of plant coexistence with plant-soil feedback as a potential stabilizing mechanism and should be addressed explicitly in coexistence research, while the traits considered here seem to play a minor role.

Mixed-Timescale Per-Group Hybrid Precoding for Multiuser Massive MIMO Systems

NASA Astrophysics Data System (ADS)

Teng, Yinglei; Wei, Min; Liu, An; Lau, Vincent; Zhang, Yong

2018-05-01

Considering the expensive radio frequency (RF) chain, huge training overhead and feedback burden issues in massive MIMO, in this letter, we propose a mixed-timescale per-group hybrid precoding (MPHP) scheme under an adaptive partially-connected RF precoding structure (PRPS), where the RF precoder is implemented using an adaptive connection network (ACN) and M analog phase shifters (APSs), where M is the number of antennas at the base station (BS). Exploiting the mixed-time stage channel state information (CSI) structure, the joint-design of ACN and APSs is formulated as a statistical signal-to-leakage-and-noise ratio (SSLNR) maximization problem, and a heuristic group RF precoding (GRFP) algorithm is proposed to provide a near-optimal solution. Simulation results show that the proposed design advances at better energy efficiency (EE) and lower hardware cost, CSI signaling overhead and computational complexity than the conventional hybrid precoding (HP) schemes.

Reducing co-administration of proton pump inhibitors and antibiotics using a computerized order entry alert and prospective audit and feedback.

PubMed

Kandel, Christopher E; Gill, Suzanne; McCready, Janine; Matelski, John; Powis, Jeff E

2016-07-22

Antibiotics and proton pump inhibitors (PPIs) are associated with Clostridium difficile infection (CDI). Both a computer order entry alert to highlight this association as well as antimicrobial stewardship directed prospective audit and feedback represent novel interventions to reduce the co-administration of antibiotics and PPIs among hospitalized patients. Consecutive patients admitted to two General Internal Medicine wards from October 1, 2010 until March 31, 2013 at a teaching hospital in Toronto, Ontario, Canada were evaluated. The baseline observation period was followed by the first phase, which involved the creation of a computerized order entry alert that was triggered when either a PPI or an antibiotic was ordered in the presence of the other. The second phase consisted of the introduction of an antibiotic stewardship-initiated prospective audit and feedback strategy. The primary outcome was the co-administration of antibiotics and PPIs during each phase. This alert led to a significant reduction in the co-administration of antibiotics and PPIs adjusted for month and secular trends, expressed as days of therapy per 100 patient days (4.99 vs. 3.14, p < 0.001) The subsequent introduction of the antibiotic stewardship program further reduced the co-administration (3.14 vs. 1.80, p <0.001). No change was observed in adjusted monthly CDI rates per 100 patient care days between the baseline and alert cohorts (0.12 vs. 0.12, p = 0.99) or the baseline and antibiotic stewardship phases (0.12 vs. 0.13, p = 0.97). Decreasing the co-administration of PPIs and antibiotics can be achieved using a simple automatic alert followed by prospective audit and feedback.

Feedback to providers improves evidence-based implantable cardioverter-defibrillator programming and reduces shocks.

PubMed

Silver, Marc T; Sterns, Laurence D; Piccini, Jonathan P; Joung, Boyoung; Ching, Chi-Keong; Pickett, Robert A; Rabinovich, Rafael; Liu, Shufeng; Peterson, Brett J; Lexcen, Daniel R

2015-03-01

Implantable cardioverter-defibrillator (ICD) shocks are associated with increased anxiety, health care utilization, and potentially mortality. The purpose of the Shock-Less Study was to determine if providing feedback reports to physicians on their adherence to evidence-based shock reduction programming could improve their programming behavior and reduce shocks. Shock-Less enrolled primary prevention (PP) and secondary prevention (SP) ICD patients between 2009 and 2012 at 118 study centers worldwide and followed patients longitudinally after their ICD implant. Center-specific therapy programming reports (TPRs) were delivered to each center 9 to 12 months after their first enrollment. The reports detailed adherence to evidence-based programming targets: number of intervals to detect ventricular fibrillation (VF NID), longest treatment interval (LTI), supraventricular tachycardia (SVT) discriminators (Wavelet, PR Logic), SVT limit, Lead Integrity Alert (LIA), and antitachycardia pacing (ATP). Clinicians programmed ICDs at their discretion. The primary outcome measure was the change in utilization of evidence-based shock reduction programming before (phase I, n = 2694 patients) and after initiation of the TPR (phase II, n = 1438 patients). Patients implanted after feedback reports (phase II) were up to 20% more likely to have their ICDs programmed in line with evidence-based shock reduction programming (eg, VF NID in PP patients 30/40 in 33.5% vs 18.6%, P < .0001). Patients implanted in phase II had a lower risk of all-cause shock (adjusted hazard ratio 0.72, 95% confidence interval 0.58-0.90, P = .003). Providing programming feedback reports improves adherence to evidence-based shock reduction programming and is associated with lower risk of ICD shocks. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shepard, Kenneth L.; Sturcken, Noah Andrew

Power controller includes an output terminal having an output voltage, at least one clock generator to generate a plurality of clock signals and a plurality of hardware phases. Each hardware phase is coupled to the at least one clock generator and the output terminal and includes a comparator. Each hardware phase is configured to receive a corresponding one of the plurality of clock signals and a reference voltage, combine the corresponding clock signal and the reference voltage to produce a reference input, generate a feedback voltage based on the output voltage, compare the reference input and the feedback voltage usingmore » the comparator and provide a comparator output to the output terminal, whereby the comparator output determines a duty cycle of the power controller. An integrated circuit including the power controller is also provided.« less

The effects of non-evaluative feedback on drivers' self-evaluation and performance.

PubMed

Dogan, Ebru; Steg, Linda; Delhomme, Patricia; Rothengatter, Talib

2012-03-01

Drivers' tend to overestimate their competences, which may result in risk taking behavior. Providing drivers with feedback has been suggested as one of the solutions to overcome drivers' inaccurate self-evaluations. In practice, many tests and driving simulators provide drivers with non-evaluative feedback, which conveys information on the level of performance but not on what caused the performance. Is this type of feedback indeed effective in reducing self-enhancement biases? The current study aimed to investigate the effect of non-evaluative performance feedback on drivers' self-evaluations using a computerized hazard perception test. A between-subjects design was used with one group receiving feedback on performance in the hazard perception test while the other group not receiving any feedback. The results indicated that drivers had a robust self-enhancement bias in their self-evaluations regardless of the presence of performance feedback and that they systematically estimated their performance to be higher than they actually achieved in the test. Furthermore, they devalued the credibility of the test instead of adjusting their self-evaluations in order to cope with the negative feelings following the failure feedback. We discuss the theoretical and practical implications of these counterproductive effects of non-evaluative feedback. Copyright © 2011 Elsevier Ltd. All rights reserved.

Year-round effects of a four-week randomized controlled trial using different types of feedback on employees' physical activity.

PubMed

Van Hoye, Karen; Wijtzes, Anne I; Lefevre, Johan; De Baere, Stijn; Boen, Filip

2018-04-12

This follow-up study investigated the year-round effects of a four-week randomized controlled trial using different types of feedback on employees' physical activity, including a need-supportive coach intervention. Participants (n = 227) were randomly assigned to a Minimal Intervention Group (MIG; no feedback), a Pedometer Group (PG; feedback on daily steps only), a Display Group (DG; feedback on daily steps, on daily moderate-to-vigorous physical activity [MVPA] and on total energy expenditure [EE]), or a Coaching Group (CoachG; same as DG with need supportive coaching). Daily physical activity level (PAL; Metabolic Equivalent of Task [MET]), number of daily steps, daily minutes of moderate to vigorous physical activity (MVPA), active daily EE (EE > 3 METs) and total daily EE were measured at five time points: before the start of the 4-week intervention, one week after the intervention, and 3, 6, and 12 months after the intervention. For minutes of MVPA, MIG showed higher mean change scores compared with the DG. For steps and daily minutes of MVPA, significantly lower mean change scores emerged for MIG compared with the PG. Participants of the CoachG showed significantly higher change scores in PAL, steps, minutes of MVPA, active EE, total EE compared with the MIG. As hypothesized, participants of the CoachG had significantly higher mean change scores in PAL and total EE compared with groups that only received feedback. However, no significant differences were found for steps, minutes of MVPA and active EE between CoachG and PG. Receiving additional need-supportive coaching resulted in a higher PAL and active EE compared with measurement (display) feedback only. These findings suggest to combine feedback on physical activity with personal coaching in order to facilitate long-term behavioral change. When it comes to increasing steps, minutes of MVPA or active EE, a pedometer constitutes a sufficient tool. Clinical Trails.gov NCT01432327 . Date registered: 12 September 2011.

Real-time functional magnetic resonance imaging neurofeedback can reduce striatal cue-reactivity to alcohol stimuli.

PubMed

Kirsch, Martina; Gruber, Isabella; Ruf, Matthias; Kiefer, Falk; Kirsch, Peter

2016-07-01

It has been shown that in alcoholic patients, alcohol-related cues produce increased activation of reward-related brain regions like the ventral striatum (VS), which has been proposed as neurobiological basis of craving. Modulating this activation might be a promising option in the treatment of alcohol addiction. One approach might be real-time functional magnetic resonance imaging neurofeedback (rtfMRI NF). This study was set up to implement and evaluate a rtfMRI approach in a group of non-addicted heavy social drinkers. Thirty-eight heavy drinking students were assigned to a real feedback group (rFB, n = 13), a yoke feedback group (yFB, n = 13) and a passive control group (noFB, n = 12). After conducting a reward task as functional localizer to identify ventral striatal regions, the participants viewed alcohol cues during three NF training blocks in a 3 T MRI scanner. The rFB group received feedback from their own and the yFB from another participants' VS. The noFB group received no feedback. The rFB and the yFB groups were instructed to downregulate the displayed activation. Activation of the VS and prefrontal control regions was compared between the groups. We found significant downregulation of striatal regions specifically in the rFB group. While the rFB and the yFB groups showed significant activation of prefrontal regions during feedback, this activation was only correlated to the reduction of striatal activation in the rFB group. We conclude that rtfMRI NF is a suitable method to reduce striatal activation to alcohol cues. It might be a promising supplement to the treatment of alcoholic patients. © 2015 Society for the Study of Addiction.

Community structure analysis of rejection sensitive personality profiles: A common neural response to social evaluative threat?

PubMed

Kortink, Elise D; Weeda, Wouter D; Crowley, Michael J; Gunther Moor, Bregtje; van der Molen, Melle J W

2018-06-01

Monitoring social threat is essential for maintaining healthy social relationships, and recent studies suggest a neural alarm system that governs our response to social rejection. Frontal-midline theta (4-8 Hz) oscillatory power might act as a neural correlate of this system by being sensitive to unexpected social rejection. Here, we examined whether frontal-midline theta is modulated by individual differences in personality constructs sensitive to social disconnection. In addition, we examined the sensitivity of feedback-related brain potentials (i.e., the feedback-related negativity and P3) to social feedback. Sixty-five undergraduate female participants (mean age = 19.69 years) participated in the Social Judgment Paradigm, a fictitious peer-evaluation task in which participants provided expectancies about being liked/disliked by peer strangers. Thereafter, they received feedback signaling social acceptance/rejection. A community structure analysis was employed to delineate personality profiles in our data. Results provided evidence of two subgroups: one group scored high on attachment-related anxiety and fear of negative evaluation, whereas the other group scored high on attachment-related avoidance and low on fear of negative evaluation. In both groups, unexpected rejection feedback yielded a significant increase in theta power. The feedback-related negativity was sensitive to unexpected feedback, regardless of valence, and was largest for unexpected rejection feedback. The feedback-related P3 was significantly enhanced in response to expected social acceptance feedback. Together, these findings confirm the sensitivity of frontal midline theta oscillations to the processing of social threat, and suggest that this alleged neural alarm system behaves similarly in individuals that differ in personality constructs relevant to social evaluation.

CPR performance in the presence of audiovisual feedback or football shoulder pads.

PubMed

Tanaka, Shota; Rodrigues, Wayne; Sotir, Susan; Sagisaka, Ryo; Tanaka, Hideharu

2017-01-01

The initiation of cardiopulmonary resuscitation (CPR) can be complicated by the use of protective equipment in contact sports, and the rate of success in resuscitating the patient depends on the time from incident to start of CPR. The aim of our study was to see if (1) previous training, (2) the presence of audiovisual feedback and (3) the presence of football shoulder pads (FSP) affected the quality of chest compressions. Six basic life support certified athletic training students (BLS-ATS), six basic life support certified emergency medical service personnel (BLS-EMS) and six advanced cardiac life support certified emergency medical service personnel (ACLS-EMS) participated in a crossover manikin study. A quasi-experimental repeated measures design was used to measure the chest compression depth (cm), rate (cpm), depth accuracy (%) and rate accuracy (%) on four different conditions by using feedback and/or FSP. Real CPR Help manufactured by ZOLL (Chelmsford, Massachusetts, USA) was used for the audiovisual feedback. Three participants from each group performed 2 min of chest compressions at baseline first, followed by compressions with FSP, with feedback and with both FSP and feedback (FSP+feedback). The other three participants from each group performed compressions at baseline first, followed by compressions with FSP+feedback, feedback and FSP. CPR performance did not differ between the groups at baseline (median (IQR), BLS-ATS: 5.0 (4.4-6.1) cm, 114(96-131) cpm; BLS-EMS: 5.4 (4.1-6.4) cm, 112(99-131) cpm; ACLS-EMS: 6.4 (5.7-6.7) cm, 138(113-140) cpm; depth p=0.10, rate p=0.37). A statistically significant difference in the percentage of depth accuracy was found with feedback (median (IQR), 13.8 (0.9-49.2)% vs 69.6 (32.3-85.8)%; p=0.0002). The rate accuracy was changed from 17.1 (0-80.7)% without feedback to 59.2 (17.3-74.3)% with feedback (p=0.50). The use of feedback was effective for depth accuracy, especially in the BLS-ATS group, regardless of the presence of FSP (median (IQR), 22.0 (7.3-36.2)% vs 71.3 (35.4-86.5)%; p=0.0002). The use of audiovisual feedback positively affects the quality of the depth of CPR. Both feedback and FSP do not alter the rate measurements. Medically trained personnel are able to deliver the desired depth regardless of the presence of FSP even though shallower chest compressions depth can be seen in CPR with FSP. A feedback device must be introduced into the athletic training settings.

CPR performance in the presence of audiovisual feedback or football shoulder pads

PubMed Central

Tanaka, Shota; Rodrigues, Wayne; Sotir, Susan; Sagisaka, Ryo; Tanaka, Hideharu

2017-01-01

Objective The initiation of cardiopulmonary resuscitation (CPR) can be complicated by the use of protective equipment in contact sports, and the rate of success in resuscitating the patient depends on the time from incident to start of CPR. The aim of our study was to see if (1) previous training, (2) the presence of audiovisual feedback and (3) the presence of football shoulder pads (FSP) affected the quality of chest compressions. Methods Six basic life support certified athletic training students (BLS-ATS), six basic life support certified emergency medical service personnel (BLS-EMS) and six advanced cardiac life support certified emergency medical service personnel (ACLS-EMS) participated in a crossover manikin study. A quasi-experimental repeated measures design was used to measure the chest compression depth (cm), rate (cpm), depth accuracy (%) and rate accuracy (%) on four different conditions by using feedback and/or FSP. Real CPR Help manufactured by ZOLL (Chelmsford, Massachusetts, USA) was used for the audiovisual feedback. Three participants from each group performed 2 min of chest compressions at baseline first, followed by compressions with FSP, with feedback and with both FSP and feedback (FSP+feedback). The other three participants from each group performed compressions at baseline first, followed by compressions with FSP+feedback, feedback and FSP. Results CPR performance did not differ between the groups at baseline (median (IQR), BLS-ATS: 5.0 (4.4–6.1) cm, 114(96–131) cpm; BLS-EMS: 5.4 (4.1–6.4) cm, 112(99–131) cpm; ACLS-EMS: 6.4 (5.7–6.7) cm, 138(113–140) cpm; depth p=0.10, rate p=0.37). A statistically significant difference in the percentage of depth accuracy was found with feedback (median (IQR), 13.8 (0.9–49.2)% vs 69.6 (32.3–85.8)%; p=0.0002). The rate accuracy was changed from 17.1 (0–80.7)% without feedback to 59.2 (17.3–74.3)% with feedback (p=0.50). The use of feedback was effective for depth accuracy, especially in the BLS-ATS group, regardless of the presence of FSP (median (IQR), 22.0 (7.3–36.2)% vs 71.3 (35.4–86.5)%; p=0.0002). Conclusions The use of audiovisual feedback positively affects the quality of the depth of CPR. Both feedback and FSP do not alter the rate measurements. Medically trained personnel are able to deliver the desired depth regardless of the presence of FSP even though shallower chest compressions depth can be seen in CPR with FSP. A feedback device must be introduced into the athletic training settings. PMID:28761704

Sequence Learning Under Uncertainty in Children: Self-Reflection vs. Self-Assertion

PubMed Central

Lange-Küttner, Christiane; Averbeck, Bruno B.; Hirsch, Silvia V.; Wießner, Isabel; Lamba, Nishtha

2012-01-01

We know that stochastic feedback impairs children’s associative stimulus–response (S–R) learning (Crone et al., 2004a; Eppinger et al., 2009), but the impact of stochastic feedback on sequence learning that involves deductive reasoning has not been not tested so far. In the current study, 8- to 11-year-old children (N = 171) learned a sequence of four left and right button presses, LLRR, RRLL, LRLR, RLRL, LRRL, and RLLR, which needed to be deduced from feedback because no directional cues were given. One group of children experienced consistent feedback only (deterministic feedback, 100% correct). In this condition, green feedback on the screen indicated that the children had been right when they were right, and red feedback indicated that the children had been wrong when they were wrong. Another group of children experienced inconsistent feedback (stochastic feedback, 85% correct, 15% false), where in some trials, green feedback on the screen could signal that children were right when in fact they were wrong, and red feedback could indicate that they were wrong when in fact they had been right. Independently of age, children’s sequence learning in the stochastic condition was initially much lower than in the deterministic condition, but increased gradually and improved with practice. Responses toward positive vs. negative feedback varied with age. Children were increasingly able to understand that they could have been wrong when feedback indicated they were right (self-reflection), but they remained unable to understand that they could have been right when feedback indicated they were wrong (self-assertion). PMID:22563324

Sequence Learning Under Uncertainty in Children: Self-Reflection vs. Self-Assertion.

PubMed

Lange-Küttner, Christiane; Averbeck, Bruno B; Hirsch, Silvia V; Wießner, Isabel; Lamba, Nishtha

2012-01-01

We know that stochastic feedback impairs children's associative stimulus-response (S-R) learning (Crone et al., 2004a; Eppinger et al., 2009), but the impact of stochastic feedback on sequence learning that involves deductive reasoning has not been not tested so far. In the current study, 8- to 11-year-old children (N = 171) learned a sequence of four left and right button presses, LLRR, RRLL, LRLR, RLRL, LRRL, and RLLR, which needed to be deduced from feedback because no directional cues were given. One group of children experienced consistent feedback only (deterministic feedback, 100% correct). In this condition, green feedback on the screen indicated that the children had been right when they were right, and red feedback indicated that the children had been wrong when they were wrong. Another group of children experienced inconsistent feedback (stochastic feedback, 85% correct, 15% false), where in some trials, green feedback on the screen could signal that children were right when in fact they were wrong, and red feedback could indicate that they were wrong when in fact they had been right. Independently of age, children's sequence learning in the stochastic condition was initially much lower than in the deterministic condition, but increased gradually and improved with practice. Responses toward positive vs. negative feedback varied with age. Children were increasingly able to understand that they could have been wrong when feedback indicated they were right (self-reflection), but they remained unable to understand that they could have been right when feedback indicated they were wrong (self-assertion).

The role of auditory feedback in music-supported stroke rehabilitation: A single-blinded randomised controlled intervention.

PubMed

van Vugt, F T; Kafczyk, T; Kuhn, W; Rollnik, J D; Tillmann, B; Altenmüller, E

2016-01-01

Learning to play musical instruments such as piano was previously shown to benefit post-stroke motor rehabilitation. Previous work hypothesised that the mechanism of this rehabilitation is that patients use auditory feedback to correct their movements and therefore show motor learning. We tested this hypothesis by manipulating the auditory feedback timing in a way that should disrupt such error-based learning. We contrasted a patient group undergoing music-supported therapy on a piano that emits sounds immediately (as in previous studies) with a group whose sounds are presented after a jittered delay. The delay was not noticeable to patients. Thirty-four patients in early stroke rehabilitation with moderate motor impairment and no previous musical background learned to play the piano using simple finger exercises and familiar children's songs. Rehabilitation outcome was not impaired in the jitter group relative to the normal group. Conversely, some clinical tests suggests the jitter group outperformed the normal group. Auditory feedback-based motor learning is not the beneficial mechanism of music-supported therapy. Immediate auditory feedback therapy may be suboptimal. Jittered delay may increase efficacy of the proposed therapy and allow patients to fully benefit from motivational factors of music training. Our study shows a novel way to test hypotheses concerning music training in a single-blinded way, which is an important improvement over existing unblinded tests of music interventions.

Facilitating the Feedback Process on a Clinical Clerkship Using a Smartphone Application.

PubMed

Joshi, Aditya; Generalla, Jenilee; Thompson, Britta; Haidet, Paul

2017-10-01

This pilot study evaluated the effects of a smartphone-triggered method of feedback delivery on students' perceptions of the feedback process. An interactive electronic feedback form was made available to students through a smartphone app. Students were asked to evaluate various aspects of the feedback process. Responses from a previous year served as control. In the first three quarters of academic year 2014-2015 (pre-implementation), only 65% of responders reported receiving oral feedback and 40% reported receiving written feedback. During the pilot phase (transition), these increased to 80% for both forms. Following full implementation in academic year 2015-2016 (post-implementation), 97% reported receiving oral feedback, and 92% reported receiving written feedback. A statistically significant difference was noted pre- to post-implementation for both oral and written feedback (p < 0.01). A significant increase from pre-implementation to transition was noted for written feedback (p < 0.01) and from transition to post-implementation for oral feedback (p < 0.01). Ninety-one and 94% of responders reported ease of access and timeliness of the feedback, 75% perceived the quality of the feedback to be good to excellent; 64% felt receiving feedback via the app improved their performance; 69% indicated the feedback method as better compared to other methods. Students acknowledged the facilitation of conversation with supervisors and the convenience of receiving feedback, as well as the promptness with which feedback was provided. The use of a drop-down menu was thought to limit the scope of conversation. These data point to the effectiveness of this method to cue supervisors to provide feedback to students.

Response of microchip solid-state laser to external frequency-shifted feedback and its applications

PubMed Central

Tan, Yidong; Zhang, Shulian; Zhang, Song; Zhang, Yongqing; Liu, Ning

2013-01-01

The response of the microchip solid-state Nd:YAG laser, which is subjected to external frequency-shifted feedback, is experimentally and theoretically analysed. The continuous weak response of the laser to the phase and amplitude of the feedback light is achieved by controlling the feedback power level, and this system can be used to achieve contact-free measurement of displacement, vibration, liquid evaporation and thermal expansion with nanometre accuracy in common room conditions without precise environmental control. Furthermore, a strong response, including chaotic harmonic and parametric oscillation, is observed, and the spectrum of this response, as examined by a frequency-stabilised Nd:YAG laser, indicates laser spectral linewidth broadening. PMID:24105389

Response of microchip solid-state laser to external frequency-shifted feedback and its applications.

PubMed

Tan, Yidong; Zhang, Shulian; Zhang, Song; Zhang, Yongqing; Liu, Ning

2013-10-09

The response of the microchip solid-state Nd:YAG laser, which is subjected to external frequency-shifted feedback, is experimentally and theoretically analysed. The continuous weak response of the laser to the phase and amplitude of the feedback light is achieved by controlling the feedback power level, and this system can be used to achieve contact-free measurement of displacement, vibration, liquid evaporation and thermal expansion with nanometre accuracy in common room conditions without precise environmental control. Furthermore, a strong response, including chaotic harmonic and parametric oscillation, is observed, and the spectrum of this response, as examined by a frequency-stabilised Nd:YAG laser, indicates laser spectral linewidth broadening.

Feedforward/feedback control synthesis for performance and robustness

NASA Technical Reports Server (NTRS)

Wie, Bong; Liu, Qiang

1990-01-01

Both feedforward and feedback control approaches for uncertain dynamical systems are investigated. The control design objective is to achieve a fast settling time (high performance) and robustness (insensitivity) to plant modeling uncertainty. Preshapong of an ideal, time-optimal control input using a 'tapped-delay' filter is shown to provide a rapid maneuver with robust performance. A robust, non-minimum-phase feedback controller is synthesized with particular emphasis on its proper implementation for a non-zero set-point control problem. The proposed feedforward/feedback control approach is robust for a certain class of uncertain dynamical systems, since the control input command computed for a given desired output does not depend on the plant parameters.

A pilot randomized controlled trial evaluating motivationally matched pedometer feedback to increase physical activity behavior in older adults.

PubMed

Strath, Scott J; Swartz, Ann M; Parker, Sarah J; Miller, Nora E; Grimm, Elizabeth K; Cashin, Susan E

2011-09-01

Increasing physical activity (PA) levels in older adults represents an important public health challenge. The purpose of this study was to evaluate the feasibility of combining individualized motivational messaging with pedometer walking step targets to increase PA in previously inactive and insufficiently active older adults. In this 12-week intervention study older adults were randomized to 1 of 4 study arms: Group 1--control; Group 2--pedometer 10,000 step goal; Group 3--pedometer step goal plus individualized motivational feedback; or Group 4--everything in Group 3 augmented with biweekly telephone feedback. 81 participants were randomized into the study, 61 participants completed the study with an average age of 63.8 ± 6.0 years. Group 1 did not differ in accumulated steps/day following the 12-week intervention compared with participants in Group 2. Participants in Groups 3 and 4 took on average 2159 (P < .001) and 2488 (P < .001) more steps/day, respectively, than those in Group 1 after the 12-week intervention. In this 12-week pilot randomized control trial, a pedometer feedback intervention partnered with individually matched motivational messaging was an effective intervention strategy to significantly increase PA behavior in previously inactive and insufficiently active older adults.

The role of automated feedback in training and retaining biological recorders for citizen science.

PubMed

van der Wal, René; Sharma, Nirwan; Mellish, Chris; Robinson, Annie; Siddharthan, Advaith

2016-06-01

The rapid rise of citizen science, with lay people forming often extensive biodiversity sensor networks, is seen as a solution to the mismatch between data demand and supply while simultaneously engaging citizens with environmental topics. However, citizen science recording schemes require careful consideration of how to motivate, train, and retain volunteers. We evaluated a novel computing science framework that allowed for the automated generation of feedback to citizen scientists using natural language generation (NLG) technology. We worked with a photo-based citizen science program in which users also volunteer species identification aided by an online key. Feedback is provided after photo (and identification) submission and is aimed to improve volunteer species identification skills and to enhance volunteer experience and retention. To assess the utility of NLG feedback, we conducted two experiments with novices to assess short-term (single session) and longer-term (5 sessions in 2 months) learning, respectively. Participants identified a specimen in a series of photos. One group received only the correct answer after each identification, and the other group received the correct answer and NLG feedback explaining reasons for misidentification and highlighting key features that facilitate correct identification. We then developed an identification training tool with NLG feedback as part of the citizen science program BeeWatch and analyzed learning by users. Finally, we implemented NLG feedback in the live program and evaluated this by randomly allocating all BeeWatch users to treatment groups that received different types of feedback upon identification submission. After 6 months separate surveys were sent out to assess whether views on the citizen science program and its feedback differed among the groups. Identification accuracy and retention of novices were higher for those who received automated feedback than for those who received only confirmation of the correct identification without explanation. The value of NLG feedback in the live program, captured through questionnaires and evaluation of the online photo-based training tool, likewise showed that the automated generation of informative feedback fostered learning and volunteer engagement and thus paves the way for productive and long-lived citizen science projects. © 2016 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

The Use of Video Feedback in Teaching Process-Approach EFL Writing

ERIC Educational Resources Information Center

Özkul, Sertaç; Ortaçtepe, Deniz

2017-01-01

This experimental study investigated the use of video feedback as an alternative to feedback with correction codes at an institution where the latter was commonly used for teaching process-approach English as a foreign language (EFL) writing. Over a 5-week period, the control and the experimental groups were provided with feedback based on…

Mathematics Student Teachers' Views on Tutor Feedback during Teaching Practice

ERIC Educational Resources Information Center

Buhagiar, Michael A.

2013-01-01

A group of students studying to become mathematics teachers were asked to comment on the tutor feedback they received during teaching practice (TP) and to offer suggestions aimed at improving this feedback. Analysis of the written data--which was collected through emails--suggests the need for: (i) all TP tutors to provide good quality feedback;…

Peer Feedback on Facebook: The Use of Social Networking Websites to Develop Writing Ability of Undergraduate Students

ERIC Educational Resources Information Center

Wichadee, Saovapa

2013-01-01

The current study explores how integrating a social networking website called Facebook with peer feedback in groups supports student learning, investigates the nature of feedback students received on their writing, and examines their attitudes towards the use of Facebook for peer feedback. The study involves 30 undergraduate students who…

Using Task Clarification, Graphic Feedback, and Verbal Feedback to Increase Closing-Task Completion in a Privately Owned Restaurant.

ERIC Educational Resources Information Center

Austin, John; Weatherly, Nic L.; Gravina, Nicole E.

2005-01-01

An informant functional assessment was used to evaluate closing-task completion by servers and dishwashers at a restaurant. Based on the functional assessment results, an intervention consisting of task clarification, posted graphic feedback, and verbal feedback was implemented and evaluated with a multiple baseline design across two groups of…

Does an Observer's Content Knowledge Influence the Feedback Offered about Mathematics Lessons?

ERIC Educational Resources Information Center

Peck, Duane C.

2016-01-01

The purpose of this study was two-fold. First, feedback from 3 different groups of observers: math content specialists, content specialists in areas other than mathematics, and building principals, was analyzed using an inductive approach to identify themes within the feedback. Second, differences in the feedback offered by participants of the 3…

Using Focus Groups to Investigate the Presence of Formative Feedback in CAA

ERIC Educational Resources Information Center

Broughton, Stephen; Hernandez-Martinez, Paul; Robinson, Carol L.

2012-01-01

The aim of this project was to examine the effectiveness of feedback offered by computer-aided assessment (CAA). CAA provides practice tests for undergraduates, and feedback to help them improve their scores and mathematical understanding. However, there is a lack of evidence-based literature on the effect of formative feedback in mathematics…

Self-regulation of the anterior insula: Reinforcement learning using real-time fMRI neurofeedback.

PubMed

Lawrence, Emma J; Su, Li; Barker, Gareth J; Medford, Nick; Dalton, Jeffrey; Williams, Steve C R; Birbaumer, Niels; Veit, Ralf; Ranganatha, Sitaram; Bodurka, Jerzy; Brammer, Michael; Giampietro, Vincent; David, Anthony S

2014-03-01

The anterior insula (AI) plays a key role in affective processing, and insular dysfunction has been noted in several clinical conditions. Real-time functional MRI neurofeedback (rtfMRI-NF) provides a means of helping people learn to self-regulate activation in this brain region. Using the Blood Oxygenated Level Dependant (BOLD) signal from the right AI (RAI) as neurofeedback, we trained participants to increase RAI activation. In contrast, another group of participants was shown 'control' feedback from another brain area. Pre- and post-training affective probes were shown, with subjective ratings and skin conductance response (SCR) measured. We also investigated a reward-related reinforcement learning model of rtfMRI-NF. In contrast to the controls, we hypothesised a positive linear increase in RAI activation in participants shown feedback from this region, alongside increases in valence ratings and SCR to affective probes. Hypothesis-driven analyses showed a significant interaction between the RAI/control neurofeedback groups and the effect of self-regulation. Whole-brain analyses revealed a significant linear increase in RAI activation across four training runs in the group who received feedback from RAI. Increased activation was also observed in the caudate body and thalamus, likely representing feedback-related learning. No positive linear trend was observed in the RAI in the group receiving control feedback, suggesting that these data are not a general effect of cognitive strategy or control feedback. The control group did, however, show diffuse activation across the putamen, caudate and posterior insula which may indicate the representation of false feedback. No significant training-related behavioural differences were observed for valence ratings, or SCR. In addition, correlational analyses based on a reinforcement learning model showed that the dorsal anterior cingulate cortex underpinned learning in both groups. In summary, these data demonstrate that it is possible to regulate the RAI using rtfMRI-NF within one scanning session, and that such reward-related learning is mediated by the dorsal anterior cingulate. Copyright © 2013 Elsevier Inc. All rights reserved.

Competence feedback improves CBT competence in trainee therapists: A randomized controlled pilot study.

PubMed

Weck, Florian; Kaufmann, Yvonne M; Höfling, Volkmar

2017-07-01

The development and improvement of therapeutic competencies are central aims in psychotherapy training; however, little is known about which training interventions are suitable for the improvement of competencies. In the current pilot study, the efficacy of feedback regarding therapeutic competencies was investigated in cognitive behavioural therapy (CBT). Totally 19 trainee therapists and 19 patients were allocated randomly to a competence feedback group (CFG) or control group (CG). Two experienced clinicians and feedback providers who were blind to the treatment conditions independently evaluated therapeutic competencies on the Cognitive Therapy Scale at five treatment times (i.e., at Sessions 1, 5, 9, 13, and 17). Whereas CFG and CG included regular supervision, only therapists in the CFG additionally received written qualitative and quantitative feedback regarding their demonstrated competencies in conducting CBT during treatment. We found a significant Time × Group interaction effect (η² = .09), which indicates a larger competence increase in the CFG in comparison to the CG. Competence feedback was demonstrated to be suitable for the improvement of therapeutic competencies in CBT. These findings may have important implications for psychotherapy training, clinical practice, and psychotherapy research. However, further research is necessary to ensure the replicability and generalizability of the findings.

Developing Business Management Students' Persuasive Writing through Blog-Based Peer-Feedback

ERIC Educational Resources Information Center

Sayed, Osama H.

2010-01-01

The present study attempted to investigate the effect of using blog-based peer feedback on the persuasive writing of EFL business management students at the community college in Bisha, King Khalid University, Saudi Arabia. The study used a pre-test/post-test experimental and control group design. An experimental group and a control group were…

The Effect of Assessment of Process after Receiving Teacher Feedback

ERIC Educational Resources Information Center

Ruegg, Rachael

2016-01-01

This exploratory study investigated the effect of assessing both process and product compared to assessing written products alone. Two groups of students received teacher feedback over a one-year period. One group was assessed on their revisions in addition to the quality of final drafts, while a second group was assessed on the quality of final…

Conditions Fostering the Use of Informative Feedback by Young Children.

ERIC Educational Resources Information Center

Teager, Joyce; Stern, Carolyn

In order to investigate the effect of reinforcement on learning, 21 disadvantaged black children, 4 to 5 years of age, were divided among three treatment groups. Group I children received only feedback (information) as to the correctness or incorrectness of their responses. Group II children received a raisin for each correct response, and group…

Evidence for a Time-Invariant Phase Variable in Human Ankle Control

PubMed Central

Gregg, Robert D.; Rouse, Elliott J.; Hargrove, Levi J.; Sensinger, Jonathon W.

2014-01-01

Human locomotion is a rhythmic task in which patterns of muscle activity are modulated by state-dependent feedback to accommodate perturbations. Two popular theories have been proposed for the underlying embodiment of phase in the human pattern generator: a time-dependent internal representation or a time-invariant feedback representation (i.e., reflex mechanisms). In either case the neuromuscular system must update or represent the phase of locomotor patterns based on the system state, which can include measurements of hundreds of variables. However, a much simpler representation of phase has emerged in recent designs for legged robots, which control joint patterns as functions of a single monotonic mechanical variable, termed a phase variable. We propose that human joint patterns may similarly depend on a physical phase variable, specifically the heel-to-toe movement of the Center of Pressure under the foot. We found that when the ankle is unexpectedly rotated to a position it would have encountered later in the step, the Center of Pressure also shifts forward to the corresponding later position, and the remaining portion of the gait pattern ensues. This phase shift suggests that the progression of the stance ankle is controlled by a biomechanical phase variable, motivating future investigations of phase variables in human locomotor control. PMID:24558485

Burnout is associated with changes in error and feedback processing.

PubMed

Gajewski, Patrick D; Boden, Sylvia; Freude, Gabriele; Potter, Guy G; Falkenstein, Michael

2017-10-01

Burnout is a pattern of complaints in individuals with emotionally demanding jobs that is often seen as a precursor of depression. One often reported symptom of burnout is cognitive decline. To analyze cognitive control and to differentiate between subclinical burnout and mild to moderate depression a double-blinded study was conducted that investigates changes in the processing of performance errors and feedback in a task switching paradigm. Fifty-one of 76 employees from emotionally demanding jobs showed a sufficient number of errors to be included in the analysis. The sample was subdivided into groups with low (EE-) and high (EE+) emotional exhaustion and no (DE-) and mild to moderate depression (DE+). The behavioral data did not significantly differ between the groups. In contrast, in the EE+ group, the error negativity (Ne/ERN) was enhanced while the error positivity (Pe) did not differ between the EE+ and EE- groups. After negative feedback the feedback-related negativity (FRN) was enhanced, while the subsequent positivity (FRP) was reduced in EE+ relative to EE-. None of these effects were observed in the DE+ vs. DE-. These results suggest an upregulation of error and negative feedback processing, while the later processing of negative feedback was attenuated in employees with subclinical burnout but not in mild to moderate depression. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhanced performance feedback and patient participation to improve hand hygiene compliance of health-care workers in the setting of established multimodal promotion: a single-centre, cluster randomised controlled trial.

PubMed

Stewardson, Andrew James; Sax, Hugo; Gayet-Ageron, Angèle; Touveneau, Sylvie; Longtin, Yves; Zingg, Walter; Pittet, Didier

2016-12-01

Hand hygiene compliance of health-care workers remains suboptimal despite standard multimodal promotion, and evidence for the effectiveness of novel interventions is urgently needed. We aimed to assess the effect of enhanced performance feedback and patient participation on hand hygiene compliance in the setting of multimodal promotion. We did a single-centre, cluster randomised controlled trial at University of Geneva Hospitals (Geneva, Switzerland). All wards hosting adult, lucid patients, and all health-care workers and patients in these wards, were eligible. After a 15-month baseline period, eligible wards were assigned by computer-generated block randomisation (1:1:1), stratified by the type of ward, to one of three groups: control, enhanced performance feedback, or enhanced performance feedback plus patient participation. Standard multimodal hand hygiene promotion was done hospital-wide throughout the study. The primary outcome was hand hygiene compliance of health-care workers (according to the WHO Five Moments of Hand Hygiene) at the opportunity level, measured by direct observation (20-min sessions) by 12 validated infection control nurses, with each ward audited at least once every 3 months. This trial is registered with ISRCTN, number ISRCTN43599478. We randomly assigned 67 wards to the control group (n=21), enhanced performance feedback (n=24), or enhanced performance feedback plus patient participation (n=22) on May 19, 2010. One ward in the control group became a high-dependency unit and was excluded from analysis. During 1367 observation sessions, 12 579 hand hygiene opportunities were recorded. Between the baseline period (April 1, 2009, to June 30, 2010) and the intervention period (July 1, 2010, to June 30, 2012), mean hand hygiene compliance increased from 66% (95% CI 62-70) to 73% (70-77) in the control group (odds ratio [OR] 1·41, 95% CI 1·21-1·63), from 65% (62-69) to 75% (72-77) in the enhanced performance feedback group (1·61, 1·41-1·84), and from 66% (62-70) to 77% (74-80) in the enhanced performance feedback plus patient participation group (1·73, 1·51-1·98). The absolute difference in compliance attributable to interventions was 3 percentage points (95% CI 0-7; p=0·19) for the enhanced performance feedback group and 4 percentage points (1-8; p=0·048) for the enhanced performance feedback plus patient participation group. Hand hygiene compliance remained significantly higher than baseline in all three groups (OR 1·21 [1·00-1·47] vs 1·38 [1·19-1·60] vs 1·36 [1·18-1·57]) during the post-intervention follow-up (Jan 1, 2013, to Dec 31, 2014). Hand hygiene compliance improved in all study groups, and neither intervention had a clinically significant effect compared with control. Improvement in control wards might reflect cross-contamination, highlighting challenges with randomised trials of behaviour change. Swiss National Science Foundation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Competition increases sensitivity of wheat (Triticum aestivum) to biotic plant-soil feedback.

PubMed

Hol, W H Gera; de Boer, Wietse; ten Hooven, Freddy; van der Putten, Wim H

2013-01-01

Plant-soil feedback (PSF) and plant competition play an important role in structuring vegetation composition, but their interaction remains unclear. Recent studies suggest that competing plants could dilute pathogenic effects, whereas the standing view is that competition may increase the sensitivity of the focal plant to PSF. In agro-ecosystems each of these two options would yield contrasting outcomes: reduced versus enhanced effects of weeds on crop biomass production. To test the effect of competition on sensitivity to PSF, we grew Triticum aestivum (Common wheat) with and without competition from a weed community composed of Vicia villosa, Chenopodium album and Myosotis arvensis. Plants were grown in sterilized soil, with or without living field inoculum from 4 farms in the UK. In the conditioning phase, field inocula had both positive and negative effects on T. aestivum shoot biomass, depending on farm. In the feedback phase the differences between shoot biomass in T. aestivum monoculture on non-inoculated and inoculated soils had mostly disappeared. However, T. aestivum plants growing in mixtures in the feedback phase were larger on non-inoculated soil than on inoculated soil. Hence, T. aestivum was more sensitive to competition when the field soil biota was present. This was supported by the statistically significant negative correlation between shoot biomass of weeds and T. aestivum, which was absent on sterilized soil. In conclusion, competition in cereal crop-weed systems appears to increase cereal crop sensitivity to soil biota.

Evidence of a Critical Phase Transition in Purely Temporal Dynamics with Long-Delayed Feedback

NASA Astrophysics Data System (ADS)

Faggian, Marco; Ginelli, Francesco; Marino, Francesco; Giacomelli, Giovanni

2018-04-01

Experimental evidence of an absorbing phase transition, so far associated with spatiotemporal dynamics, is provided in a purely temporal optical system. A bistable semiconductor laser, with long-delayed optoelectronic feedback and multiplicative noise, shows the peculiar features of a critical phenomenon belonging to the directed percolation universality class. The numerical study of a simple, effective model provides accurate estimates of the transition critical exponents, in agreement with both theory and our experiment. This result pushes forward a hard equivalence of nontrivial stochastic, long-delayed systems with spatiotemporal ones and opens a new avenue for studying out-of-equilibrium universality classes in purely temporal dynamics.

Results of adaptive feedforward on GTA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ziomek, C.D.; Denney, P.M.; Regan, A.H.

1993-01-01

This paper presents the results of the adaptive feedforward system in use on the Ground Test Accelerator (GTA). The adaptive feedforward system was shown to correct repetitive, high-frequency errors in the amplitude and phase of the RF field of the pulsed accelerator. The adaptive feedforward system was designed as an augmentation to the RF field feedback control system and was able to extend the closed-loop bandwidth and disturbance rejection by a factor of ten. Within a second implementation, the adaptive feedforward hardware was implemented in place of the feedback control system and was shown to negate both beam transients andmore » phase droop in the klystron amplifier.« less

Results of adaptive feedforward on GTA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ziomek, C.D.; Denney, P.M.; Regan, A.H.

1993-06-01

This paper presents the results of the adaptive feedforward system in use on the Ground Test Accelerator (GTA). The adaptive feedforward system was shown to correct repetitive, high-frequency errors in the amplitude and phase of the RF field of the pulsed accelerator. The adaptive feedforward system was designed as an augmentation to the RF field feedback control system and was able to extend the closed-loop bandwidth and disturbance rejection by a factor of ten. Within a second implementation, the adaptive feedforward hardware was implemented in place of the feedback control system and was shown to negate both beam transients andmore » phase droop in the klystron amplifier.« less

Adaptive vibration control using synchronous demodulation with machine tool controller motor commutation

DOEpatents

Hopkins, David James [Livermore, CA

2008-05-13

A control system and method for actively reducing vibration in a spindle housing caused by unbalance forces on a rotating spindle, by measuring the force-induced spindle-housing motion, determining control signals based on synchronous demodulation, and provide compensation for the measured displacement to cancel or otherwise reduce or attenuate the vibration. In particular, the synchronous demodulation technique is performed to recover a measured spindle housing displacement signal related only to the rotation of a machine tool spindle, and consequently rejects measured displacement not related to spindle motion or synchronous to a cycle of revolution. Furthermore, the controller actuates at least one voice-coil (VC) motor, to cancel the original force-induced motion, and adapts the magnitude of voice coil signal until this measured displacement signal is brought to a null. In order to adjust the signal to a null, it must have the correct phase relative to the spindle angle. The feedback phase signal is used to adjust a common (to both outputs) commutation offset register (offset relative to spindle encoder angle) to force the feedback phase signal output to a null. Once both of these feedback signals are null, the system is compensating properly for the spindle-induced motion.

Software for MR image overlay guided needle insertions: the clinical translation process

NASA Astrophysics Data System (ADS)

Ungi, Tamas; U-Thainual, Paweena; Fritz, Jan; Iordachita, Iulian I.; Flammang, Aaron J.; Carrino, John A.; Fichtinger, Gabor

2013-03-01

PURPOSE: Needle guidance software using augmented reality image overlay was translated from the experimental phase to support preclinical and clinical studies. Major functional and structural changes were needed to meet clinical requirements. We present the process applied to fulfill these requirements, and selected features that may be applied in the translational phase of other image-guided surgical navigation systems. METHODS: We used an agile software development process for rapid adaptation to unforeseen clinical requests. The process is based on iterations of operating room test sessions, feedback discussions, and software development sprints. The open-source application framework of 3D Slicer and the NA-MIC kit provided sufficient flexibility and stable software foundations for this work. RESULTS: All requirements were addressed in a process with 19 operating room test iterations. Most features developed in this phase were related to workflow simplification and operator feedback. CONCLUSION: Efficient and affordable modifications were facilitated by an open source application framework and frequent clinical feedback sessions. Results of cadaver experiments show that software requirements were successfully solved after a limited number of operating room tests.

Improving training of laparoscopic tissue manipulation skills using various visual force feedback types.

PubMed

Smit, Daan; Spruit, Edward; Dankelman, Jenny; Tuijthof, Gabrielle; Hamming, Jaap; Horeman, Tim

2017-01-01

Visual force feedback allows trainees to learn laparoscopic tissue manipulation skills. The aim of this experimental study was to find the most efficient visual force feedback method to acquire these skills. Retention and transfer validity to an untrained task were assessed. Medical students without prior experience in laparoscopy were randomized in three groups: Constant Force Feedback (CFF) (N = 17), Bandwidth Force Feedback (BFF) (N = 16) and Fade-in Force Feedback (N = 18). All participants performed a pretest, training, post-test and follow-up test. The study involved two dissimilar tissue manipulation tasks, one for training and one to assess transferability. Participants performed six trials of the training task. A force platform was used to record several force parameters. A paired-sample t test showed overall lower force parameter outcomes in the post-test compared to the pretest (p < .001). A week later, the force parameter outcomes were still significantly lower than found in the pretest (p < .005). Participants also performed the transfer task in the post-test (p < .02) and follow-up (p < .05) test with lower force parameter outcomes compared to the pretest. A one-way MANOVA indicated that in the post-test the CFF group applied 50 % less Mean Absolute Nonzero Force (p = .005) than the BFF group. All visual force feedback methods showed to be effective in decreasing tissue manipulation force as no major differences were found between groups in the post and follow-up trials. The BFF method is preferred for it respects individual progress and minimizes distraction.

The effects of individualized actigraph feedback on fatigue management in railroad engineers

DOT National Transportation Integrated Search

2003-01-01

A total of twenty-one participants completed the three-month study designed to assess the functionality of improving individual sleep habits with Actigraph Performance Feedback. There were eleven participants in the feedback group and ten participant...

The Effects of Standardized Feedback on Orthopedic Patient Evaluation Skills.

ERIC Educational Resources Information Center

DaRosa, Debra A.; And Others

1984-01-01

A study examined whether there are performance differences between surgery clerks provided corrective reinforcement on orthopedic history and physical examination write-ups and those assessed by traditional feedback means when both groups are exposed to the feedback instrument. (MLW)

Gray matter volume and rapid decision-making in major depressive disorder.

PubMed

Nakano, Masayuki; Matsuo, Koji; Nakashima, Mami; Matsubara, Toshio; Harada, Kenichiro; Egashira, Kazuteru; Masaki, Hiroaki; Takahashi, Kanji; Watanabe, Yoshifumi

2014-01-03

Reduced motivation and blunted decision-making are key features of major depressive disorder (MDD). Patients with MDD show abnormal decision-making when given negative feedback regarding a reward. The brain mechanisms underpinning this behavior remain unclear. In the present study, we examined the association between rapid decision-making with negative feedback and brain volume in MDD. Thirty-six patients with MDD and 54 age-, sex- and IQ-matched healthy subjects were studied. Subjects performed a rapid decision-making monetary task in which participants could make high- or low-risk choices. We compared between the 2 groups the probability that a high-risk choice followed negative feedback. In addition, we used voxel-based morphometry (VBM) to compare between group differences in gray matter volume, and the correlation between the probability for high-risk choices and brain volume. Compared to the healthy group, the MDD group showed significantly lower probabilities for high-risk choices following negative feedback. VBM analysis revealed that the MDD group had less gray matter volume in the right medial prefrontal cortex and orbitofrontal cortex (OFC) compared to the healthy group. The right OFC volume was negatively correlated with the probability that a high-risk choice followed negative feedback in patients with MDD. We did not observe these trends in healthy subjects. Patients with MDD show reduced motivation for monetary incentives when they were required to make rapid decisions following negative feedback. We observed a correlation between this reduced motivation and gray matter volume in the medial and ventral prefrontal cortex, which suggests that these brain regions are likely involved in the pathophysiology of aberrant decision-making in MDD. © 2013.

The effect of standardized patient feedback in teaching surgical residents informed consent: results of a pilot study.

PubMed

Leeper-Majors, Kristine; Veale, James R; Westbrook, Thomas S; Reed, Kendall

2003-01-01

The purpose of this pilot study was to determine the effectiveness of using feedback from a standardized patient (SP) to teach a surgical resident (SR) informed consent (IC) protocol. Four general case types of increasing difficulty were tested in a longitudinal experimental design format. The four types of cases were appendectomy, cholecystectomy, colorectal cancer, and breast cancer. Eight SRs of varying years of completion in medical school served as subjects-four in the experimental group (received performance feedback from an SP) and four in the control group (received no SP feedback). Both the control and experimental groups participated in two patient encounters per case type. The first patient encounter served as the pretest, and the second patient encounter was the posttest. In each encounter, an SP rated the resident on 14 measures using an open-ended seven-point rating scale adopted and modified from the Brown University Interpersonal Skill Evaluation (BUISE). Each resident also reviewed a videotape of an expert giving IC between pretest and the posttest for basic instructional protocol. Random stratified sampling was used to equally distribute the residents by postgraduate years. A total of 16 SPs were used in this study. All patient/SR encounters were videotaped. There was a statistically significant overall change--pretest to posttest and across cases (p = 0.001). The group effect was statistically significant (p = 0.000), with the experimental group averaging about 10 points greater than the control group. Standardized patient feedback is an effective modality in teaching surgical residents informed consent protocol. This conclusion is tentative, due to the limitations of sample size. The results of this study support continued research on the effects of standardized patient feedback to teach informed consent to surgical residents.

Instructor feedback versus no instructor feedback on performance in a laparoscopic virtual reality simulator: a randomized educational trial

PubMed Central

2012-01-01

Abstract Background Several studies have found a positive effect on the learning curve as well as the improvement of basic psychomotor skills in the operating room after virtual reality training. Despite this, the majority of surgical and gynecological departments encounter hurdles when implementing this form of training. This is mainly due to lack of knowledge concerning the time and human resources needed to train novice surgeons to an adequate level. The purpose of this trial is to investigate the impact of instructor feedback regarding time, repetitions and self-perception when training complex operational tasks on a virtual reality simulator. Methods/Design The study population consists of medical students on their 4th to 6th year without prior laparoscopic experience. The study is conducted in a skills laboratory at a centralized university hospital. Based on a sample size estimation 98 participants will be randomized to an intervention group or a control group. Both groups have to achieve a predefined proficiency level when conducting a laparoscopic salpingectomy using a surgical virtual reality simulator. The intervention group receives standardized instructor feedback of 10 to 12 min a maximum of three times. The control group receives no instructor feedback. Both groups receive the automated feedback generated by the virtual reality simulator. The study follows the CONSORT Statement for randomized trials. Main outcome measures are time and repetitions to reach the predefined proficiency level on the simulator. We include focus on potential sex differences, computer gaming experience and self-perception. Discussion The findings will contribute to a better understanding of optimal training methods in surgical education. Trial Registration NCT01497782 PMID:22373062

Mind the gap! Automated concept map feedback supports students in writing cohesive explanations.

PubMed

Lachner, Andreas; Burkhart, Christian; Nückles, Matthias

2017-03-01

Many students are challenged with the demand of writing cohesive explanations. To support students in writing cohesive explanations, we developed a computer-based feedback tool that visualizes cohesion deficits of students' explanations in a concept map. We conducted three studies to investigate the effectiveness of such feedback as well as the underlying cognitive processes. In Study 1, we found that the concept map helped students identify potential cohesion gaps in their drafts and plan remedial revisions. In Study 2, students with concept map feedback conducted revisions that resulted in more locally and globally cohesive, and also more comprehensible, explanations than the explanations of students who revised without concept map feedback. In Study 3, we replicated the findings of Study 2 by and large. More importantly, students who had received concept map feedback on a training explanation 1 week later wrote a transfer explanation without feedback that was more cohesive than the explanation of students who had received no feedback on their training explanation. The automated concept map feedback appears to particularly support the evaluation phase of the revision process. Furthermore, the feedback enabled novice writers to acquire sustainable skills in writing cohesive explanations. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A Goal-Setting and Feedback Intervention to Increase ID-Checking Behavior: An Assessment of Social Validity and Behavioral Impact

ERIC Educational Resources Information Center

Downing, Christopher O., Jr.; Geller, E. Scott

2012-01-01

A participative goal-setting and feedback intervention increased cashiers' identification-checking behavior at a large grocery store. The cashiers' identification-checking percentages increased from 0.2% at baseline to 9.7% during the intervention phase and then declined to 2.3% during withdrawal. At the control store, the percentages of…

Exploring Transitions in Notions of Identity as Perceived by Beginning Post-Compulsory Teachers

ERIC Educational Resources Information Center

Wright, Victoria; Loughlin, Theresa; Hall, Val

2018-01-01

This paper reports on Phase Two of a small-scale qualitative research project. Phase One (2015-2016) focused on pre-service student teachers' perceptions of observation and feedback in relation to their developing identity as teachers. In Phase Two, two previous participants reflected on the research findings as qualified and beginning teachers.…

Chaos synchronization in vertical-cavity surface-emitting laser based on rotated polarization-preserved optical feedback

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nazhan, Salam; Ghassemlooy, Zabih; Busawon, Krishna

2016-01-15

In this paper, the influence of the rotating polarization-preserved optical feedback on the chaos synchronization of a vertical-cavity surface-emitting laser (VCSEL) is investigated experimentally. Two VCSELs' polarization modes (XP) and (YP) are gradually rotated and re-injected back into the VCSEL. The anti-phase dynamics synchronization of the two polarization modes is evaluated using the cross-correlation function. For a fixed optical feedback, a clear relationship is found between the cross-correlation coefficient and the polarization angle θ{sub p}. It is shown that high-quality anti-phase polarization-resolved chaos synchronization is achieved at higher values of θ{sub p}. The maximum value of the cross-correlation coefficient achievedmore » is −0.99 with a zero time delay over a wide range of θ{sub p} beyond 65° with a poor synchronization dynamic at θ{sub p} less than 65°. Furthermore, it is observed that the antiphase irregular oscillation of the XP and YP modes changes with θ{sub p}. VCSEL under the rotating polarization optical feedback can be a good candidate as a chaotic synchronization source for a secure communication system.« less

Home Energy Displays: Consumer Adoption and Response

DOE Office of Scientific and Technical Information (OSTI.GOV)

LaMarche, J.; Cheney, K.; Akers, C.

2012-12-01

The focus of this project was to investigate the factors influencing consumer adoption of Home Energy Displays (HEDs) and to evaluate electricity consumption in households with basic HEDs versus enhanced feedback methods - web portals or alerts. We hypothesized that providing flexible and relatable information to users, in addition to a basic HED, would make feedback more effective and achieve persistent energy savings. In Phase I, we conducted three user research studies and found preferences for aesthetically pleasing, easy to understand feedback that is accessible through multiple media and offered free of charge. The deployment of HEDs in 150 householdsmore » planned for Phase II encountered major recruitment and HED field deployment problems. First, after extensive outreach campaigns to apartment complexes with 760 units, only 8% of building's tenants elected to receive a free HED in their homes as part of the field study. Second, the HED used, a leading market model, had a spectrum of problems, including gateway miscommunications, failure to post to a data-hosting third party, and display malfunctions. In light of these challenges, we are pursuing a modified study investigating the energy savings of a web portal versus alert-based energy feedback instead of a physical HED.« less

How do we trust strangers? The neural correlates of decision making and outcome evaluation of generalized trust

PubMed Central

Wang, Yiwen; Zhang, Zhen; Jing, Yiming; Valadez, Emilio A.

2016-01-01

This study investigates the brain correlates of decision making and outcome evaluation of generalized trust (i.e. trust in unfamiliar social agents)—a core component of social capital which facilitates civic cooperation and economic exchange. We measured 18 (9 male) Chinese participants’ event-related potentials while they played the role of the trustor in a one-shot trust game with unspecified social agents (trustees) allegedly selected from a large representative sample. At the decision-making phase, greater N2 amplitudes were found for trustors’ distrusting decisions compared to trusting decisions, which may reflect greater cognitive control exerted to distrust. Source localization identified the precentral gyrus as one possible neuronal generator of this N2 component. At the outcome evaluation phase, principal components analysis revealed that the so called feedback-related negativity was in fact driven by a reward positivity, which was greater in response to gain feedback compared to loss feedback. This reduced reward positivity following loss feedback may indicate that the absence of reward for trusting decisions was unexpected by the trustor. In addition, we found preliminary evidence suggesting that the decision-making processes may differ between high trustors and low trustors. PMID:27317927

Effectiveness of In-Home Feedback Devices in Conjunction with Energy Use Information on Residential Energy Consumption

NASA Astrophysics Data System (ADS)

Rungta, Shaily

Residential energy consumption accounts for 22% of the total energy use in the United States. The consumer's perception of energy usage and conservation are very inaccurate which is leading to growing number of individuals who try to seek out ways to use energy more wisely. Hence behavioral change in consumers with respect to energy use, by providing energy use feedback may be important in reducing home energy consumption. Real-time energy information feedback delivered via technology along with feedback interventions has been reported to produce up to 20 percent declines in residential energy consumption through past research and pilot studies. There are, however, large differences in the estimates of the effect of these different types of feedback on energy use. As part of the Energize Phoenix Program, (a U.S. Department of Energy funded program), a Dashboard Study was conducted by the Arizona State University to estimate the impact of real-time, home-energy displays in conjunction with other feedback interventions on the residential rate of energy consumption in Phoenix, while also creating awareness and encouragement to households to reduce energy consumption. The research evaluates the effectiveness of these feedback initiatives. In the following six months of field experiment, a selected number of low-income multi-family apartments in Phoenix, were divided in three groups of feedback interventions, where one group received residential energy use related education and information, the second group received the same education as well as was equipped with the in-home feedback device and the third was given the same education, the feedback device and added budgeting information. Results of the experiment at the end of the six months did not lend a consistent support to the results from literature and past pilot studies. The data revealed a statistically insignificant reduction in energy consumption for the experiment group overall and inconsistent results for individual households when compared to a randomly selected control sample. However, as per the participant survey results, the study proved effective to foster awareness among participating residents of their own patterns of residential electricity consumption and understanding of residential energy use related savings.

Feedback GAP: study protocol for a cluster-randomized trial of goal setting and action plans to increase the effectiveness of audit and feedback interventions in primary care

PubMed Central

2010-01-01

Background Audit and feedback to physicians is commonly used alone or as part of multifaceted interventions. While it can play an important role in quality improvement, the optimal design of audit and feedback is unknown. This study explores how feedback can be improved to increase acceptability and usability in primary care. The trial seeks to determine whether a theory-informed worksheet appended to feedback reports can help family physicians improve quality of care for their patients with diabetes and/or ischemic heart disease. Methods Two-arm cluster trial was conducted with participating primary care practices allocated using minimization to simple feedback or enhanced feedback group. The simple feedback group receives performance feedback reports every six months for two years regarding the proportion of their patients with diabetes and/or ischemic heart disease who are meeting quality targets. The enhanced feedback group receives these same reports as well as a theory-informed worksheet designed to facilitate goal setting and action plan development in response to the feedback reports. Participants are family physicians from across Ontario who use electronic medical records; data for rostered patients are used to produce the feedback reports and for analysis. Outcomes The primary disease outcomes are the blood pressure (BP), and low-density lipoprotein cholesterol (LDL) levels. The primary process measure is a composite score indicating the number of recommended activities (e.g., tests and prescriptions) conducted by the family physicians for their patients with diabetes and/or ischemic heart disease within the appropriate timeframe. Secondary outcomes are the proportion of patients whose results meet targets for glucose, LDL, and BP as well as the percent of patients receiving relevant prescriptions. A qualitative process evaluation using semi-structured interviews will explore perceived barriers to behaviour change in response to feedback reports and preferences with regard to feedback design. Analysis Intention-to-treat approach will be used to analyze the trial. Analysis will be performed on patient-level variables using generalized estimating equation models to adjust for covariates and account for the clustered nature of the data. The trial is powered to show small, but clinically important differences of 7 mmHG in systolic BP and 0.32 mmol/L in LDL. Trial Registration ClinicalTrials.gov NCT00996645 PMID:21167034

Feedback GAP: study protocol for a cluster-randomized trial of goal setting and action plans to increase the effectiveness of audit and feedback interventions in primary care.

PubMed

Ivers, Noah M; Tu, Karen; Francis, Jill; Barnsley, Jan; Shah, Baiju; Upshur, Ross; Kiss, Alex; Grimshaw, Jeremy M; Zwarenstein, Merrick

2010-12-17

Audit and feedback to physicians is commonly used alone or as part of multifaceted interventions. While it can play an important role in quality improvement, the optimal design of audit and feedback is unknown. This study explores how feedback can be improved to increase acceptability and usability in primary care. The trial seeks to determine whether a theory-informed worksheet appended to feedback reports can help family physicians improve quality of care for their patients with diabetes and/or ischemic heart disease. Two-arm cluster trial was conducted with participating primary care practices allocated using minimization to simple feedback or enhanced feedback group. The simple feedback group receives performance feedback reports every six months for two years regarding the proportion of their patients with diabetes and/or ischemic heart disease who are meeting quality targets. The enhanced feedback group receives these same reports as well as a theory-informed worksheet designed to facilitate goal setting and action plan development in response to the feedback reports. Participants are family physicians from across Ontario who use electronic medical records; data for rostered patients are used to produce the feedback reports and for analysis. The primary disease outcomes are the blood pressure (BP), and low-density lipoprotein cholesterol (LDL) levels. The primary process measure is a composite score indicating the number of recommended activities (e.g., tests and prescriptions) conducted by the family physicians for their patients with diabetes and/or ischemic heart disease within the appropriate timeframe. Secondary outcomes are the proportion of patients whose results meet targets for glucose, LDL, and BP as well as the percent of patients receiving relevant prescriptions. A qualitative process evaluation using semi-structured interviews will explore perceived barriers to behaviour change in response to feedback reports and preferences with regard to feedback design. Intention-to-treat approach will be used to analyze the trial. Analysis will be performed on patient-level variables using generalized estimating equation models to adjust for covariates and account for the clustered nature of the data. The trial is powered to show small, but clinically important differences of 7 mmHG in systolic BP and 0.32 mmol/L in LDL. ClinicalTrials.gov NCT00996645.

The impact of a daily smartphone-based feedback system among women with gestational diabetes on compliance, glycemic control, satisfaction, and pregnancy outcome: a randomized controlled trial.

PubMed

Miremberg, Hadas; Ben-Ari, Tal; Betzer, Tal; Raphaeli, Hagit; Gasnier, Rose; Barda, Giulia; Bar, Jacob; Weiner, Eran

2018-04-01

Patient compliance and tight glycemic control have been demonstrated to improve outcome in pregnancies complicated by gestational diabetes mellitus. The use of advanced technological tools, including smartphone-based platforms, to improve medical care and outcomes has been demonstrated in various fields of medicine, but only a few small studies were performed with gestational diabetes mellitus patients. We aimed to study the impact of introducing a smartphone-based daily feedback and communication platform between gestational diabetes mellitus patients and their physicians, on patient compliance, glycemic control, pregnancy outcome, and patient satisfaction. This is a prospective, single-center, randomized controlled trial. Newly diagnosed gestational diabetes mellitus patients presenting to our multidisciplinary diabetes-in-pregnancy clinic were randomized to: (1) routine biweekly prenatal clinic care (control group); or (2) additional daily detailed feedback on their compliance and glycemic control from the clinic team via an application installed on their smartphone (smartphone group). The primary outcome was patient compliance defined as the actual blood glucose measurements/instructed measurements ×100. The secondary outcomes included diabetes-control parameters, pregnancy, and neonatal outcomes. The study was adequately powered to detect a 20% difference in patient compliance, based on a preliminary phase that demonstrated 70% baseline compliance to glucose measurements. A total of 120 newly diagnosed gestational diabetes mellitus patients were analyzed. The 2 groups did not differ in terms of age, parity, education, body mass index, family history, maternal comorbidities, oral glucose tolerance test values, and hemoglobin A1C at randomization. The smartphone group demonstrated higher level of compliance (84 ± 0.16% vs 66 ± 0.28%, P < .001); lower mean blood glucose (105.1 ± 8.6 mg/dL vs 112.6 ± 7.4 mg/dL, P < .001); lower rates of off-target measurements both fasting (4.7 ± 0.4% vs 8.4 ± 0.6%, P < .001) and 1-hour postprandial (7.7 ± 0.8% vs 14.3 ± 0.8%, P < .001); and a lower rate of pregnancies requiring insulin treatment (13.3% vs 30.0%, P = .044). The rates of macrosomia, neonatal hypoglycemia, shoulder dystocia, and other delivery and neonatal complications did not differ between the groups. Patients in the smartphone group reported excellent satisfaction from the use of the application and from their overall prenatal care. Introduction of a smartphone-based daily feedback and communication platform between gestational diabetes mellitus patients and the multidisciplinary diabetes-in-pregnancy clinic team improved patient compliance and glycemic control, and lowered the rate of insulin treatment. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of visual feedback balance training on the balance and ankle instability in adult men with functional ankle instability.

PubMed

Nam, Seung-Min; Kim, Kyoung; Lee, Do Youn

2018-01-01

[Purpose] This study examined the effects of visual feedback balance training on the balance and ankle instability in adult men with functional ankle instability. [Subjects and Methods] Twenty eight adults with functional ankle instability, divided randomly into an experimental group, which performed visual feedback balance training for 20 minutes and ankle joint exercises for 10 minutes, and a control group, which performed ankle joint exercise for 30 minutes. Exercises were completed three times a week for 8 weeks. Bio rescue was used for balance ability. It measured limit of stability at one minute. For ankle instability was measured using Cumberland ankle instability tool (CAIT). This measure was performed before and after the experiments in each group. [Results] The experimental group had significant increase in the Limit of Stability and CAIT score. The control group had significant increase in CAIT score. While the Limit of Stability increased without significance. [Conclusion] In conclusion, visual feedback balance training can be recommended as a treatment method for patients with functional ankle instability.

MASS TRANSPORT AND TURBULENCE IN GRAVITATIONALLY UNSTABLE DISK GALAXIES. II. THE EFFECTS OF STAR FORMATION FEEDBACK

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldbaum, Nathan J.; Krumholz, Mark R.; Forbes, John C., E-mail: ngoldbau@illinois.edu

2016-08-10

Self-gravity and stellar feedback are capable of driving turbulence and transporting mass and angular momentum in disk galaxies, but the balance between them is not well understood. In the previous paper in this series, we showed that gravity alone can drive turbulence in galactic disks, regulate their Toomre Q parameters to ∼1, and transport mass inwards at a rate sufficient to fuel star formation in the centers of present-day galaxies. In this paper we extend our models to include the effects of star formation feedback. We show that feedback suppresses galaxies’ star formation rates by a factor of ∼5 andmore » leads to the formation of a multi-phase atomic and molecular interstellar medium. Both the star formation rate and the phase balance produced in our simulations agree well with observations of nearby spirals. After our galaxies reach steady state, we find that the inclusion of feedback actually lowers the gas velocity dispersion slightly compared to the case of pure self-gravity, and also slightly reduces the rate of inward mass transport. Nevertheless, we find that, even with feedback included, our galactic disks self-regulate to Q ∼ 1, and transport mass inwards at a rate sufficient to supply a substantial fraction of the inner disk star formation. We argue that gravitational instability is therefore likely to be the dominant source of turbulence and transport in galactic disks, and that it is responsible for fueling star formation in the inner parts of galactic disks over cosmological times.« less

Feedback facilitates transfer of training with US Hispanic workers in a healthcare laundry linen facility.

PubMed

Lebbon, Angela R; Lee, Sin Chien; Johnson, Douglas A

2015-12-01

This study aimed to increase safety knowledge and behaviour of US Hispanic custodial workers in healthcare through a culturally appropriate training and monitoring process. A single-group, repeated-measures, pre-test and post-test design was used to examine training effectiveness across four sets of behaviours with 23 Spanish-speaking workers. Small group, lecture-style training in Spanish with pictures and video resulted in significant improvements in knowledge and behaviour. However, additional analyses show that behavioural feedback was the critical component in improving safety behaviour during transfer of training. Findings from reaction, knowledge, behaviour and results measures suggest that group training and graphic feedback is culturally appropriate and effective with Hispanic workers. Further investigation is needed to understand cultural factors that facilitate effective development and delivery of safety training and feedback to US Hispanic workers. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

An evaluation of the feedback loops in the poverty focus of world bank operations.

PubMed

Fardoust, Shahrokh; Kanbur, Ravi; Luo, Xubei; Sundberg, Mark

2018-04-01

The World Bank Group in 2013 made the elimination of extreme poverty by 2030 a central institutional focus and purpose. This paper, based on an evaluation conducted by the Independent Evaluation Group of the World Bank Group, examines how, and how well, the Bank uses feedback loops to enhance the poverty focus of its operations. Feedback loops are important for every element of the results chain running from data, to diagnostics, to strategy formulation and finally to strategy implementation. The evaluation uses a range of instruments, including surveys of stakeholders and World Bank staff, focus group meetings, country case studies and systematic reviews of Bank lending and non-lending operations. We find that while the Bank generates useful information on poverty reduction from its projects and programs, the feedback loops - from outcomes to data analysis to diagnostics to strategy formulation and implementation - have generally been weak, with sizable variation across countries. Copyright © 2017 The World Bank. Published by Elsevier Ltd.. All rights reserved.

Development of an Internet-Based Parent Training Intervention for Children with ASD

DTIC Science & Technology

2014-10-01

had mean pretests scores that were significantly lower than did individuals with master’s degrees, all three groups per- formed comparably on the...focus groups with 8-10 key stakeholders to gain feedback on the structural elements of the program. Focus group members will participate in two focus... groups , three months apart. In the first focus group , 9    we will obtain feedback on the structure of the online systems training and self-directed

Videotaped Feedback Method to Enhance Learning in Preclinical Operative Dentistry: An Experimental Study.

PubMed

Shah, Dipali Yogesh; Dadpe, Ashwini Manish; Kalra, Dheeraj Deepak; Garcha, Vikram P

2015-12-01

The aim of this study was to investigate if a videotaped feedback method enhanced teaching and learning outcomes in a preclinical operative laboratory setting for novice learners. In 2013, 60 dental students at a dental school in India were randomly assigned to two groups: control (n=30) and experimental (n=30). The control group prepared a Class II tooth preparation for amalgam after receiving a video demonstration of the exercise. The experimental group received the same video demonstration as the control group, but they also participated in a discussion and analysis of the control groups' videotaped performance and then performed the same exercise. The self-evaluation scores (SS) and examiner evaluation scores (ES) of the two groups were compared using the unpaired t-test. The experimental group also used a five-point Likert scale to rate each item on the feedback form. The means of SS (13.65±2.43) and ES (14.75±1.97) of the experimental group were statistically higher than the means of SS (11.55±2.09) and ES (11.60±1.82) of the control group. Most students in the experimental group perceived that this technique enhanced their learning experience. Within the limits of this study, the videotaped feedback using both ideal and non-ideal examples enhanced the students' performance.

Characterization of mathematics instructional practises for prospective elementary teachers with varying levels of self-efficacy in classroom management and mathematics teaching

NASA Astrophysics Data System (ADS)

Lee, Carrie W.; Walkowiak, Temple A.; Nietfeld, John L.

2017-03-01

The purpose of this study was to investigate the relationship between prospective teachers' (PTs) instructional practises and their efficacy beliefs in classroom management and mathematics teaching. A sequential, explanatory mixed-methods design was employed. Results from efficacy surveys, implemented with 54 PTs were linked to a sample of teachers' instructional practises during the qualitative phase. In this phase, video-recorded lessons were analysed based on tasks, representations, discourse, and classroom management. Findings indicate that PTs with higher levels of mathematics teaching efficacy taught lessons characterised by tasks of higher cognitive demand, extended student explanations, student-to-student discourse, and explicit connections between representations. Classroom management efficacy seems to bear influence on the utilised grouping structures. These findings support explicit attention to PTs' mathematics teaching and classroom management efficacy throughout teacher preparation and a need for formative feedback to inform development of beliefs about teaching practises.

Midterm peer feedback in problem-based learning groups: the effect on individual contributions and achievement.

PubMed

Kamp, Rachelle J A; van Berkel, Henk J M; Popeijus, Herman E; Leppink, Jimmie; Schmidt, Henk G; Dolmans, Diana H J M

2014-03-01

Even though peer process feedback is an often used tool to enhance the effectiveness of collaborative learning environments like PBL, the conditions under which it is best facilitated still need to be investigated. Therefore, this study investigated the effects of individual versus shared reflection and goal setting on students' individual contributions to the group and their academic achievement. In addition, the influence of prior knowledge on the effectiveness of peer feedback was studied. In this pretest-intervention-posttest study 242 first year students were divided into three conditions: condition 1 (individual reflection and goal setting), condition 2 (individual and shared reflection and goal setting), and condition 3 (control group). Results indicated that the quality of individual contributions to the tutorial group did not improve after receiving the peer feedback, nor did it differ between the three conditions. With regard to academic achievement, only males in conditions 1 and 2 showed better academic achievement compared with condition 3. However, there was no difference between both ways of reflection and goal setting with regard to achievement, indicating that both ways are equally effective. Nevertheless, it is still too early to conclude that peer feedback combined with reflection and goal setting is not effective in enhancing students' individual contributions. Students only had a limited number of opportunities to improve their contributions. Therefore, future research should investigate whether an increase in number of tutorial group meetings can enhance the effectiveness of peer feedback. In addition, the effect of quality of reflection and goal setting could be taken into consideration in future research.

Connecting Health and Technology (CHAT): protocol of a randomized controlled trial to improve nutrition behaviours using mobile devices and tailored text messaging in young adults.

PubMed

Kerr, Deborah A; Pollard, Christina M; Howat, Peter; Delp, Edward J; Pickering, Mark; Kerr, Katherine R; Dhaliwal, Satvinder S; Pratt, Iain S; Wright, Janine; Boushey, Carol J

2012-06-22

Increasing intakes of fruits and vegetables intake, in tandem with reducing consumption of energy-dense and nutrient poor foods and beverages are dietary priorities to prevent chronic disease. Although most adults do not eat enough fruit and vegetables, teenagers and young adults tend to have the lowest intakes. Young adults typically consume a diet which is inconsistent with the dietary recommendations. Yet little is known about the best approaches to improve dietary intakes and behaviours among this group. This randomised controlled trial aims to evaluate the effectiveness of using a mobile device to assess dietary intake, provide tailored dietary feedback and text messages to motivate changes in fruit, vegetable and junk food consumption among young adults. The CHAT project will involve the development of the mobile device food record (MDFR), and evaluation of dietary feedback and implementation of a 6-month intervention in young adults aged 18 to 30 years. The participants will be randomly assigned to one of three groups (1) Intervention Group 1: MDFR + Text Messages + Dietary Feedback; (2) Intervention Group 2: MDFR + Dietary Feedback; (3) Control Group 3: MDFR, no feedback. All groups will undertake a 3-day dietary record using the MDFR but only the Intervention Groups 1 and 2 will receive tailored dietary feedback at baseline and at 6-months which will consist of assessment of serves of fruits, vegetables and junk food in comparison to dietary recommendations. Tailored nutrition text messages will be sent to Intervention Group 1 over the 6 months. Data will be collected at baseline and again at the 6-month completion. This trial will test if applications running on mobile devices have potential to assess diet, provide tailored feedback and nutrition messages as an effective way of improving fruit and vegetable consumption and reducing energy-dense nutrient poor foods in young adults. The CHAT project will assess the impact of the intervention on behavioural intention to eat a more healthful diet. This innovative approach if successful may provide a means to deliver a low cost health promotion program that has the potential to reach large groups, particularly young adults. Australian and New Zealand Clinical Trials Registry ACTRN12612000250831.

Connecting Health and Technology (CHAT): protocol of a randomized controlled trial to improve nutrition behaviours using mobile devices and tailored text messaging in young adults

PubMed Central

2012-01-01

Background Increasing intakes of fruits and vegetables intake, in tandem with reducing consumption of energy-dense and nutrient poor foods and beverages are dietary priorities to prevent chronic disease. Although most adults do not eat enough fruit and vegetables, teenagers and young adults tend to have the lowest intakes. Young adults typically consume a diet which is inconsistent with the dietary recommendations. Yet little is known about the best approaches to improve dietary intakes and behaviours among this group. This randomised controlled trial aims to evaluate the effectiveness of using a mobile device to assess dietary intake, provide tailored dietary feedback and text messages to motivate changes in fruit, vegetable and junk food consumption among young adults. Methods/design The CHAT project will involve the development of the mobile device food record (MDFR), and evaluation of dietary feedback and implementation of a 6-month intervention in young adults aged 18 to 30 years. The participants will be randomly assigned to one of three groups (1) Intervention Group 1: MDFR + Text Messages + Dietary Feedback; (2) Intervention Group 2: MDFR + Dietary Feedback; (3) Control Group 3: MDFR, no feedback. All groups will undertake a 3-day dietary record using the MDFR but only the Intervention Groups 1 and 2 will receive tailored dietary feedback at baseline and at 6-months which will consist of assessment of serves of fruits, vegetables and junk food in comparison to dietary recommendations. Tailored nutrition text messages will be sent to Intervention Group 1 over the 6 months. Data will be collected at baseline and again at the 6-month completion. Discussion This trial will test if applications running on mobile devices have potential to assess diet, provide tailored feedback and nutrition messages as an effective way of improving fruit and vegetable consumption and reducing energy-dense nutrient poor foods in young adults. The CHAT project will assess the impact of the intervention on behavioural intention to eat a more healthful diet. This innovative approach if successful may provide a means to deliver a low cost health promotion program that has the potential to reach large groups, particularly young adults. Trial registration Australian and New Zealand Clinical Trials Registry ACTRN12612000250831 PMID:22726532

Impact of tailored feedback in assessment of communication skills for medical students.

PubMed

Uhm, Seilin; Lee, Gui H; Jin, Jeong K; Bak, Yong I; Jeoung, Yeon O; Kim, Chan W

2015-01-01

Finding out the effective ways of teaching and assessing communication skills remain a challenging part of medication education. This study aims at exploring the usefulness and effectiveness of having additional feedback using qualitative analysis in assessment of communication skills in undergraduate medical training. We also determined the possibilities of using qualitative analysis in developing tailored strategies for improvement in communication skills training. This study was carried out on medical students (n=87) undergoing their final year clinical performance examination on communication skills using standardized patient by video-recording and transcribing their performances. Video-recordings of 26 students were randomly selected for qualitative analysis, and additional feedback was provided. We assessed the level of acceptance of communication skills scores between the study and nonstudy group and within the study group, before and after receiving feedback based on qualitative analysis. There was a statistically significant increase in the level of acceptance of feedback after delivering additional feedback using qualitative analysis, where the percentage of agreement with feedback increased from 15.4 to 80.8% (p<0.001). Incorporating feedback based on qualitative analysis for communication skills assessment gives essential information for medical students to learn and self-reflect, which could potentially lead to improved communication skills. As evident from our study, feedback becomes more meaningful and effective with additional feedback using qualitative analysis.

Investigating three types of continuous auditory feedback in visuo-manual tracking.

PubMed

Boyer, Éric O; Bevilacqua, Frédéric; Susini, Patrick; Hanneton, Sylvain

2017-03-01

The use of continuous auditory feedback for motor control and learning is still understudied and deserves more attention regarding fundamental mechanisms and applications. This paper presents the results of three experiments studying the contribution of task-, error-, and user-related sonification to visuo-manual tracking and assessing its benefits on sensorimotor learning. First results show that sonification can help decreasing the tracking error, as well as increasing the energy in participant's movement. In the second experiment, when alternating feedback presence, the user-related sonification did not show feedback dependency effects, contrary to the error and task-related feedback. In the third experiment, a reduced exposure of 50% diminished the positive effect of sonification on performance, whereas the increase of the average energy with sound was still significant. In a retention test performed on the next day without auditory feedback, movement energy was still superior for the groups previously trained with the feedback. Although performance was not affected by sound, a learning effect was measurable in both sessions and the user-related group improved its performance also in the retention test. These results confirm that a continuous auditory feedback can be beneficial for movement training and also show an interesting effect of sonification on movement energy. User-related sonification can prevent feedback dependency and increase retention. Consequently, sonification of the user's own motion appears as a promising solution to support movement learning with interactive feedback.

Impact of tailored feedback in assessment of communication skills for medical students

PubMed Central

Uhm, Seilin; Lee, Gui H.; Jin, Jeong K.; Bak, Yong I.; Jeoung, Yeon O.; Kim, Chan W.

2015-01-01

Background Finding out the effective ways of teaching and assessing communication skills remain a challenging part of medication education. This study aims at exploring the usefulness and effectiveness of having additional feedback using qualitative analysis in assessment of communication skills in undergraduate medical training. We also determined the possibilities of using qualitative analysis in developing tailored strategies for improvement in communication skills training. Methods This study was carried out on medical students (n=87) undergoing their final year clinical performance examination on communication skills using standardized patient by video-recording and transcribing their performances. Video-recordings of 26 students were randomly selected for qualitative analysis, and additional feedback was provided. We assessed the level of acceptance of communication skills scores between the study and nonstudy group and within the study group, before and after receiving feedback based on qualitative analysis. Results There was a statistically significant increase in the level of acceptance of feedback after delivering additional feedback using qualitative analysis, where the percentage of agreement with feedback increased from 15.4 to 80.8% (p<0.001). Conclusions Incorporating feedback based on qualitative analysis for communication skills assessment gives essential information for medical students to learn and self-reflect, which could potentially lead to improved communication skills. As evident from our study, feedback becomes more meaningful and effective with additional feedback using qualitative analysis. PMID:26154864

Supporting driver headway choice: the effects of discrete headway feedback when following headway instructions.

PubMed

Risto, Malte; Martens, Marieke H

2014-07-01

With specific headway instructions drivers are not able to attain the exact headways as instructed. In this study, the effects of discrete headway feedback (and the direction of headway adjustment) on headway accuracy for drivers carrying out time headway instructions were assessed experimentally. Two groups of each 10 participants (one receiving headway feedback; one control) carried out headway instructions in a driving simulator; increasing and decreasing their headway to a target headway of 2 s at speeds of 50, 80, and 100 km/h. The difference between the instructed and chosen headway was a measure for headway accuracy. The feedback group heard a sound signal at the moment that they crossed the distance of the instructed headway. Unsupported participants showed no significant difference in headway accuracy when increasing or decreasing headways. Discrete headway feedback had varying effects on headway choice accuracy. When participants decreased their headway, feedback led to higher accuracy. When increasing their headway, feedback led to a lower accuracy, compared to no headway feedback. Support did not affect driver's performance in maintaining the chosen headway. The present results suggest that (a) in its current form discrete headway feedback is not sufficient to improve the overall accuracy of chosen headways when carrying out headway instructions; (b) the effect of discrete headway feedback depends on the direction of headway adjustment. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

The effectiveness of immediate feedback during the objective structured clinical examination.

PubMed

Hodder, R V; Rivington, R N; Calcutt, L E; Hart, I R

1989-03-01

Using eight different physical examination or technical stations, 400 examinations were conducted to evaluate the effectiveness of immediate feedback during the Objective Structured Clinical Examination (OSCE). The test group comprised 50 medical students who underwent a standard 4-minute examination followed by 2 minutes of feedback. Immediately following feedback the students repeated an identical 4-minute examination scored by the same examiners. The control group consisted of 50 students from the same class who underwent an identical testing sequence, but instead of receiving feedback, they were instructed to continue their examinations for an additional 2 minutes before repeating the stations. Simple repetition of the task did not significantly improve score (mean increase 2.0%, NS). Extending the testing period from 4 to 6 minutes resulted in a small but significant increase in score (mean 6.7%, P less than 0.001). However, there was a much larger increase in the scores obtained following 2 minutes of immediate feedback compared to pre-feedback performance (mean 26.3%, P less than 0.0001). The majority of students and examiners felt that feedback, as administered in this study, was valuable both as a learning and teaching experience. Short periods of immediate feedback during an OSCE are practical and can improve competency in the performance of criterion-based tasks, at least over the short term. In addition, such feedback provides students with valuable self-assessment that may stimulate further learning.

Danish translation, cultural adaption and initial psychometric evaluation of the patient feedback form.

PubMed

Tolstrup, Lærke K; Pappot, Helle; Zangger, Graziella; Bastholt, Lars; Zwisler, Ann-Dorthe; Dieperink, Karin B

2018-04-27

No suitable Danish questionnaire exists to evaluate patient satisfaction with various patient reported outcome measures. Thus, the aim of this research project was to conduct a study on the translation and cultural adaption of an American patient reported experience measures questionnaire, "Patient Feedback Form", among Danish patients, and to examine selected psychometric properties within reliability. In the first phase of the study, the Patient Feedback Form was forward and backward translated following the methodology of existing guidelines. Subsequently, cognitive interviewing was performed with seven cancer patients and seven healthy persons (19-86 years old/6 men and 8 women) to ensure that questions were easy to understand and made sense to Danish interviewees. In the second phase, phone interviews were carried out with 95 prostate cancer patients after they had responded to the same Patient Feedback Form. Missing data was imputed using the Expectation-Maximization technique. To examine the structure of the questionnaire, an exploratory factor analysis was conducted. Cronbach's alpha was calculated to investigate internal consistency. There were only minor disagreements in the translation process, and the reconciliation went smoothly (phase 1). With regard to one item, however, it was difficult to reach a consensus. Through the qualitative validation process, the right solution was found. The results from the psychometric testing (phase 2) showed that four factors had an Eigen value > 1, but only one factor was extracted as the Scree plot had a clear "elbow", showing a one factor structure that explained 46.1% of the variance. The internal consistency was high as Cronbach's alpha was 0.89. The translated, culturally adapted, and validated version of the Patient Feedback Form seems to be suitable for measuring satisfaction with patient reported outcome measures in a Danish setting. While the results should be treated with caution due to the small sample size, psychometric testing indicates that the questionnaire is a valid instrument. However, additional psychometric testing such as hypotheses testing, responsiveness, and test-retest on a larger and more diverse sample size is required to further verify the validity of the instrument.

Adaptive Time Stepping for Transient Network Flow Simulation in Rocket Propulsion Systems

NASA Technical Reports Server (NTRS)

Majumdar, Alok K.; Ravindran, S. S.

2017-01-01

Fluid and thermal transients found in rocket propulsion systems such as propellant feedline system is a complex process involving fast phases followed by slow phases. Therefore their time accurate computation requires use of short time step initially followed by the use of much larger time step. Yet there are instances that involve fast-slow-fast phases. In this paper, we present a feedback control based adaptive time stepping algorithm, and discuss its use in network flow simulation of fluid and thermal transients. The time step is automatically controlled during the simulation by monitoring changes in certain key variables and by feedback. In order to demonstrate the viability of time adaptivity for engineering problems, we applied it to simulate water hammer and cryogenic chill down in pipelines. Our comparison and validation demonstrate the accuracy and efficiency of this adaptive strategy.

Unity PF current-source rectifier based on dynamic trilogic PWM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao Wang; Boon-Teck Ooi

1993-07-01

One remaining step in perfecting the stand-along, unity power factor, regulated current-source PWM rectifier is to reduce cost, by bringing the 12-valve converter (consisting of three single-phase full bridges that operate with two-level or bilogic PWM) to the six-valve bridge. However, the six-valve topology requires a three-level or trilogic PWM strategy that can handle feedback signals. This feature was not available until now. The paper describes a general method of translating three-phase bilogic PWM signals to three-phase trilogic PWM signals. The method of translation retains the characteristics of the bilogic PWM, including the frequency bandwidth. Experiments show that the trilogicmore » PWM signals produced by the method can not only handle stabilizing feedback signals but also signals for active filtering.« less

The Comparative Effects of Comprehensible Input, Output and Corrective Feedback on the Receptive Acquisition of L2 Vocabulary Items

ERIC Educational Resources Information Center

Nowbakht, Mohammad; Shahnazari, Mohammadtaghi

2015-01-01

In the present study, the comparative effects of comprehensible input, output and corrective feedback on the receptive acquisition of L2 vocabulary items were investigated. Two groups of beginning EFL learners participated in the study. The control group received comprehensible input only, while the experimental group received input and was…

Motor learning and the use of videotape feedback after stroke.

PubMed

Gilmore, Paula E; Spaulding, Sandi J

2007-01-01

Efforts have been made to apply motor learning theories to the rehabilitation of individuals following stroke. Motor learning poststroke has not been well investigated in the literature. This research attempted to fill the gap regarding motor learning applied to practice. This two-group research study attempted to determine the effectiveness of an experimental therapy combining videotape feedback with occupational therapy compared to only occupational therapy in learning the motor skill of donning socks and shoes after stroke. Ten participants were randomly assigned to one of the two groups and all participants were videotaped during pretest and up to 10 treatment sessions aimed at donning socks and shoes. Only one group viewed their videotape replay. The acquisition of donning socks and shoes was measured using the socks and shoes subtests of the Klein-Bell Activities of Daily Living Scale and their scores on the Canadian Occupational Performance Measure. There was no significant difference between the two groups and both groups improved. However, the group that received videotape feedback thought they performed better and were more satisfied with their ability to don shoes, lending support for the use of videotape feedback poststroke to improve satisfaction with performance.

The Effect of Tailored Web-Based Feedback and Optional Telephone Coaching on Health Improvements: A Randomized Intervention Among Employees in the Transport Service Industry

PubMed Central

Grotta, Alessandra; Pasquali, Elena; Bakkman, Linda; Bellocco, Rino; Trolle Lagerros, Ylva

2016-01-01

Background Lifestyle-related health problems are an important health concern in the transport service industry. Web- and telephone-based interventions could be suitable for this target group requiring tailored approaches. Objective To evaluate the effect of tailored Web-based health feedback and optional telephone coaching to improve lifestyle factors (body mass index—BMI, dietary intake, physical activity, stress, sleep, tobacco and alcohol consumption, disease history, self-perceived health, and motivation to change health habits), in comparison to no health feedback or telephone coaching. Methods Overall, 3,876 employees in the Swedish transport services were emailed a Web-based questionnaire. They were randomized into: control group (group A, 498 of 1238 answered, 40.23%), or intervention Web (group B, 482 of 1305 answered, 36.93%), or intervention Web + telephone (group C, 493 of 1333 answered, 36.98%). All groups received an identical questionnaire, only the interventions differed. Group B received tailored Web-based health feedback, and group C received tailored Web-based health feedback + optional telephone coaching if the participants’ reported health habits did not meet the national guidelines, or if they expressed motivation to change health habits. The Web-based feedback was fully automated. Telephone coaching was performed by trained health counselors. Nine months later, all participants received a follow-up questionnaire and intervention Web + telephone. Descriptive statistics, the chi-square test, analysis of variance, and generalized estimating equation (GEE) models were used. Results Overall, 981 of 1473 (66.60%) employees participated at baseline (men: 66.7%, mean age: 44 years, mean BMI: 26.4 kg/m2) and follow-up. No significant differences were found in reported health habits between the 3 groups over time. However, significant changes were found in motivation to change. The intervention groups reported higher motivation to improve dietary habits (144 of 301 participants, 47.8%, and 165 of 324 participants, 50.9%, for groups B and C, respectively) and physical activity habits (181 of 301 participants, 60.1%, and 207 of 324 participants, 63.9%, for B and C, respectively) compared with the control group A (122 of 356 participants, 34.3%, for diet and 177 of 356 participants, 49.7%, for physical activity). At follow-up, the intervention groups had significantly decreased motivation (group B: P<.001 for change in diet; P<.001 for change in physical activity; group C: P=.007 for change in diet; P<.001 for change in physical activity), whereas the control group reported significantly increased motivation to change diet and physical activity (P<.001 for change in diet; P<.001 for change in physical activity). Conclusion Tailored Web-based health feedback and the offering of optional telephone coaching did not have a positive health effect on employees in the transport services. However, our findings suggest an increased short-term motivation to change health behaviors related to diet and physical activity among those receiving tailored Web-based health feedback. PMID:27514859

Feedforward and feedback control of locked mode phase and rotation in DIII-D with application to modulated ECCD experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, W.; La Haye, R. J.; Lanctot, M. J.

The toroidal phase and rotation of otherwise locked magnetic islands of toroidal mode number n=1 are controlled in the DIII-D tokamak by means of applied magnetic perturbations of n=1. Pre-emptive perturbations were applied in feedforward to "catch" the mode as it slowed down and entrain it to the rotating field before complete locking, thus avoiding the associated major confinement degradation. Additionally, for the first time, the phase of the perturbation was optimized in real-time, in feedback with magnetic measurements, in order for the mode’s phase to closely match a prescribed phase, as a function of time. Experimental results confirm themore » capability to hold the mode in a given fixed-phase or to rotate it at up to 20 Hz with good uniformity. The controlcoil currents utilized in the experiments agree with the requirements estimated by an electromechanical model. Moreover, controlled rotation at 20 Hz was combined with Electron Cyclotron Current Drive (ECCD) modulated at the same frequency. This is simpler than regulating the ECCD modulation in feedback with spontaneous mode rotation, and enables repetitive, reproducible ECCD deposition at or near the island O-point, X-point and locations in between, for careful studies of how this affects the island stability. Current drive was found to be radially misaligned relative to the island, and resulting growth and shrinkage of islands matched expectations of the Modified Rutherford Equation for some discharges presented here. Finally, simulations predict the as designed ITER 3D coils can entrain a small island at sub-10 Hz frequencies.« less

Beyond the Bottom of the Foot: Topographic Organization of the Foot Dorsum in Walking.

PubMed

Klarner, Taryn; Pearcey, Gregory E P; Sun, Yao; Barss, Trevor S; Kaupp, Chelsea; Munro, Bridget; Frank, Nick; Zehr, E Paul

2017-12-01

Sensory feedback from the foot dorsum during walking has only been studied globally by whole nerve stimulation. Stimulating the main nerve innervating the dorsal surface produces a functional stumble corrective response that is phase-dependently modulated. We speculated that effects evoked by activation of discrete skin regions on the foot dorsum would be topographically organized, as with the foot sole. Nonnoxious electrical stimulation was delivered to five discrete locations on the dorsal surface of the foot during treadmill walking. Muscle activity from muscles acting at the ankle, knee, hip, and shoulder were recorded along with ankle, knee, and hip kinematics and kinetic information from forces under the foot. All data were sorted on the basis of stimulus occurrence in 12 step cycle phases, before being averaged together within a phase for subsequent analysis. Results reveal dynamic changes in reflex amplitudes and kinematics that are site specific and phase dependent. Most responses from discrete sites on the foot dorsum were seen in the swing phase suggesting function to conform foot trajectory to maintain stability of the moving limb. In general, responses from lateral stimulation differed from medial stimulation, and effects were largest from stimulation at the distal end of the foot at the metatarsals; that is, in anatomical locations where actual impact with an object in the environment is most likely during swing. Responses to stimulation extend to include muscles at the hip and shoulder. We reveal that afferent feedback from specific cutaneous locations on the foot dorsum influences stance and swing phase corrective responses. This emphasizes the critical importance of feedback from the entire foot surface in locomotor control and has application for rehabilitation after neurological injury and in footwear development.

Feedforward and feedback control of locked mode phase and rotation in DIII-D with application to modulated ECCD experiments

NASA Astrophysics Data System (ADS)

Choi, W.; La Haye, R. J.; Lanctot, M. J.; Olofsson, K. E. J.; Strait, E. J.; Sweeney, R.; Volpe, F. A.; The DIII-D Team

2018-03-01

The toroidal phase and rotation of otherwise locked magnetic islands of toroidal mode number n  =  1 are controlled in the DIII-D tokamak by means of applied magnetic perturbations of n  =  1. Pre-emptive perturbations were applied in feedforward to ‘catch’ the mode as it slowed down and entrain it to the rotating field before complete locking, thus avoiding the associated major confinement degradation. Additionally, for the first time, the phase of the perturbation was optimized in real-time, in feedback with magnetic measurements, in order for the mode’s phase to closely match a prescribed phase, as a function of time. Experimental results confirm the capability to hold the mode in a given fixed-phase or to rotate it at up to 20 Hz with good uniformity. The control-coil currents utilized in the experiments agree with the requirements estimated by an electromechanical model. Moreover, controlled rotation at 20 Hz was combined with electron cyclotron current drive (ECCD) modulated at the same frequency. This is simpler than regulating the ECCD modulation in feedback with spontaneous mode rotation, and enables repetitive, reproducible ECCD deposition at or near the island O-point, X-point and locations in between, for careful studies of how this affects the island stability. Current drive was found to be radially misaligned relative to the island, and resulting growth and shrinkage of islands matched expectations of the modified Rutherford equation for some discharges presented here. Finally, simulations predict the as designed ITER 3D coils can entrain a small island at sub-10 Hz frequencies.

Feedforward and feedback control of locked mode phase and rotation in DIII-D with application to modulated ECCD experiments

DOE PAGES

Choi, W.; La Haye, R. J.; Lanctot, M. J.; ...

2018-02-05

The toroidal phase and rotation of otherwise locked magnetic islands of toroidal mode number n=1 are controlled in the DIII-D tokamak by means of applied magnetic perturbations of n=1. Pre-emptive perturbations were applied in feedforward to "catch" the mode as it slowed down and entrain it to the rotating field before complete locking, thus avoiding the associated major confinement degradation. Additionally, for the first time, the phase of the perturbation was optimized in real-time, in feedback with magnetic measurements, in order for the mode’s phase to closely match a prescribed phase, as a function of time. Experimental results confirm themore » capability to hold the mode in a given fixed-phase or to rotate it at up to 20 Hz with good uniformity. The controlcoil currents utilized in the experiments agree with the requirements estimated by an electromechanical model. Moreover, controlled rotation at 20 Hz was combined with Electron Cyclotron Current Drive (ECCD) modulated at the same frequency. This is simpler than regulating the ECCD modulation in feedback with spontaneous mode rotation, and enables repetitive, reproducible ECCD deposition at or near the island O-point, X-point and locations in between, for careful studies of how this affects the island stability. Current drive was found to be radially misaligned relative to the island, and resulting growth and shrinkage of islands matched expectations of the Modified Rutherford Equation for some discharges presented here. Finally, simulations predict the as designed ITER 3D coils can entrain a small island at sub-10 Hz frequencies.« less

GLIMPSE: Google Glass interface for sensory feedback in myoelectric hand prostheses.

PubMed

Markovic, Marko; Karnal, Hemanth; Graimann, Bernhard; Farina, Dario; Dosen, Strahinja

2017-06-01

Providing sensory feedback to the user of the prosthesis is an important challenge. The common approach is to use tactile stimulation, which is easy to implement but requires training and has limited information bandwidth. In this study, we propose an alternative approach based on augmented reality. We have developed the GLIMPSE, a Google Glass application which connects to the prosthesis via a Bluetooth interface and renders the prosthesis states (EMG signals, aperture, force and contact) using augmented reality (see-through display) and sound (bone conduction transducer). The interface was tested in healthy subjects that used the prosthesis with (FB group) and without (NFB group) feedback during a modified clothespins test that allowed us to vary the difficulty of the task. The outcome measures were the number of unsuccessful trials, the time to accomplish the task, and the subjective ratings of the relevance of the feedback. There was no difference in performance between FB and NFB groups in the case of a simple task (basic, same-color clothespins test), but the feedback significantly improved the performance in a more complex task (pins of different resistances). Importantly, the GLIMPSE feedback did not increase the time to accomplish the task. Therefore, the supplemental feedback might be useful in the tasks which are more demanding, and thereby less likely to benefit from learning and feedforward control. The subjects integrated the supplemental feedback with the intrinsic sources (vision and muscle proprioception), developing their own idiosyncratic strategies to accomplish the task. The present study demonstrates a novel self-contained, ready-to-deploy, wearable feedback interface. The interface was successfully tested and was proven to be feasible and functionally beneficial. The GLIMPSE can be used as a practical solution but also as a general and flexible instrument to investigate closed-loop prosthesis control.

Group-Level Formative Feedback and Metadiscourse

ERIC Educational Resources Information Center

Resendes, Monica; Scardamalia, Marlene; Bereiter, Carl; Chen, Bodong; Halewood, Cindy

2015-01-01

This research explores the ability of grade 2 students to engage in productive discussion about the state of their knowledge building using group-level feedback tools to support their metadiscourse. Two aspects of knowledge work were common to the comparison and experimental classes: "Knowledge Building talk" (KB talk) involving…

Neural activations associated with feedback and retrieval success

NASA Astrophysics Data System (ADS)

Wiklund-Hörnqvist, Carola; Andersson, Micael; Jonsson, Bert; Nyberg, Lars

2017-11-01

There is substantial behavioral evidence for a phenomenon commonly called "the testing effect", i.e. superior memory performance after repeated testing compared to re-study of to-be-learned materials. However, considerably less is known about the underlying neuro-cognitive processes that are involved in the initial testing phase, and thus underlies the actual testing effect. Here, we investigated functional brain activity related to test-enhanced learning with feedback. Subjects learned foreign vocabulary across three consecutive tests with correct-answer feedback. Functional brain-activity responses were analyzed in relation to retrieval and feedback events, respectively. Results revealed up-regulated activity in fronto-striatal regions during the first successful retrieval, followed by a marked reduction in activity as a function of improved learning. Whereas feedback improved behavioral performance across consecutive tests, feedback had a negligable role after the first successful retrieval for functional brain-activity modulations. It is suggested that the beneficial effects of test-enhanced learning is regulated by feedback-induced updating of memory representations, mediated via the striatum, that might underlie the stabilization of memory commonly seen in behavioral studies of the testing effect.

Feedback in web-based questionnaires as incentive to increase compliance in studies on lifestyle factors.

PubMed

Bälter, Olle; Fondell, Elinor; Bälter, Katarina

2012-06-01

We explored the use of feedback in interactive web-based questionnaires for collecting data on lifestyle factors in epidemiological studies. Here we report from a cohort study on lifestyle factors and upper respiratory tract infections among 1805 men and women. We introduced interactivity in the form of personalized feedback and feedback on a group level regarding dietary intake, physical activity and incidence of infections in web-based questionnaires as incentives for the respondents to continue answering questions and stay in the study. The study was performed in Sweden. All participants were randomly selected from the population registry. Personalized feedback was offered in the baseline questionnaire and feedback on a group level in the five follow-up questionnaires. In total, 88 % of the participants actively chose to get personalized feedback at least once in the baseline questionnaire. The follow-up questionnaires were sent by email and the overall compliance at each follow-up was 83-84 %, despite only one reminder. In total, 74 % completed all five follow-ups. However, the compliance was higher among those who chose feedback in the baseline questionnaire compared with those who did not choose feedback. The results show that it is possible to use feedback in web questionnaires and that it has the potential to increase compliance. The majority of the participants actively chose to take part in the personalized feedback in the baseline questionnaire and future research should focus on improving the design of the feedback, which may ultimately result in even higher compliance in research studies.

Feedback in low-mass galaxies in the early Universe.

PubMed

Erb, Dawn K

2015-07-09

The formation, evolution and death of massive stars release large quantities of energy and momentum into the gas surrounding the sites of star formation. This process, generically termed 'feedback', inhibits further star formation either by removing gas from the galaxy, or by heating it to temperatures that are too high to form new stars. Observations reveal feedback in the form of galactic-scale outflows of gas in galaxies with high rates of star formation, especially in the early Universe. Feedback in faint, low-mass galaxies probably facilitated the escape of ionizing radiation from galaxies when the Universe was about 500 million years old, so that the hydrogen between galaxies changed from neutral to ionized-the last major phase transition in the Universe.

Parallel multiplex laser feedback interferometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Song; Tan, Yidong; Zhang, Shulian, E-mail: zsl-dpi@mail.tsinghua.edu.cn

2013-12-15

We present a parallel multiplex laser feedback interferometer based on spatial multiplexing which avoids the signal crosstalk in the former feedback interferometer. The interferometer outputs two close parallel laser beams, whose frequencies are shifted by two acousto-optic modulators by 2Ω simultaneously. A static reference mirror is inserted into one of the optical paths as the reference optical path. The other beam impinges on the target as the measurement optical path. Phase variations of the two feedback laser beams are simultaneously measured through heterodyne demodulation with two different detectors. Their subtraction accurately reflects the target displacement. Under typical room conditions, experimentalmore » results show a resolution of 1.6 nm and accuracy of 7.8 nm within the range of 100 μm.« less

On the Role of Auditory Feedback in Robot-Assisted Movement Training after Stroke: Review of the Literature

PubMed Central

Rodà, Antonio; Avanzini, Federico; Masiero, Stefano

2013-01-01

The goal of this paper is to address a topic that is rarely investigated in the literature of technology-assisted motor rehabilitation, that is, the integration of auditory feedback in the rehabilitation device. After a brief introduction on rehabilitation robotics, the main concepts of auditory feedback are presented, together with relevant approaches, techniques, and technologies available in this domain. Current uses of auditory feedback in the context of technology-assisted rehabilitation are then reviewed. In particular, a comparative quantitative analysis over a large corpus of the recent literature suggests that the potential of auditory feedback in rehabilitation systems is currently and largely underexploited. Finally, several scenarios are proposed in which the use of auditory feedback may contribute to overcome some of the main limitations of current rehabilitation systems, in terms of user engagement, development of acute-phase and home rehabilitation devices, learning of more complex motor tasks, and improving activities of daily living. PMID:24382952

Musical motor feedback (MMF) in walking hemiparetic stroke patients: randomized trials of gait improvement.

PubMed

Schauer, Michael; Mauritz, Karl-Heinz

2003-11-01

To demonstrate the effect of rhythmical auditory stimulation in a musical context for gait therapy in hemiparetic stroke patients, when the stimulation is played back measure by measure initiated by the patient's heel-strikes (musical motor feedback). Does this type of musical feedback improve walking more than a less specific gait therapy? The randomized controlled trial considered 23 registered stroke patients. Two groups were created by randomization: the control group received 15 sessions of conventional gait therapy and the test group received 15 therapy sessions with musical motor feedback. Inpatient rehabilitation hospital. Median post-stroke interval was 44 days and the patients were able to walk without technical aids with a speed of approximately 0.71 m/s. Gait velocity, step duration, gait symmetry, stride length and foot rollover path length (heel-on-toe-off distance). The test group showed more mean improvement than the control group: stride length increased by 18% versus 0%, symmetry deviation decreased by 58% versus 20%, walking speed increased by 27% versus 4% and rollover path length increased by 28% versus 11%. Musical motor feedback improves the stroke patient's walk in selected parameters more than conventional gait therapy. A fixed memory in the patient's mind about the song and its timing may stimulate the improvement of gait even without the presence of an external pacemaker.

Positive Feedback From Male Authority Figures Boosts Women's Math Outcomes.

PubMed

Park, Lora E; Kondrak, Cheryl L; Ward, Deborah E; Streamer, Lindsey

2018-03-01

People often search for cues in the environment to determine whether or not they will be judged or treated negatively based on their social identities. Accordingly, feedback from gatekeepers-members of majority groups who hold authority and power in a field-may be an especially important cue for those at risk of experiencing social identity threat, such as women in math settings. Across a series of studies, women who received positive ("Good job!") versus objective (score only) feedback from a male (vs. female) authority figure in math reported greater confidence; belonging; self-efficacy; more favorable Science, Technology, Engineering, and Mathematics (STEM) attitudes/identification/interest; and greater implicit identification with math. Men were affected only by the type of math feedback they received, not by the source of feedback. A meta-analysis across studies confirmed results. Together, these findings suggest that positive feedback from gatekeepers is an important situational cue that can improve the outcomes of negatively stereotyped groups.

Effectiveness of a Proactive Mail-Based Alcohol Internet Intervention for University Students: Dismantling the Assessment and Feedback Components in a Randomized Controlled Trial

PubMed Central

McCambridge, Jim; Bendtsen, Marcus; Karlsson, Nadine; Nilsen, Per

2012-01-01

Background University students in Sweden routinely receive proactive mail-based alcohol Internet interventions sent from student health services. This intervention provides personalized normative feedback on alcohol consumption with suggestions on how to decrease drinking. Earlier feasibility trials by our group and others have examined effectiveness in simple parallel-groups designs. Objective To evaluate the effectiveness of electronic screening and brief intervention, using a randomized controlled trial design that takes account of baseline assessment reactivity (and other possible effects of the research process) due to the similarity between the intervention and assessment content. The design of the study allowed for exploration of the magnitude of the assessment effects per se. Methods This trial used a dismantling design and randomly assigned 5227 students to 3 groups: (1) routine practice assessment and feedback, (2) assessment-only without feedback, and (3) neither assessment nor feedback. At baseline all participants were blinded to study participation, with no contact being made with group 3. We approached students 2 months later to participate in a cross-sectional alcohol survey. All interventions were fully automated and did not have any human involvement. All data used in the analysis were based on self-assessment using questionnaires. The participants were unaware that they were participating in a trial and thus were also blinded to which group they were randomly assigned. Results Overall, 44.69% (n = 2336) of those targeted for study completed follow-up. Attrition was similar in groups 1 (697/1742, 40.01%) and 2 (737/1742, 42.31% retained) and lower in group 3 (902/1743, 51.75% retained). Intention-to-treat analyses among all participants regardless of their baseline drinking status revealed no differences between groups in all alcohol parameters at the 2-month follow-up. Per-protocol analyses of groups 1 and 2 among those who accepted the email intervention (36.2% of the students who were offered the intervention in group 1 and 37.3% of the students in group2 ) and who were risky drinkers at baseline (60.7% follow-up rate in group 1 and 63.5% in group 2) suggested possible small beneficial effects on weekly consumption attributable to feedback. Conclusions This approach to outcome evaluation is highly conservative, and small benefits may follow the actual uptake of feedback intervention in students who are risky drinkers, the precise target group. Trial Registration International Standard Randomized Controlled Trial Number (ISRCTN): 24735383; http://www.controlled-trials.com/ISRCTN24735383 (Archived by WebCite at http://www.webcitation.org/6Awq7gjXG) PMID:23113955