TARGET's role in knowledge acquisition, engineering, validation, and documentation

NASA Technical Reports Server (NTRS)

Levi, Keith R.

1994-01-01

We investigate the use of the TARGET task analysis tool for use in the development of rule-based expert systems. We found TARGET to be very helpful in the knowledge acquisition process. It enabled us to perform knowledge acquisition with one knowledge engineer rather than two. In addition, it improved communication between the domain expert and knowledge engineer. We also found it to be useful for both the rule development and refinement phases of the knowledge engineering process. Using the network in these phases required us to develop guidelines that enabled us to easily translate the network into production rules. A significant requirement for TARGET remaining useful throughout the knowledge engineering process was the need to carefully maintain consistency between the network and the rule representations. Maintaining consistency not only benefited the knowledge engineering process, but also has significant payoffs in the areas of validation of the expert system and documentation of the knowledge in the system.

Sequential effects after practice with the dominant and non-dominant hand on the acquisition of a sliding task in schoolchildren.

PubMed

Senff, Oliver; Weigelt, Matthias

2011-03-01

This study was designed to investigate sequential effects after practice with the dominant and non-dominant hand on the acquisition of a new motor task. A total of 64 middle school children were asked to practise a cent-slide task, which required them to slide coins from one side of a cardboard into a circular target on the opposite side. Four groups practised this task within different practice schedules: (1) participants practised only with their dominant hand (right-only group); (2) participants used only their non-dominant hand (left-only group); (3) participants started to practise the skill with their dominant hand and then switched to their non-dominant hand (right-to-left group); or (4) participants started to practise the skill with their non-dominant hand and then switched to their dominant hand (left-to-right group). The acquisition of the task was facilitated after initial practice with the non-dominant hand. This was reflected in a better retention of the task and a stronger performance under a modified testing situation of the left-to-right group when compared to all other groups. Also, the left-only group showed larger interlimb transfer effects to the untrained hand than the right-only group. It is concluded that the sequence in which the dominant and non-dominant hands are used to practise influences the acquisition of new motor tasks.

Acquisition of /S/-Clusters in Hebrew-Speaking Children with Phonological Disorders

ERIC Educational Resources Information Center

Ben-David, Avivit; Ezrati, Ruth; Stulman, Navah

2010-01-01

This study examines the production and reduction patterns of initial /s/ clusters by Hebrew-speaking children with phonological disorders. Data were collected from 30 children with phonological disorders between the ages of 3;5-5;2. The data were elicited by means of a picture-naming task combined with a sentence completion task. Target words…

The Effects of Task Complexity and Input Frequency on the Acquisition of the Past Counterfactual Construction through Recasts

ERIC Educational Resources Information Center

Révész, Andrea; Sachs, Rebecca; Hama, Mika

2014-01-01

This investigation examined two techniques that may help learners focus on second language (L2) constructions when recasts are provided during meaning-based communicative activities: altering the cognitive complexity of tasks and manipulating the input frequency distributions of target constructions. We first independently assessed the validity of…

The Role of Semantic Transfer in Clitic Drop among Simultaneous and Sequential Chinese-Spanish Bilinguals

ERIC Educational Resources Information Center

Cuza, Alejandro; Perez-Leroux, Ana Teresa; Sanchez, Liliana

2013-01-01

This study examines the acquisition of the featural constraints on clitic and null distribution in Spanish among simultaneous and sequential Chinese-Spanish bilinguals from Peru. A truth value judgment task targeted the referential meaning of null objects in a negation context. Objects were elicited via two clitic elicitation tasks that targeted…

Effects of Rifle Handling, Target Acquisition, and Trigger Control on Simulated Shooting Performance

DTIC Science & Technology

2014-05-06

qualification task, and covers all of the training requirements listed in the Soldier’s Manual of Common Tasks: Warrior Skills Level 1 handbook...allow for more direct and standardized training based on common Soldier errors. If discernible patterns in these core elements of marksmanship were...more than 50 percent of variance in marksmanship performance on a standard EST weapons qualification task for participants whose 3 Snellen acuity

Spatial frequency dependence of target signature for infrared performance modeling

NASA Astrophysics Data System (ADS)

Du Bosq, Todd; Olson, Jeffrey

2011-05-01

The standard model used to describe the performance of infrared imagers is the U.S. Army imaging system target acquisition model, based on the targeting task performance metric. The model is characterized by the resolution and sensitivity of the sensor as well as the contrast and task difficulty of the target set. The contrast of the target is defined as a spatial average contrast. The model treats the contrast of the target set as spatially white, or constant, over the bandlimit of the sensor. Previous experiments have shown that this assumption is valid under normal conditions and typical target sets. However, outside of these conditions, the treatment of target signature can become the limiting factor affecting model performance accuracy. This paper examines target signature more carefully. The spatial frequency dependence of the standard U.S. Army RDECOM CERDEC Night Vision 12 and 8 tracked vehicle target sets is described. The results of human perception experiments are modeled and evaluated using both frequency dependent and independent target signature definitions. Finally the function of task difficulty and its relationship to a target set is discussed.

Integrated Eye Tracking and Neural Monitoring for Enhanced Assessment of Mild TBI

DTIC Science & Technology

2015-04-01

virtual reality driving simulator data acquisition. Data collection for the pilot study is nearly complete and data analyses are currently under way...Training for primary study procedures including neuropsychological testing, eye- tracking, virtual reality driving simulator, and EEG data acquisition is...the virtual reality driving simulator. Participants are instructed to drive along a coastal highway while performing the target detection task

Developmental hearing loss impedes auditory task learning and performance in gerbils

PubMed Central

von Trapp, Gardiner; Aloni, Ishita; Young, Stephen; Semple, Malcolm N.; Sanes, Dan H.

2016-01-01

The consequences of developmental hearing loss have been reported to include both sensory and cognitive deficits. To investigate these issues in a non-human model, auditory learning and asymptotic psychometric performance were compared between normal hearing (NH) adult gerbils and those reared with conductive hearing loss (CHL). At postnatal day 10, before ear canal opening, gerbil pups underwent bilateral malleus removal to induce a permanent CHL. Both CHL and control animals were trained to approach a water spout upon presentation of a target (Go stimuli), and withhold for foils (Nogo stimuli). To assess the rate of task acquisition and asymptotic performance, animals were tested on an amplitude modulation (AM) rate discrimination task. Behavioral performance was calculated using a signal detection theory framework. Animals reared with developmental CHL displayed a slower rate of task acquisition for AM discrimination task. Slower acquisition was explained by an impaired ability to generalize to newly introduced stimuli, as compared to controls. Measurement of discrimination thresholds across consecutive testing blocks revealed that CHL animals required a greater number of testing sessions to reach asymptotic threshold values, as compared to controls. However, with sufficient training, CHL animals approached control performance. These results indicate that a sensory impediment can delay auditory learning, and increase the risk of poor performance on a temporal task. PMID:27746215

Identification of ground targets from airborne platforms

NASA Astrophysics Data System (ADS)

Doe, Josh; Boettcher, Evelyn; Miller, Brian

2009-05-01

The US Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD) sensor performance models predict the ability of soldiers to perform a specified military discrimination task using an EO/IR sensor system. Increasingly EO/IR systems are being used on manned and un-manned aircraft for surveillance and target acquisition tasks. In response to this emerging requirement, the NVESD Modeling and Simulation division has been tasked to compare target identification performance between ground-to-ground and air-to-ground platforms for both IR and visible spectra for a set of wheeled utility vehicles. To measure performance, several forced choice experiments were designed and administered and the results analyzed. This paper describes these experiments and reports the results as well as the NVTherm model calibration factors derived for the infrared imagery.

Modeling of video compression effects on target acquisition performance

NASA Astrophysics Data System (ADS)

Cha, Jae H.; Preece, Bradley; Espinola, Richard L.

2009-05-01

The effect of video compression on image quality was investigated from the perspective of target acquisition performance modeling. Human perception tests were conducted recently at the U.S. Army RDECOM CERDEC NVESD, measuring identification (ID) performance on simulated military vehicle targets at various ranges. These videos were compressed with different quality and/or quantization levels utilizing motion JPEG, motion JPEG2000, and MPEG-4 encoding. To model the degradation on task performance, the loss in image quality is fit to an equivalent Gaussian MTF scaled by the Structural Similarity Image Metric (SSIM). Residual compression artifacts are treated as 3-D spatio-temporal noise. This 3-D noise is found by taking the difference of the uncompressed frame, with the estimated equivalent blur applied, and the corresponding compressed frame. Results show good agreement between the experimental data and the model prediction. This method has led to a predictive performance model for video compression by correlating various compression levels to particular blur and noise input parameters for NVESD target acquisition performance model suite.

Role of quality of service metrics in visual target acquisition and tracking in resource constrained environments

NASA Astrophysics Data System (ADS)

Anderson, Monica; David, Phillip

2007-04-01

Implementation of an intelligent, automated target acquisition and tracking systems alleviates the need for operators to monitor video continuously. This system could identify situations that fatigued operators could easily miss. If an automated acquisition and tracking system plans motions to maximize a coverage metric, how does the performance of that system change when the user intervenes and manually moves the camera? How can the operator give input to the system about what is important and understand how that relates to the overall task balance between surveillance and coverage? In this paper, we address these issues by introducing a new formulation of the average linear uncovered length (ALUL) metric, specially designed for use in surveilling urban environments. This metric coordinates the often competing goals of acquiring new targets and tracking existing targets. In addition, it provides current system performance feedback to system users in terms of the system's theoretical maximum and minimum performance. We show the successful integration of the algorithm via simulation.

Automation - Changes in cognitive demands and mental workload

NASA Technical Reports Server (NTRS)

Tsang, Pamela S.; Johnson, Walter W.

1987-01-01

The effect of partial automation on mental workloads in man/machine tasks is investigated experimentally. Subjective workload measures are obtained from six subjects after performance of a task battery comprising two manual (flight-path control, FC, and target acquisition, TA) tasks and one decisionmaking (engine failure, EF) task; the FC task was performed in both a fully manual (altitude and lateral control) mode and in a semiautomated mode (autmatic latitude control). The performance results and subjective evaluations are presented in graphs and characterized in detail. The automation is shown to improve objective performance and lower subjective workload significantly in the combined FC/TA task, but not in the FC task alone or in the FC/EF task.

Increasing the Department of the Navy’s Opportunities for Small Businesses and Non-Traditional Suppliers through Simplified Acquisitions Contracting and NAICS Targeting

DTIC Science & Technology

2013-08-01

Procurement Law & Policy Reviewed by: Released by: William R. Gates, Ph.D., Dean Jeffrey D. Paduan, Ph.D. Graduate School of Business...10 II. REVIEW AND ANALYSIS OF APPLICABLE LAW AND SCHOLARSHIP ..12 A. INTRODUCTION...Indefinite-Delivery task or delivery orders. Section 4004 of the Federal Acquisition Streamlining Act (FASA) of 1994, Public Law 103-355 (1994

Developmental hearing loss impedes auditory task learning and performance in gerbils.

PubMed

von Trapp, Gardiner; Aloni, Ishita; Young, Stephen; Semple, Malcolm N; Sanes, Dan H

2017-04-01

The consequences of developmental hearing loss have been reported to include both sensory and cognitive deficits. To investigate these issues in a non-human model, auditory learning and asymptotic psychometric performance were compared between normal hearing (NH) adult gerbils and those reared with conductive hearing loss (CHL). At postnatal day 10, before ear canal opening, gerbil pups underwent bilateral malleus removal to induce a permanent CHL. Both CHL and control animals were trained to approach a water spout upon presentation of a target (Go stimuli), and withhold for foils (Nogo stimuli). To assess the rate of task acquisition and asymptotic performance, animals were tested on an amplitude modulation (AM) rate discrimination task. Behavioral performance was calculated using a signal detection theory framework. Animals reared with developmental CHL displayed a slower rate of task acquisition for AM discrimination task. Slower acquisition was explained by an impaired ability to generalize to newly introduced stimuli, as compared to controls. Measurement of discrimination thresholds across consecutive testing blocks revealed that CHL animals required a greater number of testing sessions to reach asymptotic threshold values, as compared to controls. However, with sufficient training, CHL animals approached control performance. These results indicate that a sensory impediment can delay auditory learning, and increase the risk of poor performance on a temporal task. Copyright © 2016 Elsevier B.V. All rights reserved.

Navy Acquisition: Development of the AN/BSY-1 Combat System

DTIC Science & Technology

1992-01-01

AN/BSY-1, a computer-based combat system, is designed to detect, classify, track, and launch weapons at enemy surface, subsurface, and land targets. The Navy expects the AN/BSY-1 system to locate targets sooner than previous systems, allow operators to perform multiple tasks and address multiple targets concurrently, and reduce the time between detecting a target and launching weapons. The Navy has contracted with the International Business Machines (IBM) Corporation for 23 AN/BSY-1 systems, maintenance and operational trainers, and a software

Effects of TEL Confusers on Operator Target Acquisition Performance with SAR Imagery

DTIC Science & Technology

1998-12-01

processing known as the theory of signal detection (TSD) (Gescheider, 1985; Green & Swets, 1966; Macmillan & Creelman , 1991; Wilson, 1992). A TSD...localizations (Hacker & Ratcliff, 1979; Macmillan & Creelman , 1991). The index of bias in a target localization task provides a measure of the operator’s...of correct localizations substituted for hits (Macmillan & Creelman , 1991). Receiver Operating Characteristic Curves. In addition to the calculation

Embedding an Identity-Matching Task within a Prompting Hierarchy to Facilitate Acquisition of Conditional Discriminations in Children with Autism

ERIC Educational Resources Information Center

Fisher, Wayne W.; Kodak, Tiffany; Moore, James W.

2007-01-01

Least-to-most prompting hierarchies (e.g., progressing from verbal to modeled to physical prompts until the target response occurs) may be ineffective when the prompts do not cue the individual to attend to the relevant stimulus dimensions. In such cases, emission of the target response persistently requires one or more of the higher level…

Acquisition, representation and rule generation for procedural knowledge

NASA Technical Reports Server (NTRS)

Ortiz, Chris; Saito, Tim; Mithal, Sachin; Loftin, R. Bowen

1991-01-01

Current research into the design and continuing development of a system for the acquisition of procedural knowledge, its representation in useful forms, and proposed methods for automated C Language Integrated Production System (CLIPS) rule generation is discussed. The Task Analysis and Rule Generation Tool (TARGET) is intended to permit experts, individually or collectively, to visually describe and refine procedural tasks. The system is designed to represent the acquired knowledge in the form of graphical objects with the capacity for generating production rules in CLIPS. The generated rules can then be integrated into applications such as NASA's Intelligent Computer Aided Training (ICAT) architecture. Also described are proposed methods for use in translating the graphical and intermediate knowledge representations into CLIPS rules.

Sparsity based target detection for compressive spectral imagery

NASA Astrophysics Data System (ADS)

Boada, David Alberto; Arguello Fuentes, Henry

2016-09-01

Hyperspectral imagery provides significant information about the spectral characteristics of objects and materials present in a scene. It enables object and feature detection, classification, or identification based on the acquired spectral characteristics. However, it relies on sophisticated acquisition and data processing systems able to acquire, process, store, and transmit hundreds or thousands of image bands from a given area of interest which demands enormous computational resources in terms of storage, computationm, and I/O throughputs. Specialized optical architectures have been developed for the compressed acquisition of spectral images using a reduced set of coded measurements contrary to traditional architectures that need a complete set of measurements of the data cube for image acquisition, dealing with the storage and acquisition limitations. Despite this improvement, if any processing is desired, the image has to be reconstructed by an inverse algorithm in order to be processed, which is also an expensive task. In this paper, a sparsity-based algorithm for target detection in compressed spectral images is presented. Specifically, the target detection model adapts a sparsity-based target detector to work in a compressive domain, modifying the sparse representation basis in the compressive sensing problem by means of over-complete training dictionaries and a wavelet basis representation. Simulations show that the presented method can achieve even better detection results than the state of the art methods.

Effects of video compression on target acquisition performance

NASA Astrophysics Data System (ADS)

Espinola, Richard L.; Cha, Jae; Preece, Bradley

2008-04-01

The bandwidth requirements of modern target acquisition systems continue to increase with larger sensor formats and multi-spectral capabilities. To obviate this problem, still and moving imagery can be compressed, often resulting in greater than 100 fold decrease in required bandwidth. Compression, however, is generally not error-free and the generated artifacts can adversely affect task performance. The U.S. Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate recently performed an assessment of various compression techniques on static imagery for tank identification. In this paper, we expand this initial assessment by studying and quantifying the effect of various video compression algorithms and their impact on tank identification performance. We perform a series of controlled human perception tests using three dynamic simulated scenarios: target moving/sensor static, target static/sensor static, sensor tracking the target. Results of this study will quantify the effect of video compression on target identification and provide a framework to evaluate video compression on future sensor systems.

MIST VR. A laparoscopic surgery procedures trainer and evaluator.

PubMed

Sutton, C; McCloy, R; Middlebrook, A; Chater, P; Wilson, M; Stone, R

1997-01-01

The key bimanual instrument tasks involved in laparoscopic surgery have been abstracted for use in a virtual reality surgical skills evaluator and trainer. The trainer uses two laparoscopic instruments mounted on a frame with position sensors which provide instrument movement data that is translated into interactive real time graphics on a PC (P133, 16 Mb RAM, graphics acceleration card). An accurately scaled operating volume of 10 cm3 is represented by a 3D cube on the computer screen. "Camera" position and size of target objects can be varied for different skill levels. Targets appear randomly within the operating volume according to the skill task and can be grasped and manipulated with the instruments. Accuracy and errors during the tasks and time to completion are logged. Mist VR has tutorial, training, examination, analysis and configuration modes. Six tasks have been selected and include combinations of instrument approach, target acquisition, target manipulation and placement, transfer between instruments, target contact with optional diathermy, and controlled instrument withdrawal/replacement. Tasks can be configured for varying degrees of difficulty and the configurations saved to a library for reuse. Specific task configurations can be assigned to individual students. In the examination mode the supervisor can select the tasks, repetitions and order and save to a specific file for that trainee. Progress can be assessed and there is the option for playback of the training session or examination. Data analyses permit overall, including task, and right or left hand performances to be quantified. Mist VR represents a significant advance over the subjective assessment of training performances with existing "plastic box" basic trainers.

Simultaneous acquisition of EEG and NIRS during cognitive tasks for an open access dataset.

PubMed

Shin, Jaeyoung; von Lühmann, Alexander; Kim, Do-Won; Mehnert, Jan; Hwang, Han-Jeong; Müller, Klaus-Robert

2018-02-13

We provide an open access multimodal brain-imaging dataset of simultaneous electroencephalography (EEG) and near-infrared spectroscopy (NIRS) recordings. Twenty-six healthy participants performed three cognitive tasks: 1) n-back (0-, 2- and 3-back), 2) discrimination/selection response task (DSR) and 3) word generation (WG) tasks. The data provided includes: 1) measured data, 2) demographic data, and 3) basic analysis results. For n-back (dataset A) and DSR tasks (dataset B), event-related potential (ERP) analysis was performed, and spatiotemporal characteristics and classification results for 'target' versus 'non-target' (dataset A) and symbol 'O' versus symbol 'X' (dataset B) are provided. Time-frequency analysis was performed to show the EEG spectral power to differentiate the task-relevant activations. Spatiotemporal characteristics of hemodynamic responses are also shown. For the WG task (dataset C), the EEG spectral power and spatiotemporal characteristics of hemodynamic responses are analyzed, and the potential merit of hybrid EEG-NIRS BCIs was validated with respect to classification accuracy. We expect that the dataset provided will facilitate performance evaluation and comparison of many neuroimaging analysis techniques.

Modeling the effects of contrast enhancement on target acquisition performance

NASA Astrophysics Data System (ADS)

Du Bosq, Todd W.; Fanning, Jonathan D.

2008-04-01

Contrast enhancement and dynamic range compression are currently being used to improve the performance of infrared imagers by increasing the contrast between the target and the scene content, by better utilizing the available gray levels either globally or locally. This paper assesses the range-performance effects of various contrast enhancement algorithms for target identification with well contrasted vehicles. Human perception experiments were performed to determine field performance using contrast enhancement on the U.S. Army RDECOM CERDEC NVESD standard military eight target set using an un-cooled LWIR camera. The experiments compare the identification performance of observers viewing linearly scaled images and various contrast enhancement processed images. Contrast enhancement is modeled in the US Army thermal target acquisition model (NVThermIP) by changing the scene contrast temperature. The model predicts improved performance based on any improved target contrast, regardless of feature saturation or enhancement. To account for the equivalent blur associated with each contrast enhancement algorithm, an additional effective MTF was calculated and added to the model. The measured results are compared with the predicted performance based on the target task difficulty metric used in NVThermIP.

Transfer of learning on a spatial memory task between the blind and sighted people.

PubMed

Akpinar, Selcuk; Popović, Stevo; Kirazci, Sadettin

2012-12-01

The purpose of this study was to analyze the effect of two different types of feedback on a spatial memory task between the blind and blindfolded-sighted participants. Participants tried to estimate the predetermined distance by using their dominant hands. Both blind and blindfolded-sighted groups were randomly divided into two feedback subgroups as "100% frequency" and "10% bandwidth". The score of the participants was given verbally to the participants as knowledge of results (KR). The target distance was set as 60 cm. Sixty acquisition trials were performed in 4 sets each including 15 repetition afterwards immediate and delayed retention tests were undertaken. Moreover, 24 hours past the delayed retention test, the participants completed 15 no-KR trials as a transfer test (target distance was 30 cm). The results of the statistical analyses revealed no significant differences for both acquisition and retention tests. However, a significant difference was found at transfer test. 100% frequency blind group performed significantly less accurate than all other groups. As a result, it can be concluded that different types of feedback have similar effect on spatial memory task used in this study. However, types of feedback can change the performance of accuracy on transferring this skill among the blind.

Target detection cycle criteria when using the targeting task performance metric

NASA Astrophysics Data System (ADS)

Hixson, Jonathan G.; Jacobs, Eddie L.; Vollmerhausen, Richard H.

2004-12-01

The US Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate of the US Army (NVESD) has developed a new target acquisition metric to better predict the performance of modern electro-optical imagers. The TTP metric replaces the Johnson criteria. One problem with transitioning to the new model is that the difficulty of searching in a terrain has traditionally been quantified by an "N50." The N50 is the number of Johnson criteria cycles needed for the observer to detect the target half the time, assuming that the observer is not time limited. In order to make use of this empirical data base, a conversion must be found relating Johnson cycles for detection to TTP cycles for detection. This paper describes how that relationship is established. We have found that the relationship between Johnson and TTP is 1:2.7 for the recognition and identification tasks.

Impact of online visual feedback on motor acquisition and retention when learning to reach in a force field.

PubMed

Batcho, C S; Gagné, M; Bouyer, L J; Roy, J S; Mercier, C

2016-11-19

When subjects learn a novel motor task, several sources of feedback (proprioceptive, visual or auditory) contribute to the performance. Over the past few years, several studies have investigated the role of visual feedback in motor learning, yet evidence remains conflicting. The aim of this study was therefore to investigate the role of online visual feedback (VFb) on the acquisition and retention stages of motor learning associated with training in a reaching task. Thirty healthy subjects made ballistic reaching movements with their dominant arm toward two targets, on 2 consecutive days using a robotized exoskeleton (KINARM). They were randomly assigned to a group with (VFb) or without (NoVFb) VFb of index position during movement. On day 1, the task was performed before (baseline) and during the application of a velocity-dependent resistive force field (adaptation). To assess retention, participants repeated the task with the force field on day 2. Motor learning was characterized by: (1) the final endpoint error (movement accuracy) and (2) the initial angle (iANG) of deviation (motor planning). Even though both groups showed motor adaptation, the NoVFb-group exhibited slower learning and higher final endpoint error than the VFb-group. In some condition, subjects trained without visual feedback used more curved initial trajectories to anticipate for the perturbation. This observation suggests that learning to reach targets in a velocity-dependent resistive force field is possible even when feedback is limited. However, the absence of VFb leads to different strategies that were only apparent when reaching toward the most challenging target. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Verbal Interaction in "Second Life": Towards a Pedagogic Framework for Task Design

ERIC Educational Resources Information Center

Jauregi, Kristi; Canto, Silvia; de Graaff, Rick; Koenraad, Ton; Moonen, Machteld

2011-01-01

Within a European project on Networked Interaction in Foreign Language Acquisition and Research (NIFLAR), "Second Life" was used as a 3D virtual world in which language students can communicate synchronously with native speakers in the target language, while undertaking action together. For this context, a set of design principles for…

Investigation of left and right lateral fluid percussion injury in C57BL6/J mice: In vivo functional consequences

PubMed Central

Schurman, Lesley D.; Smith, Terry L.; Morales, Anthony J.; Lee, Nancy N.; Reeves, Thomas M.; Phillips, Linda L.; Lichtman, Aron H.

2017-01-01

Although rodent models of traumatic brain injury (TBI) reliably produce cognitive and motor disturbances, behavioral characterization resulting from left and right hemisphere injuries remains unexplored. Here we examined the functional consequences of targeting the left versus right parietal cortex in lateral fluid percussion injury, on Morris water maze (MWM) spatial memory tasks (fixed platform and reversal) and neurological motor deficits (neurological severity score and rotarod). In the MWM fixed platform task, right lateral injury produced a small delay in acquisition rate compared to left. However, injury to either hemisphere resulted in probe trial deficits. In the MWM reversal task, left-right performance deficits were not evident, though left lateral injury produced mild acquisition and probe trial deficits compared to sham controls. Additionally, left and right injury produced similar neurological motor task deficits, impaired righting times, and lesion volumes. Injury to either hemisphere also produced robust ipsilateral, and modest contralateral, morphological changes in reactive microglia and astrocytes. In conclusion, left and right lateral TBI impaired MWM performance, with mild fixed platform acquisition rate differences, despite similar motor deficits, histological damage, and glial cell reactivity. Thus, while both left and right lateral TBI produce cognitive deficits, laterality in mouse MWM learning and memory merits consideration in the investigation of TBI-induced cognitive consequences. PMID:28527714

Investigation of left and right lateral fluid percussion injury in C57BL6/J mice: In vivo functional consequences.

PubMed

Schurman, Lesley D; Smith, Terry L; Morales, Anthony J; Lee, Nancy N; Reeves, Thomas M; Phillips, Linda L; Lichtman, Aron H

2017-07-13

Although rodent models of traumatic brain injury (TBI) reliably produce cognitive and motor disturbances, behavioral characterization resulting from left and right hemisphere injuries remains unexplored. Here we examined the functional consequences of targeting the left versus right parietal cortex in lateral fluid percussion injury, on Morris water maze (MWM) spatial memory tasks (fixed platform and reversal) and neurological motor deficits (neurological severity score and rotarod). In the MWM fixed platform task, right lateral injury produced a small delay in acquisition rate compared to left. However, injury to either hemisphere resulted in probe trial deficits. In the MWM reversal task, left-right performance deficits were not evident, though left lateral injury produced mild acquisition and probe trial deficits compared to sham controls. Additionally, left and right injury produced similar neurological motor task deficits, impaired righting times, and lesion volumes. Injury to either hemisphere also produced robust ipsilateral, and modest contralateral, morphological changes in reactive microglia and astrocytes. In conclusion, left and right lateral TBI impaired MWM performance, with mild fixed platform acquisition rate differences, despite similar motor deficits, histological damage, and glial cell reactivity. Thus, while both left and right lateral TBI produce cognitive deficits, laterality in mouse MWM learning and memory merits consideration in the investigation of TBI-induced cognitive consequences. Copyright © 2017. Published by Elsevier B.V.

Statistical analysis of target acquisition sensor modeling experiments

NASA Astrophysics Data System (ADS)

Deaver, Dawne M.; Moyer, Steve

2015-05-01

The U.S. Army RDECOM CERDEC NVESD Modeling and Simulation Division is charged with the development and advancement of military target acquisition models to estimate expected soldier performance when using all types of imaging sensors. Two elements of sensor modeling are (1) laboratory-based psychophysical experiments used to measure task performance and calibrate the various models and (2) field-based experiments used to verify the model estimates for specific sensors. In both types of experiments, it is common practice to control or measure environmental, sensor, and target physical parameters in order to minimize uncertainty of the physics based modeling. Predicting the minimum number of test subjects required to calibrate or validate the model should be, but is not always, done during test planning. The objective of this analysis is to develop guidelines for test planners which recommend the number and types of test samples required to yield a statistically significant result.

Targeting Alertness to Improve Cognition in Older Adults: A Preliminary Report of Benefits in Executive Function and Skill Acquisition

PubMed Central

Van Vleet, Thomas M.; DeGutis, Joseph M.; Merzenich, Michael M.; Simpson, Gregory V.; Zomet, Ativ; Dabit, Sawsan

2016-01-01

Efficient self-regulation of alertness declines with age exacerbating normal declines in performance across multiple cognitive domains, including learning and skill acquisition. Previous cognitive intervention studies have shown that it is possible to enhance alertness in patients with acquired brain injury and marked attention impairments, and that this benefit generalizes to improvements in more global cognitive functions. In the current preliminary studies, we sought to test whether this approach, that targets both tonic (over a period of minutes) and phasic (moment-to-moment) alertness, can improve key executive functioning declines in older adults, and enhance the rate of skill acquisition. The results of both experiments 1 and 2 demonstrate that, compared to active control training, alertness training significantly enhanced performance in several validated executive function measures. In experiment 2, alertness training significantly improved skill acquisition compared to active control training in a well-characterized speed of processing task, with the largest benefits shown in the most challenging speed of processing blocks. The results of the current study suggest that targeting intrinsic alertness in cognitive training provides a novel approach to improve executive functions in older adults and may be a useful adjunct treatment to enhance benefits gained in other clinically validated treatments. PMID:27372902

Training and transfer effects of N-back training for brain-injured and healthy subjects.

PubMed

Lindeløv, Jonas Kristoffer; Dall, Jonas Olsen; Kristensen, Casper Daniel; Aagesen, Marie Holt; Olsen, Stine Almgren; Snuggerud, Therese Ruud; Sikorska, Anna

2016-10-01

Working memory impairments are prevalent among patients with acquired brain injury (ABI). Computerised training targeting working memory has been researched extensively using samples from healthy populations but this field remains isolated from similar research in ABI patients. We report the results of an actively controlled randomised controlled trial in which 17 patients and 18 healthy subjects completed training on an N-back task. The healthy group had superior improvements on both training tasks (SMD = 6.1 and 3.3) whereas the ABI group improved much less (SMD = 0.5 and 1.1). Neither group demonstrated transfer to untrained tasks. We conclude that computerised training facilitates improvement of specific skills rather than high-level cognition in healthy and ABI subjects alike. The acquisition of these specific skills seems to be impaired by brain injury. The most effective use of computer-based cognitive training may be to make the task resemble the targeted behaviour(s) closely in order to exploit the stimulus-specificity of learning.

Nucleus incertus inactivation impairs spatial learning and memory in rats.

PubMed

Nategh, Mohsen; Nikseresht, Sara; Khodagholi, Fariba; Motamedi, Fereshteh

2015-02-01

Nucleus incertus (NI) is a pontine nucleus which releases mainly GABA and relaxin-3 in rats. Its suggested functions include response to stress, arousal, and modulation of hippocampal theta rhythm. Since the role of NI in learning and memory has not been well characterized, therefore the involvement of this nucleus in spatial learning and memory and the aftermath hippocampal levels of c-fos and pCREB were evaluated. NI was targeted by implanting cannula in male rats. For reference memory, NI was inactivated by lidocaine (0.4 μl, 4%) at three stages of acquisition, consolidation and retrieval in Morris water maze paradigm. For working memory, NI was inactivated in acquisition and retrieval phases. Injection of lidocaine prior to the first training session of reference memory significantly increased the distance moved, suggesting that inactivation of NI delays acquisition in this spatial task. Inactivation also interfered with the retrieval phase of spatial reference memory, as the time in target quadrant for lidocaine group was less, and the escape latency was higher compared to the control group. However, no difference was observed in the consolidation phase. In the working memory task, with inter-trial intervals of 75 min, the escape latency was higher when NI was inactivated in the retrieval phase. In addition, c-fos and pCREB/CREB levels decreased in NI-inhibited rats. This study suggests that nucleus incertus might participate in acquisition of spatial reference, and retrieval of both spatial reference and working memory. Further studies should investigate possible roles of NI in the hippocampal plasticity. Copyright © 2014 Elsevier Inc. All rights reserved.

The roles of word-form frequency and phonological neighbourhood density in the acquisition of Lithuanian noun morphology.

PubMed

Savičiūtė, Eglė; Ambridge, Ben; Pine, Julian M

2018-05-01

Four- and five-year-old children took part in an elicited familiar and novel Lithuanian noun production task to test predictions of input-based accounts of the acquisition of inflectional morphology. Two major findings emerged. First, as predicted by input-based accounts, correct production rates were correlated with the input frequency of the target form, and with the phonological neighbourhood density of the noun. Second, the error patterns were not compatible with the systematic substitution of target forms by either (a) the most frequent form of that noun or (b) a single morphosyntactic default form, as might be predicted by naive versions of a constructivist and generativist account, respectively. Rather, most errors reflected near-miss substitutions of singular for plural, masculine for feminine, or nominative/accusative for a less frequent case. Together, these findings provide support for an input-based approach to morphological acquisition, but are not adequately explained by any single account in its current form.

Research and Development Project Summaries, October 1991

DTIC Science & Technology

1991-10-01

delivery methods, training cost reduction, demonstration of technology’ effectiveness, and the reduction of acquisition risk . The majority of the work...demonstrations, risk reduction developments, and cost-effectiveness investigations in simulator and training technologzv. This advanced development program is a...systems. The program is organized around specific demonstration tasks that target critical technical risks that confront future weapons system

Location of planar targets in three space from monocular images

NASA Technical Reports Server (NTRS)

Cornils, Karin; Goode, Plesent W.

1987-01-01

Many pieces of existing and proposed space hardware that would be targets of interest for a telerobot can be represented as planar or near-planar surfaces. Examples include the biostack modules on the Long Duration Exposure Facility, the panels on Solar Max, large diameter struts, and refueling receptacles. Robust and temporally efficient methods for locating such objects with sufficient accuracy are therefore worth developing. Two techniques that derive the orientation and location of an object from its monocular image are discussed and the results of experiments performed to determine translational and rotational accuracy are presented. Both the quadrangle projection and elastic matching techniques extract three-space information using a minimum of four identifiable target points and the principles of the perspective transformation. The selected points must describe a convex polygon whose geometric characteristics are prespecified in a data base. The rotational and translational accuracy of both techniques was tested at various ranges. This experiment is representative of the sensing requirements involved in a typical telerobot target acquisition task. Both techniques determined target location to an accuracy sufficient for consistent and efficient acquisition by the telerobot.

Effect of different external attention of focus instruction on learning of golf putting skill.

PubMed

Shafizadeh, Mohsen; McMorris, Terry; Sproule, John

2011-10-01

The effect of different sources of external attentional focus on learning a motor skill was assessed in the present study. 30 students (12 men, 18 women) participated voluntarily and were divided, according to type of external focus, into target, club swing, and target-club swing groups. The task was a golf putting skill. The target focus group attended to the target (hole), the club swing focus group attended to the execution of the club's swing, and the target-club swing focus group attended to both. All participants performed 50 trials of the putting skill in the acquisition phase and 10 trials in the 24-hr. delayed retention phase. The dependent variable was the error in the putting skill measured as the distance from the hole to the ball after each strike. Results showed the target-club swing focus group had better scores in the acquisition and retention phases than the other groups. It was concluded that external focus instruction helped the learners to integrate target cue with action cue and is more effective in skill learning than other external-focus instructions. These results support the claims of ecological psychology theorists concerning the effects of external focus of attention.

Achievement of Virtual and Real Objects Using a Short-Term Motor Learning Protocol in People with Duchenne Muscular Dystrophy: A Crossover Randomized Controlled Trial.

PubMed

Massetti, Thais; Fávero, Francis Meire; Menezes, Lilian Del Ciello de; Alvarez, Mayra Priscila Boscolo; Crocetta, Tânia Brusque; Guarnieri, Regiani; Nunes, Fátima L S; Monteiro, Carlos Bandeira de Mello; Silva, Talita Dias da

2018-04-01

To evaluate whether people with Duchenne muscular dystrophy (DMD) practicing a task in a virtual environment could improve performance given a similar task in a real environment, as well as distinguishing whether there is transference between performing the practice in virtual environment and then a real environment and vice versa. Twenty-two people with DMD were evaluated and divided into two groups. The goal was to reach out and touch a red cube. Group A began with the real task and had to touch a real object, and Group B began with the virtual task and had to reach a virtual object using the Kinect system. ANOVA showed that all participants decreased the movement time from the first (M = 973 ms) to the last block of acquisition (M = 783 ms) in both virtual and real tasks and motor learning could be inferred by the short-term retention and transfer task (with increasing distance of the target). However, the evaluation of task performance demonstrated that the virtual task provided an inferior performance when compared to the real task in all phases of the study, and there was no effect for sequence. Both virtual and real tasks promoted improvement of performance in the acquisition phase, short-term retention, and transfer. However, there was no transference of learning between environments. In conclusion, it is recommended that the use of virtual environments for individuals with DMD needs to be considered carefully.

Effects of Multimodal Displays About Threat Location on Target Acquisition and Attention to Visual and Auditory Communications

DTIC Science & Technology

2007-04-01

and Space Administration ( NASA ) Task Load Index ( TLX ...Report (SITREP) Example 33 Appendix B. SITREP Questionnaire Example 35 Appendix C. NASA - TLX 37 Appendix D. Demographic Questionnaire 41...Load Index ( TLX ) The NASA - TLX was used to assess the participant’s experience of workload (Hart & Staveland, 1988). This technique uses rating

Effects of Tactile, Visual, and Auditory Cues About Threat Location on Target Acquisition and Attention to Visual and Auditory Communications

DTIC Science & Technology

2006-08-01

Space Administration ( NASA ) Task Load Index ( TLX ...SITREP Questionnaire Example 33 Appendix C. NASA - TLX 35 Appendix D. Demographic Questionnaire 39 Appendix E. Post-Test Questionnaire 41...Mean ratings of physical demand by cue condition using NASA - TLX . ..................... 19 Figure 9. Mean ratings of temporal demand by cue condition

TARGET: Rapid Capture of Process Knowledge

NASA Technical Reports Server (NTRS)

Ortiz, C. J.; Ly, H. V.; Saito, T.; Loftin, R. B.

1993-01-01

TARGET (Task Analysis/Rule Generation Tool) represents a new breed of tool that blends graphical process flow modeling capabilities with the function of a top-down reporting facility. Since NASA personnel frequently perform tasks that are primarily procedural in nature, TARGET models mission or task procedures and generates hierarchical reports as part of the process capture and analysis effort. Historically, capturing knowledge has proven to be one of the greatest barriers to the development of intelligent systems. Current practice generally requires lengthy interactions between the expert whose knowledge is to be captured and the knowledge engineer whose responsibility is to acquire and represent the expert's knowledge in a useful form. Although much research has been devoted to the development of methodologies and computer software to aid in the capture and representation of some types of knowledge, procedural knowledge has received relatively little attention. In essence, TARGET is one of the first tools of its kind, commercial or institutional, that is designed to support this type of knowledge capture undertaking. This paper will describe the design and development of TARGET for the acquisition and representation of procedural knowledge. The strategies employed by TARGET to support use by knowledge engineers, subject matter experts, programmers and managers will be discussed. This discussion includes the method by which the tool employs its graphical user interface to generate a task hierarchy report. Next, the approach to generate production rules for incorporation in and development of a CLIPS based expert system will be elaborated. TARGET also permits experts to visually describe procedural tasks as a common medium for knowledge refinement by the expert community and knowledge engineer making knowledge consensus possible. The paper briefly touches on the verification and validation issues facing the CLIPS rule generation aspects of TARGET. A description of efforts to support TARGET's interoperability issues on PCs, Macintoshes and UNIX workstations concludes the paper.

Millimeter wave sensor requirements for maritime small craft identification

NASA Astrophysics Data System (ADS)

Krapels, Keith; Driggers, Ronald G.; Garcia, Jose; Boettcher, Evelyn; Prather, Dennis; Schuetz, Chrisopher; Samluk, Jesse; Stein, Lee; Kiser, William; Visnansky, Andrew; Grata, Jeremy; Wikner, David; Harris, Russ

2009-09-01

Passive millimeter wave (mmW) imagers have improved in terms of resolution sensitivity and frame rate. Currently, the Office of Naval Research (ONR), along with the US Army Research, Development and Engineering Command, Communications Electronics Research Development and Engineering Center (RDECOM CERDEC) Night Vision and Electronic Sensor Directorate (NVESD), are investigating the current state-of-the-art of mmW imaging systems. The focus of this study was the performance of mmW imaging systems for the task of small watercraft / boat identification field performance. First mmW signatures were collected. This consisted of a set of eight small watercrafts; at 5 different aspects, during the daylight hours over a 48 hour period in the spring of 2008. Target characteristics were measured and characteristic dimension, signatures, and Root Sum Squared of Target's Temperature (RRSΔT) tabulated. Then an eight-alternative, forced choice (8AFC) human perception experiment was developed and conducted at NVESD. The ability of observers to discriminate between small watercraft was quantified. Next, the task difficulty criterion, V50, was quantified by applying this data to NVESD's target acquisition models using the Targeting Task Performance (TTP) metric. These parameters can be used to evaluate sensor field performance for Anti-Terrorism / Force Protection (AT/FP) and navigation tasks for the U.S. Navy, as well as for design and evaluation of imaging passive mmW sensors for both the U.S. Navy and U.S. Coast Guard.

Role for the M1 Muscarinic Acetylcholine Receptor in Top-Down Cognitive Processing Using a Touchscreen Visual Discrimination Task in Mice.

PubMed

Gould, R W; Dencker, D; Grannan, M; Bubser, M; Zhan, X; Wess, J; Xiang, Z; Locuson, C; Lindsley, C W; Conn, P J; Jones, C K

2015-10-21

The M1 muscarinic acetylcholine receptor (mAChR) subtype has been implicated in the underlying mechanisms of learning and memory and represents an important potential pharmacotherapeutic target for the cognitive impairments observed in neuropsychiatric disorders such as schizophrenia. Patients with schizophrenia show impairments in top-down processing involving conflict between sensory-driven and goal-oriented processes that can be modeled in preclinical studies using touchscreen-based cognition tasks. The present studies used a touchscreen visual pairwise discrimination task in which mice discriminated between a less salient and a more salient stimulus to assess the influence of the M1 mAChR on top-down processing. M1 mAChR knockout (M1 KO) mice showed a slower rate of learning, evidenced by slower increases in accuracy over 12 consecutive days, and required more days to acquire (achieve 80% accuracy) this discrimination task compared to wild-type mice. In addition, the M1 positive allosteric modulator BQCA enhanced the rate of learning this discrimination in wild-type, but not in M1 KO, mice when BQCA was administered daily prior to testing over 12 consecutive days. Importantly, in discriminations between stimuli of equal salience, M1 KO mice did not show impaired acquisition and BQCA did not affect the rate of learning or acquisition in wild-type mice. These studies are the first to demonstrate performance deficits in M1 KO mice using touchscreen cognitive assessments and enhanced rate of learning and acquisition in wild-type mice through M1 mAChR potentiation when the touchscreen discrimination task involves top-down processing. Taken together, these findings provide further support for M1 potentiation as a potential treatment for the cognitive symptoms associated with schizophrenia.

Heuristic-based information acquisition and decision making among pilots.

PubMed

Wiggins, Mark W; Bollwerk, Sandra

2006-01-01

This research was designed to examine the impact of heuristic-based approaches to the acquisition of task-related information on the selection of an optimal alternative during simulated in-flight decision making. The work integrated features of naturalistic and normative decision making and strategies of information acquisition within a computer-based, decision support framework. The study comprised two phases, the first of which involved familiarizing pilots with three different heuristic-based strategies of information acquisition: frequency, elimination by aspects, and majority of confirming decisions. The second stage enabled participants to choose one of the three strategies of information acquisition to resolve a fourth (choice) scenario. The results indicated that task-oriented experience, rather than the information acquisition strategies, predicted the selection of the optimal alternative. It was also evident that of the three strategies available, the elimination by aspects information acquisition strategy was preferred by most participants. It was concluded that task-oriented experience, rather than the process of information acquisition, predicted task accuracy during the decision-making task. It was also concluded that pilots have a preference for one particular approach to information acquisition. Applications of outcomes of this research include the development of decision support systems that adapt to the information-processing capabilities and preferences of users.

Target acquisition modeling over the exact optical path: extending the EOSTAR TDA with the TOD sensor performance model

NASA Astrophysics Data System (ADS)

Dijk, J.; Bijl, P.; Oppeneer, M.; ten Hove, R. J. M.; van Iersel, M.

2017-10-01

The Electro-Optical Signal Transmission and Ranging (EOSTAR) model is an image-based Tactical Decision Aid (TDA) for thermal imaging systems (MWIR/LWIR) developed for a sea environment with an extensive atmosphere model. The Triangle Orientation Discrimination (TOD) Target Acquisition model calculates the sensor and signal processing effects on a set of input triangle test pattern images, judges their orientation using humans or a Human Visual System (HVS) model and derives the system image quality and operational field performance from the correctness of the responses. Combination of the TOD model and EOSTAR, basically provides the possibility to model Target Acquisition (TA) performance over the exact path from scene to observer. In this method ship representative TOD test patterns are placed at the position of the real target, subsequently the combined effects of the environment (atmosphere, background, etc.), sensor and signal processing on the image are calculated using EOSTAR and finally the results are judged by humans. The thresholds are converted into Detection-Recognition-Identification (DRI) ranges of the real target. In experiments is shown that combination of the TOD model and the EOSTAR model is indeed possible. The resulting images look natural and provide insight in the possibilities of combining the two models. The TOD observation task can be done well by humans, and the measured TOD is consistent with analytical TOD predictions for the same camera that was modeled in the ECOMOS project.

Children's understanding of the addition/subtraction complement principle.

PubMed

Torbeyns, Joke; Peters, Greet; De Smedt, Bert; Ghesquière, Pol; Verschaffel, Lieven

2016-09-01

In the last decades, children's understanding of mathematical principles has become an important research topic. Different from the commutativity and inversion principles, only few studies have focused on children's understanding of the addition/subtraction complement principle (if a - b = c, then c + b = a), mainly relying on verbal techniques. This contribution aimed at deepening our understanding of children's knowledge of the addition/subtraction complement principle, combining verbal and non-verbal techniques. Participants were 67 third and fourth graders (9- to 10-year-olds). Children solved two tasks in which verbal reports as well as accuracy and speed data were collected. These two tasks differed only in the order of the problems and the instructions. In the looking-back task, children were told that sometimes the preceding problem might help to answer the next problem. In the baseline task, no helpful preceding items were offered. The looking-back task included 10 trigger-target problem pairs on the complement relation. Children verbally reported looking back on about 40% of all target problems in the looking-back task; the target problems were also solved faster and more accurately than in the baseline task. These results suggest that children used their understanding of the complement principle. The verbal and non-verbal data were highly correlated. This study complements previous work on children's understanding of mathematical principles by highlighting interindividual differences in 9- to 10-year-olds' understanding of the complement principle and indicating the potential of combining verbal and non-verbal techniques to investigate (the acquisition of) this understanding. © 2016 The British Psychological Society.

Modelling eye movements in a categorical search task

PubMed Central

Zelinsky, Gregory J.; Adeli, Hossein; Peng, Yifan; Samaras, Dimitris

2013-01-01

We introduce a model of eye movements during categorical search, the task of finding and recognizing categorically defined targets. It extends a previous model of eye movements during search (target acquisition model, TAM) by using distances from an support vector machine classification boundary to create probability maps indicating pixel-by-pixel evidence for the target category in search images. Other additions include functionality enabling target-absent searches, and a fixation-based blurring of the search images now based on a mapping between visual and collicular space. We tested this model on images from a previously conducted variable set-size (6/13/20) present/absent search experiment where participants searched for categorically defined teddy bear targets among random category distractors. The model not only captured target-present/absent set-size effects, but also accurately predicted for all conditions the numbers of fixations made prior to search judgements. It also predicted the percentages of first eye movements during search landing on targets, a conservative measure of search guidance. Effects of set size on false negative and false positive errors were also captured, but error rates in general were overestimated. We conclude that visual features discriminating a target category from non-targets can be learned and used to guide eye movements during categorical search. PMID:24018720

A Review of Effect of Different Tasks on Incidental Vocabulary Acquisition

ERIC Educational Resources Information Center

Liu, Chen L.

2015-01-01

Studies of incidental vocabulary acquisition in second language learning have got more and more attention both at home and abroad. By first introducing the definition and theoretical foundations of incidental vocabulary acquisition, this paper reviews empirical studies of effect of different tasks on incidental vocabulary acquisition and points…

Magnifying visual target information and the role of eye movements in motor sequence learning.

PubMed

Massing, Matthias; Blandin, Yannick; Panzer, Stefan

2016-01-01

An experiment investigated the influence of eye movements on learning a simple motor sequence task when the visual display was magnified. The task was to reproduce a 1300 ms spatial-temporal pattern of elbow flexions and extensions. The spatial-temporal pattern was displayed in front of the participants. Participants were randomly assigned to four groups differing on eye movements (free to use their eyes/instructed to fixate) and the visual display (small/magnified). All participants had to perform a pre-test, an acquisition phase, a delayed retention test, and a transfer test. The results indicated that participants in each practice condition increased their performance during acquisition. The participants who were permitted to use their eyes in the magnified visual display outperformed those who were instructed to fixate on the magnified visual display. When a small visual display was used, the instruction to fixate induced no performance decrements compared to participants who were permitted to use their eyes during acquisition. The findings demonstrated that a spatial-temporal pattern can be learned without eye movements, but being permitting to use eye movements facilitates the response production when the visual angle is increased. Copyright © 2015 Elsevier B.V. All rights reserved.

The Effects of Sensor Performance as Modeled by Signal Detection Theory on the Performance of Reinforcement Learning in a Target Acquisition Task

NASA Astrophysics Data System (ADS)

Quirion, Nate

Unmanned Aerial Systems (UASs) today are fulfilling more roles than ever before. There is a general push to have these systems feature more advanced autonomous capabilities in the near future. To achieve autonomous behavior requires some unique approaches to control and decision making. More advanced versions of these approaches are able to adapt their own behavior and examine their past experiences to increase their future mission performance. To achieve adaptive behavior and decision making capabilities this study used Reinforcement Learning algorithms. In this research the effects of sensor performance, as modeled through Signal Detection Theory (SDT), on the ability of RL algorithms to accomplish a target localization task are examined. Three levels of sensor sensitivity are simulated and compared to the results of the same system using a perfect sensor. To accomplish the target localization task, a hierarchical architecture used two distinct agents. A simulated human operator is assumed to be a perfect decision maker, and is used in the system feedback. An evaluation of the system is performed using multiple metrics, including episodic reward curves and the time taken to locate all targets. Statistical analyses are employed to detect significant differences in the comparison of steady-state behavior of different systems.

Fatty acid amide hydrolase (-/-) mice exhibit an increased sensitivity to the disruptive effects of anandamide or oleamide in a working memory water maze task.

PubMed

Varvel, Stephen A; Cravatt, Benjamin F; Engram, April E; Lichtman, Aron H

2006-04-01

Although recent evidence suggests that fatty acid amide hydrolase (FAAH) may represent a potential therapeutic target, few published studies have investigated FAAH or its fatty acid amide substrates (FAAs) in animal models of learning and memory. Therefore, our primary goal was to determine whether FAAH (-/-) mice, which possess elevated levels of anandamide and other FAAs, would display altered performance in four Morris water maze tasks: acquisition of a hidden fixed platform, reversal learning, working memory, and probe trials. FAAH (-/-) mice failed to exhibit deficits in any task; in fact, they initially acquired the working memory task more rapidly than FAAH (+/+) mice. The second goal of this study was to investigate whether the FAAH inhibitor OL-135 (1-oxo-1[5-(2-pyridyl)-2-yl]-7-phenylheptane), anandamide, other FAAs, and methanandamide would affect working memory in both genotypes. FAAH (-/-), but not (+/+), mice displayed working memory impairments following exogenous administration of anandamide (ED(50) = 6 mg/kg) or oleamide (50 mg/kg). However, the central cannabinoid receptor (CB(1)) receptor antagonist SR141716 [N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide HCl] only blocked the disruptive effects of anandamide. Methanandamide, which is not metabolized by FAAH, disrupted working memory performance in both genotypes (ED(50) = 10 mg/kg), suggesting that CB(1) receptor signaling is unaltered by FAAH deletion. In contrast, OL-135 and other FAAs failed to affect working memory in either genotype. These results suggest that FAAH deletion does not impair spatial learning but may enhance acquisition under certain conditions. More generally, FAAH may represent a novel therapeutic target that circumvents the undesirable cognitive side effects commonly associated with direct-acting cannabinoid agonists.

Eye Choice for Acquisition of Targets in Alternating Strabismus

PubMed Central

Economides, John R.; Adams, Daniel L.

2014-01-01

In strabismus, potentially either eye can inform the brain about the location of a target so that an accurate saccade can be made. Sixteen human subjects with alternating exotropia were tested dichoptically while viewing stimuli on a tangent screen. Each trial began with a fixation cross visible to only one eye. After the subject fixated the cross, a peripheral target visible to only one eye flashed briefly. The subject's task was to look at it. As a rule, the eye to which the target was presented was the eye that acquired the target. However, when stimuli were presented in the far nasal visual field, subjects occasionally performed a “crossover” saccade by placing the other eye on the target. This strategy avoided the need to make a large adducting saccade. In such cases, information about target location was obtained by one eye and used to program a saccade for the other eye, with a corresponding latency increase. In 10/16 subjects, targets were presented on some trials to both eyes. Binocular sensory maps were also compiled to delineate the portions of the visual scene perceived with each eye. These maps were compared with subjects' pattern of eye choice for target acquisition. There was a correspondence between suppression scotoma maps and the eye used to acquire peripheral targets. In other words, targets were fixated by the eye used to perceive them. These studies reveal how patients with alternating strabismus, despite eye misalignment, manage to localize and capture visual targets in their environment. PMID:25355212

Cognitive Performance Is Highly Sensitive to Prior Experience in Mice with a Learning and Memory Deficit: Failure Leads to More Failure

ERIC Educational Resources Information Center

Hebda-Bauer, Elaine K.; Watson, Stanley J.; Akil, Huda

2005-01-01

The impact of a previously successful or unsuccessful experience on the subsequent acquisition of a related task is not well understood. The nature of past experience may have even greater impact in individuals with learning deficits, as their cognitive processes can be easily disrupted. Mice with a targeted disruption of the [alpha] and [delta]…

Low-Resolution Screening of Early Stage Acquisition Simulation Scenario Development Decisions

DTIC Science & Technology

2012-12-01

6 seconds) incorporating reload times and assumptions. Phit for min range is assumed to be 100% (excepting FGM- 148, which was estimated for a...User Interface HTN Hierarchical Task Network MCCDC Marine Corps Combat Development Command Phit Probability to hit the intended target Pkill...well beyond the scope of this study. 5. Weapon Capabilities Translation COMBATXXI develops situation probabilities to hit ( Phit ) and probabilities to

Endogenous orienting in the archer fish.

PubMed

Saban, William; Sekely, Liora; Klein, Raymond M; Gabay, Shai

2017-07-18

The literature has long emphasized the neocortex's role in volitional processes. In this work, we examined endogenous orienting in an evolutionarily older species, the archer fish, which lacks neocortex-like cells. We used Posner's classic endogenous cuing task, in which a centrally presented, spatially informative cue is followed by a target. The fish responded to the target by shooting a stream of water at it. Interestingly, the fish demonstrated a human-like "volitional" facilitation effect: their reaction times to targets that appeared on the side indicated by the precue were faster than their reaction times to targets on the opposite side. The fish also exhibited inhibition of return, an aftermath of orienting that commonly emerges only in reflexive orienting tasks in human participants. We believe that this pattern demonstrates the acquisition of an arbitrary connection between spatial orienting and a nonspatial feature of a centrally presented stimulus in nonprimate species. In the literature on human attention, orienting in response to such contingencies has been strongly associated with volitional control. We discuss the implications of these results for the evolution of orienting, and for the study of volitional processes in all species, including humans.

Selective neural pathway targeting reveals key roles of thalamostriatal projection in the control of visual discrimination.

PubMed

Kato, Shigeki; Kuramochi, Masahito; Kobayashi, Kenta; Fukabori, Ryoji; Okada, Kana; Uchigashima, Motokazu; Watanabe, Masahiko; Tsutsui, Yuji; Kobayashi, Kazuto

2011-11-23

The dorsal striatum receives converging excitatory inputs from diverse brain regions, including the cerebral cortex and the intralaminar/midline thalamic nuclei, and mediates learning processes contributing to instrumental motor actions. However, the roles of each striatal input pathway in these learning processes remain uncertain. We developed a novel strategy to target specific neural pathways and applied this strategy for studying behavioral roles of the pathway originating from the parafascicular nucleus (PF) and projecting to the dorsolateral striatum. A highly efficient retrograde gene transfer vector encoding the recombinant immunotoxin (IT) receptor was injected into the dorsolateral striatum in mice to express the receptor in neurons innervating the striatum. IT treatment into the PF of the vector-injected animals caused a selective elimination of neurons of the PF-derived thalamostriatal pathway. The elimination of this pathway impaired the response selection accuracy and delayed the motor response in the acquisition of a visual cue-dependent discrimination task. When the pathway elimination was induced after learning acquisition, it disturbed the response accuracy in the task performance with no apparent change in the response time. The elimination did not influence spontaneous locomotion, methamphetamine-induced hyperactivity, and motor skill learning that demand the function of the dorsal striatum. These results demonstrate that thalamostriatal projection derived from the PF plays essential roles in the acquisition and execution of discrimination learning in response to sensory stimulus. The temporal difference in the pathway requirement for visual discrimination suggests a stage-specific role of thalamostriatal pathway in the modulation of response time of learned motor actions.

Validating models of target acquisition performance in the dismounted soldier context

NASA Astrophysics Data System (ADS)

Glaholt, Mackenzie G.; Wong, Rachel K.; Hollands, Justin G.

2018-04-01

The problem of predicting real-world operator performance with digital imaging devices is of great interest within the military and commercial domains. There are several approaches to this problem, including: field trials with imaging devices, laboratory experiments using imagery captured from these devices, and models that predict human performance based on imaging device parameters. The modeling approach is desirable, as both field trials and laboratory experiments are costly and time-consuming. However, the data from these experiments is required for model validation. Here we considered this problem in the context of dismounted soldiering, for which detection and identification of human targets are essential tasks. Human performance data were obtained for two-alternative detection and identification decisions in a laboratory experiment in which photographs of human targets were presented on a computer monitor and the images were digitally magnified to simulate range-to-target. We then compared the predictions of different performance models within the NV-IPM software package: Targeting Task Performance (TTP) metric model and the Johnson model. We also introduced a modification to the TTP metric computation that incorporates an additional correction for target angular size. We examined model predictions using NV-IPM default values for a critical model constant, V50, and we also considered predictions when this value was optimized to fit the behavioral data. When using default values, certain model versions produced a reasonably close fit to the human performance data in the detection task, while for the identification task all models substantially overestimated performance. When using fitted V50 values the models produced improved predictions, though the slopes of the performance functions were still shallow compared to the behavioral data. These findings are discussed in relation to the models' designs and parameters, and the characteristics of the behavioral paradigm.

Levels of Information Processing in a Fitts law task (LIPFitts)

NASA Technical Reports Server (NTRS)

Mosier, K. L.; Hart, S. G.

1986-01-01

State-of-the-art flight technology has restructured the task of human operators, decreasing the need for physical and sensory resources, and increasing the quantity of cognitive effort required, changing it qualitatively. Recent technological advances have the most potential for impacting a pilot in two areas: performance and mental workload. In an environment in which timing is critical, additional cognitive processing can cause performance decrements, and increase a pilot's perception of the mental workload involved. The effects of stimulus processing demands on motor response performance and subjective mental workload are examined, using different combinations of response selection and target acquisition tasks. The information processing demands of the response selection were varied (e.g., Sternberg memory set tasks, math equations, pattern matching), as was the difficulty of the response execution. Response latency as well as subjective workload ratings varied in accordance with the cognitive complexity of the task. Movement times varied according to the difficulty of the response execution task. Implications in terms of real-world flight situations are discussed.

Camouflage target detection via hyperspectral imaging plus information divergence measurement

NASA Astrophysics Data System (ADS)

Chen, Yuheng; Chen, Xinhua; Zhou, Jiankang; Ji, Yiqun; Shen, Weimin

2016-01-01

Target detection is one of most important applications in remote sensing. Nowadays accurate camouflage target distinction is often resorted to spectral imaging technique due to its high-resolution spectral/spatial information acquisition ability as well as plenty of data processing methods. In this paper, hyper-spectral imaging technique together with spectral information divergence measure method is used to solve camouflage target detection problem. A self-developed visual-band hyper-spectral imaging device is adopted to collect data cubes of certain experimental scene before spectral information divergences are worked out so as to discriminate target camouflage and anomaly. Full-band information divergences are measured to evaluate target detection effect visually and quantitatively. Information divergence measurement is proved to be a low-cost and effective tool for target detection task and can be further developed to other target detection applications beyond spectral imaging technique.

Language acquisition is model-based rather than model-free.

PubMed

Wang, Felix Hao; Mintz, Toben H

2016-01-01

Christiansen & Chater (C&C) propose that learning language is learning to process language. However, we believe that the general-purpose prediction mechanism they propose is insufficient to account for many phenomena in language acquisition. We argue from theoretical considerations and empirical evidence that many acquisition tasks are model-based, and that different acquisition tasks require different, specialized models.

Selection and Training of Field Artillery Forward Observers: Methodologies for Improving Target Acquisition Skills

DTIC Science & Technology

1979-07-01

African scenario.) The training analysis revealed some discrepancies between the list of tasks taught in FAOBC and the list of tasks emerging from the...I tD ’. 0C-) Q) 4- ) 0 N 4- _ L ~~1 CC 0 -- .0 I 4 J0C cog 1 . wi. I -4 1- Co4- ~a) U’ cu ) 0o 0 0 CDm 0 -% o c u- CO 0) -* -- cN- LO) C’I) NO 0 - CV...population density. (Refer to Figure 3-2). The African combat scenario, closely followed by the Middle Eastern scenario, was rated as being the most

Use of force feedback to enhance graphical user interfaces

NASA Astrophysics Data System (ADS)

Rosenberg, Louis B.; Brave, Scott

1996-04-01

This project focuses on the use of force feedback sensations to enhance user interaction with standard graphical user interface paradigms. While typical joystick and mouse devices are input-only, force feedback controllers allow physical sensations to be reflected to a user. Tasks that require users to position a cursor on a given target can be enhanced by applying physical forces to the user that aid in targeting. For example, an attractive force field implemented at the location of a graphical icon can greatly facilitate target acquisition and selection of the icon. It has been shown that force feedback can enhance a users ability to perform basic functions within graphical user interfaces.

Differential long-term effects of haloperidol and risperidone on the acquisition and performance of tasks of spatial working and short-term memory and sustained attention in rats.

PubMed

Hutchings, Elizabeth J; Waller, Jennifer L; Terry, Alvin V

2013-12-01

A common feature of the neuropsychiatric disorders for which antipsychotic drugs are prescribed is cognitive dysfunction, yet the effects of long-term antipsychotic treatment on cognition are largely unknown. In the current study, we evaluated the effects of long-term oral treatment with the first-generation antipsychotic haloperidol (1.0 and 2.0 mg/kg daily) and the second-generation antipsychotic risperidone (1.25 and 2.5 mg/kg daily) on the acquisition and performance of two radial-arm maze (RAM) tasks and a five-choice serial reaction-time task (5C-SRTT) in rats during days 15-60 and 84-320 days of treatment, respectively. In the RAM, neither antipsychotic significantly affected the acquisition or performance of a spatial win shift or a delayed non-match-to-position task. Conversely, in the rats administered 5C-SRTT, haloperidol was associated with profound deficits in performance, and the subjects were not able to progress through all stages of task acquisition. Depending on the dose, risperidone was associated with a greater number of trials to meet specific performance criteria during task acquisition compared with vehicle-treated controls; however, most subjects were eventually able to achieve all levels of task acquisition. Both haloperidol and risperidone also increased the number of perseverative and time-out responses during certain stages of task acquisition, and the response and reward latencies were slightly higher than controls during several stages of the study. These results in rats suggest that while long-term treatment with haloperidol or risperidone may not significantly affect spatial working or short-term memory, both antipsychotics can (depending on dose) impair sustained attention, decrease psychomotor speed, increase compulsive-type behaviors, and impair cognitive flexibility.

Differential Long-Term Effects of Haloperidol and Risperidone on the Acquisition and Performance of Tasks of Spatial Working and Short-Term Memory and Sustained Attention in Rats

PubMed Central

Hutchings, Elizabeth J.; Waller, Jennifer L.

2013-01-01

A common feature of the neuropsychiatric disorders for which antipsychotic drugs are prescribed is cognitive dysfunction, yet the effects of long-term antipsychotic treatment on cognition are largely unknown. In the current study, we evaluated the effects of long-term oral treatment with the first-generation antipsychotic haloperidol (1.0 and 2.0 mg/kg daily) and the second-generation antipsychotic risperidone (1.25 and 2.5 mg/kg daily) on the acquisition and performance of two radial-arm maze (RAM) tasks and a five-choice serial reaction-time task (5C-SRTT) in rats during days 15–60 and 84–320 days of treatment, respectively. In the RAM, neither antipsychotic significantly affected the acquisition or performance of a spatial win shift or a delayed non–match-to-position task. Conversely, in the rats administered 5C-SRTT, haloperidol was associated with profound deficits in performance, and the subjects were not able to progress through all stages of task acquisition. Depending on the dose, risperidone was associated with a greater number of trials to meet specific performance criteria during task acquisition compared with vehicle-treated controls; however, most subjects were eventually able to achieve all levels of task acquisition. Both haloperidol and risperidone also increased the number of perseverative and time-out responses during certain stages of task acquisition, and the response and reward latencies were slightly higher than controls during several stages of the study. These results in rats suggest that while long-term treatment with haloperidol or risperidone may not significantly affect spatial working or short-term memory, both antipsychotics can (depending on dose) impair sustained attention, decrease psychomotor speed, increase compulsive-type behaviors, and impair cognitive flexibility. PMID:24042161

Evaluation of the effectiveness and efficiency of two stimulus prompt strategies with severely handicapped students.

PubMed Central

Steege, M W; Wacker, D P; McMahon, C M

1987-01-01

In this study we compared the effectiveness and efficiency of two treatment packages that used stimulus prompt sequences and task analyses for teaching community living skills to severely handicapped students. Four severely and multiply handicapped students were trained to perform four tasks: (a) making toast, (b) making popcorn, (c) operating a clothes dryer, and (d) operating a washing machine. Following baseline, each student was exposed to two types of training procedures, each involving a task analysis of the target behavior. Training Procedure 1 (Traditional) utilized a least-to-most restrictive prompt sequence. Training Procedure 2 (Prescriptive) utilized ongoing behavioral assessment data to identify discriminative stimuli. The assessment data were used to prescribe instructional prompts across successive training trials. Performance on the tasks was evaluated within a combination multiple baseline (across subjects) and probe (across tasks) design. Training conditions were counterbalanced across subjects and tasks. Results indicated that both training procedures were equally effective in increasing independent task acquisition for subjects on all tasks; however, the prescriptive procedure was the more efficient procedure. PMID:3667479

Center for Advanced Sensors Year Two Funding (FY2006)

DTIC Science & Technology

2008-02-26

Cheong, and F. Zhao (2005) "Semantics-Based Optimization Across Uncoordinated Tasks in Networked Embedded Systems," Proceedings of the 5th ACM Conference...analysis," Optical Engineering, vol. 46, 116401, 2007. R.L. Espinola, E.L. Jacobs, C.E. Halford, D.H. Tofsted and R. Vollmerhausen, "Modeling...the target acquisition performance of active imaging systems," Optics Express, vol. 15, March, 2007. C.E. Halford, A.L. Robinson, E.L. Jacobs and

Air-to-Air Target Acquisition: Factors and Means of Improvement.

DTIC Science & Technology

1980-03-01

and an atmospheric modelo B t - Bb VISTARAQ C - b derived from input quantities and an B atmospheric model Bt Bb RAE/BAC C B derived from input...seair ’ h task in a !static, fielId. I" Osi c r r, I’lut ion is, dependi- ent upon the angle of’ t hr vi:i x is, -ft wh iih -wilil1y is measured and th

Effects of variability of practice in music: a pilot study on fast goal-directed movements in pianists

PubMed Central

Bangert, Marc; Wiedemann, Anna; Jabusch, Hans-Christian

2014-01-01

Variability of Practice (VOP) refers to the acquisition of a particular target movement by practicing a range of varying targets rather than by focusing on fixed repetitions of the target only. VOP has been demonstrated to have beneficial effects on transfer to a novel task and on skill consolidation. This study extends the line of research to musical practice. In a task resembling a barrier-knockdown paradigm, 36 music students trained to perform a wide left-hand interval leap on the piano. Performance at the target distance was tested before and after a 30-min standardized training session. The high-variability group (VAR) practiced four different intervals including the target. Another group (FIX) practiced the target interval only. A third group (SPA) performed spaced practice on the target only, interweaving with periods of not playing. Transfer was tested by introducing an interval novel to either group. After a 24-h period with no further exposure to the instrument, performance was retested. All groups performed at comparable error levels before training, after training, and after the retention (RET) interval. At transfer, however, the FIX group, unlike the other groups, committed significantly more errors than in the target task. After the RET period, the effect was washed out for the FIX group but then was present for VAR. Thus, the results provide only partial support for the VOP hypothesis for the given setting. Additional exploratory observations suggest tentative benefits of VOP regarding execution speed, loudness, and performance confidence. We derive specific hypotheses and specific recommendations regarding sample selection and intervention duration for future investigations. Furthermore, the proposed leap task measurement is shown to be (a) robust enough to serve as a standard framework for studies in the music domain, yet (b) versatile enough to allow for a wide range of designs not previously investigated for music on a standardized basis. PMID:25157223

Learning by subtraction: Hippocampal activity and effects of ethanol during the acquisition and performance of response sequences.

PubMed

Ketchum, Myles J; Weyand, Theodore G; Weed, Peter F; Winsauer, Peter J

2016-05-01

Learning is believed to be reflected in the activity of the hippocampus. However, neural correlates of learning have been difficult to characterize because hippocampal activity is integrated with ongoing behavior. To address this issue, male rats (n = 5) implanted with electrodes (n = 14) in the CA1 subfield responded during two tasks within a single test session. In one task, subjects acquired a new 3-response sequence (acquisition), whereas in the other task, subjects completed a well-rehearsed 3-response sequence (performance). Both tasks though could be completed using an identical response topography and used the same sensory stimuli and schedule of reinforcement. More important, comparing neural patterns during sequence acquisition to those during sequence performance allows for a subtractive approach whereby activity associated with learning could potentially be dissociated from the activity associated with ongoing behavior. At sites where CA1 activity was closely associated with behavior, the patterns of activity were differentially modulated by key position and the serial position of a response within the schedule of reinforcement. Temporal shifts between peak activity and responding on particular keys also occurred during sequence acquisition, but not during sequence performance. Ethanol disrupted CA1 activity while producing rate-decreasing effects in both tasks and error-increasing effects that were more selective for sequence acquisition than sequence performance. Ethanol also produced alterations in the magnitude of modulations and temporal pattern of CA1 activity, although these effects were not selective for sequence acquisition. Similar to ethanol, hippocampal micro-stimulation decreased response rate in both tasks and selectively increased the percentage of errors during sequence acquisition, and provided a more direct demonstration of hippocampal involvement during sequence acquisition. Together, these results strongly support the notion that ethanol disrupts sequence acquisition by disrupting hippocampal activity and that the hippocampus is necessary for the conditioned associations required for sequence acquisition. © 2015 Wiley Periodicals, Inc.

Learning by Subtraction: Hippocampal Activity and Effects of Ethanol during the Acquisition and Performance of Response Sequences

PubMed Central

Ketchum, Myles J.; Weyand, Theodore G.; Weed, Peter F.; Winsauer, Peter J.

2015-01-01

Learning is believed to be reflected in the activity of the hippocampus. However, neural correlates of learning have been difficult to characterize because hippocampal activity is integrated with ongoing behavior. To address this issue, male rats (n=5) implanted with electrodes (n=14) in the CA1 subfield responded during two tasks within a single test session. In one task, subjects acquired a new 3-response sequence (acquisition), whereas in the other task, subjects completed a well-rehearsed 3-response sequence (performance). Both tasks though could be completed using an identical response topography and used the same sensory stimuli and schedule of reinforcement. More important, comparing neural patterns during sequence acquisition to those during sequence performance allows for a subtractive approach whereby activity associated with learning could potentially be dissociated from the activity associated with ongoing behavior. At sites where CA1 activity was closely associated with behavior, the patterns of activity were differentially modulated by key position and the serial position of a response within the schedule of reinforcement. Temporal shifts between peak activity and responding on particular keys also occurred during sequence acquisition, but not during sequence performance. Ethanol disrupted CA1 activity while producing rate-decreasing effects in both tasks and error-increasing effects that were more selective for sequence acquisition than sequence performance. Ethanol also produced alterations in the magnitude of modulations and temporal pattern of CA1 activity, although these effects were not selective for sequence acquisition. Similar to ethanol, hippocampal micro-stimulation decreased response rate in both tasks and selectively increased the percentage of errors during sequence acquisition, and provided a more direct demonstration of hippocampal involvement during sequence acquisition. Together, these results strongly support the notion that ethanol disrupts sequence acquisition by disrupting hippocampal activity and that the hippocampus is necessary for the conditioned associations required for sequence acquisition. PMID:26482846

48 CFR 237.170-2 - Approval requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

...-2 Approval requirements. (a) Acquisition of services through a contract or task order that is not performance based. (1) For acquisitions at or below $85.5 million, obtain the approval of the official... the senior procurement executive. (b) Acquisition of services through use of a contract or task order...

The Utility of Cognitive Plausibility in Language Acquisition Modeling: Evidence from Word Segmentation

ERIC Educational Resources Information Center

Phillips, Lawrence; Pearl, Lisa

2015-01-01

The informativity of a computational model of language acquisition is directly related to how closely it approximates the actual acquisition task, sometimes referred to as the model's "cognitive plausibility." We suggest that though every computational model necessarily idealizes the modeled task, an informative language acquisition…

Computer task performance by subjects with Duchenne muscular dystrophy.

PubMed

Malheiros, Silvia Regina Pinheiro; da Silva, Talita Dias; Favero, Francis Meire; de Abreu, Luiz Carlos; Fregni, Felipe; Ribeiro, Denise Cardoso; de Mello Monteiro, Carlos Bandeira

2016-01-01

Two specific objectives were established to quantify computer task performance among people with Duchenne muscular dystrophy (DMD). First, we compared simple computational task performance between subjects with DMD and age-matched typically developing (TD) subjects. Second, we examined correlations between the ability of subjects with DMD to learn the computational task and their motor functionality, age, and initial task performance. The study included 84 individuals (42 with DMD, mean age of 18±5.5 years, and 42 age-matched controls). They executed a computer maze task; all participants performed the acquisition (20 attempts) and retention (five attempts) phases, repeating the same maze. A different maze was used to verify transfer performance (five attempts). The Motor Function Measure Scale was applied, and the results were compared with maze task performance. In the acquisition phase, a significant decrease was found in movement time (MT) between the first and last acquisition block, but only for the DMD group. For the DMD group, MT during transfer was shorter than during the first acquisition block, indicating improvement from the first acquisition block to transfer. In addition, the TD group showed shorter MT than the DMD group across the study. DMD participants improved their performance after practicing a computational task; however, the difference in MT was present in all attempts among DMD and control subjects. Computational task improvement was positively influenced by the initial performance of individuals with DMD. In turn, the initial performance was influenced by their distal functionality but not their age or overall functionality.

Mental Workload during Brain-Computer Interface Training

PubMed Central

Felton, Elizabeth A.; Williams, Justin C.; Vanderheiden, Gregg C.; Radwin, Robert G.

2012-01-01

It is not well understood how people perceive the difficulty of performing brain-computer interface (BCI) tasks, which specific aspects of mental workload contribute the most, and whether there is a difference in perceived workload between participants who are able-bodied and disabled. This study evaluated mental workload using the NASA Task Load Index (TLX), a multi-dimensional rating procedure with six subscales: Mental Demands, Physical Demands, Temporal Demands, Performance, Effort, and Frustration. Able-bodied and motor disabled participants completed the survey after performing EEG-based BCI Fitts’ law target acquisition and phrase spelling tasks. The NASA-TLX scores were similar for able-bodied and disabled participants. For example, overall workload scores (range 0 – 100) for 1D horizontal tasks were 48.5 (SD = 17.7) and 46.6 (SD 10.3), respectively. The TLX can be used to inform the design of BCIs that will have greater usability by evaluating subjective workload between BCI tasks, participant groups, and control modalities. PMID:22506483

Frontal lobe activation during object alternation acquisition.

PubMed

Zald, David H; Curtis, Clayton; Chernitsky, Laura A; Pardo, José V

2005-01-01

Object alternation (OA) tasks are increasingly used as probes of ventral prefrontal functioning in humans. In the most common variant of the OA task, subjects must deduce the task rule through trial-and-error learning. To examine the neural correlates of OA acquisition, the authors measured regional cerebral blood flow with positron emission tomography while subjects acquired an OA task, performed a sensorimotor control condition, or performed already learned and practiced OA. As expected, activations emerged in the ventral prefrontal cortex. However, activation of the presupplemental motor area was more closely associated with successful task performance. The authors suggest that areas beyond the ventral prefrontal cortex are critically involved in OA acquisition. 2005 APA

The Acquisition of Temporal Reference Cross-Linguistically Using Two Acting-Out Comprehension Tasks

ERIC Educational Resources Information Center

Winskel, Heather

2004-01-01

The acquisition of temporal event referencing, encoded by the temporal connectives: then, before, after, when, while, together, until, and since in English, Thai and Lisu was investigated using two acting-out comprehension tasks, a Marble task and a Toy task. Forty children aged 3.6-7.6 years from each language participated. The Marble and Toy…

Semantic and pragmatic factors influencing deaf and hearing students' comprehension of english sentences containing numeral quantifiers.

PubMed

Kelly, Ronald R; Berent, Gerald P

2011-01-01

This research contrasted deaf and hearing students' interpretive knowledge of English sentences containing numeral quantifier phrases and indefinite noun phrases. A multiple-interpretation picture task methodology was used to assess 305 participants' judgments of the compatibility of sentence meanings with depicted discourse contexts. Participants' performance was assessed on the basis of hearing level (deaf, hearing) and grade level (middle school, high school, college). The deaf students were predicted to have differential access to specific sentence interpretations in accordance with the relative derivational complexity of the targeted sentence types. Hypotheses based on the pressures of derivational economy on acquisition were largely supported. The results also revealed that the deaf participants tended to overactivate pragmatic processes that yielded principled, though non-target, sentence interpretations. Collectively, the results not only contribute to the understanding of English acquisition under conditions of restricted access to spoken language input, they also suggest that pragmatic factors may play a broad role in influencing, and compromising, deaf students' reading comprehension and written expression.

Image guidance doses delivered during radiotherapy: Quantification, management, and reduction: Report of the AAPM Therapy Physics Committee Task Group 180.

PubMed

Ding, George X; Alaei, Parham; Curran, Bruce; Flynn, Ryan; Gossman, Michael; Mackie, T Rock; Miften, Moyed; Morin, Richard; Xu, X George; Zhu, Timothy C

2018-05-01

With radiotherapy having entered the era of image guidance, or image-guided radiation therapy (IGRT), imaging procedures are routinely performed for patient positioning and target localization. The imaging dose delivered may result in excessive dose to sensitive organs and potentially increase the chance of secondary cancers and, therefore, needs to be managed. This task group was charged with: a) providing an overview on imaging dose, including megavoltage electronic portal imaging (MV EPI), kilovoltage digital radiography (kV DR), Tomotherapy MV-CT, megavoltage cone-beam CT (MV-CBCT) and kilovoltage cone-beam CT (kV-CBCT), and b) providing general guidelines for commissioning dose calculation methods and managing imaging dose to patients. We briefly review the dose to radiotherapy (RT) patients resulting from different image guidance procedures and list typical organ doses resulting from MV and kV image acquisition procedures. We provide recommendations for managing the imaging dose, including different methods for its calculation, and techniques for reducing it. The recommended threshold beyond which imaging dose should be considered in the treatment planning process is 5% of the therapeutic target dose. Although the imaging dose resulting from current kV acquisition procedures is generally below this threshold, the ALARA principle should always be applied in practice. Medical physicists should make radiation oncologists aware of the imaging doses delivered to patients under their care. Balancing ALARA with the requirement for effective target localization requires that imaging dose be managed based on the consideration of weighing risks and benefits to the patient. © 2018 American Association of Physicists in Medicine.

Endogenous orienting in the archer fish

PubMed Central

Sekely, Liora; Klein, Raymond M.; Gabay, Shai

2017-01-01

The literature has long emphasized the neocortex’s role in volitional processes. In this work, we examined endogenous orienting in an evolutionarily older species, the archer fish, which lacks neocortex-like cells. We used Posner’s classic endogenous cuing task, in which a centrally presented, spatially informative cue is followed by a target. The fish responded to the target by shooting a stream of water at it. Interestingly, the fish demonstrated a human-like “volitional” facilitation effect: their reaction times to targets that appeared on the side indicated by the precue were faster than their reaction times to targets on the opposite side. The fish also exhibited inhibition of return, an aftermath of orienting that commonly emerges only in reflexive orienting tasks in human participants. We believe that this pattern demonstrates the acquisition of an arbitrary connection between spatial orienting and a nonspatial feature of a centrally presented stimulus in nonprimate species. In the literature on human attention, orienting in response to such contingencies has been strongly associated with volitional control. We discuss the implications of these results for the evolution of orienting, and for the study of volitional processes in all species, including humans. PMID:28673997

76 FR 39238 - Federal Acquisition Regulation; Extension of Sunset Date for Protests of Task and Delivery Orders

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-05

...-AM08 Federal Acquisition Regulation; Extension of Sunset Date for Protests of Task and Delivery Orders... against the award of task or delivery orders by DoD, NASA, and the Coast Guard from May 27, 2011, to... protests against the award of task and delivery orders from May 27, 2011, to September 30, 2016, but only...

Feature long axis size and local luminance contrast determine ship target acquisition performance: strong evidence for the TOD case

NASA Astrophysics Data System (ADS)

Bijl, Piet; Toet, Alexander; Kooi, Frank L.

2016-10-01

Visual images of a civilian target ship on a sea background were produced using a CAD model. The total set consisted of 264 images and included 3 different color schemes, 2 ship viewing aspects, 5 sun illumination conditions, 2 sea reflection values, 2 ship positions with respect to the horizon and 3 values of atmospheric contrast reduction. In a perception experiment, the images were presented on a display in a long darkened corridor. Observers were asked to indicate the range at which they were able to detect the ship and classify the following 5 ship elements: accommodation, funnel, hull, mast, and hat above the bridge. This resulted in a total of 1584 Target Acquisition (TA) range estimates for two observers. Next, the ship contour, ship elements and corresponding TA ranges were analyzed applying several feature size and contrast measures. Most data coincide on a contrast versus angular size plot using (1) the long axis as characteristic ship/ship feature size and (2) local Weber contrast as characteristic ship/ship feature contrast. Finally, the data were compared with a variety of visual performance functions assumed to be representative for Target Acquisition: the TOD (Triangle Orientation Discrimination), MRC (Minimum Resolvable Contrast), CTF (Contrast Threshold Function), TTP (Targeting Task Performance) metric and circular disc detection data for the unaided eye (Blackwell). The results provide strong evidence for the TOD case: both position and slope of the TOD curve match the ship detection and classification data without any free parameter. In contrast, the MRC and CTF are too steep, the TTP and disc detection curves are too shallow and all these curves need an overall scaling factor in order to coincide with the ship and ship feature recognition data.

Small craft ID criteria (N50/V50) for short wave infrared sensors in maritime security

NASA Astrophysics Data System (ADS)

Krapels, Keith; Driggers, Ronald G.; Larson, Paul; Garcia, Jose; Walden, Barry; Agheera, Sameer; Deaver, Dawne; Hixson, Jonathan; Boettcher, Evelyn

2008-04-01

The need for Anti-Terrorism and Force Protection (AT/FP), for both shore and sea platform protection, has resulted in a need for imager design and evaluation tools which can predict field performance against maritime asymmetric threats. In the design of tactical imaging systems for target acquisition, a discrimination criterion is required for successful sensor realization. It characterizes the difficulty of the task being performed by the observer and varies for different target sets. This criterion is used in both assessment of existing infrared sensor and in the design of new conceptual sensors. In this experiment, we collected 8 small craft signatures (military and civilian) in the short wave infrared (SWIR) band during the day. These signatures were processed to determine the targets' characteristic dimension and contrast. They were also processed to bandlimit the signature's spatial information content (simulating longer range) and a perception experiment was performed to determine the task difficulty (N50 and V50). The results are presented in this paper and can be used for maritime security imaging sensor design and evaluation.

OPSO - The OpenGL based Field Acquisition and Telescope Guiding System

NASA Astrophysics Data System (ADS)

Škoda, P.; Fuchs, J.; Honsa, J.

2006-07-01

We present OPSO, a modular pointing and auto-guiding system for the coudé spectrograph of the Ondřejov observatory 2m telescope. The current field and slit viewing CCD cameras with image intensifiers are giving only standard TV video output. To allow the acquisition and guiding of very faint targets, we have designed an image enhancing system working in real time on TV frames grabbed by BT878-based video capture card. Its basic capabilities include the sliding averaging of hundreds of frames with bad pixel masking and removal of outliers, display of median of set of frames, quick zooming, contrast and brightness adjustment, plotting of horizontal and vertical cross cuts of seeing disk within given intensity range and many more. From the programmer's point of view, the system consists of three tasks running in parallel on a Linux PC. One C task controls the video capturing over Video for Linux (v4l2) interface and feeds the frames into the large block of shared memory, where the core image processing is done by another C program calling the OpenGL library. The GUI is, however, dynamically built in Python from XML description of widgets prepared in Glade. All tasks are exchanging information by IPC calls using the shared memory segments.

Route learning in Korsakoff's syndrome: Residual acquisition of spatial memory despite profound amnesia.

PubMed

Oudman, Erik; Van der Stigchel, Stefan; Nijboer, Tanja C W; Wijnia, Jan W; Seekles, Maaike L; Postma, Albert

2016-03-01

Korsakoff's syndrome (KS) is characterized by explicit amnesia, but relatively spared implicit memory. The aim of this study was to assess to what extent KS patients can acquire spatial information while performing a spatial navigation task. Furthermore, we examined whether residual spatial acquisition in KS was based on automatic or effortful coding processes. Therefore, 20 KS patients and 20 matched healthy controls performed six tasks on spatial navigation after they navigated through a residential area. Ten participants per group were instructed to pay close attention (intentional condition), while 10 received mock instructions (incidental condition). KS patients showed hampered performance on a majority of tasks, yet their performance was superior to chance level on a route time and distance estimation tasks, a map drawing task and a route walking task. Performance was relatively spared on the route distance estimation task, but there were large variations between participants. Acquisition in KS was automatic rather than effortful, since no significant differences were obtained between the intentional and incidental condition on any task, whereas for the healthy controls, the intention to learn was beneficial for the map drawing task and the route walking task. The results of this study suggest that KS patients are still able to acquire spatial information during navigation on multiple domains despite the presence of the explicit amnesia. Residual acquisition is most likely based on automatic coding processes. © 2014 The British Psychological Society.

Dual Learning Processes in Interactive Skill Acquisition

ERIC Educational Resources Information Center

Fu, Wai-Tat; Anderson, John R.

2008-01-01

Acquisition of interactive skills involves the use of internal and external cues. Experiment 1 showed that when actions were interdependent, learning was effective with and without external cues in the single-task condition but was effective only with the presence of external cues in the dual-task condition. In the dual-task condition, actions…

Visuospatial abilities and fine motor experiences influence acquisition and maintenance of fundamentals of laparoscopic surgery (FLS) task performance.

PubMed

Harrington, Cuan M; Dicker, Patrick; Traynor, Oscar; Kavanagh, Dara O

2018-05-18

Minimally invasive surgery poses a unique learning curve due to the requirement for non-intuitive psychomotor skills. The fundamentals of laparoscopic surgery (FLS) program trains and certifies residents in such skills. However, innate predictors of FLS performance and maintenance remain to be described. This single-centre observational study aimed to assess for candidate factors influencing the acquisition and maintenance of FLS performance amongst a surgically naïve cohort. Laparoscopically naïve medical students were recruited from pre-clinical university grades. Participants completed five visuospatial/psychomotor tests and a questionnaire surveying non-surgical experiences and personality traits. Individuals completed baseline assessments of FLS standard tasks followed by an intensive training course over week one and two on inanimate box trainers. A post-training assessment was performed in week three to evaluate acquisition. Participants were withdrawn from exposure and retested at four 1-month intervals to assess maintenance requirements. Forty-nine participants enrolled with 35 (71.4%) and 33 (67.3%) completing acquisition and maintenance phases, respectively. Mean age of participants was 19.3 (± 1.2) years with 68.6% female predominance. Participants demonstrated significant improvements in all five tasks during the acquisition (p < 0.05) period and maintenance of skills with task exposure at 1-month intervals. Significant predictors of skill acquisition included: card rotations for intracorporeal knot (p = 0.027) and combined tasks (p = 0.028) and cube comparisons for extracorporeal knot (p = 0.040). During skill maintenance: Card rotations predicted performance across all tasks (p < 0.05), Cube comparisons for tasks 1/2/4/5 (p < 0.05), PicSOR for peg transfer (p = 0.017) and grooved pegboard for peg transfer (p = 0.023) and ligating-loop (p = 0.038) tasks. Musical instrument experience demonstrated associations with skill acquisition in peg transfer (p = 0.042) and intracorporeal knot (p = 0.034) while video gaming predicted performance in these tasks (p < 0.05) during the maintenance phase. A sporting background or competitive personality did not influence skill performance. Multiple visuospatial abilities and non-surgical experiences positively influenced FLS performance during skill acquisition and/or maintenance. Further consideration to these individual factors may facilitate selection of more technically adaptable surgical residents.

Changes in muscle directional tuning parallel feedforward adaptation to a visuomotor rotation.

PubMed

de Rugy, Aymar; Carroll, Timothy J

2010-06-01

When people learn to reach in a novel sensorimotor environment, there are changes in the muscle activity required to achieve task goals. Here, we assessed the time course of changes in muscle directional tuning during acquisition of a new mapping between visual information and isometric force production in the absence of feedback-based error corrections. We also measured the influence of visuomotor adaptation on corticospinal excitability, to test whether any changes in muscle directional tuning are associated with adaptations in the final output components of the sensorimotor control system. Nine right-handed subjects performed a ballistic, center-out isometric target acquisition task with the right wrist (16 targets spaced every 22.5 degrees in the joint space). Surface electromyography was recorded from four major wrist muscles, and motor evoked potentials induced by transcranial magnetic stimulation were measured at baseline, after task execution in the absence of the rotation (A1), after adaptation to the rotation (B), and after a final block of trials without rotation (A2). Changes in the directional tuning of muscles closely matched the rotation of the directional error in force, indicating that the functional contribution of muscles remained consistent over the adaptation period. In contrast to previous motor learning studies, we found only minor changes in the amount of muscular activity and no increase in corticospinal excitability. These results suggest that increased muscle co-activation occurs only when the dynamics of the limb are perturbed and/or that online error corrections or altered force requirements are necessary to elicit a component of the adaptation in the final steps of the transformation between motor goal and muscle activation.

Effects of different practice conditions on acquisition, retention, and transfer of soccer skills by 9-year-old schoolchildren.

PubMed

Vera, Juan Granda; Alvarez, José Carlos Barbero; Medina, Mariano Montilla

2008-04-01

This study was designed to examine effects of three practice models, blocked, variable, and combined, on the acquisition, retention, and transfer of new motor skills. 67 subjects (M age = 9.5 yr., SD = .3) from the fourth year of primary school (31 boys and 26 girls) were assigned at random to three different practice groups (Blocked = 22, Variable = 23, Combined = 22) to study acquisition of two skills, dribbling a soccer ball and kicking a soccer ball at a stationary target using the dominant foot. All participants received a pretest and posttest, a transfer test, and a retention test 2 wk. later. Analysis showed significant improvement after practice of kicking skills by the three groups but not in the dribbling skills, for which only the combined practice group showed any notable improvement. At the end of acquisition, the combined practice group had significantly better performance on the dribbling task than the other two groups. However, the only differences noted in performance of kicking the ball with the dominant foot were by combined practice and blocked groups.

Attention toward contexts modulates context-specificity of behavior in human predictive learning: Evidence from the n-back task.

PubMed

Uengoer, Metin; Lucke, Sara; Lachnit, Harald

2018-02-20

According to the attentional theory of context processing (ATCP), learning becomes context specific when acquired under conditions that promote attention toward contextual stimuli regardless of whether attention deployment is guided by learning experience or by other factors unrelated to learning. In one experiment with humans, we investigated whether performance in a predictive learning task can be brought under contextual control by means of a secondary task that was unrelated to predictive learning, but supposed to modulate participants' attention toward contexts. Initially, participants acquired cue-outcome relationships presented in contexts that were each composed of two elements from two dimensions. Acquisition training in the predictive learning task was combined with a one-back task that required participants to match across consecutive trials context elements belonging to one of the two dimensions. During a subsequent test, we observed that acquisition behavior in the predictive learning task was disrupted by changing the acquisition context along the dimension that was relevant for the one-back task, while there was no evidence for context specificity of predictive learning when the acquisition context was changed along the dimension that was irrelevant for the one-back task. Our results support the generality of the principles advocated by ATCP.

Acquisition, retention and transfer of simulated laparoscopic tasks using fNIR and a contextual interference paradigm.

PubMed

Shewokis, Patricia A; Shariff, Faiz U; Liu, Yichuan; Ayaz, Hasan; Castellanos, Andres; Lind, D Scott

2017-02-01

Using functional near infrared spectroscopy, a noninvasive, optical brain imaging tool that monitors changes in hemodynamics within the prefrontal cortex (PFC), we assessed performance and cognitive effort during the acquisition, retention and transfer of multiple simulated laparoscopic tasks by novice learners within a contextual interference paradigm. Third-year medical students (n = 10) were randomized to either a blocked or random practice schedule. Across 3 days, students performed 108 acquisition trials of 3 laparoscopic tasks on the LapSim ® simulator followed by delayed retention and transfer tests. Performance metrics (Global score, Total time) and hemodynamic responses (total hemoglobin (μm)) were assessed during skill acquisition, retention and transfer. All acquisition tasks resulted in significant practice schedule X trial block interactions for the left medial anterior PFC. During retention and transfer, random performed the skills in less time and had lower total hemoglobin change in the right dorsolateral PFC than blocked. Compared with blocked, random practice resulted in enhanced learning through better performance and less cognitive load for retention and transfer of simulated laparoscopic tasks. Copyright © 2016 Elsevier Inc. All rights reserved.

covert contrast: The acquisition of Mandarin tone 2 and tone 3 in L2 production and perception

NASA Astrophysics Data System (ADS)

Mar, Li-Ya

This dissertation investigates the occurrence of an intermediate stage, termed a covert contrast, in the acquisition of Mandarin Tone 2 (T2) and Tone 3 (T3) by adult speakers of American English. A covert contrast is a statistically reliable distinction produced by language learners that is not perceived by native speakers of the target language (TL). In second language (L2) acquisition, whether a learner is judged as having acquired a TL phonemic contrast has largely depended on whether the contrast was perceived and transcribed by native speakers of the TL. However, categorical perception has shown that native listeners cannot perceive a distinction between two sounds that fall within the same perceptual boundaries on the continuum of the relevant acoustic cues. In other words, it is possible that native speakers of the TL do not perceive a phonemic distinction that is produced by L2 learners when that distinction occurs within a phonemic boundary of TL. The data for the study were gathered through two elicitations of tone production, a longitudinal analysis, and two perception tasks. There were three key findings. First, both elicitations showed that most of the L2 participants produced a covert contrast between T2 and T3 on at least one of the three acoustic measures used in the study. Second, the longitudinal analysis reveals that some L2 participants progressed from making a covert contrast to a later stage of implementing an overt one, thereby supporting the claim that making a covert contrast is an intermediate stage in the process of acquiring a L2 phonemic contrast. Third, results of the perceptual tasks showed no reliable difference in identifying and discriminating Mandarin T2 and T3 on the part of the L2 learners who produced a covert contrast and those who produced an overt contrast, indicating that there was no reliable difference in the two groups' ability to perceive the target tones. In all, the occurrence of a covert contrast in the process of acquiring Mandarin T2 and T3 suggests that L2 acquisition of a tonal contrast is a gradient process, one in which an intermediate step occurs before a L2 learner reaches the final stage of implementing an overt contrast that is perceived as target-like by the native speakers of the TL.

A Near Term Approach to Embedded Training: Battle Command Visualization 101

DTIC Science & Technology

2006-05-01

Example of Task Guidance area at the end of Module 1, Exercise 1 (Level 1) ...... 26 Figure 9 Example of Robo -Scout information, accessed through the...unmanned ground vehicle (UGV) sensor, the Robo -Scout. They will be equipped with both passive and active systems to provide target acquisition, real...PIR# Track of Update RqieTemplated Required 1 Tracked & NAI 1, 2 S, T S200 synthetic L 2 hrs Vehicle type, Intel, Fires (PIR 1) Wheeled aperture radar

TOD to TTP calibration

NASA Astrophysics Data System (ADS)

Bijl, Piet; Reynolds, Joseph P.; Vos, Wouter K.; Hogervorst, Maarten A.; Fanning, Jonathan D.

2011-05-01

The TTP (Targeting Task Performance) metric, developed at NVESD, is the current standard US Army model to predict EO/IR Target Acquisition performance. This model however does not have a corresponding lab or field test to empirically assess the performance of a camera system. The TOD (Triangle Orientation Discrimination) method, developed at TNO in The Netherlands, provides such a measurement. In this study, we make a direct comparison between TOD performance for a range of sensors and the extensive historical US observer performance database built to develop and calibrate the TTP metric. The US perception data were collected doing an identification task by military personnel on a standard 12 target, 12 aspect tactical vehicle image set that was processed through simulated sensors for which the most fundamental sensor parameters such as blur, sampling, spatial and temporal noise were varied. In the present study, we measured TOD sensor performance using exactly the same sensors processing a set of TOD triangle test patterns. The study shows that good overall agreement is obtained when the ratio between target characteristic size and TOD test pattern size at threshold equals 6.3. Note that this number is purely based on empirical data without any intermediate modeling. The calibration of the TOD to the TTP is highly beneficial to the sensor modeling and testing community for a variety of reasons. These include: i) a connection between requirement specification and acceptance testing, and ii) a very efficient method to quickly validate or extend the TTP range prediction model to new systems and tasks.

Differential effects of cannabinoid receptor agonist on social discrimination and contextual fear in amygdala and hippocampus.

PubMed

Segev, Amir; Akirav, Irit

2011-04-01

We examined whether the cannabinoid receptor agonist WIN55,212-2 (WIN; 5 µg/side) microinjected into the hippocampus or the amygdala would differentially affect memory processes in a neutral vs. an aversive task. In the aversive contextual fear task, WIN into the basolateral amygdala impaired fear acquisition/consolidation, but not retrieval. In the ventral subiculum (vSub), WIN impaired fear retrieval. In the neutral social discrimination task, WIN into the vSub impaired both acquisition/consolidation and retrieval, whereas in the medial amygdala WIN impaired acquisition. The results suggest that cannabinoid signaling differentially affects memory in a task-, region-, and memory stage-dependent manner.

A behavioral task with more opportunities for memory acquisition promotes the survival of new neurons in the adult dentate gyrus.

PubMed

Aasebø, Ida E J; Kasture, Ameya Sanjay; Passeggeri, Marzia; Tashiro, Ayumu

2018-05-09

It has been suggested that the dentate gyrus, particularly its new neurons generated via adult neurogenesis, is involved in memory acquisition and recall. Here, we trained rats in two types of Morris water maze tasks that are differentially associated with these two memory processes, and examined whether new neurons are differently affected by the two tasks performed during the second week of neuronal birth. Our results indicate that the task involving more opportunities to acquire new information better supports the survival of new neurons. Further, we assessed whether the two tasks differentially induce the expression of an immediate early gene, Zif268, which is known to be induced by neuronal activation. While the two tasks differentially induce Zif268 expression in the dentate gyrus, the proportions of new neurons activated were similar between the two tasks. Thus, we conclude that while the two tasks differentially activate the dentate gyrus, the task involving more opportunities for memory acquisition during the second week of the birth of new neurons better promotes the survival of the new neurons.

Supervised learning of postural tasks in patients with poststroke hemiparesis, Parkinson's disease or cerebellar ataxia.

PubMed

Ioffe, M E; Ustinova, K I; Chernikova, L A; Kulikov, M A

2006-01-01

Supervised learning of different postural tasks in patients with lesions of the motor cortex or pyramidal system (poststroke hemiparesis: 20 patients), nigro-striatal system (Parkinson's disease: 33 patients) and cerebellum (spinocerebellar ataxia: 37 patients) was studied. A control group consisted of 13 healthy subjects. The subjects stood on a force platform and were trained to change the position of the center of pressure (CP) presented as a cursor on a monitor screen in front of the patient. Subjects were instructed to align the CP with the target and then move the target by shifting the CP in the indicated direction. Two different tasks were used. In "Balls", the target (a ball) position varied randomly, so the subject learned a general strategy of voluntary CP control. In "Bricks", the subject had to always move the target in a single direction (downward) from the top to the bottom of the screen, so that a precise postural coordination had to be learned. The training consisted of 10 sessions for each task. The number of correctly performed trials for a session (2 min for each task) was scored. The voluntary control of the CP position was initially impaired in all groups of patients in both tasks. In "Balls", there were no differences between the groups of the patients on the first day. The learning course was somewhat better in hemiparetic patients than in the other groups. In "Bricks", the initial deficit was greater in the groups of parkinsonian and cerebellar patients than in hemiparetic patients. However, learning was more efficient in parkinsonian than in hemiparetic and cerebellar patients. After 10 days of training, the hemiparetic and cerebellar patients completed the acquisition at a certain level whereas the parkinsonian patients showed the ability for further improvement. The results suggest that motor cortex, cerebellum, and basal ganglia are involved in voluntary control of posture and learning different postural tasks. However, these structures play different roles in postural control and learning: basal ganglia are mainly involved in learning a general strategy of CP control while the function of the motor cortex chiefly concerns learning a specific CP trajectory. The cerebellum is involved in both kinds of learning.

Integrated IR sensors

NASA Astrophysics Data System (ADS)

Tom, Michael; Trujillo, Edward

1994-06-01

Integrated infrared (IR) sensors which exploit modular avionics concepts can provide features such as operational flexibility, enhanced stealthiness, and ease of maintenance to meet the demands of tactical, airborne sensor systems. On-board, tactical airborne sensor systems perform target acquisition, tracking, identification, threat warning, missile launch detection, and ground mapping in support of situation awareness, self-defense, navigation, target attack, weapon support, and reconnaissance activities. The use of sensor suites for future tactical aircraft such as US Air Force's multirole fighter require a blend of sensor inputs and outputs that may vary over time. It is expected that special-role units of these tactical aircraft will be formed to conduct tasks and missions such as anti-shipping, reconnaissance, or suppression of enemy air defenses.

The Influence of Age of Acquisition in Word Reading and Other Tasks: A Never Ending Story?

ERIC Educational Resources Information Center

Bonin, Patrick; Barry, Christopher; Meot, Alain; Chalard, Marylene

2004-01-01

This paper concerns the influence of age of acquisition (AoA) in word reading and other tasks, and attempts to develop a number of issues raised by Zevin and Seidenberg (2002). Analyses performed on both rated and objective measures of AoA show that the frequency trajectory of words is a reliable predictor of their order of acquisition, which…

Classroom L2 Vocabulary Acquisition: Investigating the Role of Pedagogical Tasks and Form-Focused Instruction

ERIC Educational Resources Information Center

de la Fuente, Maria J.

2006-01-01

Framed under a cognitive approach to task-based L2 learning, this study used a pedagogical approach to investigate the effects of three vocabulary lessons (one traditional and two task-based) on acquisition of basic meanings, forms and morphological aspects of Spanish words. Quantitative analysis performed on the data suggests that the type of…

Interactive effect of acute pain and motor learning acquisition on sensorimotor integration and motor learning outcomes

PubMed Central

Dancey, Erin; Andrew, Danielle; Yielder, Paul

2016-01-01

Previous work has demonstrated differential changes in early somatosensory evoked potentials (SEPs) when motor learning acquisition occurred in the presence of acute pain; however, the learning task was insufficiently complex to determine how these underlying neurophysiological differences impacted learning acquisition and retention. To address this limitation, we have utilized a complex motor task in conjunction with SEPs. Two groups of 12 participants (n = 24) were randomly assigned to either a capsaicin (capsaicin cream) or a control (inert lotion) group. SEP amplitudes were collected at baseline, after application, and after motor learning acquisition. Participants performed a motor acquisition task followed by a pain-free retention task within 24–48 h. After motor learning acquisition, the amplitude of the N20 SEP peak significantly increased (P < 0.05) and the N24 SEP peak significantly decreased (P < 0.001) for the control group while the N18 SEP peak significantly decreased (P < 0.01) for the capsaicin group. The N30 SEP peak was significantly increased (P < 0.001) after motor learning acquisition for both groups. The P25 SEP peak decreased significantly (P < 0.05) after the application of capsaicin cream. Both groups improved in accuracy after motor learning acquisition (P < 0.001). The capsaicin group outperformed the control group before motor learning acquisition (P < 0.05) and after motor learning acquisition (P < 0.05) and approached significance at retention (P = 0.06). Improved motor learning in the presence of capsaicin provides support for the enhancement of motor learning while in acute pain. In addition, the changes in SEP peak amplitudes suggest that early SEP changes reflect neurophysiological alterations accompanying both motor learning and mild acute pain. PMID:27535371

48 CFR 316.505 - Ordering.

Code of Federal Regulations, 2010 CFR

2010-10-01

... CONTRACT TYPES TYPES OF CONTRACTS Indefinite-Delivery Contracts 316.505 Ordering. (b)(5) The HHS task-order and delivery-order ombudsman is the Director, Strategic Acquisition Service, PSC. The task-order and... of Performance Accountability, Resources and Technology ASPR/OAMCG: Chief of Acquisition Policy CDC...

Uneven Reassembly of Tense, Telicity and Discourse Features in L2 Acquisition of the Chinese "shì…de" Cleft Construction by Adult English Speakers

ERIC Educational Resources Information Center

Mai, Ziyin; Yuan, Boping

2016-01-01

This article reports an empirical study investigating L2 acquisition of the Mandarin Chinese "shì…de" cleft construction by adult English-speaking learners within the framework of the Feature Reassembly Hypothesis (Lardiere, 2009). A Sentence Completion task, an interpretation task, two Acceptability Judgement tasks, and a felicity…

The CINCS (Commanders-in-Chief) and the Acquisition Process

DTIC Science & Technology

1988-09-01

ELEMENT I PROJECT NO. TASK NO. ACCESSION NO. Washington, DC 20301 T -AO-461 WORK UNIT 11. TITLE (Inokde Seoewhly Clasifloetlon) THE CINCS AND THE ACQUISITION...Herschel Kanter Leonard Wainstein Rachel Kaganoff Barry Pavel September 1988 IDA INSTITUTE FOR DEFENSE ANALYSES Contract MDA 903 84 C 0031 Task T -AO-461...3 PREFACE This task was undertaken as part of Task T -AO-461, "Special Studies of Critical Defense Issues," Contract Number MDA 903 84 C 0031. Its

Incidental orthographic learning during a color detection task.

PubMed

Protopapas, Athanassios; Mitsi, Anna; Koustoumbardis, Miltiadis; Tsitsopoulou, Sofia M; Leventi, Marianna; Seitz, Aaron R

2017-09-01

Orthographic learning refers to the acquisition of knowledge about specific spelling patterns forming words and about general biases and constraints on letter sequences. It is thought to occur by strengthening simultaneously activated visual and phonological representations during reading. Here we demonstrate that a visual perceptual learning procedure that leaves no time for articulation can result in orthographic learning evidenced in improved reading and spelling performance. We employed task-irrelevant perceptual learning (TIPL), in which the stimuli to be learned are paired with an easy task target. Assorted line drawings and difficult-to-spell words were presented in red color among sequences of other black-colored words and images presented in rapid succession, constituting a fast-TIPL procedure with color detection being the explicit task. In five experiments, Greek children in Grades 4-5 showed increased recognition of words and images that had appeared in red, both during and after the training procedure, regardless of within-training testing, and also when targets appeared in blue instead of red. Significant transfer to reading and spelling emerged only after increased training intensity. In a sixth experiment, children in Grades 2-3 showed generalization to words not presented during training that carried the same derivational affixes as in the training set. We suggest that reinforcement signals related to detection of the target stimuli contribute to the strengthening of orthography-phonology connections beyond earlier levels of visually-based orthographic representation learning. These results highlight the potential of perceptual learning procedures for the reinforcement of higher-level orthographic representations. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Age of acquisition effects on the functional organization of language in the adult brain.

PubMed

Mayberry, Rachel I; Chen, Jen-Kai; Witcher, Pamela; Klein, Denise

2011-10-01

Using functional magnetic resonance imaging (fMRI), we neuroimaged deaf adults as they performed two linguistic tasks with sentences in American Sign Language, grammatical judgment and phonemic-hand judgment. Participants' age-onset of sign language acquisition ranged from birth to 14 years; length of sign language experience was substantial and did not vary in relation to age of acquisition. For both tasks, a more left lateralized pattern of activation was observed, with activity for grammatical judgment being more anterior than that observed for phonemic-hand judgment, which was more posterior by comparison. Age of acquisition was linearly and negatively related to activation levels in anterior language regions and positively related to activation levels in posterior visual regions for both tasks. Copyright © 2011 Elsevier Inc. All rights reserved.

Deductive reasoning, brain maturation, and science concept acquisition: Are they linked?

NASA Astrophysics Data System (ADS)

Lawson, Anton E.

The present study tested the alternative hypotheses that the poor performance of the intuitive and transitional students on the concept acquisition tasks employed in the Lawson et al. (1991) study was due either to their failure (a) to use deductive reasoning to test potentially relevant task features, as suggested by Lawson et al. (1991); (b) to identify potentially relevant features; or (c) to derive and test a successful problem-solving strategy. To test these hypotheses a training session, which consisted of a series of seven concept acquisition tasks, was designed to reveal to students key task features and the deductive reasoning pattern necessary to solve the tasks. The training was individually administered to students (ages 5-14 years). Results revealed that none of the five- and six-year-olds, approximately half of the seven-year-olds, and virtually all of the students eight years and older responded successfully to the training. These results are viewed as contradictory to the hypothesis that the intuitive and transitional students in the Lawson et al. (1991) study lacked the reasoning skills necessary to identify and test potentially relevant task features. Instead, the results support the hypothesis that their poor performance was due to their failure to use hypothetico-deductive reasoning to derive an effective strategy. Previous research is cited that indicates that the brain's frontal lobes undergo a pronounced growth spurt from about four years of age to about seven years of age. In fact, the performance of normal six-year-olds and adults with frontal lobe damage on tasks such as the Wisconsin Card Sorting Task (WCST), a task similar in many ways to the present concept acquisition tasks, has been found to be identical. Consequently, the hypothesis is advanced that maturation of the frontal lobes can explain the striking improvement in performance at age seven. A neural network of the role of the frontal lobes in task performance based upon the work of Levine and Prueitt (1989) is presented. The advance in reasoning that presumably results from effective operation of the frontal lobes is seen as a fundamental advance in intellectual development because it enables children to employ an inductive-deductive reasoning pattern to change their minds when confronted with contradictory evidence regarding features of perceptible objects, a skill necessary for descriptive concept acquisition. It is suggested that a further qualitative advance in intellectual development occurs when an analogous pattern of abductive-deductive reasoning is applied to hypothetical objects and/or processes to allow for alternative hypothesis testing and theoretical concept acquisition. Apparently this is the reasoning pattern needed to derive an effective problem-solving strategy to solve the concept acquisition tasks of Lawson et al. (1991) when direct instruction is not provided. Implications for the science classroom are suggested.

48 CFR 17.501 - General.

Code of Federal Regulations, 2011 CFR

2011-10-01

....501 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Interagency Acquisitions 17.501 General. (a) Interagency acquisitions are commonly conducted through indefinite-delivery contracts, such as task- and delivery-order...

Gene Expression Changes in the Motor Cortex Mediating Motor Skill Learning

PubMed Central

Cheung, Vincent C. K.; DeBoer, Caroline; Hanson, Elizabeth; Tunesi, Marta; D'Onofrio, Mara; Arisi, Ivan; Brandi, Rossella; Cattaneo, Antonino; Goosens, Ki A.

2013-01-01

The primary motor cortex (M1) supports motor skill learning, yet little is known about the genes that contribute to motor cortical plasticity. Such knowledge could identify candidate molecules whose targeting might enable a new understanding of motor cortical functions, and provide new drug targets for the treatment of diseases which impair motor function, such as ischemic stroke. Here, we assess changes in the motor-cortical transcriptome across different stages of motor skill acquisition. Adult rats were trained on a gradually acquired appetitive reach and grasp task that required different strategies for successful pellet retrieval, or a sham version of the task in which the rats received pellet reward without needing to develop the reach and grasp skill. Tissue was harvested from the forelimb motor-cortical area either before training commenced, prior to the initial rise in task performance, or at peak performance. Differential classes of gene expression were observed at the time point immediately preceding motor task improvement. Functional clustering revealed that gene expression changes were related to the synapse, development, intracellular signaling, and the fibroblast growth factor (FGF) family, with many modulated genes known to regulate synaptic plasticity, synaptogenesis, and cytoskeletal dynamics. The modulated expression of synaptic genes likely reflects ongoing network reorganization from commencement of training till the point of task improvement, suggesting that motor performance improves only after sufficient modifications in the cortical circuitry have accumulated. The regulated FGF-related genes may together contribute to M1 remodeling through their roles in synaptic growth and maturation. PMID:23637843

The influence of deliberate practice on musical achievement: a meta-analysis.

PubMed

Platz, Friedrich; Kopiez, Reinhard; Lehmann, Andreas C; Wolf, Anna

2014-01-01

Deliberate practice (DP) is a task-specific structured training activity that plays a key role in understanding skill acquisition and explaining individual differences in expert performance. Relevant activities that qualify as DP have to be identified in every domain. For example, for training in classical music, solitary practice is a typical training activity during skill acquisition. To date, no meta-analysis on the quantifiable effect size of deliberate practice on attained performance in music has been conducted. Yet the identification of a quantifiable effect size could be relevant for the current discussion on the role of various factors on individual difference in musical achievement. Furthermore, a research synthesis might enable new computational approaches to musical development. Here we present the first meta-analysis on the role of deliberate practice in the domain of musical performance. A final sample size of 13 studies (total N = 788) was carefully extracted to satisfy the following criteria: reported durations of task-specific accumulated practice as predictor variables and objectively assessed musical achievement as the target variable. We identified an aggregated effect size of r c = 0.61; 95% CI [0.54, 0.67] for the relationship between task-relevant practice (which by definition includes DP) and musical achievement. Our results corroborate the central role of long-term (deliberate) practice for explaining expert performance in music.

Native sound category formation in simultaneous bilingual acquisition

NASA Astrophysics Data System (ADS)

Bosch, Laura

2004-05-01

The consequences of early bilingual exposure on the perceptual reorganization processes that occur by the end of the first year of life were analyzed in a series of experiments on the capacity to discriminate vowel and consonant contrasts, comparing monolingual and bilingual infants (Catalan/Spanish) at different age levels. For bilingual infants, the discrimination of target vowel contrasts, which reflect different amount of overlapping and acoustic distance between the two languages of exposure, suggested a U-shaped developmental pattern. A similar trend was observed in the bilingual infants discrimination of a fricative voicing contrast, present in only one of the languages in their environment. The temporary decline in sensitivity found at 8 months for vowel targets and at 12 months for the voicing contrast reveals the specific perceptual processes that bilingual infants develop in order to deal with their complex linguistic input. Data from adult bilingual subjects on a lexical decision task involving these contrasts add to this developmental picture and suggest the existence of a dominant language even in simultaneous bilingual acquisition. [Work supported by JSMF 10001079BMB.

Small craft identification discrimination criteria N 50 and V 50 for visible and infrared sensors in maritime security

NASA Astrophysics Data System (ADS)

Krapels, Keith; Deaver, Dawne; Driggers, Ronald

2006-09-01

The new emphasis on Anti-Terrorism and Force Protection (AT/FP), for both shore and sea platform protection, has resulted in a need for infrared imager design and evaluation tools which demonstrate field performance against U.S. Navy AT/FP requirements. In the design of infrared imaging systems for target acquisition, a discrimination criterion is required for successful sensor realization. It characterizes the difficulty of the task being performed by the observer and varies for different target sets. This criterion is used in both assessment of existing infrared sensor and in the design of new conceptual sensors. In this experiment, we collected 12 small craft signatures (military and civilian) in the visible band during the day and the LWIR and MWIR spectra in both the day and the night environments. These signatures were processed to determine the targets' characteristic dimension and contrast. They were also processed to bandlimit the signature's spatial information content (simulating longer range) and a perception experiment was performed to determine the task difficulty (N 50 and V 50). The results are presented in this paper and can be used for Navy and Coast Guard imaging infrared sensor design and evaluation.

Midwave infrared and visible sensor performance modeling: small craft identification discrimination criteria for maritime security

NASA Astrophysics Data System (ADS)

Krapels, Keith; Driggers, Ronald G.; Deaver, Dawne; Moker, Steven K.; Palmer, John

2007-10-01

The new emphasis on Anti-Terrorism and Force Protection (AT/FP), for both shore and sea platform protection, has resulted in a need for infrared imager design and evaluation tools that demonstrate field performance against U.S. Navy AT/FP requirements. In the design of infrared imaging systems for target acquisition, a discrimination criterion is required for successful sensor realization. It characterizes the difficulty of the task being performed by the observer and varies for different target sets. This criterion is used in both assessment of existing infrared sensor and in the design of new conceptual sensors. We collected 12 small craft signatures (military and civilian) in the visible band during the day and the long-wave and midwave infrared spectra in both the day and the night environments. These signatures were processed to determine the targets' characteristic dimension and contrast. They were also processed to band limit the signature's spatial information content (simulating longer range), and a perception experiment was performed to determine the task difficulty (N50 and V50). The results are presented and can be used for Navy and Coast Guard imaging infrared sensor design and evaluation.

Study of a Tracking and Data Acquisition System (TDAS) in the 1990's

NASA Technical Reports Server (NTRS)

1981-01-01

Progress in concept definition studies, operational assessments, and technology demonstrations for the Tracking and Data Acquisition System (TDAS) is reported. The proposed TDAS will be the follow-on to the Tracking and Data Relay Satellite System and will function as a key element of the NASA End-to-End Data System, providing the tracking and data acquisition interface between user accessible data ports on Earth and the user's spaceborne equipment. Technical activities of the "spacecraft data system architecture' task and the "communication mission model' task are emphasized. The objective of the first task is to provide technology forecasts for sensor data handling, navigation and communication systems, and estimate corresponding costs. The second task is concerned with developing a parametric description of the required communication channels. Other tasks with significant activity include the "frequency plan and radio interference model' and the "Viterbi decoder/simulator study'.

Second Language Acquisition Research in Japan. JALT Applied Materials.

ERIC Educational Resources Information Center

Robinson, Peter, Ed.; Sawyer, Mark, Ed.; Ross, Steven, Ed.

This collection of papers includes the following: "Second Language Acquisition Research in Japan: Theoretical Issues" (Peter Robinson, Mark Sawyer, and Steven Ross); (2) "Focus on Form: Implicit and Explicit Form Focused Instruction Incorporated into a Communicative Task" (Hitoshi Muranoi); (3) "A Task that Works for…

Novel Composites for Wing and Fuselage Applications. Task 1; Novel Wing Design Concepts

NASA Technical Reports Server (NTRS)

Suarez, J. A.; Buttitta, C.; Flanagan, G.; DeSilva, T.; Egensteiner, W.; Bruno, J.; Mahon, J.; Rutkowski, C.; Collins, R.; Fidnarick, R.;

Unconscious symmetrical inferences: A role of consciousness in event integration.

PubMed

Alonso, Diego; Fuentes, Luis J; Hommel, Bernhard

2006-06-01

Explicit and implicit learning have been attributed to different learning processes that create different types of knowledge structures. Consistent with that claim, our study provides evidence that people integrate stimulus events differently when consciously aware versus unaware of the relationship between the events. In a first, acquisition phase participants sorted words into two categories (A and B), which were fully predicted by task-irrelevant primes-the labels of two other, semantically unrelated categories (C and D). In a second, test phase participants performed a lexical decision task, in which all word stimuli stemmed from the previous prime categories (C and D) and the (now nonpredictive) primes were the labels of the previous target categories (A and B). Reliable priming effects in the second phase demonstrated that bidirectional associations between the respective categories had been formed in the acquisition phase (A<-->C and B<-->D), but these effects were found only in participants that were unaware of the relationship between the categories! We suggest that unconscious, implicit learning of event relationships results in the rather unsophisticated integration (i.e., bidirectional association) of the underlying event representations, whereas explicit learning takes the meaning of the order of the events into account, and thus creates unidirectional associations.

An investigation on task-technology fit of mobile nursing information systems for nursing performance.

PubMed

Hsiao, Ju-Ling; Chen, Rai-Fu

2012-05-01

This study investigates factors affecting the fit between nursing tasks and mobile nursing information systems and the relationships between the task-technology fit of mobile nursing information systems and nurse performance from the perspective of task-technology fit. Survey research recruited nursing staffs as subjects from selected case hospital. A total of 310 questionnaires were sent out, and 219 copies were obtained, indicating a valid response rate of 70.6%. Collected data were analyzed using the structural equation modeling technique. Our study found that dependence tasks have positive effects on information acquisition (γ=0.234, P<.05) and information identification (γ=0.478, P<.001), and independent tasks have significant effects on information acquisition (γ=0.213, P<.05). Therefore, the introduction of mobile nursing information systems in assisting nursing practices can help facilitate both independent and dependent nursing tasks. Our study discovered that the supporting functions of mobile nursing information systems have positive effects on information integration and interpretation (γ=0.365, P<.001), as well as information acquisition (γ=0.253, P<.05). The service supports of mobile nursing information systems have positive effects on information acquisition (γ=0.318, P<.001) and information integration and interpretation (γ=0.143, P<.01). Furthermore, information identification (β=.055, P<.05), information acquisition (β=.176, P<.001), and information integration and interpretation (β=.706, P<.001) provided using mobile nursing information systems have positive effects on nursing performance, indicating 83.2% of totally explained variance. As shown, the use of mobile nursing information systems could provide nursing staffs with real-time and accurate information to increase efficiency and effectiveness in patient-care duties, further improving nursing performance.

The effects of echolalia on acquisition and generalization of receptive labeling in autistic children.

PubMed Central

Charlop, M H

1983-01-01

This investigation, consisting of two experiments, was designed to assess the effects of autistic immediate echolalia on acquisition and generalization of receptive labeling tasks. Experiment 1 addressed whether autistic children could use their echolalia to facilitate acquisition. The results indicated that incorporating echolalia (echo of the requested object's label) into the task before manual response (handing the requested object to the experimenter) facilitated receptive labeling. Experiment 2 was designed to determine the effects of incorporating echolalia into task response on acquisition and subsequent generalization. These results indicated that echolalia facilitated generalization for echolalic autistic children but not for functionally mute autistic children. The results of the experiments are discussed in terms of stimulus control. Additionally, it is proposed that perhaps in certain cases, echolalia should not be eliminated, but used to advantage in receptive responding. PMID:6833164

The effects of echolalia on acquisition and generalization of receptive labeling in autistic children.

PubMed

Charlop, M H

1983-01-01

This investigation, consisting of two experiments, was designed to assess the effects of autistic immediate echolalia on acquisition and generalization of receptive labeling tasks. Experiment 1 addressed whether autistic children could use their echolalia to facilitate acquisition. The results indicated that incorporating echolalia (echo of the requested object's label) into the task before manual response (handing the requested object to the experimenter) facilitated receptive labeling. Experiment 2 was designed to determine the effects of incorporating echolalia into task response on acquisition and subsequent generalization. These results indicated that echolalia facilitated generalization for echolalic autistic children but not for functionally mute autistic children. The results of the experiments are discussed in terms of stimulus control. Additionally, it is proposed that perhaps in certain cases, echolalia should not be eliminated, but used to advantage in receptive responding.

Reading vocabulary in children with and without hearing loss: the roles of task and word type.

PubMed

Coppens, Karien M; Tellings, Agnes; Verhoeven, Ludo; Schreuder, Robert

2013-04-01

To address the problem of low reading comprehension scores among children with hearing impairment, it is necessary to have a better understanding of their reading vocabulary. In this study, the authors investigated whether task and word type differentiate the reading vocabulary knowledge of children with and without severe hearing loss. Seventy-two children with hearing loss and 72 children with normal hearing performed a lexical and a use decision task. Both tasks contained the same 180 words divided over 7 clusters, each cluster containing words with a similar pattern of scores on 8 word properties (word class, frequency, morphological family size, length, age of acquisition, mode of acquisition, imageability, and familiarity). Whereas the children with normal hearing scored better on the 2 tasks than the children with hearing loss, the size of the difference varied depending on the type of task and word. Performance differences between the 2 groups increased as words and tasks became more complex. Despite delays, children with hearing loss showed a similar pattern of vocabulary acquisition as their peers with normal hearing. For the most precise assessment of reading vocabulary possible, a range of tasks and word types should be used.

Ground/Air Task Oriented Radar (G/ATOR)

DTIC Science & Technology

2015-12-01

Selected Acquisition Report ( SAR ) RCS: DD-A&T(Q&A)823-386 Ground/Air Task Oriented Radar (G/ATOR) As of FY 2017 President’s Budget Defense...Acquisition Management Information Retrieval (DAMIR) March 18, 2016 06:47:59 UNCLASSIFIED G/ATOR December 2015 SAR March 18, 2016 06:47:59 UNCLASSIFIED 2...Document OSD - Office of the Secretary of Defense O&S - Operating and Support PAUC - Program Acquisition Unit Cost G/ATOR December 2015 SAR March 18

Mental workload during brain-computer interface training.

PubMed

Felton, Elizabeth A; Williams, Justin C; Vanderheiden, Gregg C; Radwin, Robert G

2012-01-01

It is not well understood how people perceive the difficulty of performing brain-computer interface (BCI) tasks, which specific aspects of mental workload contribute the most, and whether there is a difference in perceived workload between participants who are able-bodied and disabled. This study evaluated mental workload using the NASA Task Load Index (TLX), a multi-dimensional rating procedure with six subscales: Mental Demands, Physical Demands, Temporal Demands, Performance, Effort, and Frustration. Able-bodied and motor disabled participants completed the survey after performing EEG-based BCI Fitts' law target acquisition and phrase spelling tasks. The NASA-TLX scores were similar for able-bodied and disabled participants. For example, overall workload scores (range 0-100) for 1D horizontal tasks were 48.5 (SD = 17.7) and 46.6 (SD 10.3), respectively. The TLX can be used to inform the design of BCIs that will have greater usability by evaluating subjective workload between BCI tasks, participant groups, and control modalities. Mental workload of brain-computer interfaces (BCI) can be evaluated with the NASA Task Load Index (TLX). The TLX is an effective tool for comparing subjective workload between BCI tasks, participant groups (able-bodied and disabled), and control modalities. The data can inform the design of BCIs that will have greater usability.

A Novel Task for the Investigation of Action Acquisition

PubMed Central

Stafford, Tom; Thirkettle, Martin; Walton, Tom; Vautrelle, Nicolas; Hetherington, Len; Port, Michael; Gurney, Kevin; Redgrave, Pete

2012-01-01

We present a behavioural task designed for the investigation of how novel instrumental actions are discovered and learnt. The task consists of free movement with a manipulandum, during which the full range of possible movements can be explored by the participant and recorded. A subset of these movements, the ‘target’, is set to trigger a reinforcing signal. The task is to discover what movements of the manipulandum evoke the reinforcement signal. Targets can be defined in spatial, temporal, or kinematic terms, can be a combination of these aspects, or can represent the concatenation of actions into a larger gesture. The task allows the study of how the specific elements of behaviour which cause the reinforcing signal are identified, refined and stored by the participant. The task provides a paradigm where the exploratory motive drives learning and as such we view it as in the tradition of Thorndike [1]. Most importantly it allows for repeated measures, since when a novel action is acquired the criterion for triggering reinforcement can be changed requiring a new action to be discovered. Here, we present data using both humans and rats as subjects, showing that our task is easily scalable in difficulty, adaptable across species, and produces a rich set of behavioural measures offering new and valuable insight into the action learning process. PMID:22675490

Benchmarking image fusion system design parameters

NASA Astrophysics Data System (ADS)

Howell, Christopher L.

2013-06-01

A clear and absolute method for discriminating between image fusion algorithm performances is presented. This method can effectively be used to assist in the design and modeling of image fusion systems. Specifically, it is postulated that quantifying human task performance using image fusion should be benchmarked to whether the fusion algorithm, at a minimum, retained the performance benefit achievable by each independent spectral band being fused. The established benchmark would then clearly represent the threshold that a fusion system should surpass to be considered beneficial to a particular task. A genetic algorithm is employed to characterize the fused system parameters using a Matlab® implementation of NVThermIP as the objective function. By setting the problem up as a mixed-integer constraint optimization problem, one can effectively look backwards through the image acquisition process: optimizing fused system parameters by minimizing the difference between modeled task difficulty measure and the benchmark task difficulty measure. The results of an identification perception experiment are presented, where human observers were asked to identify a standard set of military targets, and used to demonstrate the effectiveness of the benchmarking process.

Visual context processing deficits in schizophrenia: effects of deafness and disorganization.

PubMed

Horton, Heather K; Silverstein, Steven M

2011-07-01

Visual illusions allow for strong tests of perceptual functioning. Perceptual impairments can produce superior task performance on certain tasks (i.e., more veridical perception), thereby avoiding generalized deficit confounds while tapping mechanisms that are largely outside of conscious control. Using a task based on the Ebbinghaus illusion, a perceptual phenomenon where the perceived size of a central target object is affected by the size of surrounding inducers, we tested hypotheses related to visual integration in deaf (n = 31) and hearing (n = 34) patients with schizophrenia. In past studies, psychiatrically healthy samples displayed increased visual integration relative to schizophrenia samples and thus were less able to correctly judge target sizes. Deafness, and especially the use of sign language, leads to heightened sensitivity to peripheral visual cues and increased sensitivity to visual context. Therefore, relative to hearing subjects, deaf subjects were expected to display increased context sensitivity (ie, a more normal illusion effect as evidenced by a decreased ability to correctly judge central target sizes). Confirming the hypothesis, deaf signers were significantly more sensitive to the illusion than nonsigning hearing patients. Moreover, an earlier age of sign language acquisition, higher levels of linguistic ability, and shorter illness duration were significantly related to increased context sensitivity. As predicted, disorganization was associated with reduced context sensitivity for all subjects. The primary implications of these data are that perceptual organization impairment in schizophrenia is plastic and that it is related to a broader failure in coordinating cognitive activity.

Task Demands Control Acquisition and Storage of Visual Information

ERIC Educational Resources Information Center

Droll, Jason A.; Hayhoe, Mary M.; Triesch, Jochen; Sullivan, Brian T.

2005-01-01

Attention and working memory limitations set strict limits on visual representations, yet researchers have little appreciation of how these limits constrain the acquisition of information in ongoing visually guided behavior. Subjects performed a brick sorting task in a virtual environment. A change was made to 1 of the features of the brick being…

Adaptive Competency Acquisition: Why LPN-to-ADN Career Mobility Education Programs Work.

ERIC Educational Resources Information Center

Coyle-Rogers, Patricia G.

Adaptive competencies are the skills required to effectively complete a particular task and are the congruencies (balance) between personal skills and task demands. The differences between the adaptive competency acquisition of students in licensed practical nurse (LPN) programs and associate degree nurse (ADN) programs were examined in a…

Adult Age Differences and the Role of Cognitive Resources in Perceptual–Motor Skill Acquisition: Application of a Multilevel Negative Exponential Model

PubMed Central

Kennedy, Kristen M.; Rodrigue, Karen M.; Lindenberger, Ulman; Raz, Naftali

2010-01-01

The effects of advanced age and cognitive resources on the course of skill acquisition are unclear, and discrepancies among studies may reflect limitations of data analytic approaches. We applied a multilevel negative exponential model to skill acquisition data from 80 trials (four 20-trial blocks) of a pursuit rotor task administered to healthy adults (19–80 years old). The analyses conducted at the single-trial level indicated that the negative exponential function described performance well. Learning parameters correlated with measures of task-relevant cognitive resources on all blocks except the last and with age on all blocks after the second. Thus, age differences in motor skill acquisition may evolve in 2 phases: In the first, age differences are collinear with individual differences in task-relevant cognitive resources; in the second, age differences orthogonal to these resources emerge. PMID:20047985

Software Product Lines: Report of the 2010 US Army Software Product Line Workshop

DTIC Science & Technology

2010-06-01

requirements and statement of work ( SOW ) tasks can be in- cluded in the request for proposal (RFP) and the contract. 2.2.1 Basic Product Line Acquisition... SOW tasks in Figure 1. Two additional tasks (at the third tier level) ac- count for sustaining the production capability over the life cycle and...Acquisition Strategy RFP and SOW Initial Product Line Scope Product Line Business Case Capability Description Document Teaming Product Line

Acquisition of dental skills in preclinical technique courses: influence of spatial and manual abilities.

PubMed

Schwibbe, Anja; Kothe, Christian; Hampe, Wolfgang; Konradt, Udo

2016-10-01

Sixty years of research have not added up to a concordant evaluation of the influence of spatial and manual abilities on dental skill acquisition. We used Ackerman's theory of ability determinants of skill acquisition to explain the influence of spatial visualization and manual dexterity on the task performance of dental students in two consecutive preclinical technique courses. We measured spatial and manual abilities of applicants to Hamburg Dental School by means of a multiple choice test on Technical Aptitude and a wire-bending test, respectively. Preclinical dental technique tasks were categorized as consistent-simple and inconsistent-complex based on their contents. For analysis, we used robust regression to circumvent typical limitations in dental studies like small sample size and non-normal residual distributions. We found that manual, but not spatial ability exhibited a moderate influence on the performance in consistent-simple tasks during dental skill acquisition in preclinical dentistry. Both abilities revealed a moderate relation with the performance in inconsistent-complex tasks. These findings support the hypotheses which we had postulated on the basis of Ackerman's work. Therefore, spatial as well as manual ability are required for the acquisition of dental skills in preclinical technique courses. These results support the view that both abilities should be addressed in dental admission procedures in addition to cognitive measures.

The key to using a learning or skill acquisition plan.

PubMed

Nicholls, Delwyn; Sweet, Linda; Westerway, Sue Campbell; Gibbins, Annie

2014-11-01

A learning plan is a tool to guide the development of knowledge, skills and professional attitudes required for practice. A learning plan is an ideal tool for both supervisors and mentors to guide the process of teaching and learning a medical ultrasound examination. A good learning plan will state the learning goal, identify the learning activities and resources needed to achieve this goal, and highlight the outcome measures, which when achieved indicate the goal has been accomplished. A skill acquisition plan provides a framework for task acquisition and skill stratification; and is an extension of the application of the student learning plan. One unique feature of a skill acquisition plan is it requires the tutor to first undertake a task analysis. The task steps are progressively learnt in sequence, termed scaffolding. The skills to develop and use a learning or skill acquisition plan are also learnt, but are an integral component to the ultrasound tutors skill set. This paper will provide an outline of how to use and apply a learning and skill acquisition plan. We will review how these tools can be personalised to each student and skill teaching environment.

Periodic components of hand acceleration/deceleration impulses during telemanipulation

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

Draper, J.V.; Handel, S.

1994-01-01

Responsiveness is the ability of a telemanipulator to recreate user trajectories and impedance in time and space. For trajectory production, a key determinant of responsiveness is the ability of the system to accept user inputs, which are forces on the master handle generated by user hand acceleration/deceleration (a/d) impulses, and translate them into slave arm acceleration/deceleration. This paper presents observations of master controller a/d impulses during completion of a simple target acquisition task. Power spectral density functions (PSDF`s) calculated from hand controller a/d impulses were used to assess impulse waveform. The relative contributions of frequency intervals ranging up to 25more » Hz for three spatially different versions of the task were used to determine which frequencies were most important. The highest relative power was observed in frequencies between 1 Hz and 6 Hz. The key frequencies related to task difficulty were in the range from 2 Hz to 8 Hz. the results provide clues to the source of the performance inhibition.« less

The Effects of Study Tasks in a Computer-Based Chemistry Learning Environment

NASA Astrophysics Data System (ADS)

Urhahne, Detlef; Nick, Sabine; Poepping, Anna Christin; Schulz, Sarah Jayne

2013-12-01

The present study examines the effects of different study tasks on the acquisition of knowledge about acids and bases in a computer-based learning environment. Three different task formats were selected to create three treatment conditions: learning with gap-fill and matching tasks, learning with multiple-choice tasks, and learning only from text and figures without any additional tasks. Participants were 196 ninth-grade students who learned with a self-developed multimedia program in a pretest-posttest control group design. Research results reveal that gap-fill and matching tasks were most effective in promoting knowledge acquisition, followed by multiple-choice tasks, and no tasks at all. The findings are in line with previous research on this topic. The effects can possibly be explained by the generation-recognition model, which predicts that gap-fill and matching tasks trigger more encompassing learning processes than multiple-choice tasks. It is concluded that instructional designers should incorporate more challenging study tasks for enhancing the effectiveness of computer-based learning environments.

Cooperative Robots to Observe Moving Targets: Review.

PubMed

Khan, Asif; Rinner, Bernhard; Cavallaro, Andrea

2018-01-01

The deployment of multiple robots for achieving a common goal helps to improve the performance, efficiency, and/or robustness in a variety of tasks. In particular, the observation of moving targets is an important multirobot application that still exhibits numerous open challenges, including the effective coordination of the robots. This paper reviews control techniques for cooperative mobile robots monitoring multiple targets. The simultaneous movement of robots and targets makes this problem particularly interesting, and our review systematically addresses this cooperative multirobot problem for the first time. We classify and critically discuss the control techniques: cooperative multirobot observation of multiple moving targets, cooperative search, acquisition, and track, cooperative tracking, and multirobot pursuit evasion. We also identify the five major elements that characterize this problem, namely, the coordination method, the environment, the target, the robot and its sensor(s). These elements are used to systematically analyze the control techniques. The majority of the studied work is based on simulation and laboratory studies, which may not accurately reflect real-world operational conditions. Importantly, while our systematic analysis is focused on multitarget observation, our proposed classification is useful also for related multirobot applications.

Video-task acquisition in rhesus monkeys (Macaca mulatta) and chimpanzees (Pan troglodytes): a comparative analysis

NASA Technical Reports Server (NTRS)

Hopkins, W. D.; Washburn, D. A.; Hyatt, C. W.; Rumbaugh, D. M. (Principal Investigator)

1996-01-01

This study describes video-task acquisition in two nonhuman primate species. The subjects were seven rhesus monkeys (Macaca mulatta) and seven chimpanzees (Pan troglodytes). All subjects were trained to manipulate a joystick which controlled a cursor displayed on a computer monitor. Two criterion levels were used: one based on conceptual knowledge of the task and one based on motor performance. Chimpanzees and rhesus monkeys attained criterion in a comparable number of trials using a conceptually based criterion. However, using a criterion based on motor performance, chimpanzees reached criterion significantly faster than rhesus monkeys. Analysis of error patterns and latency indicated that the rhesus monkeys had a larger asymmetry in response bias and were significantly slower in responding than the chimpanzees. The results are discussed in terms of the relation between object manipulation skills and video-task acquisition.

Tools to Support Human Factors and Systems Engineering Interactions During Early Analysis

NASA Technical Reports Server (NTRS)

Thronesbery, Carroll; Malin, Jane T.; Holden, Kritina; Smith, Danielle Paige

2005-01-01

We describe an approach and existing software tool support for effective interactions between human factors engineers and systems engineers in early analysis activities during system acquisition. We examine the tasks performed during this stage, emphasizing those tasks where system engineers and human engineers interact. The Concept of Operations (ConOps) document is an important product during this phase, and particular attention is paid to its influences on subsequent acquisition activities. Understanding this influence helps ConOps authors describe a complete system concept that guides subsequent acquisition activities. We identify commonly used system engineering and human engineering tools and examine how they can support the specific tasks associated with system definition. We identify possible gaps in the support of these tasks, the largest of which appears to be creating the ConOps document itself. Finally, we outline the goals of our future empirical investigations of tools to support system concept definition.

Tools to Support Human Factors and Systems Engineering Interactions During Early Analysis

NASA Technical Reports Server (NTRS)

Thronesbery, Carroll; Malin, Jane T.; Holden, Kritina; Smith, Danielle Paige

2006-01-01

We describe an approach and existing software tool support for effective interactions between human factors engineers and systems engineers in early analysis activities during system acquisition. We examine the tasks performed during this stage, emphasizing those tasks where system engineers and human engineers interact. The Concept of Operations (ConOps) document is an important product during this phase, and particular attention is paid to its influences on subsequent acquisition activities. Understanding this influence helps ConOps authors describe a complete system concept that guides subsequent acquisition activities. We identify commonly used system engineering and human engineering tools and examine how they can support the specific tasks associated with system definition. We identify possible gaps in the support of these tasks, the largest of which appears to be creating the ConOps document itself. Finally, we outline the goals of our future empirical investigations of tools to support system concept definition.

The Effect of Instruction on the Acquisition of Conservation of Volume.

ERIC Educational Resources Information Center

Butts, David P.; Howe, Ann C.

Tested was the hypothesis that science instruction based on task analysis will lead to the acquisition of the ability to perform certain Piaget volume tasks which have been characterized as requiring formal operations for their solutions. A Test on Formal Operations and a Learning Hierarchies Test were given to fourth- and sixth-grade students in…

Phonological and Cognitive Correlates of Word-Reading Acquisition under Two Different Instructional Approaches in Greek.

ERIC Educational Resources Information Center

Papadopoulos, Timothy C.

2001-01-01

Examines the relationship between phonological and cognitive tasks with beginning reading acquisition. Uses two teaching techniques for tasks given first-grade students in Cyprus (n=50) and Greece (n=50). Reports differences were revealed in word-decoding accuracy, Greek students showed a higher linguistic ability, and successive processing and…

Orofacial and thumb-index finger ramp-and-hold isometric force dynamics in young neurotypical adults.

PubMed

Barlow, Steven M; Hozan, Mohsen; Lee, Jaehoon; Greenwood, Jake; Custead, Rebecca; Wardyn, Brianna; Tippin, Kaytlin

2018-04-27

The relation among several parameters of the ramp-and-hold isometric force contraction (peak force and dF/dt max during the initial phase of force recruitment, and the proportion of hold-phase at target) was quantified for the right and left thumb-index finger pinch, and lower lip midline compression in 40 neurotypical right-handed young adults (20 female/20 males) using wireless force sensors and data acquisition technology developed in our laboratory. In this visuomotor control task, participants produced ramp-and-hold isometric forces as 'rapidly and accurately' as possible to end-point target levels at 0.25, 0.5, 1 and 2 Newtons presented to a computer monitor in a randomized block design. Significant relations were found between the parameters of the ramp-and-hold lip force task and target force level, including the peak rate of force change (dF/dt max ), peak force, and the criterion percentage of force within ±5% of target during the contraction hold phase. A significant performance advantage was found among these force variables for the thumb-index finger over the lower lip. The maximum voluntary compression force (MVCF) task revealed highly significant differences in force output between the thumb-index fingers and lower lip (∼4.47-4.70 times greater for the digits versus lower lip), a significant advantage of the right thumb-index finger over the non-dominant left thumb-index finger (12% and 25% right hand advantage for males and females, respectively), and a significant sex difference (∼1.65-1.73 times greater among males). Copyright © 2018 Elsevier Ltd. All rights reserved.

D1 Receptor Activation in the Mushroom Bodies Rescues Sleep Loss Induced Learning Impairments in Drosophila

PubMed Central

Seugnet, Laurent; Suzuki, Yasuko; Vine, Lucy; Gottschalk, Laura; Shaw, Paul J

2008-01-01

Background Extended wakefulness disrupts acquisition of short term memories in mammals. However, the underlying molecular mechanisms triggered by extended waking and restored by sleep are unknown. Moreover, the neuronal circuits that depend on sleep for optimal learning remain unidentified. Results Learning was evaluated using Aversive Phototaxic Suppression (APS). In this task, flies learn to avoid light that is paired with an aversive stimulus (quinine /humidity). We demonstrate extensive homology in sleep deprivation induced learning impairment between flies and humans. Both 6 h and 12 h of sleep deprivation are sufficient to impair learning in Canton-S (Cs) flies. Moreover, learning is impaired at the end of the normal waking-day in direct correlation with time spent awake. Mechanistic studies indicate that this task requires intact mushroom bodies (MBs) and requires the Dopamine D1-like receptor (dDA1). Importantly, sleep deprivation induced learning impairments could be rescued by targeted gene expression of the dDA1 receptor to the MBs. Conclusion These data provide direct evidence that extended wakefulness disrupts learning in Drosophila. These results demonstrate that it is possible to prevent the effects of sleep deprivation by targeting a single neuronal structure and identify cellular and molecular targets adversely affected by extended waking in a genetically tractable model organism. PMID:18674913

Neural control of finger movement via intracortical brain-machine interface

NASA Astrophysics Data System (ADS)

Irwin, Z. T.; Schroeder, K. E.; Vu, P. P.; Bullard, A. J.; Tat, D. M.; Nu, C. S.; Vaskov, A.; Nason, S. R.; Thompson, D. E.; Bentley, J. N.; Patil, P. G.; Chestek, C. A.

2017-12-01

Objective. Intracortical brain-machine interfaces (BMIs) are a promising source of prosthesis control signals for individuals with severe motor disabilities. Previous BMI studies have primarily focused on predicting and controlling whole-arm movements; precise control of hand kinematics, however, has not been fully demonstrated. Here, we investigate the continuous decoding of precise finger movements in rhesus macaques. Approach. In order to elicit precise and repeatable finger movements, we have developed a novel behavioral task paradigm which requires the subject to acquire virtual fingertip position targets. In the physical control condition, four rhesus macaques performed this task by moving all four fingers together in order to acquire a single target. This movement was equivalent to controlling the aperture of a power grasp. During this task performance, we recorded neural spikes from intracortical electrode arrays in primary motor cortex. Main results. Using a standard Kalman filter, we could reconstruct continuous finger movement offline with an average correlation of ρ  =  0.78 between actual and predicted position across four rhesus macaques. For two of the monkeys, this movement prediction was performed in real-time to enable direct brain control of the virtual hand. Compared to physical control, neural control performance was slightly degraded; however, the monkeys were still able to successfully perform the task with an average target acquisition rate of 83.1%. The monkeys’ ability to arbitrarily specify fingertip position was also quantified using an information throughput metric. During brain control task performance, the monkeys achieved an average 1.01 bits s-1 throughput, similar to that achieved in previous studies which decoded upper-arm movements to control computer cursors using a standard Kalman filter. Significance. This is, to our knowledge, the first demonstration of brain control of finger-level fine motor skills. We believe that these results represent an important step towards full and dexterous control of neural prosthetic devices.

Thrive or overload? The effect of task complexity on novices' simulation-based learning.

PubMed

Haji, Faizal A; Cheung, Jeffrey J H; Woods, Nicole; Regehr, Glenn; de Ribaupierre, Sandrine; Dubrowski, Adam

2016-09-01

Fidelity is widely viewed as an important element of simulation instructional design based on its purported relationship with transfer of learning. However, higher levels of fidelity may increase task complexity to a point at which novices' cognitive resources become overloaded. In this experiment, we investigate the effects of variations in task complexity on novices' cognitive load and learning during simulation-based procedural skills training. Thirty-eight medical students were randomly assigned to simulation training on a simple or complex lumbar puncture (LP) task. Participants completed four practice trials on this task (skill acquisition). After 10 days of rest, all participants completed one additional trial on their assigned task (retention) and one trial on a 'very complex' simulation designed to be similar to the complex task (transfer). We assessed LP performance and cognitive load on each trial using multiple measures. In both groups, LP performance improved significantly during skill acquisition (p ≤ 0.047, f = 0.29-0.96) and was maintained at retention. The simple task group demonstrated superior performance compared with the complex task group throughout these phases (p ≤ 0.002, d = 1.13-2.31). Cognitive load declined significantly in the simple task group (p < 0.009, f = 0.48-0.76), but not in the complex task group during skill acquisition, and remained lower at retention (p ≤ 0.024, d = 0.78-1.39). Between retention and transfer, LP performance declined and cognitive load increased in the simple task group, whereas both remained stable in the complex task group. At transfer, no group differences were observed in LP performance and cognitive load, except that the simple task group made significantly fewer breaches of sterility (p = 0.023, d = 0.80). Reduced task complexity was associated with superior LP performance and lower cognitive load during skill acquisition and retention, but mixed results on transfer to a more complex task. These results indicate that task complexity is an important factor that may mediate (via cognitive overload) the relationship between instructional design elements (e.g. fidelity) and simulation-based learning outcomes. © 2016 John Wiley & Sons Ltd and The Association for the Study of Medical Education.

Synthetic aperture radar operator tactical target acquisition research

NASA Technical Reports Server (NTRS)

Hershberger, M. L.; Craig, D. W.

1978-01-01

A radar target acquisition research study was conducted to access the effects of two levels of 13 radar sensor, display, and mission parameters on operator tactical target acquisition. A saturated fractional-factorial screening design was employed to examine these parameters. Data analysis computed ETA squared values for main and second-order effects for the variables tested. Ranking of the research parameters in terms of importance to system design revealed four variables (radar coverage, radar resolution/multiple looks, display resolution, and display size) accounted for 50 percent of the target acquisition probability variance.

Usage of noncontact human body measurements for development of Army Work Wear Trousers

NASA Astrophysics Data System (ADS)

Dabolina, Inga; Lapkovska, Eva; Vilumsone, Ausma

2017-10-01

The paper is based on issues related to imperfections of clothing fit, garment construction solutions and control measurement systems of finished products, which were identified in the research process analysing army soldier work wear trousers. The aim is to obtain target group body measurements using noncontact anthropometrical data acquisition method (3D scanning) for selection and analysis of scanned data suitable for trouser design. Tasks include comparison of scanned data with manually taken body measurements and different corresponding human body measurement standard data for establishing potential advantages of noncontact method usage in solving different trouser design issues.

Computational Modeling for Language Acquisition: A Tutorial With Syntactic Islands.

PubMed

Pearl, Lisa S; Sprouse, Jon

2015-06-01

Given the growing prominence of computational modeling in the acquisition research community, we present a tutorial on how to use computational modeling to investigate learning strategies that underlie the acquisition process. This is useful for understanding both typical and atypical linguistic development. We provide a general overview of why modeling can be a particularly informative tool and some general considerations when creating a computational acquisition model. We then review a concrete example of a computational acquisition model for complex structural knowledge referred to as syntactic islands. This includes an overview of syntactic islands knowledge, a precise definition of the acquisition task being modeled, the modeling results, and how to meaningfully interpret those results in a way that is relevant for questions about knowledge representation and the learning process. Computational modeling is a powerful tool that can be used to understand linguistic development. The general approach presented here can be used to investigate any acquisition task and any learning strategy, provided both are precisely defined.

MDMA modifies active avoidance learning and recall in mice.

PubMed

Trigo, José Manuel; Cabrero-Castel, Araceli; Berrendero, Fernando; Maldonado, Rafael; Robledo, Patricia

2008-04-01

Several studies have suggested the existence of cognitive deficits after repeated or high doses of 3,4-methylenedioxymethamphetamine (MDMA) in humans and experimental animals. However, the extent of the impairments observed in learning or memory tasks remains unclear. The objective of this study was to evaluate the effects of different dosing regimens of MDMA on the ability of mice to learn and recall an active avoidance task. Animals were treated with MDMA (0, 1, 3, 10 and 30 mg/kg) under four different experimental conditions, and active avoidance acquisition and recall were evaluated. In experiments 1 and 2, MDMA was administered 1 h before different active avoidance training sessions. In experiments 3 and 4, mice received a repeated treatment with MDMA before or after active avoidance training, respectively. Changes in presynaptic striatal dopamine transporter (DAT) binding sites were evaluated at two different time points in animals receiving a high dose of MDMA (30 mg/kg) or saline twice a day over 4 days. MDMA administered before the active avoidance sessions interfered with the acquisition and the execution of a previously learned task. A repeated treatment with high doses of MDMA administered before training reduced acquisition of active avoidance in mice, while pre-treatment with both high and low doses of MDMA impaired recall of this task. A reduction in DAT binding was observed 4 days but not 23 days after the last MDMA administration. Acute MDMA modifies the acquisition and execution of active avoidance in mice, while repeated pre-treatment with MDMA impairs acquisition and recall of this task.

Retention of Esperanto Is Affected by Delay-Interval Task and Item Closure: A Partial Resolution of the Delay-Retention Effect

ERIC Educational Resources Information Center

Brosvic, Gary M.; Epstein, Michael L.; Dihoff, Roberta E.; Cook, Michael L.

2006-01-01

The present studies were undertaken to examine the effects of manipulating delay-interval task (Study 1) and timing of feedback (Study 2) on acquisition and retention. Participants completed a 100-item cumulative final examination, which included 50 items from each laboratory examination, plus 50 entirely new items. Acquisition and retention were…

Whole body heat stress increases motor cortical excitability and skill acquisition in humans

PubMed Central

Littmann, Andrew E.; Shields, Richard K.

2015-01-01

Objective Vigorous systemic exercise stimulates a cascade of molecular and cellular processes that enhance central nervous system (CNS) plasticity and performance. The influence of heat stress on CNS performance and learning is novel. We designed two experiments to determine whether passive heat stress 1) facilitated motor cortex excitability and 2) improved motor task acquisition compared to no heat stress. Methods Motor evoked potentials (MEPs) from the first dorsal interosseus (FDI) were collected before and after 30 minutes of heat stress at 73° C. A second cohort of subjects performed a motor learning task using the FDI either following heat or the no heat condition. Results Heat stress increased heart rate to 65% of age-predicted maximum. After heat, mean resting MEP amplitude increased 48% (P < 0.05). MEP stimulus-response amplitudes did not differ according to stimulus intensity. In the second experiment, heat stress caused a significant decrease in absolute and variable error (p < 0.05) during a novel movement task using the FDI. Conclusions Passive environmental heat stress 1) increases motor cortical excitability, and 2) enhances performance in a motor skill acquisition task. Significance Controlled heat stress may prime the CNS to enhance motor skill acquisition during rehabilitation. PMID:26616546

26 CFR 1.338-2 - Nomenclature and definitions; mechanics of the section 338 election.

Code of Federal Regulations, 2010 CFR

2010-04-01

... purchase of stock under section 338(a)(2), a reference to new target with respect to its own deemed... target is the common parent on the acquisition date. (17) Target; old target; new target. Target is the... before the close of target's acquisition date. New target refers to target for subsequent periods. (18...

26 CFR 1.338-2 - Nomenclature and definitions; mechanics of the section 338 election.

Code of Federal Regulations, 2011 CFR

2011-04-01

... purchase of stock under section 338(a)(2), a reference to new target with respect to its own deemed... target is the common parent on the acquisition date. (17) Target; old target; new target. Target is the... before the close of target's acquisition date. New target refers to target for subsequent periods. (18...

48 CFR 6.502 - Duties and responsibilities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... competition in areas such as acquisition training and research; and (vii) Initiatives that ensure task and... ACQUISITION PLANNING COMPETITION REQUIREMENTS Competition Advocates 6.502 Duties and responsibilities. (a) Agency and procuring activity competition advocates are responsible for promoting the acquisition of...

Joint Test Project Report of Combat Air Support Target Acquisition Program. SEEKVAL. Project IA2. Direct Visual Imagery Experiments.

DTIC Science & Technology

1975-01-01

Mission Zero Briefing Information ... ....... 1-A-8 Mission Zero Preflight Taped Coiments . . . 1-A-lO Mission Zero Inflight Events and Commentary . l-A...acquisitions between MAR and the target and zero range for non-acquisitions. AA 1 ... , ; "~...,, X0 ..o", xix S w...target from 35,000 feet to zero feet at nadir. If the inter-target interval was less than 35,000 feet, the device started counting on the new target

Tasks for Easily Modifiable Virtual Environments

ERIC Educational Resources Information Center

Swier, Robert

2014-01-01

Recent studies of learner interaction in virtual worlds have tended to select basic tasks involving open-ended communication. There is evidence that such tasks are supportive of language acquisition, however it may also be beneficial to consider more complex tasks. Research in task-based learning has identified features such as non-linguistic…

48 CFR 1034.004 - Acquisition strategy.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Order, Task Order, or Interagency Agreement) to the overall investment requirements and management... investment; (3) A description of the effort, by acquisition, and the plans to include required clauses in the... requirements to manage the acquisition processes through the investment lifecycle; (7) Consideration of optimal...

Acquisition of a Complex Basketball-Dribbling Task in School Children as a Function of Bilateral Practice Order

ERIC Educational Resources Information Center

Stockel, Tino; Weigelt, Matthias; Krug, Jurgen

2011-01-01

The purpose of this study was to investigate order-of-practice effects for the acquisition of a complex basketball skill in a bilateral transfer paradigm. The task required participants to dribble as fast as possible in slalom-like movements across six javelins and return to the initial position. Fifty-two right-handed school children (M age =…

The Effect of Motor Difficulty on the Acquisition of a Computer Task: A Comparison between Young and Older Adults

ERIC Educational Resources Information Center

Fezzani, K.; Albinet, C.; Thon, B.; Marquie, J. -C.

2010-01-01

The present study investigated the extent to which the impact of motor difficulty on the acquisition of a computer task varies as a function of age. Fourteen young and 14 older participants performed 352 sequences of 10 serial pointing movements with a wireless pen on a digitiser tablet. A conditional probabilistic structure governed the…

How Chunks, Long-Term Working Memory and Templates Offer a Cognitive Explanation for Neuroimaging Data on Expertise Acquisition: A Two-Stage Framework

ERIC Educational Resources Information Center

Guida, Alessandro; Gobet, Fernand; Tardieu, Hubert; Nicolas, Serge

2012-01-01

Our review of research on PET and fMRI neuroimaging of experts and expertise acquisition reveals two apparently discordant patterns in working-memory-related tasks. When experts are involved, studies show activations in brain regions typically activated during long-term memory tasks that are not observed with novices, a result that is compatible…

Selective deficit in spatial memory strategies contrast to intact response strategies in patients with schizophrenia spectrum disorders tested in a virtual navigation task.

PubMed

Wilkins, Leanne K; Girard, Todd A; Konishi, Kyoko; King, Matthew; Herdman, Katherine A; King, Jelena; Christensen, Bruce; Bohbot, Veronique D

2013-11-01

Spatial memory is impaired among persons with schizophrenia (SCZ). However, different strategies may be used to solve most spatial memory and navigation tasks. This study investigated the hypothesis that participants with schizophrenia-spectrum disorders (SSD) would demonstrate differential impairment during acquisition and retrieval of target locations when using a hippocampal-dependent spatial strategy, but not a response strategy, which is more associated with caudate function. Healthy control (CON) and SSD participants were tested using the 4-on-8 virtual maze (4/8VM), a virtual navigation task designed to differentiate between participants' use of spatial and response strategies. Consistent with our predictions, SSD participants demonstrated a differential deficit such that those who navigated using a spatial strategy made more errors and took longer to locate targets. In contrast, SSD participants who spontaneously used a response strategy performed as well as CON participants. The differential pattern of spatial-memory impairment in SSD provides only indirect support for underlying hippocampal dysfunction. These findings emphasize the importance of considering individual strategies when investigating SSD-related memory and navigation performance. Future cognitive intervention protocols may harness SSD participants' intact ability to navigate using a response strategy and/or train the deficient ability to navigate using a spatial strategy to improve navigation and memory abilities in participants with SSD. Copyright © 2013 Wiley Periodicals, Inc.

Streamlining Defense Acquisition Laws. Report of the Acquisition Law Advisory Panel to the United States Congress. Chapters 1 through 8 and Appendices

DTIC Science & Technology

1993-01-01

Scattle, Wnshington to Diane Sidebottom, Acquisition Law Task Force, Defense Systems Management College (Apr. 10, 1992). 4 8Memorandum from Debbie van...Cong., 2d Sess,, pt, 1, at 5 (1980), reprinted In 1980 U.S,C,C.A.N. 6464. 131I.R. 2414 (S.414). S.414 was introduced by Senators Birch Bayh (D..Ind...the Flowdown and Cost and Pricing Data Task Forces from Debbie von Opstal (April 28, 1991) and letter from Major Edward E, Hunt III, Director, Ethics

DoD Acquisition Workforce Education: An SBA Education Case Study

ERIC Educational Resources Information Center

Davenport, Richard W.

2009-01-01

A Department of Defense (DoD) M&S education task force is in the process of studying the Modeling and Simulation (M&S) education of the acquisition workforce. Historically, DoD acquisition workforce education is not referred to as education, but rather what the Defense Acquisition University (DAU) refers to as "practitioner training, career…

A simulation investigation of scout/attack helicopter directional control requirements for hover and low-speed tasks

NASA Technical Reports Server (NTRS)

Bivens, Courtland C.; Guercio, Joseph G.

1987-01-01

A piloted simulator experiment was conducted to investigate directional axis handling qualities requirements for low speed and hover tasks performed by a Scout/Attack helicopter. Included were the directional characteristics of various candidate light helicopter family configurations. Also, the experiment focused on conventional single main/tail rotor configurations of the OH-58 series aircraft, where the first-order yaw-axis dynamic effects that contributed to the loss of tail rotor control were modeled. Five pilots flew 22 configurations under various wind conditions. Cooper-Harper handling quality ratings were used as the primary measure of merit of each configuration. The results of the experiment indicate that rotorcraft configurations with high directional gust sensitivity require greater minimum yaw damping to maintain satisfactory handling qualities during nap-of-the-Earth flying tasks. It was also determined that both yaw damping and control response are critical handling qualities parameters in performing the air-to-air target acquisition and tracking task. Finally, the lack of substantial yaw damping and larger values of gust sensitivity increased the possibility of loss of directional control at low airspeeds for the single main/tail rotor configurations.

The event-related brain potential as an index of attention allocation in complex displays

NASA Technical Reports Server (NTRS)

Wickens, C. D.; Heffley, E. F.; Kramer, A. F.; Donchin, E.

1980-01-01

The advantages of employing the event-related brain potential (ERP) in the assessment of allocation of attention in dynamic environments are discussed. Three experiments are presented in which the P300 component of the ERP is demonstrated to be a useful index of subjects' locus of attention. The first two experiments were concerned with the allocation of attention during discrete and continuous visual monitoring tasks. The results indicated that a P300 was elicited only by stimuli to which the subject had to attend in order to perform successfully the task. The third experiment was conducted to assess the sensitivity of P300 to the manner in which attention is allocated to different aspects of a display during the performance of a 3-dimensional target acquisition task. The amplitude of the P300 was found to reflect differences between two levels of workload, as well as the task relevance of the stimuli. The results of the experiments are discussed in terms of their utility in the evaluation of the design of man-machine systems as well as in the study of the allocation of attention in operational environments.

Individual differences in social and non-social behaviors in domestic dogs (Canis familiaris) during the acquisition, extinction and reacquisition of a problem solving task.

PubMed

Shimabukuro, Carolina; Putrino, Natalia; Helbling, Julia; Tognetti, Sandra; Bentosela, Mariana

2015-04-01

Dogs are able to solve different problems by trial and error learning, but it seems that they cannot understand the means-end connection. Some studies suggest that dogs' performance is influenced by their breed and by the level of familiarity with the person they interact with. In our study, we assess individual differences in both social and non-social responses in a problem-solving task during the acquisition, extinction, and reacquisition phases. In order to investigate the effect of familiarity, in the first experiment, the human present during the task was either a familiar (the dog's owner) or unfamiliar person. In the second experiment, we compared breeds (Retrievers and Shepherds) that had previously shown differences in a communicative task. The results revealed that all groups learned the task and became more efficient in the acquisition trials. These non-social responses diminished during extinction, where an increase in social responses was observed. With regard to individual differences, dogs were more persistent in searching the reward during the second extinction trial when the owner was present (in contrast with a stranger), and also looked longer at the unfamiliar person at the beginning of the acquisition trial. On the other hand, Retrievers showed greater social motivation during reacquisition and Shepherds picked up more bones during the third acquisition trial, thus suggesting a more persistent search of the reward. These findings highlight the relevance of studying different learning schedules as well as individual differences in problem-solving ability so as to improve selection and training techniques. Copyright © 2015 Elsevier B.V. All rights reserved.

The Effects of Incentives in Acquisition Competition on Program Outcomes

DTIC Science & Technology

2012-06-01

organizational, management, and cultural issues (Madachy, EFFECTS OF INCENTIVES IN ACQUISITION COMPETITION 5 2008, Frangos , 1998). In the SEI’s direct...change from the task force on defense acquisition law and oversight Forrester, J. W. (1971). Principles of systems. Pegasus Communications. Frangos , S

Simulation/Gaming and the Acquisition of Communicative Competence in Another Language.

ERIC Educational Resources Information Center

Garcia-Carbonell, Amparo; Rising, Beverly; Montero, Begona; Watts, Frances

2001-01-01

Discussion of communicative competence in second language acquisition focuses on a theoretical and practical meshing of simulation and gaming methodology with theories of foreign language acquisition, including task-based learning, interaction, and comprehensible input. Describes experiments conducted with computer-assisted simulations in…

Characterizing the effects of droplines on target acquisition performance on a 3-D perspective display

NASA Technical Reports Server (NTRS)

Liao, Min-Ju; Johnson, Walter W.

2004-01-01

The present study investigated the effects of droplines on target acquisition performance on a 3-D perspective display in which participants were required to move a cursor into a target cube as quickly as possible. Participants' performance and coordination strategies were characterized using both Fitts' law and acquisition patterns of the 3 viewer-centered target display dimensions (azimuth, elevation, and range). Participants' movement trajectories were recorded and used to determine movement times for acquisitions of the entire target and of each of its display dimensions. The goodness of fit of the data to a modified Fitts function varied widely among participants, and the presence of droplines did not have observable impacts on the goodness of fit. However, droplines helped participants navigate via straighter paths and particularly benefited range dimension acquisition. A general preference for visually overlapping the target with the cursor prior to capturing the target was found. Potential applications of this research include the design of interactive 3-D perspective displays in which fast and accurate selection and manipulation of content residing at multiple ranges may be a challenge.

Polarimetric phenomenology in the reflective regime: a case study using polarized hyperspectral data

NASA Astrophysics Data System (ADS)

Gibney, Mark

2016-05-01

Understanding the phenomenology of polarimetric data is necessary if we want to obtain the maximum benefit when we exploit that data. To first order, polarimetric phenomenology is driven by two things; the target material type (specular or diffuse) and the illuminating source (point (sun) or extended (body emission)). Polarimetric phenomenology can then be broken into three basic categories; ([specular material/sun source], [diffuse/sun], [specular/body]) where we have assigned body emission to the IR passband where materials are generally specular. The task of interest determines the category of interest since the task determines the dominant target material and the illuminating source (eg detecting diffuse targets under trees in VNIR = [diffuse/sun] category). In this paper, a specific case study for the important [diffuse/sun] category will be presented. For the reflective regime (0.3 - 3.0um), the largest polarimetric signal is obtained when the sun illuminates a significant portion of the material BRDF lobe. This naturally points us to problems whose primary target materials are diffuse since the BRDF lobe for specular materials is tiny (low probability of acquiring on the BRDF lobe) and glinty (high probability of saturating the sensor when on lobe). In this case study, we investigated signatures of solar illuminated diffuse paints acquired by a polarimetric hyperspectral sensor. We will discuss the acquisition, reduction and exploitation of that data, and use it to illustrate the primary characteristics of reflective polarimetric phenomenology.

A Theory of Eye Movements during Target Acquisition

ERIC Educational Resources Information Center

Zelinsky, Gregory J.

2008-01-01

The gaze movements accompanying target localization were examined via human observers and a computational model (target acquisition model [TAM]). Search contexts ranged from fully realistic scenes to toys in a crib to Os and Qs, and manipulations included set size, target eccentricity, and target-distractor similarity. Observers and the model…

Automating a Detailed Cognitive Task Analysis for Structuring Curriculum

DTIC Science & Technology

1991-06-01

Cognitive Task Analysis For... cognitive task analysis o3 0 chniques. A rather substantial literature has been amassed relative to _ - cutonqed knowledge acquisition but only seven...references have been found in LO V*r data base seaci of literature specifically addressing cognitive task analysis . - A variety of forms of cognitive task analysis

48 CFR 2452.216-75 - Unpriced task orders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Unpriced task orders. 2452... 2452.216-75 Unpriced task orders. As prescribed in 2416.506-70(a), insert the following clause: Unpriced Task Orders (FEB 2006) (a) Prior to the issuance of a task order under this contract, it is...

Task-oriented rehabilitation robotics.

PubMed

Schweighofer, Nicolas; Choi, Younggeun; Winstein, Carolee; Gordon, James

2012-11-01

Task-oriented training is emerging as the dominant and most effective approach to motor rehabilitation of upper extremity function after stroke. Here, the authors propose that the task-oriented training framework provides an evidence-based blueprint for the design of task-oriented robots for the rehabilitation of upper extremity function in the form of three design principles: skill acquisition of functional tasks, active participation training, and individualized adaptive training. The previous robotic systems that incorporate elements of task-oriented trainings are then reviewed. Finally, the authors critically analyze their own attempt to design and test the feasibility of a TOR robot, ADAPT (Adaptive and Automatic Presentation of Tasks), which incorporates the three design principles. Because of its task-oriented training-based design, ADAPT departs from most other current rehabilitation robotic systems: it presents realistic functional tasks in which the task goal is constantly adapted, so that the individual actively performs doable but challenging tasks without physical assistance. To maximize efficacy for a large clinical population, the authors propose that future task-oriented robots need to incorporate yet-to-be developed adaptive task presentation algorithms that emphasize acquisition of fine motor coordination skills while minimizing compensatory movements.

Acquisition of Gender Agreement in Lithuanian: Exploring the Effect of Diminutive Usage in an Elicited Production Task

ERIC Educational Resources Information Center

Savickiene, Ineta; Kempe, Vera; Brooks, Patricia J.

2009-01-01

This study examines Lithuanian children's acquisition of gender agreement using an elicited production task. Lithuanian is a richly inflected Baltic language, with two genders and seven cases. Younger (N = 24, mean 3 ; 1, 2 ; 5-3 ; 8) and older (N = 24, mean 6 ; 3, 5 ; 6-6 ; 9) children were shown pictures of animals and asked to describe them…

The Effectiveness of Collaborative Tasks on the Acquisition of the Spanish Subjunctive and Development of Mood Selection Abilities: Exploring Form-Focused Instruction

ERIC Educational Resources Information Center

Gallego, Muriel

2016-01-01

The present study investigates whether the implementation of a dictogloss task within a proactive Focus on Form approach (e.g., Long 1991; Long and Robinson 1998) has significant effects on the acquisition of Spanish present subjunctive. A total of sixty-six learners in a fifth-semester Spanish course participated in the study and were assigned to…

An Investigation of Possible Hierarchical Dependency of Four Piaget-Type Tasks under Two Methods of Presentation to Third-, Fifth-, and Seventh-Grade Children.

ERIC Educational Resources Information Center

Phillips, Darrell Gordon

The purpose of this study was to investigate a proposed model for the acquisition of the concept of displacement volume and to compare two methods of conservation task presentation. A 12-stage hierarchical model for the acquisition of the concept was proposed, based on four primary assumptions: (1) concept attainment can be measured by…

Comparison of fMRI data from passive listening and active-response story processing tasks in children

PubMed Central

Vannest, Jennifer J.; Karunanayaka, Prasanna R.; Altaye, Mekibib; Schmithorst, Vincent J.; Plante, Elena M.; Eaton, Kenneth J.; Rasmussen, Jerod M.; Holland, Scott K.

2009-01-01

Purpose To use functional MRI methods to visualize a network of auditory and language-processing brain regions associated with processing an aurally-presented story. We compare a passive listening (PL) story paradigm to an active-response (AR) version including on-line performance monitoring and a sparse acquisition technique. Materials/Methods Twenty children (ages 11−13) completed PL and AR story processing tasks. The PL version presented alternating 30-second blocks of stories and tones; the AR version presented story segments, comprehension questions, and 5s tone sequences, with fMRI acquisitions between stimuli. fMRI data was analyzed using a general linear model approach and paired t-test identifying significant group activation. Results Both tasks activated in primary auditory cortex, superior temporal gyrus bilaterally, left inferior frontal gyrus. The AR task demonstrated more extensive activation, including dorsolateral prefrontal cortex and anterior/posterior cingulate cortex. Comparison of effect size in each paradigm showed a larger effect for the AR paradigm in a left inferior frontal ROI. Conclusion Activation patterns for story processing in children are similar in passive listening and active-response tasks. Increases in extent and magnitude of activation in the AR task are likely associated with memory and attention resources engaged across acquisition intervals. PMID:19306445

Comparison of fMRI data from passive listening and active-response story processing tasks in children.

PubMed

Vannest, Jennifer J; Karunanayaka, Prasanna R; Altaye, Mekibib; Schmithorst, Vincent J; Plante, Elena M; Eaton, Kenneth J; Rasmussen, Jerod M; Holland, Scott K

2009-04-01

To use functional MRI (fMRI) methods to visualize a network of auditory and language-processing brain regions associated with processing an aurally-presented story. We compare a passive listening (PL) story paradigm to an active-response (AR) version including online performance monitoring and a sparse acquisition technique. Twenty children (ages 11-13 years) completed PL and AR story processing tasks. The PL version presented alternating 30-second blocks of stories and tones; the AR version presented story segments, comprehension questions, and 5-second tone sequences, with fMRI acquisitions between stimuli. fMRI data was analyzed using a general linear model approach and paired t-test identifying significant group activation. Both tasks showed activation in the primary auditory cortex, superior temporal gyrus bilaterally, and left inferior frontal gyrus (IFG). The AR task demonstrated more extensive activation, including the dorsolateral prefrontal cortex and anterior/posterior cingulate cortex. Comparison of effect size in each paradigm showed a larger effect for the AR paradigm in a left inferior frontal region-of-interest (ROI). Activation patterns for story processing in children are similar in PL and AR tasks. Increases in extent and magnitude of activation in the AR task are likely associated with memory and attention resources engaged across acquisition intervals.

Whole body heat stress increases motor cortical excitability and skill acquisition in humans.

PubMed

Littmann, Andrew E; Shields, Richard K

2016-02-01

Vigorous systemic exercise stimulates a cascade of molecular and cellular processes that enhance central nervous system (CNS) plasticity and performance. The influence of heat stress on CNS performance and learning is novel. We designed two experiments to determine whether passive heat stress (1) facilitated motor cortex excitability and (2) improved motor task acquisition compared to no heat stress. Motor evoked potentials (MEPs) from the first dorsal interosseus (FDI) were collected before and after 30 min of heat stress at 73 °C. A second cohort of subjects performed a motor learning task using the FDI either following heat or the no heat condition. Heat stress increased heart rate to 65% of age-predicted maximum. After heat, mean resting MEP amplitude increased 48% (p<0.05). MEP stimulus-response amplitudes did not differ according to stimulus intensity. In the second experiment, heat stress caused a significant decrease in absolute and variable error (p<0.05) during a novel movement task using the FDI. Passive environmental heat stress (1) increases motor cortical excitability, and (2) enhances performance in a motor skill acquisition task. Controlled heat stress may prime the CNS to enhance motor skill acquisition during rehabilitation. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Hierarchical acquisition of visual specificity in spatial contextual cueing.

PubMed

Lie, Kin-Pou

2015-01-01

Spatial contextual cueing refers to visual search performance's being improved when invariant associations between target locations and distractor spatial configurations are learned incidentally. Using the instance theory of automatization and the reverse hierarchy theory of visual perceptual learning, this study explores the acquisition of visual specificity in spatial contextual cueing. Two experiments in which detailed visual features were irrelevant for distinguishing between spatial contexts found that spatial contextual cueing was visually generic in difficult trials when the trials were not preceded by easy trials (Experiment 1) but that spatial contextual cueing progressed to visual specificity when difficult trials were preceded by easy trials (Experiment 2). These findings support reverse hierarchy theory, which predicts that even when detailed visual features are irrelevant for distinguishing between spatial contexts, spatial contextual cueing can progress to visual specificity if the stimuli remain constant, the task is difficult, and difficult trials are preceded by easy trials. However, these findings are inconsistent with instance theory, which predicts that when detailed visual features are irrelevant for distinguishing between spatial contexts, spatial contextual cueing will not progress to visual specificity. This study concludes that the acquisition of visual specificity in spatial contextual cueing is more plausibly hierarchical, rather than instance-based.

Impressions of dominance are made relative to others in the visual environment.

PubMed

Re, Daniel E; Lefevre, Carmen E; DeBruine, Lisa M; Jones, Benedict C; Perrett, David I

2014-03-27

Face judgments of dominance play an important role in human social interaction. Perceived facial dominance is thought to indicate physical formidability, as well as resource acquisition and holding potential. Dominance cues in the face affect perceptions of attractiveness, emotional state, and physical strength. Most experimental paradigms test perceptions of facial dominance in individual faces, or they use manipulated versions of the same face in a forced-choice task but in the absence of other faces. Here, we extend this work by assessing whether dominance ratings are absolute or are judged relative to other faces. We presented participants with faces to be rated for dominance (target faces), while also presenting a second face (non-target faces) that was not to be rated. We found that both the masculinity and sex of the non-target face affected dominance ratings of the target face. Masculinized non-target faces decreased the perceived dominance of a target face relative to a feminized non-target face, and displaying a male non-target face decreased perceived dominance of a target face more so than a female non-target face. Perceived dominance of male target faces was affected more by masculinization of male non-target faces than female non-target faces. These results indicate that dominance perceptions can be altered by surrounding faces, demonstrating that facial dominance is judged at least partly relative to other faces.

Building words on actions: verb enactment and verb recognition in children with specific language impairment.

PubMed

Levi, Gabriel; Colonnello, Valentina; Giacchè, Roberta; Piredda, Maria Letizia; Sogos, Carla

2014-05-01

Recent studies have shown that language processing is grounded in actions. Multiple independent research findings indicate that children with specific language impairment (SLI) show subtle difficulties beyond the language domain. Uncertainties remain on possible association between body-mediated, non-linguistic expression of verbs and early manifestation of SLI during verb acquisition. The present study was conducted to determine whether verb production through non-linguistic modalities is impaired in children with SLI. Children with SLI (mean age 41 months) and typically developing children (mean age 40 months) were asked to recognize target verbs while viewing video clips showing the action associated with the verb (verb-recognition task) and to enact the action corresponding to the verb (verb-enacting task). Children with SLI performed more poorly than control children in both tasks. The present study demonstrates that early language impairment emerges at the bodily level. These findings are consistent with the embodied theories of cognition and underscore the role of action-based representations during language development. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multiple trial inhibitory avoidance acquisition and retrieval are resistant to chronic stress.

PubMed

Raya, J; Girardi, C E N; Esumi, L A; Ferreira, L B T; Hipólide, D C

2018-02-01

Chronic mild stress (CMS) is a widely accepted animal model relevant to depression that among other consequences, is chiefly known to induce anhedonia, often assessed as decreased preference for sucrose solution. CMS is also known to affect cognition, particularly memory tasks. In this study we have employed the multiple-trial inhibitory avoidance memory task (MTIA) to assess CMS effects on memory acquisition and retrieval. MTIA consists of repeated exposures to the unconditioned stimulus until a learning criterion is reached. Wistar rats underwent CMS for 5 weeks, and sucrose consumption was assessed once a week. At the end of CMS, animals were evaluated in the MTIA task. Overall decreased sucrose solution preference was highly variable. Further analyses showed that a subset of animals expressed resilience while another subset was sensitive to stress. CMS did not affect the number of acquisition sessions before reaching criterion or retrieval latency of MTIA task in neither sensitive nor resilient groups. Although tasks that assess learning ability in animal models relevant to depression indicate cognitive deficits, the ability to learn the association between compartment crossing and the aversive electric foot shock, which is strongly dependent on emotional aspects, was intact. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of automation of information-processing functions on teamwork.

PubMed

Wright, Melanie C; Kaber, David B

2005-01-01

We investigated the effects of automation as applied to different stages of information processing on team performance in a complex decision-making task. Forty teams of 2 individuals performed a simulated Theater Defense Task. Four automation conditions were simulated with computer assistance applied to realistic combinations of information acquisition, information analysis, and decision selection functions across two levels of task difficulty. Multiple measures of team effectiveness and team coordination were used. Results indicated different forms of automation have different effects on teamwork. Compared with a baseline condition, an increase in automation of information acquisition led to an increase in the ratio of information transferred to information requested; an increase in automation of information analysis resulted in higher team coordination ratings; and automation of decision selection led to better team effectiveness under low levels of task difficulty but at the cost of higher workload. The results support the use of early and intermediate forms of automation related to acquisition and analysis of information in the design of team tasks. Decision-making automation may provide benefits in more limited contexts. Applications of this research include the design and evaluation of automation in team environments.

The effects of acute hypoglycaemia on memory acquisition and recall and prospective memory in type 1 diabetes.

PubMed

Warren, R E; Zammitt, N N; Deary, I J; Frier, B M

2007-01-01

Global memory performance is impaired during acute hypoglycaemia. This study assessed whether moderate hypoglycaemia disrupts learning and recall in isolation, and utilised a novel test of prospective memory which may better reflect the role of memory in daily life than conventional tests. Thirty-six subjects with type 1 diabetes participated, 20 with normal hypoglycaemia awareness (NHA) and 16 with impaired hypoglycaemia awareness (IHA). Each underwent a hypoglycaemic clamp with target blood glucose 2.5 mmol/l. Prior to hypoglycaemia, subjects attempted to memorise instructions for a prospective memory task, and recall was assessed during hypoglycaemia. Subjects then completed the learning and immediate recall stages of three conventional memory tasks (word recall, story recall, visual recall) during hypoglycaemia. Euglycaemia was restored and delayed memory for the conventional tasks was tested. The same procedures were completed in euglycaemic control studies (blood glucose 4.5 mmol/l). Hypoglycaemia impaired performance significantly on the prospective memory task (p = 0.004). Hypoglycaemia also significantly impaired both immediate and delayed recall for the word and story recall tasks (p < 0.01 in each case). There was no significant deterioration of performance on the visual memory task. The effect of hypoglycaemia did not differ significantly between subjects with NHA and IHA. Impaired performance on the prospective memory task during hypoglycaemia demonstrates that recall is disrupted by hypoglycaemia. Impaired performance on the conventional memory tasks demonstrates that learning is also disrupted by hypoglycaemia. Results of the prospective memory task support the relevance of these findings to the everyday lives of people with diabetes.

Relative Ease in Creating Detailed Orthographic Representations Contrasted with Severe Difficulties to Maintain Them in Long-term Memory Among Dyslexic Children.

PubMed

Binamé, Florence; Danzio, Sophie; Poncelet, Martine

2015-11-01

Most research into orthographic learning abilities has been conducted in English with typically developing children using reading-based tasks. In the present study, we examined the abilities of French-speaking children with dyslexia to create novel orthographic representations for subsequent use in spelling and to maintain them in long-term memory. Their performance was compared with that of chronological age (CA)-matched and reading age (RA)-matched control children. We used an experimental task designed to provide optimal learning conditions (i.e. 10 spelling practice trials) ensuring the short-term acquisition of the spelling of the target orthographic word forms. After a 1-week delay, the long-term retention of the targets was assessed by a spelling post-test. Analysis of the results revealed that, in the short term, children with dyslexia learned the novel orthographic word forms well, only differing from both CA and RA controls on the initial decoding of the targets and from CA controls on the first two practice trials. In contrast, a dramatic drop was observed in their long-term retention relative to CA and RA controls. These results support the suggestion of the self-teaching hypothesis (Share, 1995) that initial errors in the decoding and spelling of unfamiliar words may hinder the establishment of fully specified novel orthographic representations. Copyright © 2015 John Wiley & Sons, Ltd.

Knowledge Acquisition Using Linguistic-Based Knowledge Analysis

Treesearch

Daniel L. Schmoldt

1998-01-01

Most knowledge-based system developmentefforts include acquiring knowledge from one or more sources. difficulties associated with this knowledge acquisition task are readily acknowledged by most researchers. While a variety of knowledge acquisition methods have been reported, little has been done to organize those different methods and to suggest how to apply them...

Reflections on How Color Term Acquisition Is Constrained

ERIC Educational Resources Information Center

Pitchford, Nicola J.

2006-01-01

Compared with object word learning, young children typically find learning color terms to be a difficult linguistic task. In this reflections article, I consider two questions that are fundamental to investigations into the developmental acquisition of color terms. First, I consider what constrains color term acquisition and how stable these…

Trial-unique, delayed nonmatching-to-location (TUNL) touchscreen testing for mice: sensitivity to dorsal hippocampal dysfunction.

PubMed

Kim, Chi Hun; Romberg, Carola; Hvoslef-Eide, Martha; Oomen, Charlotte A; Mar, Adam C; Heath, Christopher J; Berthiaume, Andrée-Anne; Bussey, Timothy J; Saksida, Lisa M

2015-11-01

The hippocampus is implicated in many of the cognitive impairments observed in conditions such as Alzheimer's disease (AD) and schizophrenia (SCZ). Often, mice are the species of choice for models of these diseases and the study of the relationship between brain and behaviour more generally. Thus, automated and efficient hippocampal-sensitive cognitive tests for the mouse are important for developing therapeutic targets for these diseases, and understanding brain-behaviour relationships. One promising option is to adapt the touchscreen-based trial-unique nonmatching-to-location (TUNL) task that has been shown to be sensitive to hippocampal dysfunction in the rat. This study aims to adapt the TUNL task for use in mice and to test for hippocampus-dependency of the task. TUNL training protocols were altered such that C57BL/6 mice were able to acquire the task. Following acquisition, dysfunction of the dorsal hippocampus (dHp) was induced using a fibre-sparing excitotoxin, and the effects of manipulation of several task parameters were examined. Mice could acquire the TUNL task using training optimised for the mouse (experiments 1). TUNL was found to be sensitive to dHp dysfunction in the mouse (experiments 2, 3 and 4). In addition, we observed that performance of dHp dysfunction group was somewhat consistently lower when sample locations were presented in the centre of the screen. This study opens up the possibility of testing both mouse and rat models on this flexible and hippocampus-sensitive touchscreen task.

STIS Target Acquisitions During SMOV

NASA Astrophysics Data System (ADS)

Katsanis, Rocio M.; Downes, Ron; Hartig, George; Kraemer, Steve

1997-07-01

We summarize the first results on the analysis of in-flight STIS target acquisition (ACQ and ACQ/PEAK). These results show that the STIS target acquisition (ACQ) is working very accurately for point sources (within 0.5 pixels = 0.025 arcseconds), about 4 times better than specified in the Instrument Handbook. As a result of the accuracy of the ACQ algorithm, we are no longer recommending to perform ACQ/PEAKs for the 0.2 arcsecond wide slits. For diffuse acquisitions the accuracy varies with target size. Although analysis of ACQ/PEAK data is hampered by a flight software problem, we anticipate that peakups will be accurate to roughly ±5% of the slit width (instead of the ±15% pr eviously advertised). We are implementing several enhancements to the flight software that will take effect by mid- August to improve the quality of the acquisitions.

48 CFR 2052.216-73 - Accelerated task order procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the work, the contractor shall proceed with performance of the task order subject to the monetary... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Accelerated task order....216-73 Accelerated task order procedures. As prescribed at 2016.506-70(b), the contracting officer may...

Word Fluency: A Task Analysis.

ERIC Educational Resources Information Center

Laine, Matti

It is suggested that models of human problem solving are useful in the analysis of word fluency (WF) test performance. In problem-solving terms, WF tasks would require the subject to define and clarify the conditions of the task (task acquisition), select and employ appropriate strategies, and monitor one's performance. In modern neuropsychology,…

Selecting Learning Tasks: Effects of Adaptation and Shared Control on Learning Efficiency and Task Involvement

ERIC Educational Resources Information Center

Corbalan, Gemma; Kester, Liesbeth; van Merrienboer, Jeroen J. G.

2008-01-01

Complex skill acquisition by performing authentic learning tasks is constrained by limited working memory capacity [Baddeley, A. D. (1992). Working memory. "Science, 255", 556-559]. To prevent cognitive overload, task difficulty and support of each newly selected learning task can be adapted to the learner's competence level and perceived task…

The Effects of Study Tasks in a Computer-Based Chemistry Learning Environment

ERIC Educational Resources Information Center

Urhahne, Detlef; Nick, Sabine; Poepping, Anna Christin; Schulz , Sarah Jayne

2013-01-01

The present study examines the effects of different study tasks on the acquisition of knowledge about acids and bases in a computer-based learning environment. Three different task formats were selected to create three treatment conditions: learning with gap-fill and matching tasks, learning with multiple-choice tasks, and learning only from text…

Vocabulary Acquisition through Written Input: Effects of Form-Focused, Message-Oriented, and Comprehension Tasks

ERIC Educational Resources Information Center

Tajeddin, Zia; Daraee, Dina

2013-01-01

The present study investigated the effect of form-focused and non-form-focused tasks on EFL learners' vocabulary learning through written input. The form-focused task aimed to draw students' attention to the word itself through word recognition activities. Non-form-focused tasks were divided into (a) the comprehension question task, which required…

Summary document of tasks performed on the Shuttle-C/NLS contract

NASA Technical Reports Server (NTRS)

1993-01-01

During FY92, USBI performed many programmatic related tasks. These programmatic tasks have been categorized as follows: (1) acquisition; (2) project engineering/program planning; and (3) cost. The reports associated with these tasks follow in paragraphs 1.1.1 through 1.3.3. Proceeding each task report is a brief description of the contents contained within.

48 CFR 216.403-1 - Fixed-price incentive (firm target) contracts.

Code of Federal Regulations, 2011 CFR

2011-10-01

... (firm target) contracts. 216.403-1 Section 216.403-1 Federal Acquisition Regulations System DEFENSE... CONTRACTS Incentive Contracts 216.403-1 Fixed-price incentive (firm target) contracts. (b) Application. (1... target) contracts, especially for acquisitions moving from development to production. (2) The contracting...

Improvements in Space Surveillance Processing for Wide Field of View Optical Sensors

NASA Astrophysics Data System (ADS)

Sydney, P.; Wetterer, C.

2014-09-01

For more than a decade, an autonomous satellite tracking system at the Air Force Maui Optical and Supercomputing (AMOS) observatory has been generating routine astrometric measurements of Earth-orbiting Resident Space Objects (RSOs) using small commercial telescopes and sensors. Recent work has focused on developing an improved processing system, enhancing measurement performance and response while supporting other sensor systems and missions. This paper will outline improved techniques in scheduling, detection, astrometric and photometric measurements, and catalog maintenance. The processing system now integrates with Special Perturbation (SP) based astrodynamics algorithms, allowing covariance-based scheduling and more precise orbital estimates and object identification. A merit-based scheduling algorithm provides a global optimization framework to support diverse collection tasks and missions. The detection algorithms support a range of target tracking and camera acquisition rates. New comprehensive star catalogs allow for more precise astrometric and photometric calibrations including differential photometry for monitoring environmental changes. This paper will also examine measurement performance with varying tracking rates and acquisition parameters.

Value of Web-based learning activities for nursing students who speak English as a second language.

PubMed

Koch, Jane; Salamonson, Yenna; Du, Hui Yun; Andrew, Sharon; Frost, Steven A; Dunncliff, Kirstin; Davidson, Patricia M

2011-07-01

There is an increasing need to address the educational needs of students with English as a second language. The authors assessed the value of a Web-based activity to meet the needs of students with English as a second language in a bioscience subject. Using telephone contact, we interviewed 21 Chinese students, 24 non-Chinese students with English as a second language, and 7 native English-speaking students to identify the perception of the value of the intervention. Four themes emerged from the qualitative data: (1) Language is a barrier to achievement and affects self-confidence; (2) Enhancement intervention promoted autonomous learning; (3) Focusing on the spoken word increases interaction capacity and self-confidence; (4) Assessment and examination drive receptivity and sense of importance. Targeted strategies to promote language acculturation and acquisition are valued by students. Linking language acquisition skills to assessment tasks is likely to leverage improvements in competence. Copyright 2011, SLACK Incorporated.

Selecting Senior Acquisition Officials: Assessing the Current Processes and Practices for Recruiting, Confirming, and Retaining Senior Officials in the Acquisition Workforce

DTIC Science & Technology

2016-04-21

Selecting Senior Acquisition Officials Assessing the Current Processes and Practices for Recruiting, Confirming, and Retaining Senior Officials...Task Group 2 Terms of Reference (TOR)  Selection of Senior Officials in the Acquisition Workforce – Consider ethics rules, congressional committee... Senior Acquisition positions – Re-validate the conflicts of interest and risk mitigation rules “[T]he committee directs the Chair of the Defense Business

Stress Modulates Instrumental Learning Performances in Horses (Equus caballus) in Interaction with Temperament

PubMed Central

Valenchon, Mathilde; Lévy, Frédéric; Prunier, Armelle; Moussu, Chantal; Calandreau, Ludovic; Lansade, Léa

2013-01-01

The present study investigates how the temperament of the animal affects the influence of acute stress on the acquisition and reacquisition processes of a learning task. After temperament was assessed, horses were subjected to a stressor before or after the acquisition session of an instrumental task. Eight days later, horses were subjected to a reacquisition session without any stressor. Stress before acquisition tended to enhance the number of successes at the beginning of the acquisition session. Eight days later, during the reacquisition session, contrary to non-stressed animals, horses stressed after acquisition, and, to a lesser extent, horses stressed before acquisition, did not improve their performance between acquisition and reacquisition sessions. Temperament influenced learning performances in stressed horses only. Particularly, locomotor activity improved performances whereas fearfulness impaired them under stressful conditions. Results suggest that direct exposure to a stressor tended to increase acquisition performances, whereas a state of stress induced by the memory of a stressor, because it has been previously associated with the learning context, impaired reacquisition performances. The negative effect of a state of stress on reacquisition performances appeared to be stronger when exposure to the stressor occurred after rather than before the acquisition session. Temperament had an impact on both acquisition and reacquisition processes, but under stressful conditions only. These results suggest that stress is necessary to reveal the influence of temperament on cognitive performances. PMID:23626801

48 CFR 52.216-16 - Incentive Price Revision-Firm Target.

Code of Federal Regulations, 2010 CFR

2010-10-01

...-Firm Target. 52.216-16 Section 52.216-16 Federal Acquisition Regulations System FEDERAL ACQUISITION... Clauses 52.216-16 Incentive Price Revision—Firm Target. As prescribed in 16.406(a), insert the following clause: Incentive Price Revision—Firm Target (OCT 1997) (a) General. The supplies or services identified...

48 CFR 52.216-17 - Incentive Price Revision-Successive Targets.

Code of Federal Regulations, 2010 CFR

2010-10-01

...-Successive Targets. 52.216-17 Section 52.216-17 Federal Acquisition Regulations System FEDERAL ACQUISITION... Clauses 52.216-17 Incentive Price Revision—Successive Targets. As prescribed in 16.406(b), insert the following clause: Incentive Price Revision—Successive Targets (OCT 1997) (a) General. The supplies or...

48 CFR 52.216-17 - Incentive Price Revision-Successive Targets.

Code of Federal Regulations, 2011 CFR

2011-10-01

...-Successive Targets. 52.216-17 Section 52.216-17 Federal Acquisition Regulations System FEDERAL ACQUISITION... Clauses 52.216-17 Incentive Price Revision—Successive Targets. As prescribed in 16.406(b), insert the following clause: Incentive Price Revision—Successive Targets (OCT 1997) (a) General. The supplies or...

48 CFR 52.216-16 - Incentive Price Revision-Firm Target.

Code of Federal Regulations, 2011 CFR

2011-10-01

...-Firm Target. 52.216-16 Section 52.216-16 Federal Acquisition Regulations System FEDERAL ACQUISITION... Clauses 52.216-16 Incentive Price Revision—Firm Target. As prescribed in 16.406(a), insert the following clause: Incentive Price Revision—Firm Target (OCT 1997) (a) General. The supplies or services identified...

Task conflict effect in task switching.

PubMed

Braverman, Ami; Meiran, Nachshon

2010-11-01

A part of action preparation is deciding what the relevant task is. This task-decision process is conceptually separate from response selection. To show this, the authors manipulated task conflict in a spatial task-switching paradigm, using conflict stimuli that appeared during trials with univalent targets (affording 1 task). The conflict stimuli afforded task identity because they were used as task cues with bivalent targets (affording 2 tasks) that were intermixed with the univalent targets. Thus, for univalent targets, irrelevant stimuli either caused low task conflict or high task conflict. In three experiments, the authors found poorer performance in high task conflict trials than in low task conflict trials. Task conflict was introduced during target appearance (Experiment 1) or task preparation (Experiments 2 and 3). In the latter case, the task conflict effect decreased with increasing task preparation time showing that task preparation involves task decision.

Conceptual Distance and Word Learning: Patterns of Acquisition in Samoan-English Bilingual Children

ERIC Educational Resources Information Center

Hemsley, Gayle; Holm, Alison; Dodd, Barbara

2013-01-01

This study investigated cross-linguistic influence in acquisition of a second lexicon, evaluating Samoan-English sequentially bilingual children (initial mean age 4 ; 9) during their first 18 months of school. Receptive and Expressive Vocabulary tasks evaluated acquisition of four word types: cognates, matched nouns, phrasal nouns and holonyms.…

48 CFR 1352.216-74 - Task orders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... changes can be made. (g) Task orders may be placed during the period of performance of the contract. Labor... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Task orders. 1352.216-74... SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text of Provisions and Clauses 1352.216-74 Task orders. As...

Interactional Features of Repair Negotiation in NS-NNS Interaction on Two Task Types: Information Gap and Personal Information Exchange

ERIC Educational Resources Information Center

Kitajima, Ryu

2013-01-01

The studies in task-based approaches in second language acquisition claim that controlled and goal convergent tasks such as information gap tasks surpass open-ended conversations such as personal information exchange tasks for the development of the learner's interlanguage, in that the formers promote more repair negotiation. And yet, few studies…

The Effect of Focus on Form and Task Complexity on L2 Learners' Oral Task Performance

ERIC Educational Resources Information Center

Salimi, Asghar

2015-01-01

Second Language learners' oral task performance has been one of interesting and research generating areas of investigations in the field of second language acquisition specially, task-based language teaching and learning. The main purpose of the present study is to investigate the effect of focus on form and task complexity on L2 learners' oral…

Structural plasticity in hippocampal cells related to the facilitative effect of intracranial self-stimulation on a spatial memory task.

PubMed

Chamorro-López, Jacobo; Miguéns, Miguel; Morgado-Bernal, Ignacio; Kastanauskaite, Asta; Selvas, Abraham; Cabané-Cucurella, Alberto; Aldavert-Vera, Laura; DeFelipe, Javier; Segura-Torres, Pilar

2015-12-01

Posttraining intracranial self-stimulation (SS) in the lateral hypothalamus facilitates the acquisition and retention of several implicit and explicit memory tasks. Here, intracellular injections of Lucifer yellow were used to assess morphological changes in hippocampal neurons that might be specifically related to the facilitative posttraining SS effect upon the acquisition and retention of a distributed spatial task in the Morris water maze. We examined the structure, size and branching complexity of cornus ammonis 1 (CA1) cells, and the spine density of CA1 pyramidal neurons and granular cells of the dentate gyrus (DG). Animals that received SS after each acquisition session performed faster and better than Sham ones--an improvement that was also evident in a probe trial 3 days after the last training session. The neuromorphological analysis revealed an increment in the size and branching complexity in apical CA1 dendritic arborization in SS-treated subjects as compared with Sham animals. Furthermore, increased spine density was observed in the CA1 field in SS animals, whereas no effects were observed in DG cells. Our results support the hypothesis that the facilitating effect of SS on the acquisition and retention of a spatial memory task could be related to structural plasticity in CA1 hippocampal cells. (c) 2015 APA, all rights reserved).

Selective lesion of septal cholinergic neurons in rats impairs acquisition of a delayed matching to position T-maze task by delaying the shift from a response to a place strategy.

PubMed

Fitz, Nicholas F; Gibbs, Robert B; Johnson, David A

2008-12-16

This study tested the hypothesis that septal cholinergic lesions impair acquisition of a delayed matching to position (DMP) T-maze task in male rats by affecting learning strategy. Rats received either the selective cholinergic immunotoxin, 192 IgG-saporin (SAP) or artificial cerebrospinal fluid directly into the medial septum. Two weeks later, animals were trained to acquire the DMP task. SAP-treated rats took significantly longer to acquire the task than corresponding controls. Both SAP-treated and control rats adopted a persistent turn and utilized a response strategy during early periods of training. By the time rats reached criterion the persistent turn was no longer evident, and all rats had shifted to an allocentric strategy, i.e., were relying on extramaze cues to a significant degree. During the acquisition period, SAP-treated rats spent significantly more days showing a persistent turn and using a response strategy than corresponding controls. The added time spent using a response strategy accounted entirely for the added days required to reach criterion among the SAP-treated rats. This suggests that the principal mechanism by which septal cholinergic lesions impair DMP acquisition in male rats is by increasing the predisposition to use a response vs. a place strategy, thereby affecting the ability to switch from one strategy to another.

A context-specific latent inhibition effect in a human conditioned suppression task.

PubMed

Byron Nelson, James; del Carmen Sanjuan, Maria

2006-06-01

Three studies used a computer video game preparation to demonstrate latent inhibition in adult humans. In all studies participants fired torpedoes at a target spaceship by clicking the mouse. Conditioned stimuli (CSs) were presented in the form of coloured "sensors" at the bottom of the screen. Conditioning was conducted by pairing a sensor with an attack from the target spaceship. Participants learned to suppress their rate of mouse clicking in preparation for an attack. In Experiment 1 a total of 10 preexposures to the sensor CS, prior to conditioning, retarded acquisition of suppression. In Experiment 2 the effect of preexposure was shown to be context specific. Experiment 3 showed little generalization of the preexposure effect from one sensor CS to another. Experiment 3 also showed that preexposure did not make the sensor CS inhibitory. Comparisons with conditioned suppression procedures with animals and negative-priming procedures are briefly discussed.

Sleep-Based Memory Processing Facilitates Grammatical Generalization: Evidence from Targeted Memory Reactivation

PubMed Central

Batterink, Laura J.; Paller, Ken A.

2015-01-01

Generalization — the ability to abstract regularities from specific examples and apply them to novel instances — is an essential component of language acquisition. Generalization not only depends on exposure to input during wake, but may also improve offline during sleep. Here we examined whether targeted memory reactivation during sleep can influence grammatical generalization. Participants gradually acquired the grammatical rules of an artificial language through an interactive learning procedure. Then, phrases from the language (experimental group) or stimuli from an unrelated task (control group) were covertly presented during an afternoon nap. Compared to control participants, participants re-exposed to the language during sleep showed larger gains in grammatical generalization. Sleep cues produced a bias, not necessarily a pure gain, suggesting that the capacity for memory replay during sleep is limited. We conclude that grammatical generalization was biased by auditory cueing during sleep, and by extension, that sleep likely influences grammatical generalization in general. PMID:26443322

Rapid acquisition but slow extinction of an attentional bias in space.

PubMed

Jiang, Yuhong V; Swallow, Khena M; Rosenbaum, Gail M; Herzig, Chelsey

2013-02-01

Substantial research has focused on the allocation of spatial attention based on goals or perceptual salience. In everyday life, however, people also direct attention using their previous experience. Here we investigate the pace at which people incidentally learn to prioritize specific locations. Participants searched for a T among Ls in a visual search task. Unbeknownst to them, the target was more often located in one region of the screen than in other regions. An attentional bias toward the rich region developed over dozens of trials. However, the bias did not rapidly readjust to new contexts. It persisted for at least a week and for hundreds of trials after the target's position became evenly distributed. The persistence of the bias did not reflect a long window over which visual statistics were calculated. Long-term persistence differentiates incidentally learned attentional biases from the more flexible goal-driven attention. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Modularity and hierarchical organization of action programs in children's acquisition of graphic skills.

PubMed

Manoel, Edison de J; Dantas, Luiz; Gimenez, Roberto; de Oliveira, Dalton Lustosa

2011-10-01

The organization of actions is based on modules in memory as a result of practice, easing the demand of performing more complex actions. If this modularization occurs, the elements of the module must remain invariant in new tasks. To test this hypothesis, 35 children, age 10 yr., practiced a graphic criterion task on a digital tablet and completed a complex graphic task enclosing the previous one. Total movement and pause times to draw the figure indicated skill acquisition. A module was identified by the variability of relative timing, pause time, and sequencing. Total movement to perform the criterion task did not increase significantly when it was embedded in the more complex task. Modularity was evidenced by the stability of relative timing and pause time and sequencing. The spatial position of new elements did not perturb the module, so the grammar of action may still have been forming.

Training apartment upkeep skills to rehabilitation clients: a comparison of task analytic strategies.

PubMed Central

Williams, G E; Cuvo, A J

1986-01-01

The research was designed to validate procedures to teach apartment upkeep skills to severely handicapped clients with various categorical disabilities. Methodological features of this research included performance comparisons between general and specific task analyses, effect of an impasse correction baseline procedure, social validation of training goals, natural environment assessments and contingencies, as well as long-term follow-up. Subjects were taught to perform upkeep responses on their air conditioner-heating unit, electric range, refrigerator, and electrical appliances within the context of a multiple-probe across subjects experimental design. The results showed acquisition, long-term maintenance, and generalization of the upkeep skills to a nontraining apartment. General task analyses were recommended for assessment and specific task analyses for training. The impasse correction procedure generally did not produce acquisition. PMID:3710947

A dissociation of dorso-lateral striatum and amygdala function on the same stimulus-response habit task.

PubMed

McDonald, R J; Hong, N S

2004-01-01

This experiment tested the idea that the amygdala-based learning and memory system covertly acquires a stimulus-reward (stimulus-outcome) association during acquisition of a stimulus-response (S-R) habit task developed for the eight-arm radial maze. Groups of rats were given dorso-lateral striatal or amygdala lesions and then trained on the S-R habit task on the eight-arm radial maze. Rats with neurotoxic damage to the dorso-lateral striatum were severely impaired on the acquisition of the S-R habit task but showed a conditioned-cue preference for the stimulus reinforced during S-R habit training. Rats with neurotoxic damage to the amygdala were able to acquire the S-R habit task but did not show a conditioned-cue preference for the stimulus reinforced during S-R habit training. This pattern of results represents a dissociation of learning and memory functions of the dorsal striatum and amygdala on the same task.

Dual learning processes in interactive skill acquisition.

PubMed

Fu, Wai-Tat; Anderson, John R

2008-06-01

Acquisition of interactive skills involves the use of internal and external cues. Experiment 1 showed that when actions were interdependent, learning was effective with and without external cues in the single-task condition but was effective only with the presence of external cues in the dual-task condition. In the dual-task condition, actions closer to the feedback were learned faster than actions farther away but this difference was reversed in the single-task condition. Experiment 2 tested how knowledge acquired in single and dual-task conditions would transfer to a new reward structure. Results confirmed the two forms of learning mediated by the secondary task: A declarative memory encoding process that simultaneously assigned credits to actions and a reinforcement-learning process that slowly propagated credits backward from the feedback. The results showed that both forms of learning were engaged during training, but only at the response selection stage, one form of knowledge may dominate over the other depending on the availability of attentional resources. (c) 2008 APA, all rights reserved

Neural Control of a Tracking Task via Attention-Gated Reinforcement Learning for Brain-Machine Interfaces.

PubMed

Wang, Yiwen; Wang, Fang; Xu, Kai; Zhang, Qiaosheng; Zhang, Shaomin; Zheng, Xiaoxiang

2015-05-01

Reinforcement learning (RL)-based brain machine interfaces (BMIs) enable the user to learn from the environment through interactions to complete the task without desired signals, which is promising for clinical applications. Previous studies exploited Q-learning techniques to discriminate neural states into simple directional actions providing the trial initial timing. However, the movements in BMI applications can be quite complicated, and the action timing explicitly shows the intention when to move. The rich actions and the corresponding neural states form a large state-action space, imposing generalization difficulty on Q-learning. In this paper, we propose to adopt attention-gated reinforcement learning (AGREL) as a new learning scheme for BMIs to adaptively decode high-dimensional neural activities into seven distinct movements (directional moves, holdings and resting) due to the efficient weight-updating. We apply AGREL on neural data recorded from M1 of a monkey to directly predict a seven-action set in a time sequence to reconstruct the trajectory of a center-out task. Compared to Q-learning techniques, AGREL could improve the target acquisition rate to 90.16% in average with faster convergence and more stability to follow neural activity over multiple days, indicating the potential to achieve better online decoding performance for more complicated BMI tasks.

Nonverbal imitation skills in children with specific language delay.

PubMed

Dohmen, Andrea; Chiat, Shula; Roy, Penny

2013-10-01

Research in children with language problems has focussed on verbal deficits, and we have less understanding of children's deficits with nonverbal sociocognitive skills which have been proposed to be important for language acquisition. This study was designed to investigate elicited nonverbal imitation in children with specific language delay (SLD). It is argued that difficulties in nonverbal imitation, which do not involve the processing of structural aspects of language, may be indicative of sociocognitive deficits. Participants were German-speaking typically developing children (n=60) and children with SLD (n=45) aged 2-3 ½ years. A novel battery of tasks measured their ability to imitate a range of nonverbal target acts that to a greater or lesser extent involve sociocognitive skills (body movements, instrumental acts on objects, pretend acts). Significant group differences were found for all body movement and pretend act tasks, but not for the instrumental act tasks. The poorer imitative performance of the SLD sample was not explained by motor or nonverbal cognitive skills. Thus, it appeared that the nature of the task affected children's imitation performance. It is argued that the ability to establish a sense of connectedness with the demonstrator was at the core of children's imitation difficulty in the SLD sample. Copyright © 2013 Elsevier Ltd. All rights reserved.

Somatosensory Contribution to the Initial Stages of Human Motor Learning

PubMed Central

Bernardi, Nicolò F.; Darainy, Mohammad

2015-01-01

The early stages of motor skill acquisition are often marked by uncertainty about the sensory and motor goals of the task, as is the case in learning to speak or learning the feel of a good tennis serve. Here we present an experimental model of this early learning process, in which targets are acquired by exploration and reinforcement rather than sensory error. We use this model to investigate the relative contribution of motor and sensory factors to human motor learning. Participants make active reaching movements or matched passive movements to an unseen target using a robot arm. We find that learning through passive movements paired with reinforcement is comparable with learning associated with active movement, both in terms of magnitude and durability, with improvements due to training still observable at a 1 week retest. Motor learning is also accompanied by changes in somatosensory perceptual acuity. No stable changes in motor performance are observed for participants that train, actively or passively, in the absence of reinforcement, or for participants who are given explicit information about target position in the absence of somatosensory experience. These findings indicate that the somatosensory system dominates learning in the early stages of motor skill acquisition. SIGNIFICANCE STATEMENT The research focuses on the initial stages of human motor learning, introducing a new experimental model that closely approximates the key features of motor learning outside of the laboratory. The finding indicates that it is the somatosensory system rather than the motor system that dominates learning in the early stages of motor skill acquisition. This is important given that most of our computational models of motor learning are based on the idea that learning is motoric in origin. This is also a valuable finding for rehabilitation of patients with limited mobility as it shows that reinforcement in conjunction with passive movement results in benefits to motor learning that are as great as those observed for active movement training. PMID:26490869

A Randomized Controlled Trial Evaluating the See, Tilt, Align, and Rotate (STAR) Maneuver on Skill Acquisition for Simulated Ultrasound-Guided Interventional Procedures.

PubMed

Lam, Nicholas C K; Fishburn, Steven J; Hammer, Angie R; Petersen, Timothy R; Gerstein, Neal S; Mariano, Edward R

2015-06-01

Achieving the best view of the needle and target anatomy when performing ultrasound-guided interventional procedures requires technical skill, which novices may find difficult to learn. We hypothesized that teaching novice performers to use 4 sequential steps (see, tilt, align, and rotate [STAR] method) to identify the needle under ultrasound guidance is more efficient than training with the commonly described probe movements of align, rotate, and tilt (ART). This study compared 2 instructional methods for transducer manipulation including alignment of a probe and needle by novices during a simulated ultrasound-guided nerve block. Right-handed volunteers between the ages of 18 and 55 years who had no previous ultrasound experience were recruited and randomized to 1 of 2 groups; one group was trained to troubleshoot misalignment with the ART method, and the other was trained with the new STAR maneuver. Participants performed the task, consisting of directing a needle in plane to 3 targets in a standardized gelatin phantom 3 times. The performance assessor and data analyst were blinded to group assignment. Thirty-five participants were recruited. The STAR group was able to complete the task more quickly (P < .001) and visualized the needle in a greater proportion of the procedure time (P = .004) compared to the ART group. All STAR participants were able to complete the task, whereas 41% of ART participants abandoned the task (P = .003). Novices are able to complete a simulated ultrasound-guided nerve block more quickly and efficiently when trained with the 4-step STAR maneuver compared to the ART method. © 2015 by the American Institute of Ultrasound in Medicine.

Gaze training enhances laparoscopic technical skill acquisition and multi-tasking performance: a randomized, controlled study.

PubMed

Wilson, Mark R; Vine, Samuel J; Bright, Elizabeth; Masters, Rich S W; Defriend, David; McGrath, John S

2011-12-01

The operating room environment is replete with stressors and distractions that increase the attention demands of what are already complex psychomotor procedures. Contemporary research in other fields (e.g., sport) has revealed that gaze training interventions may support the development of robust movement skills. This current study was designed to examine the utility of gaze training for technical laparoscopic skills and to test performance under multitasking conditions. Thirty medical trainees with no laparoscopic experience were divided randomly into one of three treatment groups: gaze trained (GAZE), movement trained (MOVE), and discovery learning/control (DISCOVERY). Participants were fitted with a Mobile Eye gaze registration system, which measures eye-line of gaze at 25 Hz. Training consisted of ten repetitions of the "eye-hand coordination" task from the LAP Mentor VR laparoscopic surgical simulator while receiving instruction and video feedback (specific to each treatment condition). After training, all participants completed a control test (designed to assess learning) and a multitasking transfer test, in which they completed the procedure while performing a concurrent tone counting task. Not only did the GAZE group learn more quickly than the MOVE and DISCOVERY groups (faster completion times in the control test), but the performance difference was even more pronounced when multitasking. Differences in gaze control (target locking fixations), rather than tool movement measures (tool path length), underpinned this performance advantage for GAZE training. These results suggest that although the GAZE intervention focused on training gaze behavior only, there were indirect benefits for movement behaviors and performance efficiency. Additionally, focusing on a single external target when learning, rather than on complex movement patterns, may have freed-up attentional resources that could be applied to concurrent cognitive tasks.

Le Carte Blanc or La Carte Blanche? Bilingual Children's Acquisition of French Adjective Agreement

ERIC Educational Resources Information Center

Nicoladis, Elena; Marchak, Kristan

2011-01-01

Because of less exposure to either language, bilingual children's language acquisition can be delayed relative to monolingual children in domains related to input frequency. This study predicted that the acquisition of gender agreement with adjectives in French would be delayed in bilingual children on a picture description task. The results…

Post-learning infusion of anisomycin into the anterior cingulate cortex impairs instrumental acquisition through an effect on reinforcer valuation

PubMed Central

Jonkman, Sietse; Everitt, Barry J.

2009-01-01

The integrity of the rodent anterior cingulate cortex (ACC) is essential for various aspects of instrumental behavior, but it is not clear if the ACC is important for the acquisition of a simple instrumental response. Here, it was demonstrated that post-session infusions of anisomycin into the rat ACC completely prevented the acquisition of instrumental responding. The experimental use of post-session intracranial infusions of plasticity inhibitors is assumed to affect local consolidation of plasticity, but not behavioral task performance. However, in associative appetitive conditioning, post-session intracranial infusion of pharmaco-active compounds could actually interfere with subsequent task performance indirectly through retrospective effects on the valuation of ingested rewards. Thus, it was subsequently demonstrated that the intracranial infusion of anisomycin into the ACC after sucrose pellet consumption significantly reduced subsequent pellet consumption, suggesting that the infusion of anisomycin into the ACC produced conditioned taste avoidance. In the third experiment, an innovative procedure was introduced that dissociated the effects of intracranial infusions after conditioning sessions on task-learning and unconditioned stimulus valuation. With this procedure, the infusion of anisomycin into the ACC after instrumental sessions did not affect instrumental reinforcer valuation or the acquisition of instrumental responding, suggesting that plasticity in the ACC is not necessary for the acquisition of instrumental behavior. PMID:19864297

Lexical orthography acquisition: Is handwriting better than spelling aloud?

PubMed Central

Bosse, Marie-Line; Chaves, Nathalie; Valdois, Sylviane

2014-01-01

Lexical orthography acquisition is currently described as the building of links between the visual forms and the auditory forms of whole words. However, a growing body of data suggests that a motor component could further be involved in orthographic acquisition. A few studies support the idea that reading plus handwriting is a better lexical orthographic learning situation than reading alone. However, these studies did not explore which of the cognitive processes involved in handwriting enhanced lexical orthographic acquisition. Some findings suggest that the specific movements memorized when learning to write may participate in the establishment of orthographic representations in memory. The aim of the present study was to assess this hypothesis using handwriting and spelling aloud as two learning conditions. In two experiments, fifth graders were asked to read complex pseudo-words embedded in short sentences. Immediately after reading, participants had to recall the pseudo-words' spellings either by spelling them aloud or by handwriting them down. One week later, orthographic acquisition was tested using two post-tests: a pseudo-word production task (spelling by hand in Experiment 1 or spelling aloud in Experiment 2) and a pseudo-word recognition task. Results showed no significant difference in pseudo-word recognition between the two learning conditions. In the pseudo-word production task, orthography learning improved when the learning and post-test conditions were similar, thus showing a massive encoding-retrieval match effect in the two experiments. However, a mixed model analysis of the pseudo-word production results revealed a significant learning condition effect which remained after control of the encoding-retrieval match effect. This later finding suggests that orthography learning is more efficient when mediated by handwriting than by spelling aloud, whatever the post-test production task. PMID:24575058

Lexical orthography acquisition: Is handwriting better than spelling aloud?

PubMed

Bosse, Marie-Line; Chaves, Nathalie; Valdois, Sylviane

2014-01-01

Lexical orthography acquisition is currently described as the building of links between the visual forms and the auditory forms of whole words. However, a growing body of data suggests that a motor component could further be involved in orthographic acquisition. A few studies support the idea that reading plus handwriting is a better lexical orthographic learning situation than reading alone. However, these studies did not explore which of the cognitive processes involved in handwriting enhanced lexical orthographic acquisition. Some findings suggest that the specific movements memorized when learning to write may participate in the establishment of orthographic representations in memory. The aim of the present study was to assess this hypothesis using handwriting and spelling aloud as two learning conditions. In two experiments, fifth graders were asked to read complex pseudo-words embedded in short sentences. Immediately after reading, participants had to recall the pseudo-words' spellings either by spelling them aloud or by handwriting them down. One week later, orthographic acquisition was tested using two post-tests: a pseudo-word production task (spelling by hand in Experiment 1 or spelling aloud in Experiment 2) and a pseudo-word recognition task. Results showed no significant difference in pseudo-word recognition between the two learning conditions. In the pseudo-word production task, orthography learning improved when the learning and post-test conditions were similar, thus showing a massive encoding-retrieval match effect in the two experiments. However, a mixed model analysis of the pseudo-word production results revealed a significant learning condition effect which remained after control of the encoding-retrieval match effect. This later finding suggests that orthography learning is more efficient when mediated by handwriting than by spelling aloud, whatever the post-test production task.

Acquisition and long-term retention of spatial learning in the human immunodeficiency virus-1 transgenic rat: Effects of repeated nicotine treatment

PubMed Central

Vigorito, Michael; Cao, Junran; Li, Ming D.; Chang, Sulie L.

2013-01-01

The HIV-1 transgenic (HIV-1Tg) rat shows a deficit in learning to locate a submerged platform in a multiple-trial water maze task compared to transgenic littermate and F344 control rats (Vigorito et al. 2008; Lashomb et al. 2009). Nicotine is known to have neuroprotective effects possibly by minimizing cytotoxic effects of glutamate or by modulating a cholinergic anti-inflammatory pathway. Nicotine also improves performance in a variety of learning tasks by enhancing attention and short-term memory (STM). The purpose of this study was to determine if the learning deficit in HIV-1Tg is ameliorated by repeated nicotine treatment independent of its effects on STM. HIV-1Tg and F344 rats were treated (subcutaneous) with nicotine (0.25mg/kg/injection) or saline twice daily and tested in a single-trial-per-day procedure which precludes the impact of STM on the acquisition of the spatial learning task. HIV-1Tg rats showed a deficit in the acquisition of the task and in the long-term retention for the platform location in a probe test. Nicotine did not ameliorate the deficit in HIV-1Tg rats and slightly worsened performance during acquisition. Analysis of individual differences in performance during the probe test suggested that nicotine improved performance in some F344 rats but not in HIV-1Tg rats. These results indicate that a deficit in the consolidation of long-term memory (LTM) contributes to the acquisition deficit of HIV1-Tg rats. The results, however, do not provide any evidence of the amelioration of the learning deficit observed in this behavioral model at least with the nicotine dose tested. PMID:23456952

Toward a Choice-Based Judgment Bias Task for Horses.

PubMed

Hintze, Sara; Roth, Emma; Bachmann, Iris; Würbel, Hanno

2017-01-01

Judgment bias tasks for nonhuman animals are promising tools to assess emotional valence as a measure of animal welfare. In view of establishing a valid judgment bias task for horses, the present study aimed to evaluate 2 versions (go/no-go and active choice) of an auditory judgment bias task for horses in terms of acquisition learning and discrimination of ambiguous cues. Five mares and 5 stallions were randomly assigned to the 2 designs and trained for 10 trials per day to acquire different operant responses to a low-frequency tone and a high-frequency tone, respectively. Following acquisition learning, horses were tested on 4 days with 3 ambiguous-tone trials interspersed between the 10 high-tone and low-tone trials. All 5 go/no-go horses but only one active-choice horse successfully learned their task, indicating that it is more difficult to train horses on an active choice task than on a go/no-go task. During testing, however, go/no-go horses did not differentiate between the 3 different ambiguous cues, thereby making the validity of the test results questionable in terms of emotional valence.

Robot Acquisition of Active Maps Through Teleoperation and Vector Space Analysis

NASA Technical Reports Server (NTRS)

Peters, Richard Alan, II

2003-01-01

The work performed under this contract was in the area of intelligent robotics. The problem being studied was the acquisition of intelligent behaviors by a robot. The method was to acquire action maps that describe tasks as sequences of reflexive behaviors. Action maps (a.k.a. topological maps) are graphs whose nodes represent sensorimotor states and whose edges represent the motor actions that cause the robot to proceed from one state to the next. The maps were acquired by the robot after being teleoperated or otherwise guided by a person through a task several times. During a guided task, the robot records all its sensorimotor signals. The signals from several task trials are partitioned into episodes of static behavior. The corresponding episodes from each trial are averaged to produce a task description as a sequence of characteristic episodes. The sensorimotor states that indicate episode boundaries become the nodes, and the static behaviors, the edges. It was demonstrated that if compound maps are constructed from a set of tasks then the robot can perform new tasks in which it was never explicitly trained.

Comparative muscle study fatigue with sEMG signals during the isotonic and isometric tasks for diagnostics purposes.

PubMed

Sarmiento, Jhon F; Benevides, Alessandro B; Moreira, Marcelo H; Elias, Arlindo; Bastos, Teodiano F; Silva, Ian V; Pelegrina, Claudinei C

2011-01-01

The study of fatigue is an important tool for diagnostics of disease, sports, ergonomics and robotics areas. This work deals with the analysis of sEMG most important fatigue muscle indicators with use of signal processing in isometric and isotonic tasks with the propose of standardizing fatigue protocol to select the data acquisition and processing with diagnostic proposes. As a result, the slope of the RMS, ARV and MNF indicators were successful to describe the fatigue behavior expected. Whereas that, MDF and AIF indicators failed in the description of fatigue. Similarly, the use of a constant load for sEMG data acquisition was the best strategy in both tasks.

Considering student choice when selecting instructional strategies: a comparison of three prompting systems.

PubMed

Taber-Doughty, Teresa

2005-01-01

Three secondary age students with moderate intellectual disabilities learned to use the system of least prompts, a self-operated picture prompting system, and a self-operated auditory prompting system to use a copy machine and a debit machine. Both the effectiveness and efficiency of these prompting systems were compared. Additionally, student preference of instructional method was examined. The results demonstrated that each prompting system was effective and efficient with varying students when skill acquisition and duration of task performance were measured. All students demonstrated increased independence in completing both tasks. This study found that the preferred prompting systems were more effective in terms of both skill acquisition and duration for completing tasks for students.

Concepts for fast acquisition in optical communications systems

NASA Astrophysics Data System (ADS)

Wilkerson, Brandon L.; Giggenbach, Dirk; Epple, Bernhard

2006-09-01

As free-space laser communications systems proliferate due to improved technology and transmission techniques, optical communication networks comprised of ground stations, aircraft, high altitude platforms, and satellites become an attainable goal. An important consideration for optical networks is the ability of optical communication terminals (OCT) to quickly locate one another and align their laser beams to initiate the acquisition sequence. This paper investigates promising low-cost technologies and novel approaches that will facilitate the targeting and acquisition tasks between counter terminals. Specifically, two critical technology areas are investigated: position determination (which includes location and attitude determination) and inter-terminal communications. A feasibility study identified multiple-antenna global navigation satellite system (GNSS) systems and GNSS-aided inertial systems as possible position determination solutions. Personal satellite communication systems (e.g. Iridium or Inmarsat), third generation cellular technology (IMT-2000/UMTS), and a relatively new air traffic surveillance technology called Autonomous Dependent Surveillance-Broadcast (ADS-B) were identified as possible inter-terminal communication solutions. A GNSS-aided inertial system and an ADS-B system were integrated into an OCT to demonstrate their utility in a typical optical communication scenario. Testing showed that these technologies have high potential in future OCTs, although improvements can be made to both to increase tracking accuracy.

SufD and SufC ATPase activity are required for iron acquisition during in vivo Fe-S cluster formation on SufB.

PubMed

Saini, Avneesh; Mapolelo, Daphne T; Chahal, Harsimranjit K; Johnson, Michael K; Outten, F Wayne

2010-11-02

In vivo biogenesis of Fe-S cluster cofactors requires complex biosynthetic machinery to limit release of iron and sulfide, to protect the Fe-S cluster from oxidation, and to target the Fe-S cluster to the correct apoenzyme. The SufABCDSE pathway for Fe-S cluster assembly in Escherichia coli accomplishes these tasks under iron starvation and oxidative stress conditions that disrupt Fe-S cluster metabolism. Although SufB, SufC, and SufD are all required for in vivo Suf function, their exact roles are unclear. Here we show that SufB, SufC, and SufD, coexpressed with the SufS-SufE sulfur transfer pair, purify as two distinct complexes (SufBC(2)D and SufB(2)C(2)) that contain Fe-S clusters and FADH(2). These studies also show that SufC and SufD are required for in vivo Fe-S cluster formation on SufB. Furthermore, while SufD is dispensable for in vivo sulfur transfer, it is absolutely required for in vivo iron acquisition. Finally, we demonstrate for the first time that the ATPase activity of SufC is necessary for in vivo iron acquisition during Fe-S cluster assembly.

CDP - Adaptive Supervisory Control and Data Acquisition (SCADA) Technology for Infrastructure Protection

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

Marco Carvalho; Richard Ford

2012-05-14

Supervisory Control and Data Acquisition (SCADA) Systems are a type of Industrial Control System characterized by the centralized (or hierarchical) monitoring and control of geographically dispersed assets. SCADA systems combine acquisition and network components to provide data gathering, transmission, and visualization for centralized monitoring and control. However these integrated capabilities, especially when built over legacy systems and protocols, generally result in vulnerabilities that can be exploited by attackers, with potentially disastrous consequences. Our research project proposal was to investigate new approaches for secure and survivable SCADA systems. In particular, we were interested in the resilience and adaptability of large-scale mission-criticalmore » monitoring and control infrastructures. Our research proposal was divided in two main tasks. The first task was centered on the design and investigation of algorithms for survivable SCADA systems and a prototype framework demonstration. The second task was centered on the characterization and demonstration of the proposed approach in illustrative scenarios (simulated or emulated).« less

Mathematics anxiety in children with developmental dyscalculia.

PubMed

Rubinsten, Orly; Tannock, Rosemary

2010-07-15

Math anxiety, defined as a negative affective response to mathematics, is known to have deleterious effects on math performance in the general population. However, the assumption that math anxiety is directly related to math performance, has not yet been validated. Thus, our primary objective was to investigate the effects of math anxiety on numerical processing in children with specific deficits in the acquisition of math skills (Developmental Dyscalculia; DD) by using a novel affective priming task as an indirect measure. Participants (12 children with DD and 11 typically-developing peers) completed a novel priming task in which an arithmetic equation was preceded by one of four types of priming words (positive, neutral, negative or related to mathematics). Children were required to indicate whether the equation (simple math facts based on addition, subtraction, multiplication or division) was true or false. Typically, people respond to target stimuli more quickly after presentation of an affectively-related prime than after one that is unrelated affectively. Participants with DD responded faster to targets that were preceded by both negative primes and math-related primes. A reversed pattern was present in the control group. These results reveal a direct link between emotions, arithmetic and low achievement in math. It is also suggested that arithmetic-affective priming might be used as an indirect measure of math anxiety.

Somatic Arc protein expression in hippocampal granule cells is increased in response to environmental change but independent of task-specific learning.

PubMed

Cleland, J P; Willis, E F; Bartlett, P F; Vukovic, J

2017-09-29

Activated neurons express immediate-early genes, such as Arc. Expression of Arc in the hippocampal granule cell layer, an area crucial for spatial learning and memory, is increased during acquisition of spatial learning; however, it is unclear whether this effect is related to the task-specific learning process or to nonspecific aspects of the testing procedure (e.g. exposure to the testing apparatus and exploration of the environment). Herein, we show that Arc-positive cells numbers are increased to the same extent in the granule cell layer after both acquisition of a single spatial learning event in the active place avoidance task and exploration of the testing environment, as compared to naïve (i.e. caged) mice. Repeated exposure the testing apparatus and environment did not reduce Arc expression. Furthermore, Arc expression did not correlate with performance in both adult and aged animals, suggesting that exploration of the testing environment, rather than the specific acquisition of the active place avoidance task, induces Arc expression in the dentate granule cell layer. These findings thus suggest that Arc is an experience-induced immediate-early gene.

Pilocarpine and physostigmine attenuate spatial memory impairments produced by lesions of the nucleus basalis magnocellularis.

PubMed

Murray, C L; Fibiger, H C

1986-02-01

The effects of bilateral ibotenic acid-induced lesions of the nucleus basalis magnocellularis (nBM) on the acquisition and retention of several spatial memory tasks were studied in the rat. Maintenance of spatial memory in a food search task was impaired following nBM lesions. Acquisition of spontaneous alternation and reinforced alternation in a T-maze was also significantly impaired in animals with these lesions. In contrast, the animals with nBM lesions were not impaired in the acquisition of a position habit in a T-maze. In several of the tasks there was evidence of some learning in the lesion animals after substantial training, although they were significantly deficient when compared with the controls. Administration of the cholinergic agonists physostigmine sulfate or pilocarpine nitrate prior to behavioral testing resulted in a rapid and significant improvement in the performance of the lesion animals. The ibotenate-induced lesions significantly reduced the activity of choline acetyltransferase (CAT) in the anterior and the posterior neocortex. Hippocampal CAT activity was not changed. The results indicate that the cholinergic projections originating in the nBM are involved in the learning and memory of spatial tasks.

I can, I do, and so I like: From power to action and aesthetic preferences.

PubMed

Woltin, Karl-Andrew; Guinote, Ana

2015-12-01

The current work tested the hypothesis that power increases reliance on experiences of motor fluency in forming aesthetic preferences. In 4 experiments, participants reported their aesthetic preferences regarding a variety of targets (pictures, movements, objects, and letters). Experiments 1, 2, and 3 manipulated power and motor fluency (via motoric resonance, extraocular muscle training, and dominant hand restriction). Experiment 4 manipulated power and assessed chronic interindividual differences in motor fluency. Across these experiments, power consistently increased reliance on motor fluency in aesthetic preference judgments. This finding was not mediated by differences in mood, judgment certainty, perceived task-demands or task-enjoyment, and derived from the use of motor simulations rather than from power differences in the acquisition of motor experiences. This is the first demonstration suggesting that power changes the formation of preference judgments as a function of motor fluency experiences. The implications of this research for the links between power and action, as well as the understanding of fluency processes are discussed. (c) 2015 APA, all rights reserved).

A corticostriatal deficit promotes temporal distortion of automatic action in ageing

PubMed Central

Matamales, Miriam; Skrbis, Zala; Bailey, Matthew R; Balsam, Peter D; Balleine, Bernard W; Götz, Jürgen

2017-01-01

The acquisition of motor skills involves implementing action sequences that increase task efficiency while reducing cognitive loads. This learning capacity depends on specific cortico-basal ganglia circuits that are affected by normal ageing. Here, combining a series of novel behavioural tasks with extensive neuronal mapping and targeted cell manipulations in mice, we explored how ageing of cortico-basal ganglia networks alters the microstructure of action throughout sequence learning. We found that, after extended training, aged mice produced shorter actions and displayed squeezed automatic behaviours characterised by ultrafast oligomeric action chunks that correlated with deficient reorganisation of corticostriatal activity. Chemogenetic disruption of a striatal subcircuit in young mice reproduced age-related within-sequence features, and the introduction of an action-related feedback cue temporarily restored normal sequence structure in aged mice. Our results reveal static properties of aged cortico-basal ganglia networks that introduce temporal limits to action automaticity, something that can compromise procedural learning in ageing. PMID:29058672

Predicting successful tactile mapping of virtual objects.

PubMed

Brayda, Luca; Campus, Claudio; Gori, Monica

2013-01-01

Improving spatial ability of blind and visually impaired people is the main target of orientation and mobility (O&M) programs. In this study, we use a minimalistic mouse-shaped haptic device to show a new approach aimed at evaluating devices providing tactile representations of virtual objects. We consider psychophysical, behavioral, and subjective parameters to clarify under which circumstances mental representations of spaces (cognitive maps) can be efficiently constructed with touch by blindfolded sighted subjects. We study two complementary processes that determine map construction: low-level perception (in a passive stimulation task) and high-level information integration (in an active exploration task). We show that jointly considering a behavioral measure of information acquisition and a subjective measure of cognitive load can give an accurate prediction and a practical interpretation of mapping performance. Our simple TActile MOuse (TAMO) uses haptics to assess spatial ability: this may help individuals who are blind or visually impaired to be better evaluated by O&M practitioners or to evaluate their own performance.

Automating Acquisitions: The Planning Process.

ERIC Educational Resources Information Center

Bryant, Bonita

1984-01-01

Account of process followed at large academic library in preparing for automation of acquisition and fund accounting functions highlights planning criteria, local goals, planning process elements (selecting participants, assigning tasks, devising timetable, providing foundations, evaluating systems, determining costs, formulating recommendations).…

Autonomous Closed-Loop Tasking, Acquisition, Processing, and Evaluation for Situational Awareness Feedback

NASA Technical Reports Server (NTRS)

Frye, Stuart; Mandl, Dan; Cappelaere, Pat

2016-01-01

This presentation describes the closed loop satellite autonomy methods used to connect users and the assets on Earth Orbiter- 1 (EO-1) and similar satellites. The base layer is a distributed architecture based on Goddard Mission Services Evolution Concept (GMSEC) thus each asset still under independent control. Situational awareness is provided by a middleware layer through common Application Programmer Interface (API) to GMSEC components developed at GSFC. Users setup their own tasking requests, receive views into immediate past acquisitions in their area of interest, and into future feasibilities for acquisition across all assets. Automated notifications via pubsub feeds are returned to users containing published links to image footprints, algorithm results, and full data sets. Theme-based algorithms are available on-demand for processing.

Semantic acquisition without memories: evidence from transient global amnesia.

PubMed

Guillery, B; Desgranges, B; Katis, S; de la Sayette, V; Viader, F; Eustache, F

2001-12-04

Transient global amnesia (TGA), characterised by a profound anterograde amnesia, is a model of interest to study the acquisition of novel meanings independent of episodic functioning. Three patients were tested during a TGA attack, two in the early recovery phase and the third during the acute phase of TGA, with a semantic priming task involving a restructuring process of conceptual knowledge. During TGA, all patients demonstrated priming effects. Results obtained the day after the episode with the same task showed that these effects persisted at least one day. Episodic memory seems not to be critical for the formation of novel connections among unrelated semantic representations, in accordance with Tulving's model of memory, i.e. episodic memory is not necessary for the acquisition of semantic information.

Effects of the novel compound aniracetam (Ro 13-5057) upon impaired learning and memory in rodents.

PubMed

Cumin, R; Bandle, E F; Gamzu, E; Haefely, W E

1982-01-01

The effect of aniracetam (Ro 13-5057, 1-anisoyl-2-pyrrolidinone) was studied on various forms of experimentally impaired cognitive functions (learning and memory) in rodents and produced the following effects: (1) almost complete prevention of the incapacity to learn a discrete escape response in rats exposed to sublethal hypercapnia immediately before the acquisition session; (2) partial (rats) or complete (mice) prevention of the scopolamine-induced short-term amnesia for a passive avoidance task; (3) complete protection against amnesia for a passive avoidance task in rats submitted to electroconvulsive shock immediately after avoidance acquisition; (4) prevention of the long-term retention- or retrieval-deficit for a passive avoidance task induced in rats and mice by chloramphenicol or cycloheximide administered immediately after acquisition; (5) reversal, when administered as late as 1 h before the retention test, of the deficit in retention or retrieval of a passive avoidance task induced by cycloheximide injected 2 days previously; (6) prevention of the deficit in the retrieval of an active avoidance task induced in mice by subconvulsant electroshock or hypercapnia applied immediately before retrieval testing (24 h after acquisition). These improvements or normalizations of impaired cognitive functions were seen at oral aniracetam doses of 10-100 mg/kg. Generally, the dose-response curves were bell-shaped. The mechanisms underlying the activity of aniracetam and its 'therapeutic window' are unknown. Piracetam, another pyrrolidinone derivative was used for comparison. It was active only in six of nine tests and had about one-tenth the potency of aniracetam. The results indicate that aniracetam improves cognitive functions which are impaired by different procedure and in different phases of the learning and memory process.

MK-801 increases the baseline level of anxiety in mice introduced to a spatial memory task without prior habituation.

PubMed

Ennaceur, A; Michalikova, S; van Rensburg, R; Chazot, P L

2011-01-01

C57BL/6J mice were introduced to a nine arm radial maze without prior habituation and trained in the acquisition of a working memory task in 16 sessions, one session per day. In this maze mice need to climb onto an upward inclined bridge in order to reach and cross onto an arm. They received in each session an i.p. injection of MK-801 (0.1 mg/kg) 30 min before training or immediately after training. MK-801 pre-treated mice made significantly more entries onto the bridges, fewer entries onto the arms and took significantly longer time to make a first arm visit compared to saline and MK-801 post-treated mice during the first 3 session blocks (4 sessions per block). These results indicate that MK-801 induced anxiety which was extended throughout the first 3 session blocks. MK-801 pre-treated mice made also significantly more errors and required more sessions to reach the criterion compared to saline and MK-801 post-treated mice. Administration of MK-801 after training did not affect the acquisition of the task. The present results indicate that MK-801 pre-treatment impaired the acquisition of a spatial task and this can be accounted for by its effect on the baseline level of anxiety which was elevated. The introduction of mice to the acquisition of the task without prior habituation demonstrates that a drug treatment can affect learning and memory by increasing and/or prolonging anxiety. Such effect may be confounded with learning and memory performance and not detected with pre-habituation training procedures, particularly when the number of sessions is determined a-priori. Copyright © 2011 Elsevier Ltd. All rights reserved.

Place and direction learning in a spatial T-maze task by neonatal piglets

PubMed Central

Elmore, Monica R. P.; Dilger, Ryan N.; Johnson, Rodney W.

2013-01-01

Pigs are a valuable animal model for studying neurodevelopment in humans due to similarities in brain structure and growth. The development and validation of behavioral tests to assess learning and memory in neonatal piglets are needed. The present study evaluated the capability of 2-wk old piglets to acquire a novel place and direction learning spatial T-maze task. Validity of the task was assessed by the administration of scopolamine, an anti-cholinergic drug that acts on the hippocampus and other related structures, to impair spatial memory. During acquisition, piglets were trained to locate a milk reward in a constant place in space, as well as direction (east or west), in a plus-shaped maze using extra-maze visual cues. Following acquisition, reward location was reversed and piglets were re-tested to assess learning and working memory. The performance of control piglets in the maze improved over time (P < 0.0001), reaching performance criterion (80% correct) on day 5 of acquisition. Correct choices decreased in the reversal phase (P < 0.0001), but improved over time. In a separate study, piglets were injected daily with either phosphate buffered saline (PBS; control) or scopolamine prior to testing. Piglets administered scopolamine showed impaired performance in the maze compared to controls (P = 0.03), failing to reach performance criterion after 6 days of acquisition testing. Collectively, these data demonstrate that neonatal piglets can be tested in a spatial T-maze task to assess hippocampal-dependent learning and memory. PMID:22526690

Atypical Acquisition and Atypical Expression of Memory Consolidation Gains in a Motor Skill in Young Female Adults with ADHD

ERIC Educational Resources Information Center

Adi-Japha, Esther; Fox, Orly; Karni, Avi

2011-01-01

Individuals with ADHD often show performance deficits in motor tasks. It is not clear, however, whether this reflects less effective acquisition of skill (procedural knowledge), or deficient consolidation into long-term memory, in ADHD. The aim of the study was to compare the acquisition of skilled motor performance, the expression of…

Acquisition of Dental Skills in Preclinical Technique Courses: Influence of Spatial and Manual Abilities

ERIC Educational Resources Information Center

Schwibbe, Anja; Kothe, Christian; Hampe, Wolfgang; Konradt, Udo

2016-01-01

Sixty years of research have not added up to a concordant evaluation of the influence of spatial and manual abilities on dental skill acquisition. We used Ackerman's theory of ability determinants of skill acquisition to explain the influence of spatial visualization and manual dexterity on the task performance of dental students in two…

Spatial learning in rats: correlation with cortical choline acetyltransferase and improvement with NGF following NBM damage.

PubMed

Mandel, R J; Gage, F H; Thal, L J

1989-06-01

Rats display an acquisition deficit in a circular water maze following excitotoxic lesions of the nucleus basalis magnocellularis (NBM). Experiments were therefore performed to determine if acquisition behavior on this task could predict the degree of cortical cholinergic deafferentation and if the acquisition deficit could be pharmacologically reversed. Performance on acquisition was highly correlated with the lesion-induced reduction in cortical choline acetyltransferase (ChAT) activity. Accuracy of spatial behavior was highly correlated to percentage ChAT depletion (r = 0.75). Neither lesioned rats nor controls displayed a retention deficit after a 9-day interval, nor did either group display a passive-avoidance retention deficit. To test the causal relationship between cholinergic dysfunction and spatial behavior, the central nervous system cholinergic enhancer nerve growth factor (NGF) was intraventricularly infused for 4 weeks. NGF infusion resulted in improved acquisition of the water maze task compared to NBM-lesioned rats receiving vehicle infusion and untreated rats with NBM lesions. These studies indicate that the decrease in cortical ChAT activity is likely to be responsible for the observed acquisition deficit and that pharmacological manipulations can be successfully used to improve behavior following NBM lesions.

Practice schedules for surgical skills: the role of task characteristics and proactive interference on psychomotor skills acquisition.

PubMed

Willis, Ross E; Curry, Eileen; Gomez, Pedro Pablo

2013-01-01

Although break periods during training sessions are desirable, it is unclear what learners should do during these breaks. Some educators recommend that learners abstain from all task-related practice; however, it is possible that switching to an alternate exercise during break periods can also be effective. The construct of proactive interference (PI) posits that new learning is disrupted by prior learning. PI can be "released" when the nature of the task is changed after several practice trials. In this study, we examined the existence of PI in motor learning under 5 training conditions that differed in contrast to a target exercise. Preclinical medical students (n = 75) performed 1 trial of peg transfer as a pretest. Participants were then randomly assigned to 1 of 5 training conditions: mass practice, similar exercise (laparoscopic bean transfer), dissimilar exercise (open suturing), observation, or rest. Participants in the mass practice condition practiced peg transfer in 3 training blocks of 15 minutes, each separated by a 5-minute break. Participants in the other conditions performed 3 training blocks consisting of 15 minutes of peg transfer followed by an interspersed alternate exercise. On completion of 3 training blocks, participants performed 1 additional peg transfer trial as a posttest. Despite having trained for the same amount of time on the target task, Analysis of Covariance on posttest scores using pretest scores as the covariate indicated a significant main effect for training condition (p = 0.009). Participants engaging in mass practice performed significantly worse than participants in the dissimilar (p = 0.012), observation (p = 0.022), and rest (p < 0.001) conditions. Additionally, participants in the similar exercise condition performed worse than participants in the rest condition (p = 0.03). When learning a laparoscopic task, a break comprised of dissimilar practice or unrelated activities is effective in releasing PI and improving performance. © 2013 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Acquisition, Conservation, and Loss of Dual-Targeted Proteins in Land Plants1[W][OA

PubMed Central

Xu, Lin; Carrie, Chris; Law, Simon R.; Murcha, Monika W.; Whelan, James

2013-01-01

The dual-targeting ability of a variety of proteins from Physcomitrella patens, rice (Oryza sativa), and Arabidopsis (Arabidopsis thaliana) was tested to determine when dual targeting arose and to what extent it was conserved in land plants. Overall, the targeting ability of over 80 different proteins from rice and P. patens, representing 42 dual-targeted proteins in Arabidopsis, was tested. We found that dual targeting arose early in land plant evolution, as it was evident in many cases with P. patens proteins that were conserved in rice and Arabidopsis. Furthermore, we found that the acquisition of dual-targeting ability is still occurring, evident in P. patens as well as rice and Arabidopsis. The loss of dual-targeting ability appears to be rare, but does occur. Ascorbate peroxidase represents such an example. After gene duplication in rice, individual genes encode proteins that are targeted to a single organelle. Although we found that dual targeting was generally conserved, the ability to detect dual-targeted proteins differed depending on the cell types used. Furthermore, it appears that small changes in the targeting signal can result in a loss (or gain) of dual-targeting ability. Overall, examination of the targeting signals within this study did not reveal any clear patterns that would predict dual-targeting ability. The acquisition of dual-targeting ability also appears to be coordinated between proteins. Mitochondrial intermembrane space import and assembly protein40, a protein involved in oxidative folding in mitochondria and peroxisomes, provides an example where acquisition of dual targeting is accompanied by the dual targeting of substrate proteins. PMID:23257241

48 CFR 316.505 - Ordering.

Code of Federal Regulations, 2011 CFR

2011-10-01

... and delivery-order ombudsman is the Director, Strategic Acquisition Service, PSC. The task-order and... Services HRSA: Associate Administrator, Office of Operations IHS: Director, Office of Management Services... Senior Advisor to the Director (Other than R & D) PSC: Director, Strategic Acquisition Service SAMHSA...

31 CFR 30.14 - Q-14: How does section 111 of EESA operate in connection with an acquisition, merger, or...

Code of Federal Regulations, 2011 CFR

2011-07-01

... recipient (target) is acquired by an entity that is not an affiliate of the target (acquirer) in an acquisition of any form, including a purchase of substantially all of the assets of the target, such that the acquirer after the transaction would have been treated as a TARP recipient if the target had received the...

Real-Time Reconnaissance-A Systems Look At Advanced Technology

NASA Astrophysics Data System (ADS)

Lapp, Henry

1981-12-01

An important role for reconnaissance is the location and identification of targets in real time. Current technology has been compartmented into sensors, automatic target recognizers, data links, ground exploitation and finally dissemination. In the days of bring home film recce, this segmentation of functions was appropriate. With the current emphasis on real time decision making from outputs of high resolution sensors this thinking has to be re-analyzed. A total systems approach to data management must be employed using the constraints imposed by technology as well as the atmosphere, survivable flight profiles, and the human workload. This paper will analyze the target acquisition through exploitation tasks and discuss the current advanced development technology that are applicable. A philosophy of processing data to get information as early as possible in the data handling chain is examined in the context of ground exploitation and dissemination needs. Examples of how the various real time sensors (screeners and processors), jam resistant data links and near real time ground data handling systems fit into this scenario are discussed. Specific DoD programs will be used to illustrate the credibility of this integrated approach.

Air-To-Air Visual Target Acquisition Pilot Interview Survey.

DTIC Science & Technology

1979-01-01

8217top’ 5 p~lots in air-tu-air visual target acqui- sition in your squadron," would/could you do it? yes no Comment : 2. Is the term "acquisition" as...meaningful as "spotting" and "seeing" in 1he con- text of visually detecting a "bogey" or another aircraft? yes no Comment : 3. Would/could you rank all...squadron pilots on the basis of their visual target acquisition capability? yes no Comment : 4. Is there a minimum number of observations requi.red for

A Modification to the Computer Generated Acquisition Documents System (CGADS) for Microcomputer Use in a Program Office Environment.

DTIC Science & Technology

1985-09-01

FILL. MOVE ALPHA-RESPONSE TO RESPONSE. 221C-RUN-TASKS-EXIT. EXIT. 2220-DISPLAY-TASK-MENU. PERFORM 5000- OETER -NISC-TASK-VALS. MOVE 1 TO ANSWER-FILE-KEY...INDEX-FIELD-2 ELSE MOVE 4 TO ANSWER-FILE-KEY SUBTRACT 200 FROM INDEX-FIELD-2. 5000- OETER -MISC-TASK-VALS. IF AREA-NUMBER a ŕ" MOVE 1 TO TASK-FILE-REC-NUM

Intact implicit learning in autism spectrum conditions.

PubMed

Brown, Jamie; Aczel, Balazs; Jiménez, Luis; Kaufman, Scott Barry; Grant, Kate Plaisted

2010-09-01

Individuals with autism spectrum condition (ASC) have diagnostic impairments in skills that are associated with an implicit acquisition; however, it is not clear whether ASC individuals show specific implicit learning deficits. We compared ASC and typically developing (TD) individuals matched for IQ on five learning tasks: four implicit learning tasks--contextual cueing, serial reaction time, artificial grammar learning, and probabilistic classification learning tasks--that used procedures expressly designed to minimize the use of explicit strategies, and one comparison explicit learning task, paired associates learning. We found implicit learning to be intact in ASC. Beyond no evidence of differences, there was evidence of statistical equivalence between the groups on all the implicit learning tasks. This was not a consequence of compensation by explicit learning ability or IQ. Furthermore, there was no evidence to relate implicit learning to ASC symptomatology. We conclude that implicit mechanisms are preserved in ASC and propose that it is disruption by other atypical processes that impact negatively on the development of skills associated with an implicit acquisition.

What Is the Influence of Morphological Knowledge in the Early Stages of Reading Acquisition Among Low SES Children? A Graphical Modeling Approach

PubMed Central

Colé, Pascale; Cavalli, Eddy; Duncan, Lynne G.; Theurel, Anne; Gentaz, Edouard; Sprenger-Charolles, Liliane; El-Ahmadi, Abdessadek

2018-01-01

Children from low-SES families are known to show delays in aspects of language development which underpin reading acquisition such as vocabulary and listening comprehension. Research on the development of morphological skills in this group is scarce, and no studies exist in French. The present study investigated the involvement of morphological knowledge in the very early stages of reading acquisition (decoding), before reading comprehension can be reliably assessed. We assessed listening comprehension, receptive vocabulary, phoneme awareness, morphological awareness as well as decoding, word reading and non-verbal IQ in 703 French first-graders from low-SES families after 3 months of formal schooling (November). Awareness of derivational morphology was assessed using three oral tasks: Relationship Judgment (e.g., do these words belong to the same family or not? heat-heater … ham-hammer); Lexical Sentence Completion [e.g., Someone who runs is a …? (runner)]; and Non-lexical Sentence Completion [e.g., Someone who lums is a…? (lummer)]. The tasks differ on implicit/explicit demands and also tap different kinds of morphological knowledge. The Judgement task measures the phonological and semantic properties of the morphological relationship and the Sentence Completion tasks measure knowledge of morphological production rules. Data were processed using a graphical modeling approach which offers key information about how skills known to be involved in learning to read are organized in memory. This modeling approach was therefore useful in revealing a potential network which expresses the conditional dependence structure between skills, after which recursive structural equation modeling was applied to test specific hypotheses. Six main conclusions can be drawn from these analyses about low SES reading acquisition: (1) listening comprehension is at the heart of the reading acquisition process; (2) word reading depends directly on phonemic awareness and indirectly on listening comprehension; (3) decoding depends on word reading; (4) Morphological awareness and vocabulary have an indirect influence on word reading via both listening comprehension and phoneme awareness; (5) the components of morphological awareness assessed by our tasks have independent relationships with listening comprehension; and (6) neither phonemic nor morphological awareness influence vocabulary directly. The implications of these results with regard to early reading acquisition among low SES groups are discussed. PMID:29725313

What Is the Influence of Morphological Knowledge in the Early Stages of Reading Acquisition Among Low SES Children? A Graphical Modeling Approach.

PubMed

Colé, Pascale; Cavalli, Eddy; Duncan, Lynne G; Theurel, Anne; Gentaz, Edouard; Sprenger-Charolles, Liliane; El-Ahmadi, Abdessadek

2018-01-01

Children from low-SES families are known to show delays in aspects of language development which underpin reading acquisition such as vocabulary and listening comprehension. Research on the development of morphological skills in this group is scarce, and no studies exist in French. The present study investigated the involvement of morphological knowledge in the very early stages of reading acquisition (decoding), before reading comprehension can be reliably assessed. We assessed listening comprehension, receptive vocabulary, phoneme awareness, morphological awareness as well as decoding, word reading and non-verbal IQ in 703 French first-graders from low-SES families after 3 months of formal schooling (November). Awareness of derivational morphology was assessed using three oral tasks: Relationship Judgment (e.g., do these words belong to the same family or not? heat-heater … ham-hammer); Lexical Sentence Completion [e.g., Someone who runs is a …? (runner)]; and Non-lexical Sentence Completion [e.g., Someone who lums is a…? (lummer)]. The tasks differ on implicit/explicit demands and also tap different kinds of morphological knowledge. The Judgement task measures the phonological and semantic properties of the morphological relationship and the Sentence Completion tasks measure knowledge of morphological production rules. Data were processed using a graphical modeling approach which offers key information about how skills known to be involved in learning to read are organized in memory. This modeling approach was therefore useful in revealing a potential network which expresses the conditional dependence structure between skills, after which recursive structural equation modeling was applied to test specific hypotheses. Six main conclusions can be drawn from these analyses about low SES reading acquisition: (1) listening comprehension is at the heart of the reading acquisition process; (2) word reading depends directly on phonemic awareness and indirectly on listening comprehension; (3) decoding depends on word reading; (4) Morphological awareness and vocabulary have an indirect influence on word reading via both listening comprehension and phoneme awareness; (5) the components of morphological awareness assessed by our tasks have independent relationships with listening comprehension; and (6) neither phonemic nor morphological awareness influence vocabulary directly. The implications of these results with regard to early reading acquisition among low SES groups are discussed.

Search and detection modeling of military imaging systems

NASA Astrophysics Data System (ADS)

Maurer, Tana; Wilson, David L.; Driggers, Ronald G.

2013-04-01

For more than 50 years, the U.S. Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD) has been studying the science behind the human processes of searching and detecting, and using that knowledge to develop and refine its models for military imaging systems. Modeling how human observers perform military tasks while using imaging systems in the field and linking that model with the physics of the systems has resulted in the comprehensive sensor models we have today. These models are used by the government, military, industry, and academia for sensor development, sensor system acquisition, military tactics development, and war-gaming. From the original hypothesis put forth by John Johnson in 1958, to modeling time-limited search, to modeling the impact of motion on target detection, to modeling target acquisition performance in different spectral bands, the concept of search has a wide-ranging history. Our purpose is to present a snapshot of that history; as such, it will begin with a description of the search-modeling task, followed by a summary of highlights from the early years, and concluding with a discussion of search and detection modeling today and the changing battlefield. Some of the topics to be discussed will be classic search, clutter, computational vision models and the ACQUIRE model with its variants. We do not claim to present a complete history here, but rather a look at some of the work that has been done, and this is meant to be an introduction to an extensive amount of work on a complex topic. That said, it is hoped that this overview of the history of search and detection modeling of military imaging systems pursued by NVESD directly, or in association with other government agencies or contractors, will provide both the novice and experienced search modeler with a useful historical summary and an introduction to current issues and future challenges.

Particulate and Gaseous Emissions Measurement System (PAGEMS) Project

NASA Technical Reports Server (NTRS)

Kostic, Milivoje

2003-01-01

Professor Kostic will work on the current UEET program of the Aerosol and Particulate task. This task will focus on: how to acquire experimental data through Labview software how to make the data acquisition system more efficient trouble existing problem of the labview software recommend a better system improve existing system with better data and usually friendly.Three different assignments in this project included:Particle-Size Distribution Data Presentation;Error or Uncertainty Analysis of Measurement Results; and Enhancement of LabVlRN Data Acquisition Program for GRC PAGEMS Project.

Applications of Task-Based Learning in TESOL

ERIC Educational Resources Information Center

Shehadeh, Ali, Ed.; Coombe, Christine, Ed.

2010-01-01

Why are many teachers around the world moving toward task-based learning (TBL)? This shift is based on the strong belief that TBL facilitates second language acquisition and makes second language learning and teaching more principled and effective. Based on insights gained from using tasks as research tools, this volume shows how teachers can use…

Object Clitic Omission in Child Spanish: Evaluating Representational and Processing Accounts

ERIC Educational Resources Information Center

Mateu, Victoria Eugenia

2015-01-01

This study explores the widely documented difficulty children have with object clitics in the acquisition of Romance languages. It reports on two experiments: a production task and a comprehension task. Results from the elicitation task confirm that object omission occurs at nonnegligible rates in 2- and 3-year-olds. Findings from the…

"'The 'Moustache' Sits down First": On the Acquisition of Metonymy

ERIC Educational Resources Information Center

Falkum, Ingrid L.; Recasens, Marta; Clark, Eve V.

2017-01-01

This study investigates preschoolers' ability to understand and produce novel metonyms. We gave forty-seven children (aged 2;9-5;9) and twenty-seven adults one comprehension task and two elicitation tasks. The first elicitation task investigated their ability to use metonyms as referential shorthands, and the second their willingness to name…

Comparison versus Contrast: Task Specifics Affect Category Acquisition

ERIC Educational Resources Information Center

Ankowski, Amber A.; Vlach, Haley A.; Sandhofer, Catherine M.

2013-01-01

A large literature has documented that comparison and contrast lead to better performance in a variety of tasks. However, studies of comparison and contrast present contradictory conclusions as to when and how these processes benefit learners. Across four studies, we examined how the specifics of the comparison and contrast task affect performance…

Learner Use of Holistic Language Units in Multimodal, Task-Based Synchronous Computer-Mediated Communication

ERIC Educational Resources Information Center

Collentine, Karina

2009-01-01

Second language acquisition (SLA) researchers strive to understand the language and exchanges that learners generate in synchronous computer-mediated communication (SCMC). Doughty and Long (2003) advocate replacing open-ended SCMC with task-based language teaching (TBLT) design principles. Since most task-based SCMC (TB-SCMC) research addresses an…

Frontal and Parietal Contributions to Probabilistic Association Learning

PubMed Central

Rushby, Jacqueline A.; Vercammen, Ans; Loo, Colleen; Short, Brooke

2011-01-01

Neuroimaging studies have shown both dorsolateral prefrontal (DLPFC) and inferior parietal cortex (iPARC) activation during probabilistic association learning. Whether these cortical brain regions are necessary for probabilistic association learning is presently unknown. Participants' ability to acquire probabilistic associations was assessed during disruptive 1 Hz repetitive transcranial magnetic stimulation (rTMS) of the left DLPFC, left iPARC, and sham using a crossover single-blind design. On subsequent sessions, performance improved relative to baseline except during DLPFC rTMS that disrupted the early acquisition beneficial effect of prior exposure. A second experiment examining rTMS effects on task-naive participants showed that neither DLPFC rTMS nor sham influenced naive acquisition of probabilistic associations. A third experiment examining consecutive administration of the probabilistic association learning test revealed early trial interference from previous exposure to different probability schedules. These experiments, showing disrupted acquisition of probabilistic associations by rTMS only during subsequent sessions with an intervening night's sleep, suggest that the DLPFC may facilitate early access to learned strategies or prior task-related memories via consolidation. Although neuroimaging studies implicate DLPFC and iPARC in probabilistic association learning, the present findings suggest that early acquisition of the probabilistic cue-outcome associations in task-naive participants is not dependent on either region. PMID:21216842

Task-Based Language Teaching for Beginner-Level Learners of L2 French: An Exploratory Study

ERIC Educational Resources Information Center

Erlam, Rosemary; Ellis, Rod

2018-01-01

This study investigated the effect of input-based tasks on the acquisition of vocabulary and grammar by beginner-level learners of L2 French and reported the introduction of task-based teaching as an innovation in a state secondary school. The experimental group (n = 19) completed a series of focused input-based language tasks, taught by their…

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1988-01-01

The Office of Space Operation (OSO) tasks addressed include: Deep Space Network (DSN) advanced systems and systems implementation. The Office of Space Science and Applications (OSSA) tasks discussed include SETI data controllers and simulated performance for narrowband signal detection.

Balanced bilingualism and early age of second language acquisition as the underlying mechanisms of a bilingual executive control advantage: why variations in bilingual experiences matter

PubMed Central

Yow, W. Quin; Li, Xiaoqian

2015-01-01

Recent studies revealed inconsistent evidences of a bilingual advantage in executive processing. One potential source of explanation is the multifaceted experience of the bilinguals in these studies. This study seeks to test whether bilinguals who engage in language selection more frequently would perform better in executive control tasks than those bilinguals who engage in language selection less frequently. We examined the influence of the degree of bilingualism (i.e., language proficiency, frequency of use of two languages, and age of second language acquisition) on executive functioning in bilingual young adults using a comprehensive battery of executive control tasks. Seventy-two 18- to 25-years-old English–Mandarin bilinguals performed four computerized executive function (EF) tasks (Stroop, Eriksen flanker, number–letter switching, and n-back task) that measure the EF components: inhibition, mental-set shifting, and information updating and monitoring. Results from multiple regression analyses, structural equation modeling, and bootstrapping supported the positive association between age of second language acquisition and the interference cost in the Stroop task. Most importantly, we found a significant effect of balanced bilingualism (balanced usage of and balanced proficiency in two languages) on the Stroop and number–letter task (mixing cost only), indicating that a more balanced use and a more balanced level of proficiency in two languages resulted in better executive control skills in the adult bilinguals. We did not find any significant effect of bilingualism on flanker or n-back task. These findings provided important insights to the underlying mechanisms of the bilingual cognitive advantage hypothesis, demonstrating that regular experience with extensive practice in controlling attention to their two language systems results in better performance in related EFs such as inhibiting prepotent responses and global set-shifting. PMID:25767451

Balanced bilingualism and early age of second language acquisition as the underlying mechanisms of a bilingual executive control advantage: why variations in bilingual experiences matter.

PubMed

Yow, W Quin; Li, Xiaoqian

2015-01-01

Recent studies revealed inconsistent evidences of a bilingual advantage in executive processing. One potential source of explanation is the multifaceted experience of the bilinguals in these studies. This study seeks to test whether bilinguals who engage in language selection more frequently would perform better in executive control tasks than those bilinguals who engage in language selection less frequently. We examined the influence of the degree of bilingualism (i.e., language proficiency, frequency of use of two languages, and age of second language acquisition) on executive functioning in bilingual young adults using a comprehensive battery of executive control tasks. Seventy-two 18- to 25-years-old English-Mandarin bilinguals performed four computerized executive function (EF) tasks (Stroop, Eriksen flanker, number-letter switching, and n-back task) that measure the EF components: inhibition, mental-set shifting, and information updating and monitoring. Results from multiple regression analyses, structural equation modeling, and bootstrapping supported the positive association between age of second language acquisition and the interference cost in the Stroop task. Most importantly, we found a significant effect of balanced bilingualism (balanced usage of and balanced proficiency in two languages) on the Stroop and number-letter task (mixing cost only), indicating that a more balanced use and a more balanced level of proficiency in two languages resulted in better executive control skills in the adult bilinguals. We did not find any significant effect of bilingualism on flanker or n-back task. These findings provided important insights to the underlying mechanisms of the bilingual cognitive advantage hypothesis, demonstrating that regular experience with extensive practice in controlling attention to their two language systems results in better performance in related EFs such as inhibiting prepotent responses and global set-shifting.

Maternal immune activation during pregnancy in rats impairs working memory capacity of the offspring.

PubMed

Murray, Brendan G; Davies, Don A; Molder, Joel J; Howland, John G

2017-05-01

Maternal immune activation during pregnancy is an environmental risk factor for psychiatric illnesses such as schizophrenia in the offspring. Patients with schizophrenia display an array of cognitive symptoms, including impaired working memory capacity. Rodent models have been developed to understand the relationship between maternal immune activation and the cognitive symptoms of schizophrenia. The present experiment was designed to test whether maternal immune activation with the viral mimetic polyinosinic:polycytidylic acid (polyI:C) during pregnancy affects working memory capacity of the offspring. Pregnant Long Evans rats were treated with either saline or polyI:C (4mg/kg; i.v.) on gestational day 15. Male offspring of the litters (2-3months of age) were subsequently trained on a nonmatching-to-sample task with odors. After a criterion was met, the rats were tested on the odor span task, which requires rats to remember an increasing span of different odors to receive food reward. Rats were tested using delays of approximately 40s during the acquisition of the task. Importantly, polyI:C- and saline-treated offspring did not differ in performance of the nonmatching-to-sample task suggesting that both groups could perform a relatively simple working memory task. In contrast, polyI:C-treated offspring had reduced span capacity in the middle and late phases of odor span task acquisition. After task acquisition, the rats were tested using the 40s delay and a 10min delay. Both groups showed a delay-dependent decrease in span, although the polyI:C-treated offspring had significantly lower spans regardless of delay. Our results support the validity of the maternal immune activation model for studying the cognitive symptoms of neurodevelopmental disorders such as schizophrenia. Copyright © 2017 Elsevier Inc. All rights reserved.

Learning and performance under alternative instructional manifestations of experimental practice

NASA Astrophysics Data System (ADS)

Ford, Michael J.

Before we can understand how students learn "to do" science, we must make explicit our assumptions about what scientific practice is. This study compares the learning outcomes of two sixth-grade instructional units on experimentation, each based on a particular characterization of practice. In one unit, instruction focused on acquisition and application of the control of variables strategy (CVS; Chen & Klahr, 1999), which is consistent with a popular conception of science education, stemming from Piaget, as the mastery of logical forms. In the other unit, students designed experimental apparatus to answer a target question, and instruction emphasized practices of rendering and transforming the material world in ways that support scientific understanding. Students in both groups were assessed for CVS acquisition and subsequent experimental performance on a novel task, and group performances on these assessments different across instructional conditions. I will argue that student understandings of goals, norms of instructional expectation, and strategies explain these differences, in some cases by supporting performance and in other cases by hindering it. I will also argue that the results question the role typically attributed to logical method in learning to design experiments.

Automated detection of fluorescent cells in in-resin fluorescence sections for integrated light and electron microscopy.

PubMed

Delpiano, J; Pizarro, L; Peddie, C J; Jones, M L; Griffin, L D; Collinson, L M

2018-04-26

Integrated array tomography combines fluorescence and electron imaging of ultrathin sections in one microscope, and enables accurate high-resolution correlation of fluorescent proteins to cell organelles and membranes. Large numbers of serial sections can be imaged sequentially to produce aligned volumes from both imaging modalities, thus producing enormous amounts of data that must be handled and processed using novel techniques. Here, we present a scheme for automated detection of fluorescent cells within thin resin sections, which could then be used to drive automated electron image acquisition from target regions via 'smart tracking'. The aim of this work is to aid in optimization of the data acquisition process through automation, freeing the operator to work on other tasks and speeding up the process, while reducing data rates by only acquiring images from regions of interest. This new method is shown to be robust against noise and able to deal with regions of low fluorescence. © 2018 The Authors. Journal of Microscopy published by JohnWiley & Sons Ltd on behalf of Royal Microscopical Society.

The forward masking effects of low-level laser glare on target location performance in a visual search task

NASA Astrophysics Data System (ADS)

Reddix, M. D.; Dandrea, J. A.; Collyer, P. D.

1992-01-01

The present study examined the effects of low-intensity laser glue, far below a level that would cause ocular damage or flashblindness, on the visually guided performance of aviators. With a forward-masking paradigm, this study showed that the time at which laser glare is experienced, relative to initial acquisition of visual information, differentially affects the speed and accuracy of target-location performance. Brief exposure (300 ms) to laser glare, terminating with a visual scene's onset, produced significant decrements in target-location performance relative to a no-glare control whereas a 150 and 300-ms delay of display onset (DDO) had very little effect. The intensity of the light entering the eye and producing these effects was far below the Maximum Permissible Exposure (MPE) limit for safe viewing of coherent light produced by an argon laser. In addition, these effects were modulated by the distance of the target from the center of the visual display. This study demonstrated that the presence of laser glare is not sufficient, in and of itself, to diminish target-location performance. The time at which laser glare is experienced is an important factor in determining the probability and extent of visually mediated performance decrements.

Cognitive processes in children's reading and attention: the role of working memory, divided attention, and response inhibition.

PubMed

Savage, Robert; Cornish, Kim; Manly, Tom; Hollis, Chris

2006-08-01

Children experiencing attention difficulties have documented cognitive deficits in working memory (WM), response inhibition and dual tasks. Recent evidence suggests however that these same cognitive processes are also closely associated with reading acquisition. This paper therefore explores whether these variables predicted attention difficulties or reading among 123 children with and without significant attention problems sampled from the school population. Children were screened using current WM and attention task measures. Three factors explained variance in WM and attention tasks. Response inhibition tasks loaded mainly with central executive measures, but a dual processing task loaded with the visual-spatial WM measures. Phonological loop measures loaded independently of attention measures. After controls for age, IQ and attention-group membership, phonological loop and 'central processing' measures both predicted reading ability. A 'visual memory/dual-task' factor predicted attention group membership after controls for age, IQ and reading ability. Results thus suggest that some of the processes previously assumed to be predictive of attention problems may reflect processes involved in reading acquisition. Visual memory and dual-task functioning are, however, purer indices of cognitive difficulty in children experiencing attention problems.

Target Acquisition for Projectile Vision-Based Navigation

DTIC Science & Technology

2014-03-01

Future Work 20 8. References 21 Appendix A. Simulation Results 23 Appendix B. Derivation of Ground Resolution for a Diffraction-Limited Pinhole Camera...results for visual acquisition (left) and target recognition (right). ..........19 Figure B-1. Differential object and image areas for pinhole camera...projectile and target (measured in terms of the angle ) will depend on target heading. In particular, because we have aligned the x axis along the

Effects of Scene Modulation Image Blur and Noise Upon Human Target Acquisition Performance.

DTIC Science & Technology

1997-06-01

AFRL-HE-WP-TR-1998-0012 UNITED STATES AIR FORCE RESEARCH LABORATORY EFFECTS OF SCENE MODULATION IMAGE BLUR AND NOISE UPON HUMAN TARGET...COVERED INTERIM (July 1996 - August 1996) TITLE AND SUBTITLE Effects of Scene Modulation Image Blur and Noise Upon Human Target Acquisition...dilemma in image transmission and display is that we must compromise between die conflicting constraints of dynamic range and noise . Three target

Rapid target foraging with reach or gaze: The hand looks further ahead than the eye

PubMed Central

2017-01-01

Real-world tasks typically consist of a series of target-directed actions and often require choices about which targets to act on and in what order. Such choice behavior can be assessed from an optimal foraging perspective whereby target selection is shaped by a balance between rewards and costs. Here we evaluated such decision-making in a rapid movement foraging task. On a given trial, participants were presented with 15 targets of varying size and value and were instructed to harvest as much reward as possible by either moving a handle to the targets (hand task) or by briefly fixating them (eye task). The short trial duration enabled participants to harvest about half the targets, ensuring that total reward was due to choice behavior. We developed a probabilistic model to predict target-by-target harvesting choices that considered the rewards and movement-related costs (i.e., target distance and size) associated with the current target as well as future targets. In the hand task, in comparison to the eye task, target choice was more strongly influenced by movement-related costs and took into account a greater number of future targets, consistent with the greater costs associated with arm movement. In both tasks, participants exhibited near-optimal behaviour and in a constrained version of the hand task in which choices could only be based on target positions, participants consistently chose among the shortest movement paths. Our results demonstrate that people can rapidly and effectively integrate values and movement-related costs associated with current and future targets when sequentially harvesting targets. PMID:28683138

Sugar ingestion and dichotic listening: Increased perceptual capacity is more than motivation.

PubMed

Scheel, Matthew H; Ambrose, Aimee L

2014-01-01

Participants ingested a sugar drink or a sugar-free drink and then engaged in a pair of dichotic listening tasks. Tasks presented category labels then played a series of word pairs, one in the left ear and one in the right. Participants attempted to identify pairs containing a target category member. Target category words were homonyms. For example, arms appeared as a target in the "body parts" category. Nontargets that played along with targets were related to a category-appropriate version of the target (e.g., sleeves), a category-inappropriate version (e.g., weapons), or were unrelated to either version of the target (e.g., plant). Hence, an effect of nontarget type on number of targets missed was evidence that participants processed nontargets for meaning. In the divided attention task, participants monitored both ears. In the focused attention task, participants monitored the left ear. Half the participants in each group had the divided attention task before the focused attention task; the other half had the focused attention task before the divided attention task. We set task lengths to about 12 min so working on the first task would give sufficient time for metabolizing sugar from the drink before the start of the second task. Nontarget word type significantly affected targets missed in both tasks. Drink type affected performance in the divided attention task only after sufficient time for converting sugar into blood glucose. The result supports an energy model for the effect of sugar ingestion on perceptual tasks rather than a motivational model.

Choice of saccade endpoint under risk

PubMed Central

Ackermann, John F.; Landy, Michael S.

2013-01-01

Eye movements function to bring detailed information onto the high-resolution region of the retina. Previous research has shown that human observers select fixation points that maximize information acquisition and minimize target location uncertainty. In this study, we ask whether human observers choose the saccade endpoint that maximizes gain when there are explicit rewards associated with correctly detecting the target. Observers performed an 8-alternative forced-choice detection task for a contrast-defined target in noise. After a single saccade, observers indicated the target location. Each potential target location had an associated reward that was known to the observer. In some conditions, the reward at one location was higher than at the other locations. We compared human saccade endpoints to those of an ideal observer that maximizes expected gain given the respective human observer's visibility map, i.e., d′ for target detection as a function of retinal location. Varying the location of the highest reward had a significant effect on human observers' distribution of saccade endpoints. Both human and ideal observers show a high density of saccades made toward the highest rewarded and actual target locations. But humans' overall spatial distributions of saccade endpoints differed significantly from the ideal observer as they made a greater number of saccade to locations far from the highest rewarded and actual target locations. Suboptimal choice of saccade endpoint, possibly in combination with suboptimal integration of information across saccades, had a significant effect on human observers' ability to correctly detect the target and maximize gain. PMID:24023277

As naturalistic as it gets: subtitles in the English classroom in Norway

PubMed Central

Vulchanova, Mila; Aurstad, Lisa M. G.; Kvitnes, Ingrid E. N.; Eshuis, Hendrik

2015-01-01

This study aimed to investigate the effects of subtitles in the context of authentic material on second language comprehension and potentially, second language acquisition for Norwegian learners of English. Participants in the study were 49 17-year-old students and 65 16-year-old students, who were all native speakers of Norwegian learning English as an L2 in high school. Both age groups were divided into three Conditions, where one group watched an episode of the American animated cartoon Family Guy with Norwegian subtitles, one group with English subtitles, and one group watched the episode with no subtitles. On a comprehension questionnaire conducted immediately after watching the episode positive short-term effects of both native language (L1) and target language (L2) subtitles were found for both age groups. However, no differences in terms of the language of the subtitles were found in the older and more advanced group. Four weeks later the participants responded to a word definition task and a word recall task to investigate potential long-term effects of the subtitles. The only long-term effect was found in the word definition task and was modulated by age. We found, however, that native language subtitles impact negatively on performance on the comprehension task. The results from this study suggest that the mere presence of subtitles as an additional source of information enhances learners' comprehension of the plot and content in animated audio-visual material in their L2. The absence of differences in terms of the language of the subtitles in the more advanced group suggests that both intralanguage and interlanguage subtitles can aid target language comprehension in very advanced learners, most probably due to better consolidated vocabulary knowledge in that group. The two groups differed also on predictors of performance on the two lexical tasks. While in the less proficient younger group, vocabulary status best predicted performance on both tasks (vocabulary predicts vocabulary), for the very advanced older group, grammar was a stronger predictor, highlighting the importance of generic language competence and skills in L2 tasks for highly proficient L2 users. We also found an effect of written L2 skills on performance on both lexical tasks indicative of the role of orthography in vocabulary consolidation. PMID:25620938

Variable strategy model of the human operator

NASA Astrophysics Data System (ADS)

Phillips, John Michael

Human operators often employ discontinuous or "bang-bang" control strategies when performing large-amplitude acquisition tasks. The current study applies Variable Structure Control (VSC) techniques to model human operator behavior during acquisition tasks. The result is a coupled, multi-input model replicating the discontinuous control strategy. In the VSC formulation, a switching surface is the mathematical representation of the operator's control strategy. The performance of the Variable Strategy Model (VSM) is evaluated by considering several examples, including the longitudinal control of an aircraft during the visual landing task. The aircraft landing task becomes an acquisition maneuver whenever large initial offsets occur. Several different strategies are explored in the VSM formulation for the aircraft landing task. First, a switching surface is constructed from literal interpretations of pilot training literature. This approach yields a mathematical representation of how a pilot is trained to fly a generic aircraft. This switching surface is shown to bound the trajectory response of a group of pilots performing an offset landing task in an aircraft simulator study. Next, front-side and back-side landing strategies are compared. A back-side landing strategy is found to be capable of landing an aircraft flying on either the front side or back side of the power curve. However, the front-side landing strategy is found to be insufficient for landing an aircraft flying on the back side. Finally, a more refined landing strategy is developed that takes into the account the specific aircraft's dynamic characteristics. The refined strategy is translated back into terminology similar to the existing pilot training literature.

A Symbolic Model of the Nonconscious Acquisition of Information.

ERIC Educational Resources Information Center

Ling, Charles X.; Marinov, Marin

1994-01-01

Challenges Smolensky's theory that human intuitive/nonconscious cognitive processes can only be accurately explained in terms of subsymbolic computations in artificial neural networks. Symbolic learning models of two cognitive tasks involving nonconscious acquisition of information are presented: learning production rules and artificial finite…

Interactive effects of age-of-acquisition and repetition priming in the lexical decision task. A multiple-loci account.

PubMed

Spataro, Pietro; Longobardi, Emiddia; Saraulli, Daniele; Rossi-Arnaud, Clelia

2013-01-01

The analysis of the interaction between repetition priming and age of acquisition may be used to shed further light on the question of which stages of elaboration are affected by this psycholinguistic variable. In the present study we applied this method in the context of two versions of a lexical decision task that differed in the type of non-words employed at test. When the non-words were illegal and unpronounceable, repetition priming was primarily based on the analysis of orthographic information, while phonological processes were additionally recruited only when using legal pronounceable non-words. The results showed a significant interaction between repetition priming and age of acquisition in both conditions, with priming being greater for late- than for early-acquired words. These findings support a multiple-loci account, indicating that age of acquisition influences implicit memory by facilitating the retrieval of both the orthographic and the phonological representations of studied words.

Comparison of six electromyography acquisition setups on hand movement classification tasks

PubMed Central

Pizzolato, Stefano; Tagliapietra, Luca; Cognolato, Matteo; Reggiani, Monica; Müller, Henning

2017-01-01

Hand prostheses controlled by surface electromyography are promising due to the non-invasive approach and the control capabilities offered by machine learning. Nevertheless, dexterous prostheses are still scarcely spread due to control difficulties, low robustness and often prohibitive costs. Several sEMG acquisition setups are now available, ranging in terms of costs between a few hundred and several thousand dollars. The objective of this paper is the relative comparison of six acquisition setups on an identical hand movement classification task, in order to help the researchers to choose the proper acquisition setup for their requirements. The acquisition setups are based on four different sEMG electrodes (including Otto Bock, Delsys Trigno, Cometa Wave + Dormo ECG and two Thalmic Myo armbands) and they were used to record more than 50 hand movements from intact subjects with a standardized acquisition protocol. The relative performance of the six sEMG acquisition setups is compared on 41 identical hand movements with a standardized feature extraction and data analysis pipeline aimed at performing hand movement classification. Comparable classification results are obtained with three acquisition setups including the Delsys Trigno, the Cometa Wave and the affordable setup composed of two Myo armbands. The results suggest that practical sEMG tests can be performed even when costs are relevant (e.g. in small laboratories, developing countries or use by children). All the presented datasets can be used for offline tests and their quality can easily be compared as the data sets are publicly available. PMID:29023548

Comparison of six electromyography acquisition setups on hand movement classification tasks.

PubMed

Pizzolato, Stefano; Tagliapietra, Luca; Cognolato, Matteo; Reggiani, Monica; Müller, Henning; Atzori, Manfredo

2017-01-01

Hand prostheses controlled by surface electromyography are promising due to the non-invasive approach and the control capabilities offered by machine learning. Nevertheless, dexterous prostheses are still scarcely spread due to control difficulties, low robustness and often prohibitive costs. Several sEMG acquisition setups are now available, ranging in terms of costs between a few hundred and several thousand dollars. The objective of this paper is the relative comparison of six acquisition setups on an identical hand movement classification task, in order to help the researchers to choose the proper acquisition setup for their requirements. The acquisition setups are based on four different sEMG electrodes (including Otto Bock, Delsys Trigno, Cometa Wave + Dormo ECG and two Thalmic Myo armbands) and they were used to record more than 50 hand movements from intact subjects with a standardized acquisition protocol. The relative performance of the six sEMG acquisition setups is compared on 41 identical hand movements with a standardized feature extraction and data analysis pipeline aimed at performing hand movement classification. Comparable classification results are obtained with three acquisition setups including the Delsys Trigno, the Cometa Wave and the affordable setup composed of two Myo armbands. The results suggest that practical sEMG tests can be performed even when costs are relevant (e.g. in small laboratories, developing countries or use by children). All the presented datasets can be used for offline tests and their quality can easily be compared as the data sets are publicly available.

Hippocampal Context Processing during Acquisition of a Predictive Learning Task Is Associated with Renewal in Extinction Recall.

PubMed

Lissek, Silke; Glaubitz, Benjamin; Schmidt-Wilcke, Tobias; Tegenthoff, Martin

2016-05-01

Renewal is defined as the recovery of an extinguished response if extinction and retrieval contexts differ. The context dependency of extinction, as demonstrated by renewal, has important implications for extinction-based therapies. Persons showing renewal (REN) exhibit higher hippocampal activation during extinction in associative learning than those without renewal (NOREN), demonstrating hippocampal context processing, and recruit ventromedial pFC in retrieval. Apart from these findings, brain processes generating renewal remain largely unknown. Conceivably, processing differences in task-relevant brain regions that ultimately lead to renewal may occur already in initial acquisition of associations. Therefore, in two fMRI studies, we investigated overall brain activation and hippocampal activation in REN and NOREN during acquisition of an associative learning task in response to presentation of a context alone or combined with a cue. Results of two studies demonstrated significant activation differences between the groups: In Study 1, a support vector machine classifier correctly assigned participants' brain activation patterns to REN and NOREN groups, respectively. In Study 2, REN and NOREN showed similar hippocampal involvement during context-only presentation, suggesting processing of novelty, whereas overall hippocampal activation to the context-cue compound, suggesting compound encoding, was higher in REN. Positive correlations between hippocampal activation and renewal level indicated more prominent hippocampal processing in REN. Results suggest that hippocampal processing of the context-cue compound rather than of context only during initial learning is related to a subsequent renewal effect. Presumably, REN participants use distinct encoding strategies during acquisition of context-related tasks, which reflect in their brain activation patterns and contribute to a renewal effect.

Relations between Semantic and Cognitive Development in the One-Word Stage: The Specificity Hypothesis.

ERIC Educational Resources Information Center

Gopnik, Alison; Meltzoff, Andrew N.

1986-01-01

Compares two types of semantic development (the acquisition of disappearance words and success-failure words) to performance on two types of cognitive tasks (object-permanence and means-ends tasks) among infants. (HOD)

Brain lateralisation and motor learning: selective effects of dominant and non-dominant hand practice on the early acquisition of throwing skills.

PubMed

Stöckel, Tino; Weigelt, Matthias

2012-01-01

Findings from neurosciences indicate that the two brain hemispheres are specialised for the processing of distinct movement features. How this knowledge can be useful in motor learning remains unclear. Two experiments were conducted to investigate the influence of initial practice with the dominant vs non-dominant hand on the acquisition of novel throwing skills. Within a transfer design two groups practised a novel motor task with the same amount of practice on each hand, but in opposite hand-order. In Experiment 1, participants acquired the position throw in basketball, which places high demands on throwing accuracy. Participants practising this task with their non-dominant hand first, before changing to the dominant hand, showed better skill acquisition than participants practising in opposite order. In Experiment 2 participants learned the overarm throw in team handball, which requires great throwing strength. Participants initially practising with their dominant hand benefited more from practice than participants beginning with their non-dominant hand. These results indicate that spatial accuracy tasks are learned better after initial practice with the non-dominant hand, whereas initial practice with the dominant hand is more efficient for maximum force production tasks. The effects are discussed in terms of brain lateralisation and bilateral practice schedules.

Paired-Associate and Feedback-Based Weather Prediction Tasks Support Multiple Category Learning Systems.

PubMed

Li, Kaiyun; Fu, Qiufang; Sun, Xunwei; Zhou, Xiaoyan; Fu, Xiaolan

2016-01-01

It remains unclear whether probabilistic category learning in the feedback-based weather prediction task (FB-WPT) can be mediated by a non-declarative or procedural learning system. To address this issue, we compared the effects of training time and verbal working memory, which influence the declarative learning system but not the non-declarative learning system, in the FB and paired-associate (PA) WPTs, as the PA task recruits a declarative learning system. The results of Experiment 1 showed that the optimal accuracy in the PA condition was significantly decreased when the training time was reduced from 7 to 3 s, but this did not occur in the FB condition, although shortened training time impaired the acquisition of explicit knowledge in both conditions. The results of Experiment 2 showed that the concurrent working memory task impaired the optimal accuracy and the acquisition of explicit knowledge in the PA condition but did not influence the optimal accuracy or the acquisition of self-insight knowledge in the FB condition. The apparent dissociation results between the FB and PA conditions suggested that a non-declarative or procedural learning system is involved in the FB-WPT and provided new evidence for the multiple-systems theory of human category learning.

Paired-Associate and Feedback-Based Weather Prediction Tasks Support Multiple Category Learning Systems

PubMed Central

Li, Kaiyun; Fu, Qiufang; Sun, Xunwei; Zhou, Xiaoyan; Fu, Xiaolan

2016-01-01

It remains unclear whether probabilistic category learning in the feedback-based weather prediction task (FB-WPT) can be mediated by a non-declarative or procedural learning system. To address this issue, we compared the effects of training time and verbal working memory, which influence the declarative learning system but not the non-declarative learning system, in the FB and paired-associate (PA) WPTs, as the PA task recruits a declarative learning system. The results of Experiment 1 showed that the optimal accuracy in the PA condition was significantly decreased when the training time was reduced from 7 to 3 s, but this did not occur in the FB condition, although shortened training time impaired the acquisition of explicit knowledge in both conditions. The results of Experiment 2 showed that the concurrent working memory task impaired the optimal accuracy and the acquisition of explicit knowledge in the PA condition but did not influence the optimal accuracy or the acquisition of self-insight knowledge in the FB condition. The apparent dissociation results between the FB and PA conditions suggested that a non-declarative or procedural learning system is involved in the FB-WPT and provided new evidence for the multiple-systems theory of human category learning. PMID:27445958

Deaf children's non-verbal working memory is impacted by their language experience

PubMed Central

Marshall, Chloë; Jones, Anna; Denmark, Tanya; Mason, Kathryn; Atkinson, Joanna; Botting, Nicola; Morgan, Gary

2015-01-01

Several recent studies have suggested that deaf children perform more poorly on working memory tasks compared to hearing children, but these studies have not been able to determine whether this poorer performance arises directly from deafness itself or from deaf children's reduced language exposure. The issue remains unresolved because findings come mostly from (1) tasks that are verbal as opposed to non-verbal, and (2) involve deaf children who use spoken communication and therefore may have experienced impoverished input and delayed language acquisition. This is in contrast to deaf children who have been exposed to a sign language since birth from Deaf parents (and who therefore have native language-learning opportunities within a normal developmental timeframe for language acquisition). A more direct, and therefore stronger, test of the hypothesis that the type and quality of language exposure impact working memory is to use measures of non-verbal working memory (NVWM) and to compare hearing children with two groups of deaf signing children: those who have had native exposure to a sign language, and those who have experienced delayed acquisition and reduced quality of language input compared to their native-signing peers. In this study we investigated the relationship between NVWM and language in three groups aged 6–11 years: hearing children (n = 28), deaf children who were native users of British Sign Language (BSL; n = 8), and deaf children who used BSL but who were not native signers (n = 19). We administered a battery of non-verbal reasoning, NVWM, and language tasks. We examined whether the groups differed on NVWM scores, and whether scores on language tasks predicted scores on NVWM tasks. For the two executive-loaded NVWM tasks included in our battery, the non-native signers performed less accurately than the native signer and hearing groups (who did not differ from one another). Multiple regression analysis revealed that scores on the vocabulary measure predicted scores on those two executive-loaded NVWM tasks (with age and non-verbal reasoning partialled out). Our results suggest that whatever the language modality—spoken or signed—rich language experience from birth, and the good language skills that result from this early age of acquisition, play a critical role in the development of NVWM and in performance on NVWM tasks. PMID:25999875

A robust close-range photogrammetric target extraction algorithm for size and type variant targets

NASA Astrophysics Data System (ADS)

Nyarko, Kofi; Thomas, Clayton; Torres, Gilbert

2016-05-01

The Photo-G program conducted by Naval Air Systems Command at the Atlantic Test Range in Patuxent River, Maryland, uses photogrammetric analysis of large amounts of real-world imagery to characterize the motion of objects in a 3-D scene. Current approaches involve several independent processes including target acquisition, target identification, 2-D tracking of image features, and 3-D kinematic state estimation. Each process has its own inherent complications and corresponding degrees of both human intervention and computational complexity. One approach being explored for automated target acquisition relies on exploiting the pixel intensity distributions of photogrammetric targets, which tend to be patterns with bimodal intensity distributions. The bimodal distribution partitioning algorithm utilizes this distribution to automatically deconstruct a video frame into regions of interest (ROI) that are merged and expanded to target boundaries, from which ROI centroids are extracted to mark target acquisition points. This process has proved to be scale, position and orientation invariant, as well as fairly insensitive to global uniform intensity disparities.

WE-EF-207-01: FEATURED PRESENTATION and BEST IN PHYSICS (IMAGING): Task-Driven Imaging for Cone-Beam CT in Interventional Guidance

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

Gang, G; Stayman, J; Ouadah, S

2015-06-15

Purpose: This work introduces a task-driven imaging framework that utilizes a patient-specific anatomical model, mathematical definition of the imaging task, and a model of the imaging system to prospectively design acquisition and reconstruction techniques that maximize task-based imaging performance. Utility of the framework is demonstrated in the joint optimization of tube current modulation and view-dependent reconstruction kernel in filtered-backprojection reconstruction and non-circular orbit design in model-based reconstruction. Methods: The system model is based on a cascaded systems analysis of cone-beam CT capable of predicting the spatially varying noise and resolution characteristics as a function of the anatomical model and amore » wide range of imaging parameters. Detectability index for a non-prewhitening observer model is used as the objective function in a task-driven optimization. The combination of tube current and reconstruction kernel modulation profiles were identified through an alternating optimization algorithm where tube current was updated analytically followed by a gradient-based optimization of reconstruction kernel. The non-circular orbit is first parameterized as a linear combination of bases functions and the coefficients were then optimized using an evolutionary algorithm. The task-driven strategy was compared with conventional acquisitions without modulation, using automatic exposure control, and in a circular orbit. Results: The task-driven strategy outperformed conventional techniques in all tasks investigated, improving the detectability of a spherical lesion detection task by an average of 50% in the interior of a pelvis phantom. The non-circular orbit design successfully mitigated photon starvation effects arising from a dense embolization coil in a head phantom, improving the conspicuity of an intracranial hemorrhage proximal to the coil. Conclusion: The task-driven imaging framework leverages a knowledge of the imaging task within a patient-specific anatomical model to optimize image acquisition and reconstruction techniques, thereby improving imaging performance beyond that achievable with conventional approaches. 2R01-CA-112163; R01-EB-017226; U01-EB-018758; Siemens Healthcare (Forcheim, Germany)« less

The capability of static and dynamic features to distinguish competent from genuinely expert practitioners in pediatric diagnosis.

PubMed

Loveday, Thomas; Wiggins, Mark W; Searle, Ben J; Festa, Marino; Schell, David

2013-02-01

The authors describe the development of a new, more objective method of distinguishing experienced competent nonexpert from expert practitioners within pediatric intensive care. Expert performance involves the acquisition and use of refined feature-event associations (cues) in the operational environment. Competent non-experts, although experienced, possess rudimentary cue associations in memory. Thus, they cannot respond as efficiently or as reliably as their expert counterparts, particularly when key diagnostic information is unavailable, such as that provided by dynamic cues. This study involved the application of four distinct tasks in which the use of relevant cues could be expected to increase both the accuracy and the efficiency of diagnostic performance. These tasks included both static and dynamic stimuli that were varied systematically. A total of 50 experienced pediatric intensive staff took part in the study. The sample clustered into two levels across the tasks: Participants who performed at a consistently high level throughout the four tasks were labeled experts, and participants who performed at a lower level throughout the tasks were labeled competent nonexperts. The groups differed in their responses to the diagnostic scenarios presented in two of the tasks and their ability to maintain performance in the absence of dynamic features. Experienced pediatricians can be decomposed into two groups on the basis of their capacity to acquire and use cues; these groups differ in their diagnostic accuracy and in their ability to maintain performance in the absence of dynamic features. The tasks may be used to identify practitioners who are failing to acquire expertise at a rate consistent with their experience, position, or training. This information may be used to guide targeted training efforts.

Acquisition How to Guide: Planning, Preparing, and Processing Acquisition Packages

DTIC Science & Technology

1993-08-01

of Task Outline. In very simple acquisitions, the project officer or COR, with the advice and counsel of the Contract Specialist, may...three concise sentences , each limited to a single idea. Use simple sentence structure (i.e., subject-verb-complement/object). The natural order of words... in a sentence tells the function of each word. Use a paragraph to state a single idea and elaborate on it. State the

Coast Guard Deepwater Acquisition Programs: Background, Oversight Issues, and Options for Congress

DTIC Science & Technology

2011-03-18

NUMBER 5e . TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Congressional Research Service,Library Of Congress,101...Deepwater Acquisition into asset-based Acquisition Program Baselines, the proposed changes align projects that were formerly grouped under...Integrated Coast Guard Systems (ICGS)—an industry team led by Lockheed Martin and Northrop Grumman Ship Systems ( NGSS ). ICGS was awarded an indefinite

Coast Guard Deepwater Acquisition Programs: Background, Oversight Issues, and Options for Congress

DTIC Science & Technology

2011-04-14

NUMBER 5e . TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Congressional Research Service,The Library of Congress...disaggregation of the Deepwater Acquisition into asset-based Acquisition Program Baselines, the proposed changes align projects that were formerly grouped...industry team led by Lockheed Martin and Northrop Grumman Ship Systems ( NGSS ). ICGS was awarded an indefinite delivery, indefinite quantity (ID/IQ

Measuring Grammatical Development in Bilingual Mandarin-English Speaking Children with a Sentence Repetition Task

ERIC Educational Resources Information Center

Woon, Chai Ping; Yap, Ngee Thai; Lim, Hui Woan; Wong, Bee Eng

2014-01-01

Sentence repetition (SR) tasks have been used to measure children's expressive language skills in normal and abnormal language development, and to examine the development of the speaking skills in second language acquisition, as well as to survey the proficiency of bilingual language development. Recently, SR tasks have been recognized as a…

Enhancing Negotiation of Meaning through Task Familiarity Using Subtitled Videos in an Online TBLL Environment

ERIC Educational Resources Information Center

Arslanyilmaz, Abdurrahman; Pedersen, Susan

2010-01-01

This study examines the effects of task familiarity through the use of subtitled videos on negotiation of meaning in an online task-based language learning (TBLL) environment. It explores the amount of negotiation of meaning produced by non-native speakers (NNSs) aimed at improving input comprehension to enhance second language acquisition. Ten…

Managing Academic Tasks in Junior High School: Background, Design, and Methodology. (R & D Rep. No. 6185).

ERIC Educational Resources Information Center

Doyle, Walter; And Others

This report describes the conceptual background, design, and methodology for a study of management of academic tasks in junior high school. Previous research suggests that tasks students accomplish in classrooms determine what they actually learn, and acquisition of higher cognitive skills related to interpretation and planning is essential for…

Internet protocol network mapper

DOEpatents

Youd, David W.; Colon III, Domingo R.; Seidl, Edward T.

2016-02-23

A network mapper for performing tasks on targets is provided. The mapper generates a map of a network that specifies the overall configuration of the network. The mapper inputs a procedure that defines how the network is to be mapped. The procedure specifies what, when, and in what order the tasks are to be performed. Each task specifies processing that is to be performed for a target to produce results. The procedure may also specify input parameters for a task. The mapper inputs initial targets that specify a range of network addresses to be mapped. The mapper maps the network by, for each target, executing the procedure to perform the tasks on the target. The results of the tasks represent the mapping of the network defined by the initial targets.

Endophysical Models Based on Empirical Data

NASA Astrophysics Data System (ADS)

Jahn, Robert G.; Dunne, Brenda J.

2005-10-01

Any proposed endophysical models need to acknowledge a number of subjective correlates that have been well established in such objectively quantifiable experimental contexts as anomalous human/machine interactions and remote perception information acquisition. Most notable of these factors are conscious and unconscious intention; gender disparities; serial position effects; intrinsic uncertainties; elusive replicability; and emotional resonance between the participants and the devices, process, and tasks. Perhaps even more pertinent are the insensitivities of the anomalous effects to spatial and temporal separations of the participants from the physical targets. Inclusion of subjective coordinates in the models, and exclusion of physical distance and time, raise formidable issues of specification, quantification, and dynamical formulation from both the physical and psychological perspectives. A few primitive examples of possible approaches are presented.

Helicopter human factors

NASA Technical Reports Server (NTRS)

Hart, Sandra G.

1988-01-01

The state-of-the-art helicopter and its pilot are examined using the tools of human-factors analysis. The significant role of human error in helicopter accidents is discussed; the history of human-factors research on helicopters is briefly traced; the typical flight tasks are described; and the noise, vibration, and temperature conditions typical of modern military helicopters are characterized. Also considered are helicopter controls, cockpit instruments and displays, and the impact of cockpit design on pilot workload. Particular attention is given to possible advanced-technology improvements, such as control stabilization and augmentation, FBW and fly-by-light systems, multifunction displays, night-vision goggles, pilot night-vision systems, night-vision displays with superimposed symbols, target acquisition and designation systems, and aural displays. Diagrams, drawings, and photographs are provided.

Reach on sound: a key to object permanence in visually impaired children.

PubMed

Fazzi, Elisa; Signorini, Sabrina Giovanna; Bomba, Monica; Luparia, Antonella; Lanners, Josée; Balottin, Umberto

2011-04-01

The capacity to reach an object presented through sound clue indicates, in the blind child, the acquisition of object permanence and gives information over his/her cognitive development. To assess cognitive development in congenitally blind children with or without multiple disabilities. Cohort study. Thirty-seven congenitally blind subjects (17 with associated multiple disabilities, 20 mainly blind) were enrolled. We used Bigelow's protocol to evaluate "reach on sound" capacity over time (at 6, 12, 18, 24, and 36 months), and a battery of clinical, neurophysiological and cognitive instruments to assess clinical features. Tasks n.1 to 5 were acquired by most of the mainly blind children by 12 months of age. Task 6 coincided with a drop in performance, and the acquisition of the subsequent tasks showed a less agehomogeneous pattern. In blind children with multiple disabilities, task acquisition rates were lower, with the curves dipping in relation to the more complex tasks. The mainly blind subjects managed to overcome Fraiberg's "conceptual problem"--i.e., they acquired the ability to attribute an external object with identity and substance even when it manifested its presence through sound only--and thus developed the ability to reach an object presented through sound. Instead, most of the blind children with multiple disabilities presented poor performances on the "reach on sound" protocol and were unable, before 36 months of age, to develop the strategies needed to resolve Fraiberg's "conceptual problem". Copyright © 2011 Elsevier Ltd. All rights reserved.

Deveopment of Liquid Hydrogen Target and Data Acquisition System for MUSE

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

Briscoe, William John

The product describes the results of an R and D grant to produce a conceptual design of a liquid hydrogen target and a data acquisition for the MUSE Proton Radius Measurement at the Paul Scherrer Institute in Villigen, Switzerland.

Limitations of contrast enhancement for infrared target identification

NASA Astrophysics Data System (ADS)

Du Bosq, Todd W.; Fanning, Jonathan D.

2009-05-01

Contrast enhancement and dynamic range compression are currently being used to improve the performance of infrared imagers by increasing the contrast between the target and the scene content. Automatic contrast enhancement techniques do not always achieve this improvement. In some cases, the contrast can increase to a level of target saturation. This paper assesses the range-performance effects of contrast enhancement for target identification as a function of image saturation. Human perception experiments were performed to determine field performance using contrast enhancement on the U.S. Army RDECOM CERDEC NVESD standard military eight target set using an un-cooled LWIR camera. The experiments compare the identification performance of observers viewing contrast enhancement processed images at various levels of saturation. Contrast enhancement is modeled in the U.S. Army thermal target acquisition model (NVThermIP) by changing the scene contrast temperature. The model predicts improved performance based on any improved target contrast, regardless of specific feature saturation or enhancement. The measured results follow the predicted performance based on the target task difficulty metric used in NVThermIP for the non-saturated cases. The saturated images reduce the information contained in the target and performance suffers. The model treats the contrast of the target as uniform over spatial frequency. As the contrast is enhanced, the model assumes that the contrast is enhanced uniformly over the spatial frequencies. After saturation, the spatial cues that differentiate one tank from another are located in a limited band of spatial frequencies. A frequency dependent treatment of target contrast is needed to predict performance of over-processed images.

Reprint of: Early Behavioural Facilitation by Temporal Expectations in Complex Visual-motor Sequences.

PubMed

Heideman, Simone G; van Ede, Freek; Nobre, Anna C

2018-05-24

In daily life, temporal expectations may derive from incidental learning of recurring patterns of intervals. We investigated the incidental acquisition and utilisation of combined temporal-ordinal (spatial/effector) structure in complex visual-motor sequences using a modified version of a serial reaction time (SRT) task. In this task, not only the series of targets/responses, but also the series of intervals between subsequent targets was repeated across multiple presentations of the same sequence. Each participant completed three sessions. In the first session, only the repeating sequence was presented. During the second and third session, occasional probe blocks were presented, where a new (unlearned) spatial-temporal sequence was introduced. We first confirm that participants not only got faster over time, but that they were slower and less accurate during probe blocks, indicating that they incidentally learned the sequence structure. Having established a robust behavioural benefit induced by the repeating spatial-temporal sequence, we next addressed our central hypothesis that implicit temporal orienting (evoked by the learned temporal structure) would have the largest influence on performance for targets following short (as opposed to longer) intervals between temporally structured sequence elements, paralleling classical observations in tasks using explicit temporal cues. We found that indeed, reaction time differences between new and repeated sequences were largest for the short interval, compared to the medium and long intervals, and that this was the case, even when comparing late blocks (where the repeated sequence had been incidentally learned), to early blocks (where this sequence was still unfamiliar). We conclude that incidentally acquired temporal expectations that follow a sequential structure can have a robust facilitatory influence on visually-guided behavioural responses and that, like more explicit forms of temporal orienting, this effect is most pronounced for sequence elements that are expected at short inter-element intervals. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Neural control of cursor trajectory and click by a human with tetraplegia 1000 days after implant of an intracortical microelectrode array

NASA Astrophysics Data System (ADS)

Simeral, J. D.; Kim, S.-P.; Black, M. J.; Donoghue, J. P.; Hochberg, L. R.

2011-04-01

The ongoing pilot clinical trial of the BrainGate neural interface system aims in part to assess the feasibility of using neural activity obtained from a small-scale, chronically implanted, intracortical microelectrode array to provide control signals for a neural prosthesis system. Critical questions include how long implanted microelectrodes will record useful neural signals, how reliably those signals can be acquired and decoded, and how effectively they can be used to control various assistive technologies such as computers and robotic assistive devices, or to enable functional electrical stimulation of paralyzed muscles. Here we examined these questions by assessing neural cursor control and BrainGate system characteristics on five consecutive days 1000 days after implant of a 4 × 4 mm array of 100 microelectrodes in the motor cortex of a human with longstanding tetraplegia subsequent to a brainstem stroke. On each of five prospectively-selected days we performed time-amplitude sorting of neuronal spiking activity, trained a population-based Kalman velocity decoding filter combined with a linear discriminant click state classifier, and then assessed closed-loop point-and-click cursor control. The participant performed both an eight-target center-out task and a random target Fitts metric task which was adapted from a human-computer interaction ISO standard used to quantify performance of computer input devices. The neural interface system was further characterized by daily measurement of electrode impedances, unit waveforms and local field potentials. Across the five days, spiking signals were obtained from 41 of 96 electrodes and were successfully decoded to provide neural cursor point-and-click control with a mean task performance of 91.3% ± 0.1% (mean ± s.d.) correct target acquisition. Results across five consecutive days demonstrate that a neural interface system based on an intracortical microelectrode array can provide repeatable, accurate point-and-click control of a computer interface to an individual with tetraplegia 1000 days after implantation of this sensor.

Neural control of cursor trajectory and click by a human with tetraplegia 1000 days after implant of an intracortical microelectrode array

PubMed Central

Simeral, J D; Kim, S-P; Black, M J; Donoghue, J P; Hochberg, L R

2013-01-01

The ongoing pilot clinical trial of the BrainGate neural interface system aims in part to assess the feasibility of using neural activity obtained from a small-scale, chronically implanted, intracortical microelectrode array to provide control signals for a neural prosthesis system. Critical questions include how long implanted microelectrodes will record useful neural signals, how reliably those signals can be acquired and decoded, and how effectively they can be used to control various assistive technologies such as computers and robotic assistive devices, or to enable functional electrical stimulation of paralyzed muscles. Here we examined these questions by assessing neural cursor control and BrainGate system characteristics on five consecutive days 1000 days after implant of a 4 × 4 mm array of 100 microelectrodes in the motor cortex of a human with longstanding tetraplegia subsequent to a brainstem stroke. On each of five prospectively-selected days we performed time-amplitude sorting of neuronal spiking activity, trained a population-based Kalman velocity decoding filter combined with a linear discriminant click state classifier, and then assessed closed-loop point-and-click cursor control. The participant performed both an eight-target center-out task and a random target Fitts metric task which was adapted from a human-computer interaction ISO standard used to quantify performance of computer input devices. The neural interface system was further characterized by daily measurement of electrode impedances, unit waveforms and local field potentials. Across the five days, spiking signals were obtained from 41 of 96 electrodes and were successfully decoded to provide neural cursor point-and-click control with a mean task performance of 91.3% ± 0.1% (mean ± s.d.) correct target acquisition. Results across five consecutive days demonstrate that a neural interface system based on an intracortical microelectrode array can provide repeatable, accurate point-and-click control of a computer interface to an individual with tetraplegia 1000 days after implantation of this sensor. PMID:21436513

The Utility of Cognitive Plausibility in Language Acquisition Modeling: Evidence From Word Segmentation.

PubMed

Phillips, Lawrence; Pearl, Lisa

2015-11-01

The informativity of a computational model of language acquisition is directly related to how closely it approximates the actual acquisition task, sometimes referred to as the model's cognitive plausibility. We suggest that though every computational model necessarily idealizes the modeled task, an informative language acquisition model can aim to be cognitively plausible in multiple ways. We discuss these cognitive plausibility checkpoints generally and then apply them to a case study in word segmentation, investigating a promising Bayesian segmentation strategy. We incorporate cognitive plausibility by using an age-appropriate unit of perceptual representation, evaluating the model output in terms of its utility, and incorporating cognitive constraints into the inference process. Our more cognitively plausible model shows a beneficial effect of cognitive constraints on segmentation performance. One interpretation of this effect is as a synergy between the naive theories of language structure that infants may have and the cognitive constraints that limit the fidelity of their inference processes, where less accurate inference approximations are better when the underlying assumptions about how words are generated are less accurate. More generally, these results highlight the utility of incorporating cognitive plausibility more fully into computational models of language acquisition. Copyright © 2015 Cognitive Science Society, Inc.

What top-down task sets do for us: an ERP study on the benefits of advance preparation in visual search.

PubMed

Eimer, Martin; Kiss, Monika; Nicholas, Susan

2011-12-01

When target-defining features are specified in advance, attentional target selection in visual search is controlled by preparatory top-down task sets. We used ERP measures to study voluntary target selection in the absence of such feature-specific task sets, and to compare it to selection that is guided by advance knowledge about target features. Visual search arrays contained two different color singleton digits, and participants had to select one of these as target and report its parity. Target color was either known in advance (fixed color task) or had to be selected anew on each trial (free color-choice task). ERP correlates of spatially selective attentional target selection (N2pc) and working memory processing (SPCN) demonstrated rapid target selection and efficient exclusion of color singleton distractors from focal attention and working memory in the fixed color task. In the free color-choice task, spatially selective processing also emerged rapidly, but selection efficiency was reduced, with nontarget singleton digits capturing attention and gaining access to working memory. Results demonstrate the benefits of top-down task sets: Feature-specific advance preparation accelerates target selection, rapidly resolves attentional competition, and prevents irrelevant events from attracting attention and entering working memory.

Task-driven imaging in cone-beam computed tomography.

PubMed

Gang, G J; Stayman, J W; Ouadah, S; Ehtiati, T; Siewerdsen, J H

Conventional workflow in interventional imaging often ignores a wealth of prior information of the patient anatomy and the imaging task. This work introduces a task-driven imaging framework that utilizes such information to prospectively design acquisition and reconstruction techniques for cone-beam CT (CBCT) in a manner that maximizes task-based performance in subsequent imaging procedures. The framework is employed in jointly optimizing tube current modulation, orbital tilt, and reconstruction parameters in filtered backprojection reconstruction for interventional imaging. Theoretical predictors of noise and resolution relates acquisition and reconstruction parameters to task-based detectability. Given a patient-specific prior image and specification of the imaging task, an optimization algorithm prospectively identifies the combination of imaging parameters that maximizes task-based detectability. Initial investigations were performed for a variety of imaging tasks in an elliptical phantom and an anthropomorphic head phantom. Optimization of tube current modulation and view-dependent reconstruction kernel was shown to have greatest benefits for a directional task (e.g., identification of device or tissue orientation). The task-driven approach yielded techniques in which the dose and sharp kernels were concentrated in views contributing the most to the signal power associated with the imaging task. For example, detectability of a line pair detection task was improved by at least three fold compared to conventional approaches. For radially symmetric tasks, the task-driven strategy yielded results similar to a minimum variance strategy in the absence of kernel modulation. Optimization of the orbital tilt successfully avoided highly attenuating structures that can confound the imaging task by introducing noise correlations masquerading at spatial frequencies of interest. This work demonstrated the potential of a task-driven imaging framework to improve image quality and reduce dose beyond that achievable with conventional imaging approaches.

Modeling human target acquisition in ground-to-air weapon systems

NASA Technical Reports Server (NTRS)

Phatak, A. V.; Mohr, R. L.; Vikmanis, M.; Wei, K. C.

1982-01-01

The problems associated with formulating and validating mathematical models for describing and predicting human target acquisition response are considered. In particular, the extension of the human observer model to include the acquisition phase as well as the tracking segment is presented. Relationship of the Observer model structure to the more complex Standard Optimal Control model formulation and to the simpler Transfer Function/Noise representation is discussed. Problems pertinent to structural identifiability and the form of the parameterization are elucidated. A systematic approach toward the identification of the observer acquisition model parameters from ensemble tracking error data is presented.

Pushing spatial and temporal resolution for functional and diffusion MRI in the Human Connectome Project

PubMed Central

Uğurbil, Kamil; Xu, Junqian; Auerbach, Edward J.; Moeller, Steen; Vu, An; Duarte-Carvajalino, Julio M.; Lenglet, Christophe; Wu, Xiaoping; Schmitter, Sebastian; Van de Moortele, Pierre Francois; Strupp, John; Sapiro, Guillermo; De Martino, Federico; Wang, Dingxin; Harel, Noam; Garwood, Michael; Chen, Liyong; Feinberg, David A.; Smith, Stephen M.; Miller, Karla L.; Sotiropoulos, Stamatios N; Jbabdi, Saad; Andersson, Jesper L; Behrens, Timothy EJ; Glasser, Matthew F.; Van Essen, David; Yacoub, Essa

2013-01-01

The human connectome project (HCP) relies primarily on three complementary magnetic resonance (MR) methods. These are: 1) resting state functional MR imaging (rfMRI) which uses correlations in the temporal fluctuations in an fMRI time series to deduce ‘functional connectivity’; 2) diffusion imaging (dMRI), which provides the input for tractography algorithms used for the reconstruction of the complex axonal fiber architecture; and 3) task based fMRI (tfMRI), which is employed to identify functional parcellation in the human brain in order to assist analyses of data obtained with the first two methods. We describe technical improvements and optimization of these methods as well as instrumental choices that impact speed of acquisition of fMRI and dMRI images at 3 Tesla, leading to whole brain coverage with 2 mm isotropic resolution in 0.7 second for fMRI, and 1.25 mm isotropic resolution dMRI data for tractography analysis with three-fold reduction in total data acquisition time. Ongoing technical developments and optimization for acquisition of similar data at 7 Tesla magnetic field are also presented, targeting higher resolution, specificity of functional imaging signals, mitigation of the inhomogeneous radio frequency (RF) fields and power deposition. Results demonstrate that overall, these approaches represent a significant advance in MR imaging of the human brain to investigate brain function and structure. PMID:23702417

77 FR 21087 - Renewal of Department of Defense Federal Advisory Committees

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-09

..., engineering, and manufacturing, and will ensure the identification of new technologies and new applications of... for Acquisition, Technology and Logistics, the Chairman of the Joint Chiefs of Staff, and as requested..., technology, manufacturing, acquisition process, and other matters of special interest to the DoD. Tasks...

Age of Acquisition and Imageability: A Cross-Task Comparison

ERIC Educational Resources Information Center

Ploetz, Danielle M.; Yates, Mark

2016-01-01

Previous research has reported an imageability effect on visual word recognition. Words that are high in imageability are recognised more rapidly than are those lower in imageability. However, later researchers argued that imageability was confounded with age of acquisition. In the current research, these two factors were manipulated in a…

75 FR 10190 - Defense Federal Acquisition Regulation Supplement; Payment of Costs Prior to Definitization...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-05

... Acquisition Regulation Supplement; Payment of Costs Prior to Definitization-Definition of Contract Action... the definition of ``contract action'' at DFARS 217.7401. This is not a significant regulatory action... paragraph (a)(3) to read as follows: 217.7401 Definitions. * * * * * (a) * * * (2) It includes task orders...

Inexpensive Data Acquisition with a Sound Card

ERIC Educational Resources Information Center

Hassan, Umer; Pervaiz, Saad; Anwar, Muhammad Sabieh

2011-01-01

Signal generators, oscilloscopes, and data acquisition (DAQ) systems are standard components of the modern experimental physics laboratory. The sound card, a built-in component in the ubiquitous personal computer, can be utilized for all three of these tasks and offers an attractive option for labs in developing countries such as…

Improved Acquisition for System Sustainment: Availability-Based Importance Framework for Maintenance, Repair, and Overhaul Acquisition

DTIC Science & Technology

2015-06-30

when these equipment failures cause some of the worst accidents and environmental damages in human history such as the March 2011 Fukushima Nuclear ...ultimately facilitate the MRO acquisition process through effective maintenance triggers and supplier selection Task 2. Stochastic Availability Importance...dollars with a replacement plan lasting for several decades [GAO 2004]. A budget reduction of about 29 percent since 1990 has “forced the branches of the

Prediction Markets for Defense Acquisition: The Devil is in the Details

DTIC Science & Technology

2010-05-01

1 Bill Gates, Pete Coughlan, Noah Myung, Jeremy Arkes Professors of Economics Naval Postgraduate School Prediction Markets for Defense Acquisition...Acquisition: The Devil is in the Details 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT NUMBER 5e...TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) Naval Postgraduate School,Monterey,CA,93943 8. PERFORMING

Mathematics anxiety in children with developmental dyscalculia

PubMed Central

2010-01-01

Background Math anxiety, defined as a negative affective response to mathematics, is known to have deleterious effects on math performance in the general population. However, the assumption that math anxiety is directly related to math performance, has not yet been validated. Thus, our primary objective was to investigate the effects of math anxiety on numerical processing in children with specific deficits in the acquisition of math skills (Developmental Dyscalculia; DD) by using a novel affective priming task as an indirect measure. Methods Participants (12 children with DD and 11 typically-developing peers) completed a novel priming task in which an arithmetic equation was preceded by one of four types of priming words (positive, neutral, negative or related to mathematics). Children were required to indicate whether the equation (simple math facts based on addition, subtraction, multiplication or division) was true or false. Typically, people respond to target stimuli more quickly after presentation of an affectively-related prime than after one that is unrelated affectively. Result Participants with DD responded faster to targets that were preceded by both negative primes and math-related primes. A reversed pattern was present in the control group. Conclusion These results reveal a direct link between emotions, arithmetic and low achievement in math. It is also suggested that arithmetic-affective priming might be used as an indirect measure of math anxiety. PMID:20633269

Portable and Accessible Video Modeling: Teaching a Series of Novel Skills within School and Community Settings

ERIC Educational Resources Information Center

Taber-Doughty, Teresa; Miller, Bridget; Shurr, Jordan; Wiles, Benjamin

2013-01-01

This study examined the effectiveness of self-operated video models on the skill acquisition of a series of novel tasks taught in community-based settings. In addition, the percent of independent task transitions and the duration at which four secondary students with a moderate intellectual disability transitioned between tasks was also examined.…

Effects of Task Index Variations On Transfer of Training Criteria. Final Report.

ERIC Educational Resources Information Center

Mirabella, Angelo; Wheaton, George R.

The concluding series of a research program designed to validate a battery of task indexes for use in forecasting the effectiveness of training devices is described. Phase I collated 17 task indexes and applied them to sonar training devices, while in Phase II the 17 index battery was validated, using skill acquisition measures as criteria.…

Dissociable effects of practice variability on learning motor and timing skills.

PubMed

Caramiaux, Baptiste; Bevilacqua, Frédéric; Wanderley, Marcelo M; Palmer, Caroline

2018-01-01

Motor skill acquisition inherently depends on the way one practices the motor task. The amount of motor task variability during practice has been shown to foster transfer of the learned skill to other similar motor tasks. In addition, variability in a learning schedule, in which a task and its variations are interweaved during practice, has been shown to help the transfer of learning in motor skill acquisition. However, there is little evidence on how motor task variations and variability schedules during practice act on the acquisition of complex motor skills such as music performance, in which a performer learns both the right movements (motor skill) and the right time to perform them (timing skill). This study investigated the impact of rate (tempo) variability and the schedule of tempo change during practice on timing and motor skill acquisition. Complete novices, with no musical training, practiced a simple musical sequence on a piano keyboard at different rates. Each novice was assigned to one of four learning conditions designed to manipulate the amount of tempo variability across trials (large or small tempo set) and the schedule of tempo change (randomized or non-randomized order) during practice. At test, the novices performed the same musical sequence at a familiar tempo and at novel tempi (testing tempo transfer), as well as two novel (but related) sequences at a familiar tempo (testing spatial transfer). We found that practice conditions had little effect on learning and transfer performance of timing skill. Interestingly, practice conditions influenced motor skill learning (reduction of movement variability): lower temporal variability during practice facilitated transfer to new tempi and new sequences; non-randomized learning schedule improved transfer to new tempi and new sequences. Tempo (rate) and the sequence difficulty (spatial manipulation) affected performance variability in both timing and movement. These findings suggest that there is a dissociable effect of practice variability on learning complex skills that involve both motor and timing constraints.

Age of acquisition affects the retrieval of grammatical category information.

PubMed

Bai, Lili; Ma, Tengfei; Dunlap, Susan; Chen, Baoguo

2013-01-01

This study investigated age of acquisition (AoA) effects on processing grammatical category information of Chinese single-character words. In Experiment 1, nouns and verbs that were acquired at different ages were used as materials in a grammatical category decision task. Results showed that the grammatical category information of earlier acquired nouns and verbs was easier to retrieve. In Experiment 2, AoA and predictability from orthography to grammatical category were manipulated in a grammatical category decision task. Results showed larger AoA effects under lower predictability conditions. In Experiment 3, a semantic category decision task was used with the same materials as those in Experiment 2. Different results were found from Experiment 2, suggesting that the grammatical category decision task is not merely the same as the semantic category decision task, but rather involves additional processing of grammatical category information. Therefore the conclusions of Experiments 1 and 2 were strengthened. In summary, it was found for the first time that AoA affects the retrieval of grammatical category information, thus providing new evidence in support of the arbitrary mapping hypothesis.

Classification and data acquisition with incomplete data

NASA Astrophysics Data System (ADS)

Williams, David P.

In remote-sensing applications, incomplete data can result when only a subset of sensors (e.g., radar, infrared, acoustic) are deployed at certain regions. The limitations of single sensor systems have spurred interest in employing multiple sensor modalities simultaneously. For example, in land mine detection tasks, different sensor modalities are better-suited to capture different aspects of the underlying physics of the mines. Synthetic aperture radar sensors may be better at detecting surface mines, while infrared sensors may be better at detecting buried mines. By employing multiple sensor modalities to address the detection task, the strengths of the disparate sensors can be exploited in a synergistic manner to improve performance beyond that which would be achievable with either single sensor alone. When multi-sensor approaches are employed, however, incomplete data can be manifested. If each sensor is located on a separate platform ( e.g., aircraft), each sensor may interrogate---and hence collect data over---only partially overlapping areas of land. As a result, some data points may be characterized by data (i.e., features) from only a subset of the possible sensors employed in the task. Equivalently, this scenario implies that some data points will be missing features. Increasing focus in the future on using---and fusing data from---multiple sensors will make such incomplete-data problems commonplace. In many applications involving incomplete data, it is possible to acquire the missing data at a cost. In multi-sensor remote-sensing applications, data is acquired by deploying sensors to data points. Acquiring data is usually an expensive, time-consuming task, a fact that necessitates an intelligent data acquisition process. Incomplete data is not limited to remote-sensing applications, but rather, can arise in virtually any data set. In this dissertation, we address the general problem of classification when faced with incomplete data. We also address the closely related problem of active data acquisition, which develops a strategy to acquire missing features and labels that will most benefit the classification task. We first address the general problem of classification with incomplete data, maintaining the view that all data (i.e., information) is valuable. We employ a logistic regression framework within which we formulate a supervised classification algorithm for incomplete data. This principled, yet flexible, framework permits several interesting extensions that allow all available data to be utilized. One extension incorporates labeling error, which permits the usage of potentially imperfectly labeled data in learning a classifier. A second major extension converts the proposed algorithm to a semi-supervised approach by utilizing unlabeled data via graph-based regularization. Finally, the classification algorithm is extended to the case in which (image) data---from which features are extracted---are available from multiple resolutions. Taken together, this family of incomplete-data classification algorithms exploits all available data in a principled manner by avoiding explicit imputation. Instead, missing data is integrated out analytically with the aid of an estimated conditional density function (conditioned on the observed features). This feat is accomplished by invoking only mild assumptions. We also address the problem of active data acquisition by determining which missing data should be acquired to most improve performance. Specifically, we examine this data acquisition task when the data to be acquired can be either labels or features. The proposed approach is based on a criterion that accounts for the expected benefit of the acquisition. This approach, which is applicable for any general missing data problem, exploits the incomplete-data classification framework introduced in the first part of this dissertation. This data acquisition approach allows for the acquisition of both labels and features. Moreover, several types of feature acquisition are permitted, including the acquisition of individual or multiple features for individual or multiple data points, which may be either labeled or unlabeled. Furthermore, if different types of data acquisition are feasible for a given application, the algorithm will automatically determine the most beneficial type of data to acquire. Experimental results on both benchmark machine learning data sets and real (i.e., measured) remote-sensing data demonstrate the advantages of the proposed incomplete-data classification and active data acquisition algorithms.

Dynamic whole body PET parametric imaging: II. Task-oriented statistical estimation

PubMed Central

Karakatsanis, Nicolas A.; Lodge, Martin A.; Zhou, Y.; Wahl, Richard L.; Rahmim, Arman

2013-01-01

In the context of oncology, dynamic PET imaging coupled with standard graphical linear analysis has been previously employed to enable quantitative estimation of tracer kinetic parameters of physiological interest at the voxel level, thus, enabling quantitative PET parametric imaging. However, dynamic PET acquisition protocols have been confined to the limited axial field-of-view (~15–20cm) of a single bed position and have not been translated to the whole-body clinical imaging domain. On the contrary, standardized uptake value (SUV) PET imaging, considered as the routine approach in clinical oncology, commonly involves multi-bed acquisitions, but is performed statically, thus not allowing for dynamic tracking of the tracer distribution. Here, we pursue a transition to dynamic whole body PET parametric imaging, by presenting, within a unified framework, clinically feasible multi-bed dynamic PET acquisition protocols and parametric imaging methods. In a companion study, we presented a novel clinically feasible dynamic (4D) multi-bed PET acquisition protocol as well as the concept of whole body PET parametric imaging employing Patlak ordinary least squares (OLS) regression to estimate the quantitative parameters of tracer uptake rate Ki and total blood distribution volume V. In the present study, we propose an advanced hybrid linear regression framework, driven by Patlak kinetic voxel correlations, to achieve superior trade-off between contrast-to-noise ratio (CNR) and mean squared error (MSE) than provided by OLS for the final Ki parametric images, enabling task-based performance optimization. Overall, whether the observer's task is to detect a tumor or quantitatively assess treatment response, the proposed statistical estimation framework can be adapted to satisfy the specific task performance criteria, by adjusting the Patlak correlation-coefficient (WR) reference value. The multi-bed dynamic acquisition protocol, as optimized in the preceding companion study, was employed along with extensive Monte Carlo simulations and an initial clinical FDG patient dataset to validate and demonstrate the potential of the proposed statistical estimation methods. Both simulated and clinical results suggest that hybrid regression in the context of whole-body Patlak Ki imaging considerably reduces MSE without compromising high CNR. Alternatively, for a given CNR, hybrid regression enables larger reductions than OLS in the number of dynamic frames per bed, allowing for even shorter acquisitions of ~30min, thus further contributing to the clinical adoption of the proposed framework. Compared to the SUV approach, whole body parametric imaging can provide better tumor quantification, and can act as a complement to SUV, for the task of tumor detection. PMID:24080994

Dynamic whole-body PET parametric imaging: II. Task-oriented statistical estimation.

PubMed

Karakatsanis, Nicolas A; Lodge, Martin A; Zhou, Y; Wahl, Richard L; Rahmim, Arman

2013-10-21

In the context of oncology, dynamic PET imaging coupled with standard graphical linear analysis has been previously employed to enable quantitative estimation of tracer kinetic parameters of physiological interest at the voxel level, thus, enabling quantitative PET parametric imaging. However, dynamic PET acquisition protocols have been confined to the limited axial field-of-view (~15-20 cm) of a single-bed position and have not been translated to the whole-body clinical imaging domain. On the contrary, standardized uptake value (SUV) PET imaging, considered as the routine approach in clinical oncology, commonly involves multi-bed acquisitions, but is performed statically, thus not allowing for dynamic tracking of the tracer distribution. Here, we pursue a transition to dynamic whole-body PET parametric imaging, by presenting, within a unified framework, clinically feasible multi-bed dynamic PET acquisition protocols and parametric imaging methods. In a companion study, we presented a novel clinically feasible dynamic (4D) multi-bed PET acquisition protocol as well as the concept of whole-body PET parametric imaging employing Patlak ordinary least squares (OLS) regression to estimate the quantitative parameters of tracer uptake rate Ki and total blood distribution volume V. In the present study, we propose an advanced hybrid linear regression framework, driven by Patlak kinetic voxel correlations, to achieve superior trade-off between contrast-to-noise ratio (CNR) and mean squared error (MSE) than provided by OLS for the final Ki parametric images, enabling task-based performance optimization. Overall, whether the observer's task is to detect a tumor or quantitatively assess treatment response, the proposed statistical estimation framework can be adapted to satisfy the specific task performance criteria, by adjusting the Patlak correlation-coefficient (WR) reference value. The multi-bed dynamic acquisition protocol, as optimized in the preceding companion study, was employed along with extensive Monte Carlo simulations and an initial clinical (18)F-deoxyglucose patient dataset to validate and demonstrate the potential of the proposed statistical estimation methods. Both simulated and clinical results suggest that hybrid regression in the context of whole-body Patlak Ki imaging considerably reduces MSE without compromising high CNR. Alternatively, for a given CNR, hybrid regression enables larger reductions than OLS in the number of dynamic frames per bed, allowing for even shorter acquisitions of ~30 min, thus further contributing to the clinical adoption of the proposed framework. Compared to the SUV approach, whole-body parametric imaging can provide better tumor quantification, and can act as a complement to SUV, for the task of tumor detection.

Household Task Delegation among High-Fertility Forager-Horticulturalists of Lowland Bolivia.

PubMed

Stieglitz, Jonathan; Gurven, Michael; Kaplan, Hillard; Hooper, Paul L

2013-04-01

Human kin cooperation is universal, leading researchers to label humans as "cooperative breeders." Despite widespread interest in human cooperation, there has been no systematic study of how household economic decision making occurs. We document age and sex profiles of task delegation by parents to children ages 4-18 among Bolivian forager-horticulturalists. We test for sex differences in the probability of delegation and examine whether tasks are more likely delegated as household labor demand increases. We also test whether food acquisition tasks are more likely delegated to higher producers. We find mixed support for the prediction that girls are more likely delegated domestic and alloparenting tasks than boys ( n = 173 children). Both sexes are more likely delegated tasks during rice harvest months; number of coresident young children is also associated with greater probability of delegated allocare, although the effect retains significance for girls only. For both sexes, father absence is associated with greater probability of delegation, particularly for food acquisition tasks. Children delegated rice harvesting achieve 45% higher mean daily caloric returns from harvesting than children not delegated harvesting. Our results therefore suggest that delegation increases household economic efficiency. We find mixed support for the hypothesis that delegation prepares children for sex-specific adult roles.

Household Task Delegation among High-Fertility Forager-Horticulturalists of Lowland Bolivia

PubMed Central

Stieglitz, Jonathan; Gurven, Michael; Kaplan, Hillard; Hooper, Paul L.

2013-01-01

Human kin cooperation is universal, leading researchers to label humans as “cooperative breeders.” Despite widespread interest in human cooperation, there has been no systematic study of how household economic decision making occurs. We document age and sex profiles of task delegation by parents to children ages 4–18 among Bolivian forager-horticulturalists. We test for sex differences in the probability of delegation and examine whether tasks are more likely delegated as household labor demand increases. We also test whether food acquisition tasks are more likely delegated to higher producers. We find mixed support for the prediction that girls are more likely delegated domestic and alloparenting tasks than boys (n = 173 children). Both sexes are more likely delegated tasks during rice harvest months; number of coresident young children is also associated with greater probability of delegated allocare, although the effect retains significance for girls only. For both sexes, father absence is associated with greater probability of delegation, particularly for food acquisition tasks. Children delegated rice harvesting achieve 45% higher mean daily caloric returns from harvesting than children not delegated harvesting. Our results therefore suggest that delegation increases household economic efficiency. We find mixed support for the hypothesis that delegation prepares children for sex-specific adult roles. PMID:25284827

Microcomputer data acquisition and control.

PubMed

East, T D

1986-01-01

In medicine and biology there are many tasks that involve routine well defined procedures. These tasks are ideal candidates for computerized data acquisition and control. As the performance of microcomputers rapidly increases and cost continues to go down the temptation to automate the laboratory becomes great. To the novice computer user the choices of hardware and software are overwhelming and sadly most of the computer sales persons are not at all familiar with real-time applications. If you want to bill your patients you have hundreds of packaged systems to choose from; however, if you want to do real-time data acquisition the choices are very limited and confusing. The purpose of this chapter is to provide the novice computer user with the basics needed to set up a real-time data acquisition system with the common microcomputers. This chapter will cover the following issues necessary to establish a real time data acquisition and control system: Analysis of the research problem: Definition of the problem; Description of data and sampling requirements; Cost/benefit analysis. Choice of Microcomputer hardware and software: Choice of microprocessor and bus structure; Choice of operating system; Choice of layered software. Digital Data Acquisition: Parallel Data Transmission; Serial Data Transmission; Hardware and software available. Analog Data Acquisition: Description of amplitude and frequency characteristics of the input signals; Sampling theorem; Specification of the analog to digital converter; Hardware and software available; Interface to the microcomputer. Microcomputer Control: Analog output; Digital output; Closed-Loop Control. Microcomputer data acquisition and control in the 21st Century--What is in the future? High speed digital medical equipment networks; Medical decision making and artificial intelligence.

Standards for data acquisition and software-based analysis of in vivo electroencephalography recordings from animals. A TASK1-WG5 report of the AES/ILAE Translational Task Force of the ILAE.

PubMed

Moyer, Jason T; Gnatkovsky, Vadym; Ono, Tomonori; Otáhal, Jakub; Wagenaar, Joost; Stacey, William C; Noebels, Jeffrey; Ikeda, Akio; Staley, Kevin; de Curtis, Marco; Litt, Brian; Galanopoulou, Aristea S

2017-11-01

Electroencephalography (EEG)-the direct recording of the electrical activity of populations of neurons-is a tremendously important tool for diagnosing, treating, and researching epilepsy. Although standard procedures for recording and analyzing human EEG exist and are broadly accepted, there are no such standards for research in animal models of seizures and epilepsy-recording montages, acquisition systems, and processing algorithms may differ substantially among investigators and laboratories. The lack of standard procedures for acquiring and analyzing EEG from animal models of epilepsy hinders the interpretation of experimental results and reduces the ability of the scientific community to efficiently translate new experimental findings into clinical practice. Accordingly, the intention of this report is twofold: (1) to review current techniques for the collection and software-based analysis of neural field recordings in animal models of epilepsy, and (2) to offer pertinent standards and reporting guidelines for this research. Specifically, we review current techniques for signal acquisition, signal conditioning, signal processing, data storage, and data sharing, and include applicable recommendations to standardize collection and reporting. We close with a discussion of challenges and future opportunities, and include a supplemental report of currently available acquisition systems and analysis tools. This work represents a collaboration on behalf of the American Epilepsy Society/International League Against Epilepsy (AES/ILAE) Translational Task Force (TASK1-Workgroup 5), and is part of a larger effort to harmonize video-EEG interpretation and analysis methods across studies using in vivo and in vitro seizure and epilepsy models. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Postnatal MK-801 treatment of female rats impairs acquisition of working memory, but not reference memory in an eight-arm radial maze; no beneficial effects of enriched environment.

PubMed

Nozari, Masoumeh; Mansouri, Farshad Alizadeh; Shabani, Mohammad; Nozari, Hojat; Atapour, Nafiseh

2015-07-01

Memory impairment has been documented in MK-801 (NMDA receptor antagonist) model of schizophrenia, but less is known on the rescue and/or differential effects of MK-801 on short- and long-term memories. We determined the effects of MK-801 treatment and/or enriched environment (EE) on acquisition of reference and working memory in developing rats. Female Wistar rats were injected with MK-801 (1 mg/kg) from postnatal days (P) 6-10. Task acquisition, working memory error (WME), and reference memory error (RME) were assessed in an eight-arm radial maze task. Behavioral performance of rats was also tested in an open field test before (P35-P40) and after (P65-P70) radial maze training to assess anxiety and locomotion. EE was applied from birth up to the end of experiments. MK-801 treatment did not influence task acquisition in the radial maze; however, by the end of training, MK-801-treated rats made significantly more WME, but not RME, compared to control rats. Ratio of WME to total error was also significantly higher in MK-801 group. EE prevented MK-801-associated behaviors in the open field but did not exert beneficial effects on working memory deficit in the radial maze task. EE per se affected behavioral performance of rats only in the open field test. Our results suggest that postnatal MK-801 treatment differentially affects working and reference memory in a young brain. Anxiety and hyperactivity associated with MK-801 are observed more severely in adulthood. Dissociation of the positive effects of EE may suggest selective modification of distinct pathways.

Enhancement of human cognitive performance using transcranial magnetic stimulation (TMS)

PubMed Central

Luber, Bruce; Lisanby, and Sarah H.

2014-01-01

Here we review the usefulness of transcranial magnetic stimulation (TMS) in modulating cortical networks in ways that might produce performance enhancements in healthy human subjects. To date over sixty studies have reported significant improvements in speed and accuracy in a variety of tasks involving perceptual, motor, and executive processing. Two basic categories of enhancement mechanisms are suggested by this literature: direct modulation of a cortical region or network that leads to more efficient processing, and addition-by-subtraction, which is disruption of processing which competes or distracts from task performance. Potential applications of TMS cognitive enhancement, including research into cortical function, rehabilitation therapy in neurological and psychiatric illness, and accelerated skill acquisition in healthy individuals are discussed, as are methods of optimizing the magnitude and duration of TMS-induced performance enhancement, such as improvement of targeting through further integration of brain imaging with TMS. One technique, combining multiple sessions of TMS with concurrent TMS/task performance to induce Hebbian-like learning, appears to be promising for prolonging enhancement effects. While further refinements in the application of TMS to cognitive enhancement can still be made, and questions remain regarding the mechanisms underlying the observed effects, this appears to be a fruitful area of investigation that may shed light on the basic mechanisms of cognitive function and their therapeutic modulation. PMID:23770409

Reading and visual processing in Greek dyslexic children: an eye-movement study.

PubMed

Hatzidaki, Anna; Gianneli, Maria; Petrakis, Eftichis; Makaronas, Nikolaos; Aslanides, Ioannis M

2011-02-01

We examined the impact of the effects of dyslexia on various processing and cognitive components (e.g., reading speed and accuracy) in a language with high phonological and orthographic consistency. Greek dyslexic children were compared with a chronological age-matched group on tasks that tested participants' phonological and orthographic awareness during reading and spelling, as well as their efficiency to detect a specific target-letter during a sequential visual search task. Dyslexic children showed impaired reading and spelling that was reflected in slow reading speed and error-prone performance, especially for non-words. Eye movement measures of text reading also provided supporting evidence for a reading deficit, with dyslexic participants producing more fixations and longer fixation duration as opposed to non-dyslexic participants. The results of the visual search task showed similar performance between the two groups, but when they were compared with the results of text reading, dyslexic participants were found to be able to process fewer stimuli (i.e., letters) at each fixation than non-dyslexics. Our findings further suggest that, although Greek dyslexics have the advantage of a consistent orthographic system which facilitates acquisition of reading and phonological awareness, they demonstrate more impaired access to orthographic forms than dyslexics of other transparent orthographies. Copyright © 2010 John Wiley & Sons, Ltd.

Habitual attention in older and young adults.

PubMed

Jiang, Yuhong V; Koutstaal, Wilma; Twedell, Emily L

2016-12-01

Age-related decline is pervasive in tasks that require explicit learning and memory, but such reduced function is not universally observed in tasks involving incidental learning. It is unknown if habitual attention, involving incidental probabilistic learning, is preserved in older adults. Previous research on habitual attention investigated contextual cuing in young and older adults, yet contextual cuing relies not only on spatial attention but also on context processing. Here we isolated habitual attention from context processing in young and older adults. Using a challenging visual search task in which the probability of finding targets was greater in 1 of 4 visual quadrants in all contexts, we examined the acquisition, persistence, and spatial-reference frame of habitual attention. Although older adults showed slower visual search times and steeper search slopes (more time per additional item in the search display), like young adults they rapidly acquired a strong, persistent search habit toward the high-probability quadrant. In addition, habitual attention was strongly viewer-centered in both young and older adults. The demonstration of preserved viewer-centered habitual attention in older adults suggests that it may be used to counter declines in controlled attention. This, in turn, suggests the importance, for older adults, of maintaining habit-related spatial arrangements. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Ability/Motivation Interactions in Complex Skill Acquisition

DTIC Science & Technology

1988-04-28

attentional resources. Finally, in the declarative knowledge phase, performance is slow and error prone. Once the learner has come to an adequate cognitive...mediation by the learner. After a substantial amount of consistent task practice, skilled performance becomes fast , accurate, and the task can often be

East Europe Report, Economic and Industrial Affairs

DTIC Science & Technology

1984-05-02

stations). While the first part of the task will undoubtedly be resolved in the coming decades, the prospects of very cheap energy acquisition have...34Information Theoretic Research Programs in Japan," INFORMATIK, No 1, 1983. 6. The area of information acquisition and processing is understood here in a...an,VH-!- T%be.^tl0?ed iS the traininS of »killed irrigation workers, the acquisition of milking licenses, the training of herdsmen and women with

Patients with Parkinson's disease learn to control complex systems-an indication for intact implicit cognitive skill learning.

PubMed

Witt, Karsten; Daniels, Christine; Daniel, Victoria; Schmitt-Eliassen, Julia; Volkmann, Jens; Deuschl, Günther

2006-01-01

Implicit memory and learning mechanisms are composed of multiple processes and systems. Previous studies demonstrated a basal ganglia involvement in purely cognitive tasks that form stimulus response habits by reinforcement learning such as implicit classification learning. We will test the basal ganglia influence on two cognitive implicit tasks previously described by Berry and Broadbent, the sugar production task and the personal interaction task. Furthermore, we will investigate the relationship between certain aspects of an executive dysfunction and implicit learning. To this end, we have tested 22 Parkinsonian patients and 22 age-matched controls on two implicit cognitive tasks, in which participants learned to control a complex system. They interacted with the system by choosing an input value and obtaining an output that was related in a complex manner to the input. The objective was to reach and maintain a specific target value across trials (dynamic system learning). The two tasks followed the same underlying complex rule but had different surface appearances. Subsequently, participants performed an executive test battery including the Stroop test, verbal fluency and the Wisconsin card sorting test (WCST). The results demonstrate intact implicit learning in patients, despite an executive dysfunction in the Parkinsonian group. They lead to the conclusion that the basal ganglia system affected in Parkinson's disease does not contribute to the implicit acquisition of a new cognitive skill. Furthermore, the Parkinsonian patients were able to reach a specific goal in an implicit learning context despite impaired goal directed behaviour in the WCST, a classic test of executive functions. These results demonstrate a functional independence of implicit cognitive skill learning and certain aspects of executive functions.

Vibrotactile Discrimination Training Affects Brain Connectivity in Profoundly Deaf Individuals

PubMed Central

González-Garrido, Andrés A.; Ruiz-Stovel, Vanessa D.; Gómez-Velázquez, Fabiola R.; Vélez-Pérez, Hugo; Romo-Vázquez, Rebeca; Salido-Ruiz, Ricardo A.; Espinoza-Valdez, Aurora; Campos, Luis R.

2017-01-01

Early auditory deprivation has serious neurodevelopmental and cognitive repercussions largely derived from impoverished and delayed language acquisition. These conditions may be associated with early changes in brain connectivity. Vibrotactile stimulation is a sensory substitution method that allows perception and discrimination of sound, and even speech. To clarify the efficacy of this approach, a vibrotactile oddball task with 700 and 900 Hz pure-tones as stimuli [counterbalanced as target (T: 20% of the total) and non-target (NT: 80%)] with simultaneous EEG recording was performed by 14 profoundly deaf and 14 normal-hearing (NH) subjects, before and after a short training period (five 1-h sessions; in 2.5–3 weeks). A small device worn on the right index finger delivered sound-wave stimuli. The training included discrimination of pure tone frequency and duration, and more complex natural sounds. A significant P300 amplitude increase and behavioral improvement was observed in both deaf and normal subjects, with no between group differences. However, a P3 with larger scalp distribution over parietal cortical areas and lateralized to the right was observed in the profoundly deaf. A graph theory analysis showed that brief training significantly increased fronto-central brain connectivity in deaf subjects, but not in NH subjects. Together, ERP tools and graph methods depicted the different functional brain dynamic in deaf and NH individuals, underlying the temporary engagement of the cognitive resources demanded by the task. Our findings showed that the index-fingertip somatosensory mechanoreceptors can discriminate sounds. Further studies are necessary to clarify brain connectivity dynamics associated with the performance of vibrotactile language-related discrimination tasks and the effect of lengthier training programs. PMID:28220063

Vibrotactile Discrimination Training Affects Brain Connectivity in Profoundly Deaf Individuals.

PubMed

González-Garrido, Andrés A; Ruiz-Stovel, Vanessa D; Gómez-Velázquez, Fabiola R; Vélez-Pérez, Hugo; Romo-Vázquez, Rebeca; Salido-Ruiz, Ricardo A; Espinoza-Valdez, Aurora; Campos, Luis R

2017-01-01

Early auditory deprivation has serious neurodevelopmental and cognitive repercussions largely derived from impoverished and delayed language acquisition. These conditions may be associated with early changes in brain connectivity. Vibrotactile stimulation is a sensory substitution method that allows perception and discrimination of sound, and even speech. To clarify the efficacy of this approach, a vibrotactile oddball task with 700 and 900 Hz pure-tones as stimuli [counterbalanced as target (T: 20% of the total) and non-target (NT: 80%)] with simultaneous EEG recording was performed by 14 profoundly deaf and 14 normal-hearing (NH) subjects, before and after a short training period (five 1-h sessions; in 2.5-3 weeks). A small device worn on the right index finger delivered sound-wave stimuli. The training included discrimination of pure tone frequency and duration, and more complex natural sounds. A significant P300 amplitude increase and behavioral improvement was observed in both deaf and normal subjects, with no between group differences. However, a P3 with larger scalp distribution over parietal cortical areas and lateralized to the right was observed in the profoundly deaf. A graph theory analysis showed that brief training significantly increased fronto-central brain connectivity in deaf subjects, but not in NH subjects. Together, ERP tools and graph methods depicted the different functional brain dynamic in deaf and NH individuals, underlying the temporary engagement of the cognitive resources demanded by the task. Our findings showed that the index-fingertip somatosensory mechanoreceptors can discriminate sounds. Further studies are necessary to clarify brain connectivity dynamics associated with the performance of vibrotactile language-related discrimination tasks and the effect of lengthier training programs.

Age of second language acquisition affects nonverbal conflict processing in children: an fMRI study.

PubMed

Mohades, Seyede Ghazal; Struys, Esli; Van Schuerbeek, Peter; Baeken, Chris; Van De Craen, Piet; Luypaert, Robert

2014-09-01

In their daily communication, bilinguals switch between two languages, a process that involves the selection of a target language and minimization of interference from a nontarget language. Previous studies have uncovered the neural structure in bilinguals and the activation patterns associated with performing verbal conflict tasks. One question that remains, however is whether this extra verbal switching affects brain function during nonverbal conflict tasks. In this study, we have used fMRI to investigate the impact of bilingualism in children performing two nonverbal tasks involving stimulus-stimulus and stimulus-response conflicts. Three groups of 8-11-year-old children--bilinguals from birth (2L1), second language learners (L2L), and a control group of monolinguals (1L1)--were scanned while performing a color Simon and a numerical Stroop task. Reaction times and accuracy were logged. Compared to monolingual controls, bilingual children showed higher behavioral congruency effect of these tasks, which is matched by the recruitment of brain regions that are generally used in general cognitive control, language processing or to solve language conflict situations in bilinguals (caudate nucleus, posterior cingulate gyrus, STG, precuneus). Further, the activation of these areas was found to be higher in 2L1 compared to L2L. The coupling of longer reaction times to the recruitment of extra language-related brain areas supports the hypothesis that when dealing with language conflicts the specialization of bilinguals hampers the way they can process with nonverbal conflicts, at least at early stages in life.

Perirhinal and Postrhinal, but Not Lateral Entorhinal, Cortices Are Essential for Acquisition of Trace Eyeblink Conditioning

ERIC Educational Resources Information Center

Suter, Eugenie E.; Weiss, Craig; Disterhoft, John F.

2013-01-01

The acquisition of temporal associative tasks such as trace eyeblink conditioning is hippocampus-dependent, while consolidated performance is not. The parahippocampal region mediates much of the input and output of the hippocampus, and perirhinal (PER) and entorhinal (EC) cortices support persistent spiking, a possible mediator of temporal…

Evidence for the Utility of a Photovoice Task as an Empathic Skill Acquisition Strategy among Counselors-in-Training

ERIC Educational Resources Information Center

Lenz, A. Stephen; Sangganjanavanich, Varunee Faii

2013-01-01

An instructional technique derived from photovoice was compared with a didactic approach for empathic skill acquisition among 38 master's-level counselors-in-training. Participants in the photovoice condition demonstrated marked improvements in quality of empathic statements compared with those receiving didactic lecture. Considerations for…

Data-Acquisition System With Remotely Adjustable Amplifiers

NASA Technical Reports Server (NTRS)

Nurge, Mark A.; Larson, William E.; Hallberg, Carl G.; Thayer, Steven W.; Ake, Jeffrey C.; Gleman, Stuart M.; Thompson, David L.; Medelius, Pedro J.; Crawford, Wayne A.; Vangilder, Richard M.;

The Effects of Elaboration and Rehearsal on Long-Term Retention of Shape Names by Kindergarteners

ERIC Educational Resources Information Center

Gallimore, Ronald; And Others

1977-01-01

Elaboration and overt rehearsal are compared as instructional paradigms for memory retention. Superior long-term retention was produced in the elaboration condition when the initial acquisition effects were statistically removed. Short-term data suggest acquisition was complexly affected by experimental condition, I.Q., and task. Elaboration…

Criterion-Related Validity of Measuring Sight-Word Acquisition with Curriculum-Based Assessment

ERIC Educational Resources Information Center

Burns, Matthew K.; Mosack, Jill L.

2005-01-01

Curriculum-Based Assessment for Instructional Design (CBA-ID) provides data used to ensure an appropriately challenging learning task. One aspect of appropriate challenge measured by CBA-ID, called the acquisition rate (AR), involves the amount of new information a student could acquire and retain during initial learning. Previous research…

Extensive Reading in Enhancing Lexical Chunks Acquisition

ERIC Educational Resources Information Center

Pereyra, Nilsa

2015-01-01

The purpose of this action research was to investigate the effect of extensive reading and related activities on the acquisition of lexical chunks in EFL students. Seven adult EFL learners with an Intermediate level volunteered to take part in the 16 week project following Extensive Reading principles combined with tasks based on the Lexical…

The Effects of Echolalia on Acquisition and Generalization of Receptive Labeling in Autistic Children.

ERIC Educational Resources Information Center

Charlop, Marjorie H.

1983-01-01

Two experiments, with about five autistic children (two to 14 years old) in each experiment, assessed the effects of autistic immediate echolalia on acquisition and generalization of receptive labeling tasks. These results indicated that echolalia faciliated generalization for echolalic autistic children but not for functionally mute autistic…

Computer Skills Acquisition: A Review and Future Directions for Research.

ERIC Educational Resources Information Center

Gattiker, Urs E.

A review of past research on training employees for computer-mediated work leads to the development of theory and propositions concerning the relationship between different variables, such as: (1) individual factors; (2) task and person-computer interface; (3) characteristics of training design for the acquisition of computer skills; and (4) the…

The Acquisition of Notions of Qualitative Speed: The Importance of Spatial and Temporal Alignment.

ERIC Educational Resources Information Center

Perry, Bruce; Obenauf, Patricia

1987-01-01

Reports on a study which investigated the order of acquisition of intuitive notions of qualitative speed. Results indicated that an array of prerequisites, equivalent, and independent relationships existed among the tasks administered. Confirmed the evolution of reasoning for notions of qualitative speed found by Piaget. (Author/TW)

Mechanical Power Flow Changes during Multijoint Movement Acquisition

ERIC Educational Resources Information Center

Kadota, Koji; Matsuo, Tomoyuki; Hashizume, Ken; Tezuka, Kazushi

2006-01-01

We investigated the differences in mechanical power flow in early and late practice stages during a cyclic movement consisting of upper arm circumduction to clarify the change in mechanical energy use with skill acquisition. Seven participants practiced the task every other day until their joint angular movements conformed to those of an expert.…

Data Acquisition System(DAS) Sustaining Engineering

NASA Technical Reports Server (NTRS)

1998-01-01

This paper presents general information describing the Data Acquisition System contract, a summary of objectives, tasks performed and completed. The hardware deliverables which are comprised of: 1) Two ground DAS units; 2) Two flight DAS units; 3) Logistic spares; and 4) Shipping containers are described. Also included are the data requirements and scope of the contract.

Verb Particle and Preposition Acquisition in Language-Impaired Preschoolers.

ERIC Educational Resources Information Center

Watkins, Ruth V.; Rice, Mabel L.

1991-01-01

This study examined the acquisition of verb particles and prepositions in language-impaired, language-matched, and age-matched preschool children (total n=42). Results indicated that the use of verb particles constituted a particularly challenging task for the language-impaired subjects relative to both the age-matched and language-matched peers.…

77 FR 8166 - Partner Vetting in USAID Acquisitions

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-14

... of this nature are outside the scope of the Proposed Rule, we are not addressing them in this Final... Partner vetting in USAID Acquisitions: Source Selection vs. Vetting Comment 1: ``USAID declares that... ``post-award'' nature of task orders, we have added a contract clause at 752.216-70 which includes the...

Acquisition of Reading and Spelling in a Syllabo-Alphabetic Writing System.

ERIC Educational Resources Information Center

Patel, P. G.; Soper, Henry V.

1987-01-01

Examined written language tasks in 120 Gujarati-speaking children from grades two through four to assess the development of such skills in a syllabo-alphabetic writing system. Results indicated that the syllabo-alphabetic system of Devanagari proved to follow the models of reading acquisition constructed for alphabetic systems. (MM)

Order of stimulus presentation influences children's acquisition in receptive identification tasks.

PubMed

Petursdottir, Anna Ingeborg; Aguilar, Gabriella

2016-03-01

Receptive identification is usually taught in matching-to-sample format, which entails the presentation of an auditory sample stimulus and several visual comparison stimuli in each trial. Conflicting recommendations exist regarding the order of stimulus presentation in matching-to-sample trials. The purpose of this study was to compare acquisition in receptive identification tasks under 2 conditions: when the sample was presented before the comparisons (sample first) and when the comparisons were presented before the sample (comparison first). Participants included 4 typically developing kindergarten-age boys. Stimuli, which included birds and flags, were presented on a computer screen. Acquisition in the 2 conditions was compared in an adapted alternating-treatments design combined with a multiple baseline design across stimulus sets. All participants took fewer trials to meet the mastery criterion in the sample-first condition than in the comparison-first condition. © 2015 Society for the Experimental Analysis of Behavior.

Incidental Vocabulary Acquisition: The Effects of Task Type, Word Occurrence and Their Combination

ERIC Educational Resources Information Center

Laufer, Batia; Rozovski-Roitblat, Bella

2011-01-01

We investigated how long-term retention of new words was affected by task type, number of word occurrences in the teaching materials and the combination of the two factors. The tasks were: reading a text with occasional Focus on Form when learners used dictionaries (T+F), or reading a text with Focus on Forms, i.e. word focused exercises (T+Fs).…

Transitioning from Targeted to Comprehensive Mass Spectrometry Using Genetic Algorithms.

PubMed

Jaffe, Jacob D; Feeney, Caitlin M; Patel, Jinal; Lu, Xiaodong; Mani, D R

2016-11-01

Targeted proteomic assays are becoming increasingly popular because of their robust quantitative applications enabled by internal standardization, and they can be routinely executed on high performance mass spectrometry instrumentation. However, these assays are typically limited to 100s of analytes per experiment. Considerable time and effort are often expended in obtaining and preparing samples prior to targeted analyses. It would be highly desirable to detect and quantify 1000s of analytes in such samples using comprehensive mass spectrometry techniques (e.g., SWATH and DIA) while retaining a high degree of quantitative rigor for analytes with matched internal standards. Experimentally, it is facile to port a targeted assay to a comprehensive data acquisition technique. However, data analysis challenges arise from this strategy concerning agreement of results from the targeted and comprehensive approaches. Here, we present the use of genetic algorithms to overcome these challenges in order to configure hybrid targeted/comprehensive MS assays. The genetic algorithms are used to select precursor-to-fragment transitions that maximize the agreement in quantification between the targeted and the comprehensive methods. We find that the algorithm we used provided across-the-board improvement in the quantitative agreement between the targeted assay data and the hybrid comprehensive/targeted assay that we developed, as measured by parameters of linear models fitted to the results. We also found that the algorithm could perform at least as well as an independently-trained mass spectrometrist in accomplishing this task. We hope that this approach will be a useful tool in the development of quantitative approaches for comprehensive proteomics techniques. Graphical Abstract ᅟ.

Transitioning from Targeted to Comprehensive Mass Spectrometry Using Genetic Algorithms

NASA Astrophysics Data System (ADS)

Jaffe, Jacob D.; Feeney, Caitlin M.; Patel, Jinal; Lu, Xiaodong; Mani, D. R.

2016-11-01

Targeted proteomic assays are becoming increasingly popular because of their robust quantitative applications enabled by internal standardization, and they can be routinely executed on high performance mass spectrometry instrumentation. However, these assays are typically limited to 100s of analytes per experiment. Considerable time and effort are often expended in obtaining and preparing samples prior to targeted analyses. It would be highly desirable to detect and quantify 1000s of analytes in such samples using comprehensive mass spectrometry techniques (e.g., SWATH and DIA) while retaining a high degree of quantitative rigor for analytes with matched internal standards. Experimentally, it is facile to port a targeted assay to a comprehensive data acquisition technique. However, data analysis challenges arise from this strategy concerning agreement of results from the targeted and comprehensive approaches. Here, we present the use of genetic algorithms to overcome these challenges in order to configure hybrid targeted/comprehensive MS assays. The genetic algorithms are used to select precursor-to-fragment transitions that maximize the agreement in quantification between the targeted and the comprehensive methods. We find that the algorithm we used provided across-the-board improvement in the quantitative agreement between the targeted assay data and the hybrid comprehensive/targeted assay that we developed, as measured by parameters of linear models fitted to the results. We also found that the algorithm could perform at least as well as an independently-trained mass spectrometrist in accomplishing this task. We hope that this approach will be a useful tool in the development of quantitative approaches for comprehensive proteomics techniques.

Oculomotor selection underlies feature retention in visual working memory.

PubMed

Hanning, Nina M; Jonikaitis, Donatas; Deubel, Heiner; Szinte, Martin

2016-02-01

Oculomotor selection, spatial task relevance, and visual working memory (WM) are described as three processes highly intertwined and sustained by similar cortical structures. However, because task-relevant locations always constitute potential saccade targets, no study so far has been able to distinguish between oculomotor selection and spatial task relevance. We designed an experiment that allowed us to dissociate in humans the contribution of task relevance, oculomotor selection, and oculomotor execution to the retention of feature representations in WM. We report that task relevance and oculomotor selection lead to dissociable effects on feature WM maintenance. In a first task, in which an object's location was encoded as a saccade target, its feature representations were successfully maintained in WM, whereas they declined at nonsaccade target locations. Likewise, we observed a similar WM benefit at the target of saccades that were prepared but never executed. In a second task, when an object's location was marked as task relevant but constituted a nonsaccade target (a location to avoid), feature representations maintained at that location did not benefit. Combined, our results demonstrate that oculomotor selection is consistently associated with WM, whereas task relevance is not. This provides evidence for an overlapping circuitry serving saccade target selection and feature-based WM that can be dissociated from processes encoding task-relevant locations. Copyright © 2016 the American Physiological Society.

TFTR diagnostic control and data acquisition system

NASA Astrophysics Data System (ADS)

Sauthoff, N. R.; Daniels, R. E.

1985-05-01

General computerized control and data-handling support for TFTR diagnostics is presented within the context of the Central Instrumentation, Control and Data Acquisition (CICADA) System. Procedures, hardware, the interactive man-machine interface, event-driven task scheduling, system-wide arming and data acquisition, and a hierarchical data base of raw data and results are described. Similarities in data structures involved in control, monitoring, and data acquisition afford a simplification of the system functions, based on ``groups'' of devices. Emphases and optimizations appropriate for fusion diagnostic system designs are provided. An off-line data reduction computer system is under development.

TFTR diagnostic control and data acquisition system

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

Sauthoff, N.R.; Daniels, R.E.; PPL Computer Division

1985-05-01

General computerized control and data-handling support for TFTR diagnostics is presented within the context of the Central Instrumentation, Control and Data Acquisition (CICADA) System. Procedures, hardware, the interactive man--machine interface, event-driven task scheduling, system-wide arming and data acquisition, and a hierarchical data base of raw data and results are described. Similarities in data structures involved in control, monitoring, and data acquisition afford a simplification of the system functions, based on ''groups'' of devices. Emphases and optimizations appropriate for fusion diagnostic system designs are provided. An off-line data reduction computer system is under development.

Bidirectional interactions between circadian entrainment and cognitive performance

PubMed Central

Gritton, Howard J.; Kantorowski, Ana; Sarter, Martin; Lee, Theresa M.

2012-01-01

Circadian rhythms influence a variety of physiological and behavioral processes; however, little is known about how circadian rhythms interact with the organisms' ability to acquire and retain information about their environment. These experiments tested whether rats trained outside their endogenous active period demonstrate the same rate of acquisition, daily performance, and remote memory ability as their nocturnally trained counterparts in tasks of sustained attention and spatial memory. Furthermore, we explored how daily task training influenced circadian patterns of activity. We found that rats demonstrate better acquisition and performance on an operant task requiring attentional effort when trained during the dark-phase. Time of day did not affect acquisition or performance on the Morris water maze; however, when animals were retested 2 wk after their last day of training, they showed better remote memory if training originally occurred during the dark-phase. Finally, attentional, but not spatial, task performance during the light-phase promotes a shift toward diurnality and the synchronization of activity to the time of daily training; this shift was most robust when the demands on the cognitive control of attention were highest. Our findings support a theory of bidirectional interactions between cognitive performance and circadian processes and are consistent with the view that the circadian abnormalities associated with shift-work, aging, and neuropsychiatric illnesses may contribute to the deleterious effects on cognition often present in these populations. Furthermore, these findings suggest that time of day should be an important consideration for a variety of cognitive tasks principally used in psychological and neuroscience research. PMID:22383380

Effects of prior cocaine self-administration on cognitive performance in female cynomolgus monkeys.

PubMed

Kromrey, Sarah A; Gould, Robert W; Nader, Michael A; Czoty, Paul W

2015-06-01

Cocaine use has been associated with cognitive impairments that may contribute to poor treatment outcomes. However, the degree to which these deficits extend into periods of abstinence has not been completely elucidated. This study tested whether prior experience self-administering cocaine affected acquisition of two cognitive tasks in 16 adult female cynomolgus monkeys. Seven monkeys had previously self-administered cocaine but had not had access to cocaine for 2 months at the start of this study. After monkeys were trained to respond on a touchscreen, associative learning and behavioral flexibility were assessed using a stimulus discrimination (SD) and reversal (SDR) task from the CANTAB battery. Performance on this task was monitored over the subsequent 3 months. Additionally, working memory was assessed with a delayed match-to-sample (DMS) task. Cocaine-naïve monkeys required fewer total trials and made fewer errors and omissions before acquiring the SD and SDR tasks compared with monkeys who had previously self-administered cocaine; two monkeys in the latter group did not acquire the task. However, this cognitive impairment dissipated over several months of exposure to the task. The number of sessions for touch training and delays required to establish a performance-based curve on the DMS task did not differ between groups. Results suggest that cocaine exposure can impair the ability to learn a novel task requiring behavioral inhibition and flexibility, even after an extended period of abstinence. However, this deficit did not extend to maintenance of the task or to acquisition of a working memory task.

Obstacle Avoidance and Target Acquisition for Robot Navigation Using a Mixed Signal Analog/Digital Neuromorphic Processing System

PubMed Central

Milde, Moritz B.; Blum, Hermann; Dietmüller, Alexander; Sumislawska, Dora; Conradt, Jörg; Indiveri, Giacomo; Sandamirskaya, Yulia

2017-01-01

Neuromorphic hardware emulates dynamics of biological neural networks in electronic circuits offering an alternative to the von Neumann computing architecture that is low-power, inherently parallel, and event-driven. This hardware allows to implement neural-network based robotic controllers in an energy-efficient way with low latency, but requires solving the problem of device variability, characteristic for analog electronic circuits. In this work, we interfaced a mixed-signal analog-digital neuromorphic processor ROLLS to a neuromorphic dynamic vision sensor (DVS) mounted on a robotic vehicle and developed an autonomous neuromorphic agent that is able to perform neurally inspired obstacle-avoidance and target acquisition. We developed a neural network architecture that can cope with device variability and verified its robustness in different environmental situations, e.g., moving obstacles, moving target, clutter, and poor light conditions. We demonstrate how this network, combined with the properties of the DVS, allows the robot to avoid obstacles using a simple biologically-inspired dynamics. We also show how a Dynamic Neural Field for target acquisition can be implemented in spiking neuromorphic hardware. This work demonstrates an implementation of working obstacle avoidance and target acquisition using mixed signal analog/digital neuromorphic hardware. PMID:28747883

Obstacle Avoidance and Target Acquisition for Robot Navigation Using a Mixed Signal Analog/Digital Neuromorphic Processing System.

PubMed

Milde, Moritz B; Blum, Hermann; Dietmüller, Alexander; Sumislawska, Dora; Conradt, Jörg; Indiveri, Giacomo; Sandamirskaya, Yulia

2017-01-01

Neuromorphic hardware emulates dynamics of biological neural networks in electronic circuits offering an alternative to the von Neumann computing architecture that is low-power, inherently parallel, and event-driven. This hardware allows to implement neural-network based robotic controllers in an energy-efficient way with low latency, but requires solving the problem of device variability, characteristic for analog electronic circuits. In this work, we interfaced a mixed-signal analog-digital neuromorphic processor ROLLS to a neuromorphic dynamic vision sensor (DVS) mounted on a robotic vehicle and developed an autonomous neuromorphic agent that is able to perform neurally inspired obstacle-avoidance and target acquisition. We developed a neural network architecture that can cope with device variability and verified its robustness in different environmental situations, e.g., moving obstacles, moving target, clutter, and poor light conditions. We demonstrate how this network, combined with the properties of the DVS, allows the robot to avoid obstacles using a simple biologically-inspired dynamics. We also show how a Dynamic Neural Field for target acquisition can be implemented in spiking neuromorphic hardware. This work demonstrates an implementation of working obstacle avoidance and target acquisition using mixed signal analog/digital neuromorphic hardware.

Subsea control and data acquisition

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

Not Available

1990-01-01

This book contains papers presented at the conference on subsea control and data acquisition. The tasks performed by subsea control systems, although fairly straightforward, are dominated by an alien environment and the high costs associated with failure and repair. The evolution of systems design has resulted in a growing confidence in equipment reliability. In the future, however, more searching demands may include active regulation of valves and the use of data for reservoir management purposes. The emphasis of the papers is on technical depth and understanding, with particular attention being paid to the science control and data monitoring in relationmore » to the task of hydrocarbon recovery.« less

Virtual Reality Training System for Anytime/Anywhere Acquisition of Surgical Skills: A Pilot Study.

PubMed

Zahiri, Mohsen; Booton, Ryan; Nelson, Carl A; Oleynikov, Dmitry; Siu, Ka-Chun

2018-03-01

This article presents a hardware/software simulation environment suitable for anytime/anywhere surgical skills training. It blends the advantages of physical hardware and task analogs with the flexibility of virtual environments. This is further enhanced by a web-based implementation of training feedback accessible to both trainees and trainers. Our training system provides a self-paced and interactive means to attain proficiency in basic tasks that could potentially be applied across a spectrum of trainees from first responder field medical personnel to physicians. This results in a powerful training tool for surgical skills acquisition relevant to helping injured warfighters.

Nucleus accumbens dopamine D2-receptor expressing neurons control behavioral flexibility in a place discrimination task in the IntelliCage.

PubMed

Macpherson, Tom; Morita, Makiko; Wang, Yanyan; Sasaoka, Toshikuni; Sawa, Akira; Hikida, Takatoshi

2016-07-01

Considerable evidence has demonstrated a critical role for the nucleus accumbens (NAc) in the acquisition and flexibility of behavioral strategies. These processes are guided by the activity of two discrete neuron types, dopamine D1- or D2-receptor expressing medium spiny neurons (D1-/D2-MSNs). Here we used the IntelliCage, an automated group-housing experimental cage apparatus, in combination with a reversible neurotransmission blocking technique to examine the role of NAc D1- and D2-MSNs in the acquisition and reversal learning of a place discrimination task. We demonstrated that NAc D1- and D2-MSNs do not mediate the acquisition of the task, but that suppression of activity in D2-MSNs impairs reversal learning and increased perseverative errors. Additionally, global knockout of the dopamine D2L receptor isoform produced a similar behavioral phenotype to D2-MSN-blocked mice. These results suggest that D2L receptors and NAc D2-MSNs act to suppress the influence of previously correct behavioral strategies allowing transfer of behavioral control to new strategies. © 2016 Macpherson et al.; Published by Cold Spring Harbor Laboratory Press.

External Control of Knowledge of Results: Learner Involvement Enhances Motor Skill Transfer.

PubMed

Figueiredo, L S; Ugrinowitsch, H; Freire, A B; Shea, J B; Benda, R N

2018-04-01

Providing the learner control over aspects of practice has improved the process of motor skill acquisition, and self-controlled knowledge of results (KR) schedules have shown specific advantages over externally controlled ones. A possible explanation is that self-controlled KR schedules lead learners to more active task involvement, permitting deeper information processing. This study tested this explanatory hypothesis. Thirty undergraduate volunteers of both sexes, aged 18 to 35, all novices in the task, practiced transporting a tennis ball in a specified sequence within a time goal. We compared a high-involvement group (involvement yoked, IY), notified in advance about upcoming KR trials, to self-controlled KR (SC) and yoked KR (YK) groups. The experiment consisted of three phases: acquisition, retention, and transfer. We found both IY and SC groups to be superior to YK for transfer of learning. Postexperiment participant questionnaires confirmed a preference for receiving KR after learner-perceived good trials, even though performance on those trials did not differ from performance on trials without KR. Equivalent IY and SC performances provide support for the benefits of task involvement and deeper information processing when KR is self-controlled in motor skill acquisition.

Combining factual and heuristic knowledge in knowledge acquisition

NASA Technical Reports Server (NTRS)

Gomez, Fernando; Hull, Richard; Karr, Clark; Hosken, Bruce; Verhagen, William

1992-01-01

A knowledge acquisition technique that combines heuristic and factual knowledge represented as two hierarchies is described. These ideas were applied to the construction of a knowledge acquisition interface to the Expert System Analyst (OPERA). The goal of OPERA is to improve the operations support of the computer network in the space shuttle launch processing system. The knowledge acquisition bottleneck lies in gathering knowledge from human experts and transferring it to OPERA. OPERA's knowledge acquisition problem is approached as a classification problem-solving task, combining this approach with the use of factual knowledge about the domain. The interface was implemented in a Symbolics workstation making heavy use of windows, pull-down menus, and other user-friendly devices.

Unstable Memories Create a High-Level Representation that Enables Learning Transfer.

PubMed

Mosha, Neechi; Robertson, Edwin M

2016-01-11

A memory is unstable, making it susceptible to interference and disruption, after its acquisition [1-4]. The function or possible benefit of a memory being unstable at its acquisition is not well understood. Potentially, instability may be critical for the communication between recently acquired memories, which would allow learning in one task to be transferred to the other subsequent task [1, 5]. Learning may be transferred between any memories that are unstable, even between different types of memory. Here, we test the link between a memory being unstable and the transfer of learning to a different type of memory task. We measured how learning in one task transferred to and thus improved learning in a subsequent task. There was transfer from a motor skill to a word list task and, vice versa, from a word list to a motor skill task. What was transferred was a high-level relationship between elements, rather than knowledge of the individual elements themselves. Memory instability was correlated with subsequent transfer, suggesting that transfer was related to the instability of the memory. Using different methods, we stabilized the initial memory, preventing it from being susceptible to interference, and found that these methods consistently prevented transfer to the subsequent memory task. This suggests that the transfer of learning across diverse tasks is due to a high-level representation that can only be formed when a memory is unstable. Our work has identified an important function of memory instability. Copyright © 2016 Elsevier Ltd. All rights reserved.

Acquisition and extinction of human avoidance behavior: attenuating effect of safety signals and associations with anxiety vulnerabilities.

PubMed

Sheynin, Jony; Beck, Kevin D; Servatius, Richard J; Myers, Catherine E

2014-01-01

While avoidance behavior is often an adaptive strategy, exaggerated avoidance can be detrimental and result in the development of psychopathologies, such as anxiety disorders. A large animal literature shows that the acquisition and extinction of avoidance behavior in rodents depends on individual differences (e.g., sex, strain) and might be modulated by the presence of environmental cues. However, there is a dearth of such reports in human literature, mainly due to the lack of adequate experimental paradigms. In the current study, we employed a computer-based task, where participants control a spaceship and attempt to gain points by shooting an enemy spaceship that appears on the screen. Warning signals predict on-screen aversive events; the participants can learn a protective response to escape or avoid these events. This task has been recently used to reveal facilitated acquisition of avoidance behavior in individuals with anxiety vulnerability due to female sex or inhibited personality. Here, we extended the task to include an extinction phase, and tested the effect of signals that appeared during "safe" periods. Healthy young adults (n = 122) were randomly assigned to a testing condition with or without such signals. Results showed that the addition of safety signals during the acquisition phase impaired acquisition (in females) and facilitated extinction of the avoidance behavior. We also replicated our recent finding of an association between female sex and longer avoidance duration and further showed that females continued to demonstrate more avoidance behavior even on extinction trials when the aversive events no longer occurred. This study is the first to show sex differences on the acquisition and extinction of human avoidance behavior and to demonstrate the role of safety signals in such behavior, highlighting the potential relevance of safety signals for cognitive therapies that focus on extinction learning to treat anxiety symptoms.

Acquisition and Extinction of Human Avoidance Behavior: Attenuating Effect of Safety Signals and Associations with Anxiety Vulnerabilities

PubMed Central

Sheynin, Jony; Beck, Kevin D.; Servatius, Richard J.; Myers, Catherine E.

2014-01-01

While avoidance behavior is often an adaptive strategy, exaggerated avoidance can be detrimental and result in the development of psychopathologies, such as anxiety disorders. A large animal literature shows that the acquisition and extinction of avoidance behavior in rodents depends on individual differences (e.g., sex, strain) and might be modulated by the presence of environmental cues. However, there is a dearth of such reports in human literature, mainly due to the lack of adequate experimental paradigms. In the current study, we employed a computer-based task, where participants control a spaceship and attempt to gain points by shooting an enemy spaceship that appears on the screen. Warning signals predict on-screen aversive events; the participants can learn a protective response to escape or avoid these events. This task has been recently used to reveal facilitated acquisition of avoidance behavior in individuals with anxiety vulnerability due to female sex or inhibited personality. Here, we extended the task to include an extinction phase, and tested the effect of signals that appeared during “safe” periods. Healthy young adults (n = 122) were randomly assigned to a testing condition with or without such signals. Results showed that the addition of safety signals during the acquisition phase impaired acquisition (in females) and facilitated extinction of the avoidance behavior. We also replicated our recent finding of an association between female sex and longer avoidance duration and further showed that females continued to demonstrate more avoidance behavior even on extinction trials when the aversive events no longer occurred. This study is the first to show sex differences on the acquisition and extinction of human avoidance behavior and to demonstrate the role of safety signals in such behavior, highlighting the potential relevance of safety signals for cognitive therapies that focus on extinction learning to treat anxiety symptoms. PMID:25309373

Optimum viewing distance for target acquisition

NASA Astrophysics Data System (ADS)

Holst, Gerald C.

2015-05-01

Human visual system (HVS) "resolution" (a.k.a. visual acuity) varies with illumination level, target characteristics, and target contrast. For signage, computer displays, cell phones, and TVs a viewing distance and display size are selected. Then the number of display pixels is chosen such that each pixel subtends 1 min-1. Resolution of low contrast targets is quite different. It is best described by Barten's contrast sensitivity function. Target acquisition models predict maximum range when the display pixel subtends 3.3 min-1. The optimum viewing distance is nearly independent of magnification. Noise increases the optimum viewing distance.

Training Apartment Upkeep Skills to Rehabilitation Clients: A Comparison of Task Analytic Strategies.

ERIC Educational Resources Information Center

Williams, George E.; Cuvo, Anthony J.

1986-01-01

Six severely handicapped clients were taught to perform upkeep responses on their air conditioner-heating unit, electric range, refrigerator, and electrical appliances. Results showed acquisition, long-term maintenance, and generalization of upkeep skills to a nontraining apartment. General task analyses were recommended for assessment and…

Scaling a Single Attribute: A Methodological Study of Conservation

ERIC Educational Resources Information Center

Hofmann, Richard J.; Trepanier, Mary

1975-01-01

This study was designed to assess the acquisition of conservation of number on equal addition tasks through scalogram analysis to determine if this analysis defines a scale or continuum. Ten block tasks administered to 85 kindergarten children validated Piaget's theory that cognitive development is sequential and continuous. (Author/ED)

Research into Practice: The Task-Based Approach to Instructed Second Language Acquisition

ERIC Educational Resources Information Center

East, Martin

2017-01-01

This article discusses the phenomenon of task-based language teaching (TBLT) in instructed additional language settings. It begins from the premise that, despite considerable theoretical and empirical support, TBLT remains a contested endeavour. Critics of TBLT argue that, particularly with regard to time-limited foreign language instructional…

An Experimental Analysis of Memory Processing

ERIC Educational Resources Information Center

Wright, Anthony A.

2007-01-01

Rhesus monkeys were trained and tested in visual and auditory list-memory tasks with sequences of four travel pictures or four natural/environmental sounds followed by single test items. Acquisitions of the visual list-memory task are presented. Visual recency (last item) memory diminished with retention delay, and primacy (first item) memory…

Visual performance on detection tasks with double-targets of the same and different difficulty.

PubMed

Chan, Alan H S; Courtney, Alan J; Ma, C W

2002-10-20

This paper reports a study of measurement of horizontal visual sensitivity limits for 16 subjects in single-target and double-targets detection tasks. Two phases of tests were conducted in the double-targets task; targets of the same difficulty were tested in phase one while targets of different difficulty were tested in phase two. The range of sensitivity for the double-targets test was found to be smaller than that for single-target in both the same and different target difficulty cases. The presence of another target was found to affect performance to a marked degree. Interference effect of the difficult target on detection of the easy one was greater than that of the easy one on the detection of the difficult one. Performance decrement was noted when correct percentage detection was plotted against eccentricity of target in both the single-target and double-targets tests. Nevertheless, the non-significant correlation found between the performance for the two tasks demonstrated that it was impossible to predict quantitatively ability for detection of double targets from the data for single targets. This indicated probable problems in generalizing data for single target visual lobes to those for multiple targets. Also lobe area values obtained from measurements using a single-target task cannot be applied in a mathematical model for situations with multiple occurrences of targets.

Evaluation of Cognitive Function of Children with Developmental Disabilities by means of Button-Press Task

NASA Astrophysics Data System (ADS)

Nakazono, Shogo; Kobori, Satoshi

The button-press task means that the subject observes a moving target and presses a button to stop it when the target enters a specified area on a computer display. Subjects perform normal task, suppressed task and delayed task. In the suppressed task, the moving target disappears at some point during the trial. In the delayed task, there is some lag time between the time of pressing button and of stopping target. In these tasks, subjects estimate the movement of the target, and press the button considering his/her own reaction time. In our previous study, we showed that cognitive and motor function was able to be evaluated by these tasks. In this study, we examined error data of children with developmental disabilities to evaluate the cognitive function, and investigated the learning processes. Moreover, we discussed the developmental stages by comparing the children with disabilities to normal control children, and we clarified the behavior characteristics of children with developmental disabilities. Asa result, it was shown that our evaluation method and system for the button-press task were effective to evaluate cognitive ability of children with developmental disabilities.

"Smart inhibition": electrophysiological evidence for the suppression of conflict-generating task rules during task switching.

PubMed

Meiran, Nachshon; Hsieh, Shulan; Chang, Chi-Chih

2011-09-01

A major challenge for task switching is maintaining a balance between high task readiness and effectively ignoring irrelevant task rules. This calls for finely tuned inhibition that targets only the source of interference without adversely influencing other task-related representations. The authors show that irrelevant task rules generating response conflict are inhibited, causing their inefficient execution on the next trial (indicating the presence of competitor rule suppression[CRS];Meiran, Hsieh, & Dimov, Journal of Experimental Psychology: Learning, Memory and Cognition, 36, 992-1002, 2010). To determine whether CRS influences task rules, rather than target stimuli or responses, the authors focused on the processing of the task cue before the target stimulus was presented and before the response could be chosen. As was predicted, CRS was found in the event-related potentials in two time windows during task cue processing. It was also found in three time windows after target presentation. Source localization analyses suggest the involvement of the right dorsal prefrontal cortex in all five time windows.

High Efficiency Multi-shot Interleaved Spiral-In/Out Acquisition for High Resolution BOLD fMRI

PubMed Central

Jung, Youngkyoo; Samsonov, Alexey A.; Liu, Thomas T.; Buracas, Giedrius T.

2012-01-01

Growing demand for high spatial resolution BOLD functional MRI faces a challenge of the spatial resolution vs. coverage or temporal resolution tradeoff, which can be addressed by methods that afford increased acquisition efficiency. Spiral acquisition trajectories have been shown to be superior to currently prevalent echo-planar imaging in terms of acquisition efficiency, and high spatial resolution can be achieved by employing multiple-shot spiral acquisition. The interleaved spiral in-out trajectory is preferred over spiral-in due to increased BOLD signal CNR and higher acquisition efficiency than that of spiral-out or non-interleaved spiral in/out trajectories (1), but to date applicability of the multi-shot interleaved spiral in-out for high spatial resolution imaging has not been studied. Herein we propose multi-shot interleaved spiral in-out acquisition and investigate its applicability for high spatial resolution BOLD fMRI. Images reconstructed from interleaved spiral-in and -out trajectories possess artifacts caused by differences in T2* decay, off-resonance and k-space errors associated with the two trajectories. We analyze the associated errors and demonstrate that application of conjugate phase reconstruction and spectral filtering can substantially mitigate these image artifacts. After applying these processing steps, the multishot interleaved spiral in-out pulse sequence yields high BOLD CNR images at in-plane resolution below 1x1 mm while preserving acceptable temporal resolution (4 s) and brain coverage (15 slices of 2 mm thickness). Moreover, this method yields sufficient BOLD CNR at 1.5 mm isotropic resolution for detection of activation in hippocampus associated with cognitive tasks (Stern memory task). The multi-shot interleaved spiral in-out acquisition is a promising technique for high spatial resolution BOLD fMRI applications. PMID:23023395

A model for combined targeting and tracking tasks in computer applications.

PubMed

Senanayake, Ransalu; Hoffmann, Errol R; Goonetilleke, Ravindra S

2013-11-01

Current models for targeted-tracking are discussed and shown to be inadequate as a means of understanding the combined task of tracking, as in the Drury's paradigm, and having a final target to be aimed at, as in the Fitts' paradigm. It is shown that the task has to be split into components that are, in general, performed sequentially and have a movement time component dependent on the difficulty of the individual component of the task. In some cases, the task time may be controlled by the Fitts' task difficulty, and in others, it may be dominated by the Drury's task difficulty. Based on an experiment carried out that captured movement time in combinations of visually controlled and ballistic movements, a model for movement time in targeted-tracking was developed.

Metamorphological awareness and EFL students' memory, retention, and retrieval of English adjectival lexicons.

PubMed

Zhang, Lawrence Jun

2002-12-01

Research has shown that foreign or second language learners' metalinguistic awareness has important effects on their acquisition of the target language. Important among a multitude of the concerns are problems these learners encounter when they have to process the morphological features of individual words, particularly in the acquisition of literacy skills. Nevertheless, for students who learn English as a foreign or second language for academic purposes, one of the biggest challenges in their advanced study is how they can effectively remember, retain, and retrieve the colossal number of newly learnt English vocabulary, including adjectival lexicons, to enhance their academic success. Results from the present report on the effects of metamorphological awareness of 65 adult Chinese EFL learners' memory, retention, and retrieval of adjectival lexicons show that, although the subjects in the two groups did not differ significantly in their performance on a pretest designed to check their lexical knowledge and no sex difference was observed, statistically significant differences were found between the two groups in both conditions (immediate and delayed retrievals) on a posttest. The experimental group and women predominantly performed better in the memory-retention-retrieval tasks assigned to them. Implications for educational research and practices are also discussed.

Task Analysis and the Ability Requirements of Tasks: Collected Papers.

DTIC Science & Technology

1981-09-01

Skill. In F. A . Bilodeau (ed.) Acquisition of Skill, New York: Academic Pr.sS, 1066, 147-167. Kennedy, R. S., Bittner, A. C., Jr. & Harbeson, M. M...o.-iL cili * ii It~ ti(-t Iat :iiiss, iil- aind whose tasks ite menitt into- Cilirnori1 risk eLect- ielt ’. T: i s iLu,’ ie r t, r-io-.’I i-i viii d

Defense Science Board Task Force Report on Cyber Defense Management

DTIC Science & Technology

2016-09-01

manage cyber security is often a verymanual and labor intensive process. When a crisis hits, DoD responses range from highly automatedand instrumented...DSB Task Force Report on Cyber Defense Management September 2016 (U) This page intentionally blank REPORT OF THE DEFENSE SCIENCE BOARD STUDY ON Cyber ...DEFENSE FOR ACQUISITION, TECHNOLOGY & LOGISTICS SUBJECT: Final Report of the Defense Science Board (DSB) Task Force on Cyber Defense Management I am

PACS 2000: quality control using the task allocation chart

NASA Astrophysics Data System (ADS)

Norton, Gary S.; Romlein, John R.; Lyche, David K.; Richardson, Ronald R., Jr.

2000-05-01

Medical imaging's technological evolution in the next century will continue to include Picture Archive and Communication Systems (PACS) and teleradiology. It is difficult to predict radiology's future in the new millennium with both computed radiography and direct digital capture competing as the primary image acquisition methods for routine radiography. Changes in Computed Axial Tomography (CT) and Magnetic Resonance Imaging (MRI) continue to amaze the healthcare community. No matter how the acquisition, display, and archive functions change, Quality Control (QC) of the radiographic imaging chain will remain an important step in the imaging process. The Task Allocation Chart (TAC) is a tool that can be used in a medical facility's QC process to indicate the testing responsibilities of the image stakeholders and the medical informatics department. The TAC shows a grid of equipment to be serviced, tasks to be performed, and the organization assigned to perform each task. Additionally, skills, tasks, time, and references for each task can be provided. QC of the PACS must be stressed as a primary element of a PACS' implementation. The TAC can be used to clarify responsibilities during warranty and paid maintenance periods. Establishing a TAC a part of a PACS implementation has a positive affect on patient care and clinical acceptance.

Evidence for the Task-Induced Involvement Construct in Incidental Vocabulary Acquisition through Digital Gaming

ERIC Educational Resources Information Center

Reynolds, Barry Lee

2017-01-01

This article reports on an investigation of the suitability of mobile vocabulary games for inducing a state of incidental vocabulary acquisition. Draw Something, a social digital drawing game in which players draw and guess words, was selected as a focus for this investigation. Results from an exploratory factor analysis of the questionnaire data…

Does the Acquisition of Spatial Skill Involve a Shift from Algorithm to Memory Retrieval?

ERIC Educational Resources Information Center

Frank, David J.; Macnamara, Brooke N.

2017-01-01

Performance on verbal and mathematical tasks is enhanced when participants shift from using algorithms to retrieving information directly from memory (Siegler, 1988a). However, it is unknown whether a shift to retrieval is involved in dynamic spatial skill acquisition. For example, do athletes mentally extrapolate the trajectory of the ball, or do…

The Effect of Experience on the Acquisition of a Non-Native Vowel Contrast

ERIC Educational Resources Information Center

Simon, Ellen; D'Hulster, Tijs

2012-01-01

This study examines the effect of second language experience on the acquisition of the English vowel contrast /epsilon/-/ae/ by native speakers of Dutch. It reports on the results of production and perception tasks performed by three groups of native Dutch learners of English in Belgium, differing in experience with English, as measured through…

Motivation in a Computer-Supported Collaborative Learning Scenario and Its Impact on Learning Activities and Knowledge Acquisition

ERIC Educational Resources Information Center

Schoor, Cornelia; Bannert, Maria

2011-01-01

Addressing a drawback in current research on computer-supported collaborative learning (CSCL), this study investigated the influence of motivation on learning activities and knowledge acquisition during CSCL. Participants' (N = 200 university students) task was to develop a handout for which they had first an individual preparing phase followed by…

Aspects of the Acquisition of Object Control and ECM-Type Verbs in European Portuguese

ERIC Educational Resources Information Center

Santos, Ana Lúcia; Gonçalves, Anabela; Hyams, Nina

2016-01-01

We investigate the acquisition of sentential complementation under causative, perception, and object control verbs in European Portuguese, a language rich in complement types, including the typologically marked inflected infinitives. We tested 58 children between 3 and 5 years of age and 24 adults on a sentence completion task. The results support…

Designing Interaction as a Learning Process: Supporting Users' Domain Knowledge Development in Interaction

ERIC Educational Resources Information Center

Choi, Jung-Min

2010-01-01

The primary concern in current interaction design is focused on how to help users solve problems and achieve goals more easily and efficiently. While users' sufficient knowledge acquisition of operating a product or system is considered important, their acquisition of problem-solving knowledge in the task domain has largely been disregarded. As a…

Effect of Acquisition Rates on Off-Task Behavior with Children Identified as Having Learning Disabilities

ERIC Educational Resources Information Center

Burns, Matthew K.; Dean, Vincent J.

2005-01-01

Research has consistently demonstrated the importance of providing an appropriate level of challenge, called the instructional level, within curricular material. Although the instructional level is a generally well-defined and researched construct, much less data exist on the acquisition rate (AR) component of an appropriate level of challenge.…

French and Spanish-Speaking Children Use Different Visual and Motor Units during Spelling Acquisition

ERIC Educational Resources Information Center

Kandel, Sonia; Valdois, Sylviane

2006-01-01

This study used a copying task to examine spelling acquisition in French and Spanish from a perception and action perspective. Experiment 1 compared French and Spanish-speaking monolingual children's performance. Experiment 2 analysed the behaviour of bilingual children when copying words in French and Spanish. Gaze lift analysis showed that in…

Strategy Selection for Cognitive Skill Acquisition Depends on Task Demands and Working Memory Capacity

ERIC Educational Resources Information Center

Hinze, Scott R.; Bunting, Michael F; Pellegrino, James W.

2009-01-01

The involvement of working memory capacity (WMC) in ruled-based cognitive skill acquisition is well-established, but the duration of its involvement and its role in learning strategy selection are less certain. Participants (N=610) learned four logic rules, their corresponding symbols, or logic gates, and the appropriate input-output combinations…

Robotic technology results in faster and more robust surgical skill acquisition than traditional laparoscopy.

PubMed

Moore, Lee J; Wilson, Mark R; Waine, Elizabeth; Masters, Rich S W; McGrath, John S; Vine, Samuel J

2015-03-01

Technical surgical skills are said to be acquired quicker on a robotic rather than laparoscopic platform. However, research examining this proposition is scarce. Thus, this study aimed to compare the performance and learning curves of novices acquiring skills using a robotic or laparoscopic system, and to examine if any learning advantages were maintained over time and transferred to more difficult and stressful tasks. Forty novice participants were randomly assigned to either a robotic- or laparoscopic-trained group. Following one baseline trial on a ball pick-and-drop task, participants performed 50 learning trials. Participants then completed an immediate retention trial and a transfer trial on a two-instrument rope-threading task. One month later, participants performed a delayed retention trial and a stressful multi-tasking trial. The results revealed that the robotic-trained group completed the ball pick-and-drop task more quickly and accurately than the laparoscopic-trained group across baseline, immediate retention, and delayed retention trials. Furthermore, the robotic-trained group displayed a shorter learning curve for accuracy. The robotic-trained group also performed the more complex rope-threading and stressful multi-tasking transfer trials better. Finally, in the multi-tasking trial, the robotic-trained group made fewer tone counting errors. The results highlight the benefits of using robotic technology for the acquisition of technical surgical skills.

Stride-Cycle Influences on Goal-Directed Head Movements Made During Walking

NASA Technical Reports Server (NTRS)

Peters, Brian T.; vanEmmerik, Richard E. A.; Bloomberg, Jacob J.

2006-01-01

Horizontal head movements were studied in six subjects as they made rapid horizontal gaze adjustments while walking. The aim of the present research was to determine if gait-cycle events alter the head movement response to a visual target acquisition task. Gaze shifts of approximately 40deg were elicited by a step change in the position of a visual target from a central location to a second location in the left or right horizontal periphery. The timing of the target position change was constrained to occur at 25,50,75 and 100% of the stride cycle. The trials were randomly presented as the subjects walked on a treadmill at their preferred speed (range: 1.25 to 1.48 m/s, mean: 1.39 +/- 0.09 m/s ) . Analyses focused on the movement onset latencies of the head and eyes and on the peak velocity and saccade amplitude of the head movement response. A comparison of the group means indicated that the head movement onset lagged the eye onset (262 ms versus 252 ms). The head and eye movement onset latencies were not affected by either the direction of the target change nor the point in the gait cycle during which the target relocation occurred. However, the presence of an interaction between the gait cycle events and the direction of the visual target shift indicates that the peak head saccade velocity and head saccade amplitude are affected by the natural head oscillations that occur while walking.

The influence of open goals on the acquisition of problem-relevant information.

PubMed

Moss, Jarrod; Kotovsky, Kenneth; Cagan, Jonathan

2007-09-01

There have been a number of recent findings indicating that unsolved problems, or open goals more generally, influence cognition even when the current task has no relation to the task in which the goal was originally set. It was hypothesized that open goals would influence what information entered the problem-solving process. Three studies were conducted to establish the effect of open goals on the acquisition of problem-relevant information. It was found that problem-relevant information, or hints, presented implicitly in a 2nd task in between attempts at solving problems aided problem solving. This effect cannot be attributed to strategic behavior after participants caught on to the manipulation, as most participants were not aware of the relationship. The implications of this research are discussed, including potential contributions to our understanding of insight, incubation, transfer, and creativity. 2007 APA

Nimodipine alters acquisition of a visual discrimination task in chicks.

PubMed

Deyo, R; Panksepp, J; Conner, R L

1990-03-01

Chicks 5 days old received intraperitoneal injections of nimodipine 30 min before training on either a visual discrimination task (0, 0.5, 1.0, or 5.0 mg/kg) or a test of separation-induced distress vocalizations (0, 0.5, or 2.5 mg/kg). Chicks receiving 1.0 mg/kg nimodipine made significantly fewer visual discrimination errors than vehicle controls by trials 41-60, but did not differ from controls 24 h later. Chicks in the 5 mg/kg group made significantly more errors when compared to controls both during acquisition of the task and during retention. Nimodipine did not alter separation-induced distress vocalizations at any of the doses tested, suggesting that nimodipine's effects on learning cannot be attributed to a reduction in separation distress. These data indicate that nimodipine's facilitation of learning in young subjects is dose dependent, but nimodipine failed to enhance retention.

A multilevel modeling approach to examining individual differences in skill acquisition for a computer-based task.

PubMed

Nair, Sankaran N; Czaja, Sara J; Sharit, Joseph

2007-06-01

This article explores the role of age, cognitive abilities, prior experience, and knowledge in skill acquisition for a computer-based simulated customer service task. Fifty-two participants aged 50-80 performed the task over 4 consecutive days following training. They also completed a battery that assessed prior computer experience and cognitive abilities. The data indicated that overall quality and efficiency of performance improved with practice. The predictors of initial level of performance and rate of change in performance varied according to the performance parameter assessed. Age and fluid intelligence predicted initial level and rate of improvement in overall quality, whereas crystallized intelligence and age predicted initial e-mail processing time, and crystallized intelligence predicted rate of change in e-mail processing time over days. We discuss the implications of these findings for the design of intervention strategies.

The effect of the video game Quizlet on the acquisition of science vocabulary for children with learning disabilities

NASA Astrophysics Data System (ADS)

Boyce, Deborah Ann

The purpose of this study was to investigate the impact of the learning video game Quizlet on students with learning disabilities in the science classroom. Specifically this study investigated (a) student academic performance, (b) student on-task behavior, and (c) student satisfaction using the learning video game. Student academic performance was measured in terms of vocabulary acquisition, and student engagement was measured in relation to on-task behaviors. Seven middle school students, three female and four male participated in the study. A single subject design with ABABAB phases and maintenance data collection was utilized. Results show that all students increased their grades in science vocabulary and increased on-task behaviors. A follow-up student satisfaction survey determined that the intervention was acceptable to all students. Additional studies to assess the effects of Quizlet are recommended.

The emergence of the visual word form: Longitudinal evolution of category-specific ventral visual areas during reading acquisition

PubMed Central

Monzalvo, Karla; Dehaene, Stanislas

2018-01-01

How does education affect cortical organization? All literate adults possess a region specialized for letter strings, the visual word form area (VWFA), within the mosaic of ventral regions involved in processing other visual categories such as objects, places, faces, or body parts. Therefore, the acquisition of literacy may induce a reorientation of cortical maps towards letters at the expense of other categories such as faces. To test this cortical recycling hypothesis, we studied how the visual cortex of individual children changes during the first months of reading acquisition. Ten 6-year-old children were scanned longitudinally 6 or 7 times with functional magnetic resonance imaging (fMRI) before and throughout the first year of school. Subjects were exposed to a variety of pictures (words, numbers, tools, houses, faces, and bodies) while performing an unrelated target-detection task. Behavioral assessment indicated a sharp rise in grapheme–phoneme knowledge and reading speed in the first trimester of school. Concurrently, voxels specific to written words and digits emerged at the VWFA location. The responses to other categories remained largely stable, although right-hemispheric face-related activity increased in proportion to reading scores. Retrospective examination of the VWFA voxels prior to reading acquisition showed that reading encroaches on voxels that are initially weakly specialized for tools and close to but distinct from those responsive to faces. Remarkably, those voxels appear to keep their initial category selectivity while acquiring an additional and stronger responsivity to words. We propose a revised model of the neuronal recycling process in which new visual categories invade weakly specified cortex while leaving previously stabilized cortical responses unchanged. PMID:29509766

Feature Acquisition with Imbalanced Training Data

NASA Technical Reports Server (NTRS)

Thompson, David R.; Wagstaff, Kiri L.; Majid, Walid A.; Jones, Dayton L.

2011-01-01

This work considers cost-sensitive feature acquisition that attempts to classify a candidate datapoint from incomplete information. In this task, an agent acquires features of the datapoint using one or more costly diagnostic tests, and eventually ascribes a classification label. A cost function describes both the penalties for feature acquisition, as well as misclassification errors. A common solution is a Cost Sensitive Decision Tree (CSDT), a branching sequence of tests with features acquired at interior decision points and class assignment at the leaves. CSDT's can incorporate a wide range of diagnostic tests and can reflect arbitrary cost structures. They are particularly useful for online applications due to their low computational overhead. In this innovation, CSDT's are applied to cost-sensitive feature acquisition where the goal is to recognize very rare or unique phenomena in real time. Example applications from this domain include four areas. In stream processing, one seeks unique events in a real time data stream that is too large to store. In fault protection, a system must adapt quickly to react to anticipated errors by triggering repair activities or follow- up diagnostics. With real-time sensor networks, one seeks to classify unique, new events as they occur. With observational sciences, a new generation of instrumentation seeks unique events through online analysis of large observational datasets. This work presents a solution based on transfer learning principles that permits principled CSDT learning while exploiting any prior knowledge of the designer to correct both between-class and withinclass imbalance. Training examples are adaptively reweighted based on a decomposition of the data attributes. The result is a new, nonparametric representation that matches the anticipated attribute distribution for the target events.

The emergence of the visual word form: Longitudinal evolution of category-specific ventral visual areas during reading acquisition.

PubMed

Dehaene-Lambertz, Ghislaine; Monzalvo, Karla; Dehaene, Stanislas

2018-03-01

How does education affect cortical organization? All literate adults possess a region specialized for letter strings, the visual word form area (VWFA), within the mosaic of ventral regions involved in processing other visual categories such as objects, places, faces, or body parts. Therefore, the acquisition of literacy may induce a reorientation of cortical maps towards letters at the expense of other categories such as faces. To test this cortical recycling hypothesis, we studied how the visual cortex of individual children changes during the first months of reading acquisition. Ten 6-year-old children were scanned longitudinally 6 or 7 times with functional magnetic resonance imaging (fMRI) before and throughout the first year of school. Subjects were exposed to a variety of pictures (words, numbers, tools, houses, faces, and bodies) while performing an unrelated target-detection task. Behavioral assessment indicated a sharp rise in grapheme-phoneme knowledge and reading speed in the first trimester of school. Concurrently, voxels specific to written words and digits emerged at the VWFA location. The responses to other categories remained largely stable, although right-hemispheric face-related activity increased in proportion to reading scores. Retrospective examination of the VWFA voxels prior to reading acquisition showed that reading encroaches on voxels that are initially weakly specialized for tools and close to but distinct from those responsive to faces. Remarkably, those voxels appear to keep their initial category selectivity while acquiring an additional and stronger responsivity to words. We propose a revised model of the neuronal recycling process in which new visual categories invade weakly specified cortex while leaving previously stabilized cortical responses unchanged.

Acquisition of Motor and Cognitive Skills through Repetition in Typically Developing Children

PubMed Central

Magallón, Sara; Narbona, Juan; Crespo-Eguílaz, Nerea

2016-01-01

Background Procedural memory allows acquisition, consolidation and use of motor skills and cognitive routines. Automation of procedures is achieved through repeated practice. In children, improvement in procedural skills is a consequence of natural neurobiological development and experience. Methods The aim of the present research was to make a preliminary evaluation and description of repetition-based improvement of procedures in typically developing children (TDC). Ninety TDC children aged 6–12 years were asked to perform two procedural learning tasks. In an assembly learning task, which requires predominantly motor skills, we measured the number of assembled pieces in 60 seconds. In a mirror drawing learning task, which requires more cognitive functions, we measured time spent and efficiency. Participants were tested four times for each task: three trials were consecutive and the fourth trial was performed after a 10-minute nonverbal interference task. The influence of repeated practice on performance was evaluated by means of the analysis of variance with repeated measures and the paired-sample test. Correlation coefficients and simple linear regression test were used to examine the relationship between age and performance. Results TDC achieved higher scores in both tasks through repetition. Older children fitted more pieces than younger ones in assembling learning and they were faster and more efficient at the mirror drawing learning task. Conclusions These findings indicate that three consecutive trials at a procedural task increased speed and efficiency, and that age affected basal performance in motor-cognitive procedures. PMID:27384671

Acquisition of Motor and Cognitive Skills through Repetition in Typically Developing Children.

PubMed

Magallón, Sara; Narbona, Juan; Crespo-Eguílaz, Nerea

2016-01-01

Procedural memory allows acquisition, consolidation and use of motor skills and cognitive routines. Automation of procedures is achieved through repeated practice. In children, improvement in procedural skills is a consequence of natural neurobiological development and experience. The aim of the present research was to make a preliminary evaluation and description of repetition-based improvement of procedures in typically developing children (TDC). Ninety TDC children aged 6-12 years were asked to perform two procedural learning tasks. In an assembly learning task, which requires predominantly motor skills, we measured the number of assembled pieces in 60 seconds. In a mirror drawing learning task, which requires more cognitive functions, we measured time spent and efficiency. Participants were tested four times for each task: three trials were consecutive and the fourth trial was performed after a 10-minute nonverbal interference task. The influence of repeated practice on performance was evaluated by means of the analysis of variance with repeated measures and the paired-sample test. Correlation coefficients and simple linear regression test were used to examine the relationship between age and performance. TDC achieved higher scores in both tasks through repetition. Older children fitted more pieces than younger ones in assembling learning and they were faster and more efficient at the mirror drawing learning task. These findings indicate that three consecutive trials at a procedural task increased speed and efficiency, and that age affected basal performance in motor-cognitive procedures.

Reliabilities of mental rotation tasks: limits to the assessment of individual differences.

PubMed

Hirschfeld, Gerrit; Thielsch, Meinald T; Zernikow, Boris

2013-01-01

Mental rotation tasks with objects and body parts as targets are widely used in cognitive neuropsychology. Even though these tasks are well established to study between-groups differences, the reliability on an individual level is largely unknown. We present a systematic study on the internal consistency and test-retest reliability of individual differences in mental rotation tasks comparing different target types and orders of presentations. In total n = 99 participants (n = 63 for the retest) completed the mental rotation tasks with hands, feet, faces, and cars as targets. Different target types were presented in either randomly mixed blocks or blocks of homogeneous targets. Across all target types, the consistency (split-half reliability) and stability (test-retest reliabilities) were good or acceptable both for intercepts and slopes. At the level of individual targets, only intercepts showed acceptable reliabilities. Blocked presentations resulted in significantly faster and numerically more consistent and stable responses. Mental rotation tasks-especially in blocked variants-can be used to reliably assess individual differences in global processing speed. However, the assessment of the theoretically important slope parameter for individual targets requires further adaptations to mental rotation tests.

Speech acquisition predicts regions of enhanced cortical response to auditory stimulation in autism spectrum individuals.

PubMed

Samson, F; Zeffiro, T A; Doyon, J; Benali, H; Mottron, L

2015-09-01

A continuum of phenotypes makes up the autism spectrum (AS). In particular, individuals show large differences in language acquisition, ranging from precocious speech to severe speech onset delay. However, the neurological origin of this heterogeneity remains unknown. Here, we sought to determine whether AS individuals differing in speech acquisition show different cortical responses to auditory stimulation and morphometric brain differences. Whole-brain activity following exposure to non-social sounds was investigated. Individuals in the AS were classified according to the presence or absence of Speech Onset Delay (AS-SOD and AS-NoSOD, respectively) and were compared with IQ-matched typically developing individuals (TYP). AS-NoSOD participants displayed greater task-related activity than TYP in the inferior frontal gyrus and peri-auditory middle and superior temporal gyri, which are associated with language processing. Conversely, the AS-SOD group only showed enhanced activity in the vicinity of the auditory cortex. We detected no differences in brain structure between groups. This is the first study to demonstrate the existence of differences in functional brain activity between AS individuals divided according to their pattern of speech development. These findings support the Trigger-threshold-target model and indicate that the occurrence of speech onset delay in AS individuals depends on the location of cortical functional reallocation, which favors perception in AS-SOD and language in AS-NoSOD. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

First In-Orbit Experience of TerraSAR-X Flight Dynamics Operations

NASA Technical Reports Server (NTRS)

Kahle, R.; Kazeminejad, B.; Kirschner, M.; Yoon, Y.; Kiehling, R.; D'Amico, S.

2007-01-01

TerraSAR-X is an advanced synthetic aperture radar satellite system for scientific and commercial applications that is realized in a public-private partnership between the German Aerospace Center (DLR) and the Astrium GmbH. TerraSAR-X was launched at June 15, 2007 on top of a Russian DNEPR-1 rocket into a 514 km sun-synchronous dusk-dawn orbit with an 11-day repeat cycle and will be operated for a period of at least 5 years during which it will provide high resolution SAR-data in the X-band. Due to the objectives of the interferometric campaigns the satellite has to comply to tight orbit control requirements, which are formulated in the form of a 250 m toroidal tube around a pre-flight determined reference trajectory (see [1] for details). The acquisition of the reference orbit was one of the main and key activities during the Launch and Early Orbit Phase (LEOP) and had to compensate for both injection errors and spacecraft safe mode attitude control thruster activities. The paper summarizes the activities of GSOC flight dynamics team during both LEOP and early Commissioning Phase, where the main tasks have been 1) the first-acquisition support via angle-tracking and GPS-based orbit determination, 2) maneuver planning for target orbit acquisition and maintenance, and 3) precise orbit and attitude determination for SAR processing support. Furthermore, a presentation on the achieved results and encountered problems will be addressed.

Effects of context and word class on lexical retrieval in Chinese speakers with anomic aphasia.

PubMed

Law, Sam-Po; Kong, Anthony Pak-Hin; Lai, Loretta Wing-Shan; Lai, Christy

2015-01-01

Differences in processing nouns and verbs have been investigated intensely in psycholinguistics and neuropsychology in past decades. However, the majority of studies examining retrieval of these word classes have involved tasks of single word stimuli or responses. While the results have provided rich information for addressing issues about grammatical class distinctions, it is unclear whether they have adequate ecological validity for understanding lexical retrieval in connected speech which characterizes daily verbal communication. Previous investigations comparing retrieval of nouns and verbs in single word production and connected speech have reported either discrepant performance between the two contexts with presence of word class dissociation in picture naming but absence in connected speech, or null effects of word class. In addition, word finding difficulties have been found to be less severe in connected speech than picture naming. However, these studies have failed to match target stimuli of the two word classes and between tasks on psycholinguistic variables known to affect performance in response latency and/or accuracy. The present study compared lexical retrieval of nouns and verbs in picture naming and connected speech from picture description, procedural description, and story-telling among 19 Chinese speakers with anomic aphasia and their age, gender, and education matched healthy controls, to understand the influence of grammatical class on word production across speech contexts when target items were balanced for confounding variables between word classes and tasks. Elicitation of responses followed the protocol of the AphasiaBank consortium (http://talkbank.org/AphasiaBank/). Target words for confrontation naming were based on well-established naming tests, while those for narrative were drawn from a large database of normal speakers. Selected nouns and verbs in the two contexts were matched for age-of-acquisition (AoA) and familiarity. Influence of imageability was removed through statistical control. When AoA and familiarity were balanced, nouns were retrieved better than verbs, and performance was higher in picture naming than connected speech. When imageability was further controlled for, only the effect of task remained significant. The absence of word class effects when confounding variables are controlled for is similar to many previous reports; however, the pattern of better word retrieval in naming is rare but compatible with the account that processing demands are higher in narrative than naming. The overall findings have strongly suggested the importance of including connected speech tasks in any language assessment and evaluation of language rehabilitation of individuals with aphasia.

Effects of context and word class on lexical retrieval in Chinese speakers with anomic aphasia

PubMed Central

Law, Sam-Po; Kong, Anthony Pak-Hin; Lai, Loretta Wing-Shan; Lai, Christy

2014-01-01

Background Differences in processing nouns and verbs have been investigated intensely in psycholinguistics and neuropsychology in past decades. However, the majority of studies examining retrieval of these word classes have involved tasks of single word stimuli or responses. While the results have provided rich information for addressing issues about grammatical class distinctions, it is unclear whether they have adequate ecological validity for understanding lexical retrieval in connected speech which characterizes daily verbal communication. Previous investigations comparing retrieval of nouns and verbs in single word production and connected speech have reported either discrepant performance between the two contexts with presence of word class dissociation in picture naming but absence in connected speech, or null effects of word class. In addition, word finding difficulties have been found to be less severe in connected speech than picture naming. However, these studies have failed to match target stimuli of the two word classes and between tasks on psycholinguistic variables known to affect performance in response latency and/or accuracy. Aims The present study compared lexical retrieval of nouns and verbs in picture naming and connected speech from picture description, procedural description, and story-telling among 19 Chinese speakers with anomic aphasia and their age, gender, and education matched healthy controls, to understand the influence of grammatical class on word production across speech contexts when target items were balanced for confounding variables between word classes and tasks. Methods & Procedures Elicitation of responses followed the protocol of the AphasiaBank consortium (http://talkbank.org/AphasiaBank/). Target words for confrontation naming were based on well-established naming tests, while those for narrative were drawn from a large database of normal speakers. Selected nouns and verbs in the two contexts were matched for age-of-acquisition (AoA) and familiarity. Influence of imageability was removed through statistical control. Outcomes & Results When AoA and familiarity were balanced, nouns were retrieved better than verbs, and performance was higher in picture naming than connected speech. When imageability was further controlled for, only the effect of task remained significant. Conclusions The absence of word class effects when confounding variables are controlled for is similar to many previous reports; however, the pattern of better word retrieval in naming is rare but compatible with the account that processing demands are higher in narrative than naming. The overall findings have strongly suggested the importance of including connected speech tasks in any language assessment and evaluation of language rehabilitation of individuals with aphasia. PMID:25505810

Evaluating the Predictive Validity of the Computerized Comprehension Task: Comprehension Predicts Production

PubMed Central

Friend, Margaret; Schmitt, Sara A.; Simpson, Adrianne M.

2017-01-01

Until recently, the challenges inherent in measuring comprehension have impeded our ability to predict the course of language acquisition. The present research reports on a longitudinal assessment of the convergent and predictive validity of the CDI: Words and Gestures and the Computerized Comprehension Task (CCT). The CDI: WG and the CCT evinced good convergent validity however the CCT better predicted subsequent parent reports of language production. Language sample data in the third year confirm this finding: the CCT accounted for 24% of the variance in unique word use. These studies provide evidence for the utility of a behavior-based approach to predicting the course of language acquisition into production. PMID:21928878

An Ad-Hoc Adaptive Pilot Model for Pitch Axis Gross Acquisition Tasks

NASA Technical Reports Server (NTRS)

Hanson, Curtis E.

2012-01-01

An ad-hoc algorithm is presented for real-time adaptation of the well-known crossover pilot model and applied to pitch axis gross acquisition tasks in a generic fighter aircraft. Off-line tuning of the crossover model to human pilot data gathered in a fixed-based high fidelity simulation is first accomplished for a series of changes in aircraft dynamics to provide expected values for model parameters. It is shown that in most cases, for this application, the traditional crossover model can be reduced to a gain and a time delay. The ad-hoc adaptive pilot gain algorithm is shown to have desirable convergence properties for most types of changes in aircraft dynamics.

An evolutionary algorithm that constructs recurrent neural networks.

PubMed

Angeline, P J; Saunders, G M; Pollack, J B

1994-01-01

Standard methods for simultaneously inducing the structure and weights of recurrent neural networks limit every task to an assumed class of architectures. Such a simplification is necessary since the interactions between network structure and function are not well understood. Evolutionary computations, which include genetic algorithms and evolutionary programming, are population-based search methods that have shown promise in many similarly complex tasks. This paper argues that genetic algorithms are inappropriate for network acquisition and describes an evolutionary program, called GNARL, that simultaneously acquires both the structure and weights for recurrent networks. GNARL's empirical acquisition method allows for the emergence of complex behaviors and topologies that are potentially excluded by the artificial architectural constraints imposed in standard network induction methods.

Intragenomic spread of plastid-targeting presequences in the coccolithophore Emiliania huxleyi.

PubMed

Burki, Fabien; Hirakawa, Yoshihisa; Keeling, Patrick J

2012-09-01

Nucleus-encoded plastid-targeted proteins of photosynthetic organisms are generally equipped with an N-terminal presequence required for crossing the plastid membranes. The acquisition of these presequences played a fundamental role in the establishment of plastids. Here, we report a unique case of two non-homologous proteins possessing completely identical presequences consisting of a bipartite plastid-targeting signal in the coccolithophore Emiliania huxleyi. We further show that this presequence is highly conserved in five additional proteins that did not originally function in plastids, representing de novo plastid acquisitions. These are among the most recent cases of presequence spreading from gene to gene and shed light on important evolutionary processes that have been usually erased by the ancient history of plastid evolution. We propose a mechanism of acquisition involving genomic duplications and gene replacement through non-homologous recombination that may have played a more general role for equipping proteins with targeting information.

A deficit in optimizing task solution but robust and well-retained speed and accuracy gains in complex skill acquisition in Parkinson׳s disease: multi-session training on the Tower of Hanoi Puzzle.

PubMed

Vakil, Eli; Hassin-Baer, Sharon; Karni, Avi

2014-05-01

There are inconsistent results in the research literature relating to whether a procedural memory dysfunction exists as a core deficit in Parkinson׳s disease (PD). To address this issue, we examined the acquisition and long-term retention of a cognitive skill in patients with moderately severe PD. To this end, we used a computerized version of the Tower of Hanoi Puzzle. Sixteen patients with PD (11 males, age 60.9±10.26 years, education 13.8±3.5 years, disease duration 8.6±4.7 years, UPDRS III "On" score 16±5.3) were compared with 20 healthy individuals matched for age, gender, education and MMSE scores. The patients were assessed while taking their anti-Parkinsonian medication. All participants underwent three consecutive practice sessions, 24-48h apart, and a retention-test session six months later. A computerized version of the Tower of Hanoi Puzzle, with four disks, was used for training. Participants completed the task 18 times in each session. Number of moves (Nom) to solution, and time per move (Tpm), were used as measures of acquisition and retention of the learned skill. Robust learning, a significant reduction in Nom and a concurrent decrease in Tpm, were found across all three training sessions, in both groups. Moreover, both patients and controls showed significant savings for both measures at six months post-training. However, while their Tpm was no slower than that of controls, patients with PD required more Nom (in 3rd and 4th sessions) and tended to stabilize on less-than-optimal solutions. The results do not support the notion of a core deficit in gaining speed (fluency) or generating procedural memory in PD. However, PD patients settled on less-than-optimal solutions of the task, i.e., less efficient task solving process. The results are consistent with animal studies of the effects of dopamine depletion on task exploration. Thus, patients with PD may have a problem in exploring for optimal task solution rather than in skill acquisition and retention per se. Copyright © 2014. Published by Elsevier Ltd.

Second Language Acquisition as Situated Practice: Task Accomplishment in the French Second Language Classroom

ERIC Educational Resources Information Center

Mondada, Lorenza; Doehler, Simona Pekarek

2004-01-01

This article provides an empirically based perspective on the contribution of conversation analysis (CA) and sociocultural theory to our understanding of learners' second language (L2) practices within what we call a strong socio-interactionist perspective. It explores the interactive (re)configuration of tasks in French second language…

Effect of Modality and Task Type on Interlanguage Variation

ERIC Educational Resources Information Center

Kim, Hye Yeong

2017-01-01

An essential component for assessing the accuracy and fluency of language learners is understanding how mode of communication and task type affect performance in second-language (L2) acquisition. This study investigates how text-based synchronous computer-mediated communication (SCMC) and face-to-face (F2F) oral interaction can influence the…

Test-Task Authenticity: The Multiple Perspectives

ERIC Educational Resources Information Center

Gan, Zhengdong

2012-01-01

Leung and Lewkowicz remind us that the debate over the past two decades that is most relevant to ELT (English languge teaching) pedagogy and curriculum concerns test-task authenticity. This paper first reviews how the authenticity debate in the literature of second language acquisition, pedagogy and testing has evolved. Drawing on a body of…

The Role of Input and Output Tasks in Grammar Instruction: Theoretical, Empirical and Pedagogical Considerations

ERIC Educational Resources Information Center

Benati, Alessandro

2017-01-01

In this paper, a review of the role of input, output and instruction in second language acquisition is provided. Several pedagogical interventions in grammar instruction (e.g., processing instruction, input enhancement, structured output and collaborative output tasks) are presented and their effectiveness reviewed. A final and overall evaluation…

Instruction-First and Problem-Solving-First Approaches: Alternative Pathways to Learning Complex Tasks

ERIC Educational Resources Information Center

Likourezos, Vicki; Kalyuga, Slava

2017-01-01

According to cognitive load theory, using worked examples is an effective and efficient instructional strategy for initial cognitive skill acquisition for novice learners, as it reduces cognitive load and frees up cognitive resources to build task competence. Contrary to this, productive failure (as well as invention learning, desirable…

Attention to the Second Language

ERIC Educational Resources Information Center

Wickens, Christopher D.

2007-01-01

Attention to a task, and the language it requires to be performed, can be described in relation to two theoretical models which have prompted research into the effects of task demands on learning and performance outside the field of second language acquisition (SLA). These are the SEEV (selection, effort, expectancy and value) model of selective…

Prerequisite Skills That Support Learning through Video Modeling

ERIC Educational Resources Information Center

MacDonald, Rebecca P. F.; Dickson, Chata A.; Martineau, Meaghan; Ahearn, William H.

2015-01-01

The purpose of this study was to evaluate the relationship between tasks that require delayed discriminations such as delayed imitation and delayed matching to sample on acquisition of skills using video modeling. Twenty-nine participants with an ASD diagnosis were assessed on a battery of tasks including both immediate and delayed imitation and…

Comparing Nouns and Verbs in a Lexical Task

ERIC Educational Resources Information Center

Cordier, Francoise; Croizet, Jean-Claude; Rigalleau, Francois

2013-01-01

We analyzed the differential processing of nouns and verbs in a lexical decision task. Moderate and high-frequency nouns and verbs were compared. The characteristics of our material were specified at the formal level (number of letters and syllables, number of homographs, orthographic neighbors, frequency and age of acquisition), and at the…

Sources, Developments and Directions of Task-Based Language Teaching

ERIC Educational Resources Information Center

Bygate, Martin

2016-01-01

This paper provides an outline of the origins, the current shape and the potential directions of task-based language teaching (TBLT) as an approach to language pedagogy. It first offers a brief description of TBLT and considers its origins within language teaching methodology and second language acquisition. It then summarises the current position…

Effects of Self-Monitoring and Recruiting Teacher Attention on Pre-Vocational Skills

ERIC Educational Resources Information Center

Rouse, Christina A.; Everhart-Sherwood, Julie M.; Alber-Morgan, Sheila R.

2014-01-01

This study examined the effects of teaching self-monitoring and recruiting teacher attention on the acquisition, generalization, and maintenance of pre-vocational tasks by two sixth grade boys with moderate to severe intellectual disability. While completing pre-vocational tasks (e.g., sorting hangers by size, weighing amounts in ounces), the…

Plural Acquisition in Children with Specific Language Impairment.

ERIC Educational Resources Information Center

Oetting, Janna B.; Rice, Mabel L.

1993-01-01

A plural elicitation task and a nominal compounding task were administered to 18 children (age 5-6 years) with specific language impairment (SLI) and 2 control groups. SLI children's performance was affected by input frequency; three explanations within a model of linguistic normalcy are proposed to account for this frequency effect. (Author/DB)

Age of acquisition in sport: starting early matters.

PubMed

Hernandez, Arturo E; Mattarella-Micke, Andrew; Redding, Richard W T; Woods, Elizabeth A; Beilock, Sian

2011-01-01

Although the age at which a skill is learned (age of acquisition [AoA]) is one of the most studied predictors of success in domains ranging from language to music, very little work has focused on this factor in sports. In order to uncover how the age at which a skill is learned relates to how athletes cognitively represent that skill, we asked a group of skilled golfers who learned to play golf before (early learners) or after (late learners) the age of 10 to take a series of putts on an indoor putting green. Golfers putted in isolation (single-task condition), while monitoring a stream of words presented over a loudspeaker (dual-task condition), or while being instructed to attend to specific aspects of their golf swing (skill-focused condition). Early and late learners putted equally well in the single-task and dual-task conditions. However, in the skill-focused condition, golfers who learned earlier performed worse than those who learned later. The results are consistent with the notion that AoA influences the manner in which sports, like other domains such as language and music, are represented in memory.

Memory consolidation and contextual interference effects with computer games.

PubMed

Shewokis, Patricia A

2003-10-01

Some investigators of the contextual interference effect contend that there is a direct relation between the amount of practice and the contextual interference effect based on the prediction that the improvement in learning tasks in a random practice schedule, compared to a blocked practice schedule, increases in magnitude as the amount of practice during acquisition on the tasks increases. Research using computer games in contextual interference studies has yielded a large effect (f = .50) with a random practice schedule advantage during transfer. These investigations had a total of 36 and 72 acquisition trials, respectively. The present study tested this prediction by having 72 college students, who were randomly assigned to a blocked or random practice schedule, practice 102 trials of three computer-game tasks across three days. After a 24-hr. interval, 6 retention and 5 transfer trials were performed. Dependent variables were time to complete an event in seconds and number of errors. No significant differences were found for retention and transfer. These results are discussed in terms of how the amount of practice, task-related factors, and memory consolidation mediate the contextual interference effect.

Task relevance regulates the interaction between reward expectation and emotion.

PubMed

Wei, Ping; Kang, Guanlan

2014-06-01

In the present study, we investigated the impact of reward expectation on the processing of emotional facial expression using a cue-target paradigm. A cue indicating the reward condition of each trial (incentive vs. non-incentive) was followed by the presentation of a picture of an emotional face, the target. Participants were asked to discriminate the emotional expression of the target face in Experiment 1, to discriminate the gender of the target face in Experiment 2, and to judge a number superimposed on the center of the target face as even or odd in Experiment 3, rendering the emotional expression of the target face as task relevant in Experiment 1 but task irrelevant in Experiments 2 and 3. Faster reaction times (RTs) were observed in the monetary incentive condition than in the non-incentive condition, demonstrating the effect of reward on facilitating task concentration. Moreover, the reward effect (i.e., RTs in non-incentive conditions versus incentive conditions) was larger for emotional faces than for neutral faces when emotional expression was task relevant but not when it was task irrelevant. The findings suggest that top-down incentive motivation biased attentional processing toward task-relevant stimuli, and that task relevance played an important role in regulating the influence of reward expectation on the processing of emotional stimuli.

Attending to unrelated targets boosts short-term memory for color arrays.

PubMed

Makovski, Tal; Swallow, Khena M; Jiang, Yuhong V

2011-05-01

Detecting a target typically impairs performance in a second, unrelated task. It has been recently reported however, that detecting a target in a stream of distractors can enhance long-term memory of faces and scenes that were presented concurrently with the target (the attentional boost effect). In this study we ask whether target detection also enhances performance in a visual short-term memory task, where capacity limits are severe. Participants performed two tasks at once: a one shot, color change detection task and a letter-detection task. In Experiment 1, a central letter appeared at the same time as 3 or 5 color patches (memory display). Participants encoded the colors and pressed the spacebar if the letter was a T (target). After a short retention interval, a probe display of color patches appeared. Performance on the change detection task was enhanced when a target, rather than a distractor, appeared with the memory display. This effect was not modulated by memory load or the frequency of trials in which a target appeared. However, there was no enhancement when the target appeared at the same time as the probe display (Experiment 2a) or during the memory retention interval (Experiment 2b). Together these results suggest that detecting a target facilitates the encoding of unrelated information into visual short-term memory. Copyright © 2010 Elsevier Ltd. All rights reserved.

Distributed Training Enhances Implicit Sequence Acquisition in Children with Specific Language Impairment

ERIC Educational Resources Information Center

Desmottes, Lise; Meulemans, Thierry; Patinec, Marie-Aude; Maillart, Christelle

2017-01-01

Purpose: This study explored the effects of 2 different training structures on the implicit acquisition of a sequence in a serial reaction time (SRT) task in children with and without specific language impairment (SLI). Method: All of the children underwent 3 training sessions, followed by a retention session 2 weeks after the last session. In the…

Tracking "Learning Behaviours" in the Incidental Acquisition of Two Dimensional Adjectives by Japanese Beginner Learners of L2 English

ERIC Educational Resources Information Center

Shintani, Natsuko; Ellis, Rod

2014-01-01

The purpose of this article is to examine both the process and product of vocabulary learning in a task-based instructional context. The article reports a study that investigated the acquisition of two dimensional adjectives ("big" and "small") by six-year-old Japanese children who were complete beginners. It tracked the…

Use of Tactual Materials on the Achievement of Content Specific Vocabulary and Terminology Acquisition within an Intermediate Level Science Curriculum

ERIC Educational Resources Information Center

Terry, Brian H.

2012-01-01

In this quasi-experimental study, the researcher investigated the effectiveness of three tactual strategies and one non-tactual strategy of content specific vocabulary acquisition. Flash cards, task cards, and learning wheels served as the tactual strategies, and vocabulary review sheets served as a non-tactual strategy. The sample (n = 85)…

Age/Order of Acquisition Effects and the Cumulative Learning of Foreign Words: A Word Training Study

ERIC Educational Resources Information Center

Izura, Cristina; Perez, Miguel A.; Agallou, Elizabeth; Wright, Victoria C.; Marin, Javier; Stadthagen-Gonzalez, Hans; Ellis, Andrew W.

2011-01-01

Early acquired words are processed faster than later acquired words in lexical and semantic tasks. Demonstrating such age of acquisition (AoA) effects beyond reasonable doubt, and then investigating those effects empirically, is complicated by the natural correlation between AoA and other word properties such as frequency and imageability. In an…

Asymmetries in Phonological Development: The Case of Word-Final Cluster Acquisition in Welsh-English Bilingual Children

ERIC Educational Resources Information Center

Mayr, Robert; Howells, Gwennan; Lewis, Rhonwen

2015-01-01

This study provides the first systematic account of word-final cluster acquisition in bilingual children. To this end, forty Welsh-English bilingual children differing in language dominance and age (2;6 to 5;0) participated in a picture-naming task in English and Welsh. The results revealed significant age and dominance effects on cluster…

Age and Input Effects in the Acquisition of Mood in Heritage Portuguese

ERIC Educational Resources Information Center

Flores, Cristina; Santos, Ana Lúcia; Jesus, Alice; Marques, Rui

2017-01-01

The present study analyzes the effect of age and amount of input in the acquisition of European Portuguese as a heritage language. An elicited production task centred on mood choice in complement clauses was applied to a group of fifty bilingual children (six- to sixteen-year-olds) who are acquiring Portuguese as a minority language in a German…

Navigating to the Future: Understanding Common Tasks in a Multi-Campus Environment in the Dramatically Changing Acquisition World

ERIC Educational Resources Information Center

Bock, Julia; Burgos-Mira, Rosemary

2010-01-01

In the context of a diverse, multi-campus university, this study discusses historical factors and recent changes in scholarly communication and the economic impact of these changes as we seek to forge stronger cooperation among our campuses. After consulting literature, the authors found that issues relating to acquisitions of multi-campus…

More than Words: Fast Acquisition and Generalization of Orthographic Regularities during Novel Word Learning in Adults

ERIC Educational Resources Information Center

Laine, Matti; Polonyi, Tünde; Abari, Kálmán

2014-01-01

In literates, reading is a fundamental channel for acquiring new vocabulary both in the mother tongue and in foreign languages. By using an artificial language learning task, we examined the acquisition of novel written words and their embedded regularities (an orthographic surface feature and a syllabic feature) in three groups of university…

Families and Literacy: The Contribution of Out-of-School Experiences to Children's Acquisition of Literacy. Final Report.

ERIC Educational Resources Information Center

Chall, Jeanne; Snow, Catherine

Addressing the question of why some children manage to continue successfully through the later stages of literacy acquisition while others are unable to meet the challenges presented by fourth and fifth grade reading tasks, an 18-month, in-depth study was conducted of the home environment factors influencing the reading comprehension of second,…

Machinery health prognostics: A systematic review from data acquisition to RUL prediction

NASA Astrophysics Data System (ADS)

Lei, Yaguo; Li, Naipeng; Guo, Liang; Li, Ningbo; Yan, Tao; Lin, Jing

2018-05-01

Machinery prognostics is one of the major tasks in condition based maintenance (CBM), which aims to predict the remaining useful life (RUL) of machinery based on condition information. A machinery prognostic program generally consists of four technical processes, i.e., data acquisition, health indicator (HI) construction, health stage (HS) division, and RUL prediction. Over recent years, a significant amount of research work has been undertaken in each of the four processes. And much literature has made an excellent overview on the last process, i.e., RUL prediction. However, there has not been a systematic review that covers the four technical processes comprehensively. To fill this gap, this paper provides a review on machinery prognostics following its whole program, i.e., from data acquisition to RUL prediction. First, in data acquisition, several prognostic datasets widely used in academic literature are introduced systematically. Then, commonly used HI construction approaches and metrics are discussed. After that, the HS division process is summarized by introducing its major tasks and existing approaches. Afterwards, the advancements of RUL prediction are reviewed including the popular approaches and metrics. Finally, the paper provides discussions on current situation, upcoming challenges as well as possible future trends for researchers in this field.

Does colour preference have a role in colour term acquisition?

PubMed

Pitchford, Nicola J; Davis, Emma E; Scerif, Gaia

2009-11-01

A developmental association exists between colour preference and emerging colour term acquisition in young children. Colour preference might influence colour term acquisition by directing attention towards or away from a particular colour, making it more or less memorable. To investigate the role that colour preference may have in the acquisition of colour terms, experimental tasks of colour preference, discrimination, attention, memory, and new colour term learning, were given to three groups of participants (preschool children; primary school children; and adults). Each task utilized the same colour stimuli, which were four computer-simulated colours, matched perceptually to four different Munsell chips, drawn from the same colour category. Three colours varied systematically from an anchor colour (10PB 4/8) only in saturation (10PB 4/4), luminance (10PB 6/8), or hue (5P 4/8). Results showed that within-category colour preferences emerged with age, and that when established within individuals, most preferred colours were named significantly more accurately than least preferred colours, although this association did not appear to be mediated directly by attention or memory. Rather, perceptual saliency was shown to have a mediating role, to some extent, in determining the relationship between colour preference and the cognitive processing of colour.

No Evidence for a Saccadic Range Effect for Visually Guided and Memory-Guided Saccades in Simple Saccade-Targeting Tasks

PubMed Central

Vitu, Françoise; Engbert, Ralf; Kliegl, Reinhold

2016-01-01

Saccades to single targets in peripheral vision are typically characterized by an undershoot bias. Putting this bias to a test, Kapoula [1] used a paradigm in which observers were presented with two different sets of target eccentricities that partially overlapped each other. Her data were suggestive of a saccadic range effect (SRE): There was a tendency for saccades to overshoot close targets and undershoot far targets in a block, suggesting that there was a response bias towards the center of eccentricities in a given block. Our Experiment 1 was a close replication of the original study by Kapoula [1]. In addition, we tested whether the SRE is sensitive to top-down requirements associated with the task, and we also varied the target presentation duration. In Experiments 1 and 2, we expected to replicate the SRE for a visual discrimination task. The simple visual saccade-targeting task in Experiment 3, entailing minimal top-down influence, was expected to elicit a weaker SRE. Voluntary saccades to remembered target locations in Experiment 3 were expected to elicit the strongest SRE. Contrary to these predictions, we did not observe a SRE in any of the tasks. Our findings complement the results reported by Gillen et al. [2] who failed to find the effect in a saccade-targeting task with a very brief target presentation. Together, these results suggest that unlike arm movements, saccadic eye movements are not biased towards making saccades of a constant, optimal amplitude for the task. PMID:27658191

Analytical performance of the various acquisition modes in Orbitrap MS and MS/MS.

PubMed

Kaufmann, Anton

2018-04-30

Quadrupole Orbitrap instruments (Q Orbitrap) permit high-resolution mass spectrometry (HRMS)-based full scan acquisitions and have a number of acquisition modes where the quadrupole isolates a particular mass range prior to a possible fragmentation and HRMS-based acquisition. Selecting the proper acquisition mode(s) is essential if trace analytes are to be quantified in complex matrix extracts. Depending on the particular requirements, such as sensitivity, selectivity of detection, linear dynamic range, and speed of analysis, different acquisition modes may have to be chosen. This is particularly important in the field of multi-residue analysis (e.g., pesticides or veterinary drugs in food samples) where a large number of analytes within a complex matrix have to be detected and reliably quantified. Meeting the specific detection and quantification performance criteria for every targeted compound may be challenging. It is the aim of this paper to describe the strengths and the limitations of the currently available Q Orbitrap acquisition modes. In addition, the incorporation of targeted acquisitions between full scan experiments is discussed. This approach is intended to integrate compounds that require an additional degree of sensitivity or selectivity into multi-residue methods. This article is protected by copyright. All rights reserved.

Concept definition for space station technology development experiments. Experiment definition, task 2

NASA Technical Reports Server (NTRS)

1986-01-01

The second task of a study with the overall objective of providing a conceptual definition of the Technology Development Mission Experiments proposed by LaRC on space station is discussed. During this task, the information (goals, objectives, and experiment functional description) assembled on a previous task was translated into the actual experiment definition. Although still of a preliminary nature, aspects such as: environment, sensors, data acquisition, communications, handling, control telemetry requirements, crew activities, etc., were addressed. Sketches, diagrams, block diagrams, and timeline analyses of crew activities are included where appropriate.

Working Memory and Reinforcement Schedule Jointly Determine Reinforcement Learning in Children: Potential Implications for Behavioral Parent Training

PubMed Central

Segers, Elien; Beckers, Tom; Geurts, Hilde; Claes, Laurence; Danckaerts, Marina; van der Oord, Saskia

2018-01-01

Introduction: Behavioral Parent Training (BPT) is often provided for childhood psychiatric disorders. These disorders have been shown to be associated with working memory impairments. BPT is based on operant learning principles, yet how operant principles shape behavior (through the partial reinforcement (PRF) extinction effect, i.e., greater resistance to extinction that is created when behavior is reinforced partially rather than continuously) and the potential role of working memory therein is scarcely studied in children. This study explored the PRF extinction effect and the role of working memory therein using experimental tasks in typically developing children. Methods: Ninety-seven children (age 6–10) completed a working memory task and an operant learning task, in which children acquired a response-sequence rule under either continuous or PRF (120 trials), followed by an extinction phase (80 trials). Data of 88 children were used for analysis. Results: The PRF extinction effect was confirmed: We observed slower acquisition and extinction in the PRF condition as compared to the continuous reinforcement (CRF) condition. Working memory was negatively related to acquisition but not extinction performance. Conclusion: Both reinforcement contingencies and working memory relate to acquisition performance. Potential implications for BPT are that decreasing working memory load may enhance the chance of optimally learning through reinforcement. PMID:29643822

Robot-Assisted Needle Steering

PubMed Central

Reed, Kyle B.; Majewicz, Ann; Kallem, Vinutha; Alterovitz, Ron; Goldberg, Ken; Cowan, Noah J.; Okamura, Allison M.

2012-01-01

Needle insertion is a critical aspect of many medical treatments, diagnostic methods, and scientific studies, and is considered to be one of the simplest and most minimally invasive medical procedures. Robot-assisted needle steering has the potential to improve the effectiveness of existing medical procedures and enable new ones by allowing increased accuracy through more dexterous control of the needle tip path and acquisition of targets not accessible by straight-line trajectories. In this article, we describe a robot-assisted needle steering system that uses three integrated controllers: a motion planner concerned with guiding the needle around obstacles to a target in a desired plane, a planar controller that maintains the needle in the desired plane, and a torsion compensator that controls the needle tip orientation about the axis of the needle shaft. Experimental results from steering an asymmetric-tip needle in artificial tissue demonstrate the effectiveness of the system and its sensitivity to various environmental and control parameters. In addition, we show an example of needle steering in ex vivo biological tissue to accomplish a clinically relevant task, and highlight challenges of practical needle steering implementation. PMID:23028210

Priority Science Targets for Future Sample Return Missions within the Solar System Out to the Year 2050

NASA Technical Reports Server (NTRS)

McCubbin, F. M.; Allton, J. H.; Barnes, J. J.; Boyce, J. W.; Burton, A. S.; Draper, D. S.; Evans, C. A.; Fries, M. D.; Jones, J. H.; Keller, L. P.;

Effect of pregabalin on fear-based conditioned avoidance learning and spatial learning in a mouse model of scopolamine-induced amnesia.

PubMed

Sałat, Kinga; Podkowa, Adrian; Malikowska, Natalia; Trajer, Jędrzej

2017-03-01

Cognitive deficits are one of the frequent symptoms accompanying epilepsy or its treatment. In this study, the effect on cognition of intraperitoneally administered antiepileptic drug, pregabalin (10 mg/kg), was investigated in scopolamine-induced memory-impaired mice in the passive avoidance task and Morris water maze task. The effect of scopolamine and pregabalin on animals' locomotor activity was also studied. In the retention phase of the passive avoidance task, pregabalin reversed memory deficits induced by scopolamine (p < 0.05). During the acquisition phase of the Morris water maze pregabalin-treated memory-impaired mice performed the test with longer escape latencies than the vehicle-treated mice (significant at p < 0.05 on Day 5, and at p < 0.001 on Day 6). There were no differences in this parameter between the scopolamine-treated control group and pregabalin-treated memory-impaired mice, which indicated that pregabalin had no influence on spatial learning in this task. During the probe trial a significant difference (p < 0.05) was observed in terms of the mean number of target crossings between vehicle-treated mice and pregabalin-treated memory-impaired mice but there was no difference between the scopolamine-treated control group and mice treated with pregabalin + scopolamine. Pregabalin did not influence locomotor activity increased by scopolamine. In passive avoidance task, pregabalin reversed learning deficits induced by scopolamine. In the Morris water maze, pregabalin did not influence spatial learning deficits induced by scopolamine. These results are relevant for epileptic patients treated with pregabalin and those who use it for other therapeutic indications (anxiety, pain).

Bird community conservation and carbon offsets in western North America.

PubMed

Schuster, Richard; Martin, Tara G; Arcese, Peter

2014-01-01

Conservation initiatives to protect and restore valued species and communities in human-dominated landscapes face huge challenges linked to the cost of acquiring habitat. We ask how the sale of forest carbon offsets could reduce land acquisition costs, and how the alternate goals of maximizing α or β-diversity in focal communities could affect the prioritization land parcels over a range of conservation targets. Maximizing total carbon storage and carbon sequestration potential reduced land acquisition costs by up to 48%. Maximizing β rather than α-diversity within forest and savannah bird communities reduced acquisition costs by up to 15%, and when these solutions included potential carbon credit revenues, acquisition cost reductions up to 32% were achieved. However, the total cost of conservation networks increased exponentially as area targets increased in all scenarios. Our results indicate that carbon credit sales have the potential to enhance conservation outcomes in human-dominated landscapes by reducing the net acquisition costs of land conservation in old and maturing forests essential for the persistence of old forest plant and animal communities. Maximizing β versus α-diversity may further reduce costs by reducing the total area required to meet conservation targets and enhancing landscape heterogeneity. Although the potential value of carbon credit sales declined as a fraction of total acquisition costs, even conservative scenarios using a carbon credit value of $12.5/T suggest reductions in acquisition cost of up to $235 M, indicating that carbon credit sales could substantially reduce the costs of conservation.

Bird Community Conservation and Carbon Offsets in Western North America

PubMed Central

Schuster, Richard; Martin, Tara G.; Arcese, Peter

2014-01-01

Conservation initiatives to protect and restore valued species and communities in human-dominated landscapes face huge challenges linked to the cost of acquiring habitat. We ask how the sale of forest carbon offsets could reduce land acquisition costs, and how the alternate goals of maximizing α or β-diversity in focal communities could affect the prioritization land parcels over a range of conservation targets. Maximizing total carbon storage and carbon sequestration potential reduced land acquisition costs by up to 48%. Maximizing β rather than α-diversity within forest and savannah bird communities reduced acquisition costs by up to 15%, and when these solutions included potential carbon credit revenues, acquisition cost reductions up to 32% were achieved. However, the total cost of conservation networks increased exponentially as area targets increased in all scenarios. Our results indicate that carbon credit sales have the potential to enhance conservation outcomes in human-dominated landscapes by reducing the net acquisition costs of land conservation in old and maturing forests essential for the persistence of old forest plant and animal communities. Maximizing β versus α-diversity may further reduce costs by reducing the total area required to meet conservation targets and enhancing landscape heterogeneity. Although the potential value of carbon credit sales declined as a fraction of total acquisition costs, even conservative scenarios using a carbon credit value of $12.5/T suggest reductions in acquisition cost of up to $235 M, indicating that carbon credit sales could substantially reduce the costs of conservation. PMID:24918621

What Program Managers Need to Know: A New Book to Accelerate Acquisition Competence

DTIC Science & Technology

2015-02-01

FEB 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE What Program Managers Need to Know: A New Book to...Accelerate Acquisition Competence 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f...ANSI Std Z39-18 What Program Managers Need to Know A New Book to Accelerate Acquisition Competence Col. William T. Cooley n Brian C. Ruhm Cooley is

Acquiring and disseminating unpublished economic and social development materials in Africa: The case of the National Institute of Development Research and Documentation University of Botswana

NASA Technical Reports Server (NTRS)

Kwafo-Akoto, Kate

1994-01-01

Generally in Africa, the identification and acquisition of both published and unpublished documents can be an extremely difficult task due, among other factors, to the unsatisfactory state of the publishing industry and the poor state of bibliographic control. This paper analyzes the various problems involved in the acquisition of documents in Africa and illustrates them with the author's personal experience as an acquisitions librarian working on an information project which necessitated travel to about 15 African countries.

Increasing Coverage of Appropriate Vaccinations

PubMed Central

Jacob, Verughese; Chattopadhyay, Sajal K.; Hopkins, David P.; Morgan, Jennifer Murphy; Pitan, Adesola A.; Clymer, John

2016-01-01

Context Population-level coverage for immunization against many vaccine-preventable diseases remains below optimal rates in the U.S. The Community Preventive Services Task Force recently recommended several interventions to increase vaccination coverage based on systematic reviews of the evaluation literature. The present study provides the economic results from those reviews. Evidence acquisition A systematic review was conducted (search period, January 1980 through February 2012) to identify economic evaluations of 12 interventions recommended by the Task Force. Evidence was drawn from included studies; estimates were constructed for the population reach of each strategy, cost of implementation, and cost per additional vaccinated person because of the intervention. Analyses were conducted in 2014. Evidence synthesis Reminder systems, whether for clients or providers, were among the lowest-cost strategies to implement and the most cost effective in terms of additional people vaccinated. Strategies involving home visits and combination strategies in community settings were both costly and less cost effective. Strategies based in settings such as schools and managed care organizations that reached the target population achieved additional vaccinations in the middle range of cost effectiveness. Conclusions The interventions recommended by the Task Force differed in reach, cost, and cost effectiveness. This systematic review presents the economic information for 12 effective strategies to increase vaccination coverage that can guide implementers in their choice of interventions to fit their local needs, available resources, and budget. PMID:26847663

It Pays to Go Off-Track: Practicing with Error-Augmenting Haptic Feedback Facilitates Learning of a Curve-Tracing Task

PubMed Central

Williams, Camille K.; Tremblay, Luc; Carnahan, Heather

2016-01-01

Researchers in the domain of haptic training are now entering the long-standing debate regarding whether or not it is best to learn a skill by experiencing errors. Haptic training paradigms provide fertile ground for exploring how various theories about feedback, errors and physical guidance intersect during motor learning. Our objective was to determine how error minimizing, error augmenting and no haptic feedback while learning a self-paced curve-tracing task impact performance on delayed (1 day) retention and transfer tests, which indicate learning. We assessed performance using movement time and tracing error to calculate a measure of overall performance – the speed accuracy cost function. Our results showed that despite exhibiting the worst performance during skill acquisition, the error augmentation group had significantly better accuracy (but not overall performance) than the error minimization group on delayed retention and transfer tests. The control group’s performance fell between that of the two experimental groups but was not significantly different from either on the delayed retention test. We propose that the nature of the task (requiring online feedback to guide performance) coupled with the error augmentation group’s frequent off-target experience and rich experience of error-correction promoted information processing related to error-detection and error-correction that are essential for motor learning. PMID:28082937

Gastrodia elata Bl. Attenuated learning deficits induced by forced-swimming stress in the inhibitory avoidance task and Morris water maze.

PubMed

Chen, Pei-Ju; Liang, Keng-Chen; Lin, Hui-Chen; Hsieh, Ching-Liang; Su, Kuan-Pin; Hung, Mei-Chu; Sheen, Lee-Yan

2011-06-01

This study adopted the forced-swimming paradigm to induce depressive symptoms in rats and evaluated the effects on learning and memory processing. Furthermore, the effects of the water extract of Gastrodia elata Bl., a well-known Chinese traditional medicine, on amnesia in rats subjected to the forced-swimming procedure were studied. Rats were subjected to the forced-swimming procedure, and the inhibitory avoidance task and Morris water maze were used to assess learning and memory performance. The acquisition of the two tasks was mostly impaired after the 15-minute forced-swimming procedure. Administration of the water extract of G. elata Bl. for 21 consecutive days at a dosage of 0.5 or 1.0 g/kg of body weight significantly improved retention in the inhibitory avoidance test, and the lower dose showed a better effect than the higher one and the antidepressant fluoxetine (18 mg/kg of body weight). In the Morris water maze, the lower dose of the water extract of G. elata Bl. significantly improved retention by shortening escape latency in the first test session and increasing the time in searching the target zone during the probe test. These findings suggest that water extracts of G. elata Bl. ameliorate the learning and memory deficits induced by forced swimming.

Mind Wandering and Task-Focused Attention: ERP Correlates.

PubMed

Gonçalves, Óscar F; Rêgo, Gabriel; Conde, Tatiana; Leite, Jorge; Carvalho, Sandra; Lapenta, Olívia Morgan; Boggio, Paulo S

2018-05-15

Previous studies looking at how Mind Wandering (MW) impacts performance in distinct Focused Attention (FA) systems, using the Attention Network Task (ANT), showed that the presence of pure MW thoughts did not impact the overall performance of ANT (alert, orienting and conflict) performance. However, it still remains unclear if the lack of interference of MW in the ANT, reported at the behavioral level, has a neurophysiological correspondence. We hypothesize that a distinct cortical processing may be required to meet attentional demands during MW. The objective of the present study was to test if, given similar levels of ANT performance, individuals predominantly focusing on MW or FA show distinct cortical processing. Thirty-three healthy participants underwent an EEG high-density acquisition while they were performing the ANT. MW was assessed following the ANT using an adapted version of the Resting State Questionnaire (ReSQ). The following ERP's were analyzed: pN1, pP1, P1, N1, pN, and P3. At the behavioral level, participants were slower and less accurate when responding to incongruent than to congruent targets (conflict effect), benefiting from the presentation of the double (alerting effect) and spatial (orienting effect) cues. Consistent with the behavioral data, ERP's waves were discriminative of distinct attentional effects. However, these results remained true irrespective of the MW condition, suggesting that MW imposed no additional cortical demand in alert, orienting, and conflict attention tasks.

The Impact of Topic Interest, L2 Proficiency, and Gender on EFL Incidental Vocabulary Acquisition through Reading

ERIC Educational Resources Information Center

Lee, Sunjung; Pulido, Diana

2017-01-01

This study investigated the impact of topic interest, alongside L2 proficiency and gender, on L2 vocabulary acquisition through reading. A repeated-measures design was used with 135 Korean EFL students. Control variables included topic familiarity, prior target-word knowledge, and target-word difficulty (word length, class, and concreteness).…

Assisting People with Multiple Disabilities by Improving Their Computer Pointing Efficiency with an Automatic Target Acquisition Program

ERIC Educational Resources Information Center

Shih, Ching-Hsiang; Shih, Ching-Tien; Peng, Chin-Ling

2011-01-01

This study evaluated whether two people with multiple disabilities would be able to improve their pointing performance through an Automatic Target Acquisition Program (ATAP) and a newly developed mouse driver (i.e. a new mouse driver replaces standard mouse driver, and is able to monitor mouse movement and intercept click action). Initially, both…

Two Simon tasks with different sources of conflict: an ERP study of motion- and location-based compatibility effects.

PubMed

Galashan, Daniela; Wittfoth, Matthias; Fehr, Thorsten; Herrmann, Manfred

2008-07-01

Behavioral and electrophysiological correlates of two Simon tasks were examined using comparable stimuli but different task-irrelevant and conflict-inducing stimulus features. Whereas target shape was always the task-relevant stimulus attribute, either target location (location-based task) or motion direction within the target stimuli (motion-based task) was used as a source of conflict. Data from ten healthy participants who performed both tasks are presented. In the motion-based task the incompatible condition showed smaller P300 amplitudes at Pz than the compatible condition and the location-based task yielded a trend towards a reduced P300 amplitude in the incompatible condition. For both tasks, no P300 latency differences between the conditions were found at Pz. The results suggest that the motion-based task elicits behavioral and electrophysiological effects comparable with regular Simon tasks. As all stimuli in the motion-based Simon task were presented centrally the present data strongly argue against the attention-shifting account as an explanatory approach.

Scene Configuration and Object Reliability Affect the Use of Allocentric Information for Memory-Guided Reaching

PubMed Central

Klinghammer, Mathias; Blohm, Gunnar; Fiehler, Katja

2017-01-01

Previous research has shown that egocentric and allocentric information is used for coding target locations for memory-guided reaching movements. Especially, task-relevance determines the use of objects as allocentric cues. Here, we investigated the influence of scene configuration and object reliability as a function of task-relevance on allocentric coding for memory-guided reaching. For that purpose, we presented participants images of a naturalistic breakfast scene with five objects on a table and six objects in the background. Six of these objects served as potential reach-targets (= task-relevant objects). Participants explored the scene and after a short delay, a test scene appeared with one of the task-relevant objects missing, indicating the location of the reach target. After the test scene vanished, participants performed a memory-guided reaching movement toward the target location. Besides removing one object from the test scene, we also shifted the remaining task-relevant and/or task-irrelevant objects left- or rightwards either coherently in the same direction or incoherently in opposite directions. By varying object coherence, we manipulated the reliability of task-relevant and task-irrelevant objects in the scene. In order to examine the influence of scene configuration (distributed vs. grouped arrangement of task-relevant objects) on allocentric coding, we compared the present data with our previously published data set (Klinghammer et al., 2015). We found that reaching errors systematically deviated in the direction of object shifts, but only when the objects were task-relevant and their reliability was high. However, this effect was substantially reduced when task-relevant objects were distributed across the scene leading to a larger target-cue distance compared to a grouped configuration. No deviations of reach endpoints were observed in conditions with shifts of only task-irrelevant objects or with low object reliability irrespective of task-relevancy. Moreover, when solely task-relevant objects were shifted incoherently, the variability of reaching endpoints increased compared to coherent shifts of task-relevant objects. Our results suggest that the use of allocentric information for coding targets for memory-guided reaching depends on the scene configuration, in particular the average distance of the reach target to task-relevant objects, and the reliability of task-relevant allocentric information. PMID:28450826

Scene Configuration and Object Reliability Affect the Use of Allocentric Information for Memory-Guided Reaching.

PubMed

Klinghammer, Mathias; Blohm, Gunnar; Fiehler, Katja

2017-01-01

Previous research has shown that egocentric and allocentric information is used for coding target locations for memory-guided reaching movements. Especially, task-relevance determines the use of objects as allocentric cues. Here, we investigated the influence of scene configuration and object reliability as a function of task-relevance on allocentric coding for memory-guided reaching. For that purpose, we presented participants images of a naturalistic breakfast scene with five objects on a table and six objects in the background. Six of these objects served as potential reach-targets (= task-relevant objects). Participants explored the scene and after a short delay, a test scene appeared with one of the task-relevant objects missing, indicating the location of the reach target. After the test scene vanished, participants performed a memory-guided reaching movement toward the target location. Besides removing one object from the test scene, we also shifted the remaining task-relevant and/or task-irrelevant objects left- or rightwards either coherently in the same direction or incoherently in opposite directions. By varying object coherence, we manipulated the reliability of task-relevant and task-irrelevant objects in the scene. In order to examine the influence of scene configuration (distributed vs. grouped arrangement of task-relevant objects) on allocentric coding, we compared the present data with our previously published data set (Klinghammer et al., 2015). We found that reaching errors systematically deviated in the direction of object shifts, but only when the objects were task-relevant and their reliability was high. However, this effect was substantially reduced when task-relevant objects were distributed across the scene leading to a larger target-cue distance compared to a grouped configuration. No deviations of reach endpoints were observed in conditions with shifts of only task-irrelevant objects or with low object reliability irrespective of task-relevancy. Moreover, when solely task-relevant objects were shifted incoherently, the variability of reaching endpoints increased compared to coherent shifts of task-relevant objects. Our results suggest that the use of allocentric information for coding targets for memory-guided reaching depends on the scene configuration, in particular the average distance of the reach target to task-relevant objects, and the reliability of task-relevant allocentric information.

PLÉIADES: Responsiveness, Flexibility, Reactivity

NASA Astrophysics Data System (ADS)

Gabriel-Robez, C.; Lees, R.; Bernard, M.

2012-08-01

By the end of 2011, Astrium GEO-Information Services launched Pléiades 1, the first of two identical optical imaging satellites that will be operated on a phased orbit. This satellite system, designed by the French Space Agency, CNES, based upon French Defense specifications, will provide 50-cm products in record time. The overall aim of this paper is to describe the benefits of the innovative features of Pléiades 1 and its operations, so as to assess their combined potential in emergency situations, crisis recovery, regular monitoring or large area mapping. Specific care will be brought to describe the reactivity enabled by the system. Based on real-life examples, the paper will lead the analysis on the two main components of the system. On the one hand, the space segment will be presented through the following characteristics: revisit capacity, agility, acquisition capacity and acquisition scenarios (target, single-pass mosaics, stereo, tristereo, linear monitoring, persistent surveillance). On the other hand, the flexibility of the ground segment will be assessed. The benefits of multiple tasking plans per day, direct tasking capacity, automated processing and on-line ordering and delivering will be illustrated, tested and qualified for applications requiring a high level of responsiveness and reactivity. The presentation will end with a summary of the benefits of the space segment features and the flexibility of the ground segment, fine-tuned to answer both military and civilian / commercial needs. The analysis will be extended in the perspective of the second Pléiades' launch, highlighting the advantages of having two satellites operating on a phased orbit, affording a daily revisit anywhere on Earth, with very high resolution.

Reflector automatic acquisition and pointing based on auto-collimation theodolite.

PubMed

Luo, Jun; Wang, Zhiqian; Wen, Zhuoman; Li, Mingzhu; Liu, Shaojin; Shen, Chengwu

2018-01-01

An auto-collimation theodolite (ACT) for reflector automatic acquisition and pointing is designed based on the principle of autocollimators and theodolites. First, the principle of auto-collimation and theodolites is reviewed, and then the coaxial ACT structure is developed. Subsequently, the acquisition and pointing strategies for reflector measurements are presented, which first quickly acquires the target over a wide range and then points the laser spot to the charge coupled device zero position. Finally, experiments are conducted to verify the acquisition and pointing performance, including the calibration of the ACT, the comparison of the acquisition mode and pointing mode, and the accuracy measurement in horizontal and vertical directions. In both directions, a measurement accuracy of ±3″ is achieved. The presented ACT is suitable for automatic pointing and monitoring the reflector over a small scanning area and can be used in a wide range of applications such as bridge structure monitoring and cooperative target aiming.

Reflector automatic acquisition and pointing based on auto-collimation theodolite

NASA Astrophysics Data System (ADS)

Luo, Jun; Wang, Zhiqian; Wen, Zhuoman; Li, Mingzhu; Liu, Shaojin; Shen, Chengwu

2018-01-01

An auto-collimation theodolite (ACT) for reflector automatic acquisition and pointing is designed based on the principle of autocollimators and theodolites. First, the principle of auto-collimation and theodolites is reviewed, and then the coaxial ACT structure is developed. Subsequently, the acquisition and pointing strategies for reflector measurements are presented, which first quickly acquires the target over a wide range and then points the laser spot to the charge coupled device zero position. Finally, experiments are conducted to verify the acquisition and pointing performance, including the calibration of the ACT, the comparison of the acquisition mode and pointing mode, and the accuracy measurement in horizontal and vertical directions. In both directions, a measurement accuracy of ±3″ is achieved. The presented ACT is suitable for automatic pointing and monitoring the reflector over a small scanning area and can be used in a wide range of applications such as bridge structure monitoring and cooperative target aiming.

Influence of mental practice on development of voluntary control of a novel motor acquisition task.

PubMed

Creelman, Jim

2003-08-01

The purpose of this investigation was to assess whether mental practice facilitates the development of voluntary control over the recruitment of the abductor hallucis muscle to produce isolated big toe abduction. A sample of convenience of 15 women and 20 men with a mean age of 28.8 yr. (SD=5.7) and healthy feet, who were unable voluntarily to abduct the big toe, were randomly assigned to one of three groups, a mental practice group, a physical practice group, and a group who performed a control movement during practice. Each subject received neuromuscular electrical stimulation to introduce the desired movement prior to each of five practice bouts over a single session lasting 2 hr. Big toe abduction active range of motion and surface electromyographic (EMG) output of the abductor hallucis and extensor digitorum brevis muscles were measured prior to the first practice bout and following each practice bout, yielding seven acquisition trials. Acquisition is defined as an improvement in both active range of motion and in the difference between the integrated EMG of the abductor hallucis and extensor digitorum brevis muscles during successive acquisition trials. Seven members of both the mental and physical practice groups and one member of the control group met the acquisition criteria. Chi-square analysis indicated the group difference was statistically significant, suggesting mental practice was effective for this task.

Treadmill performance of mice with cerebellar lesions: 1. Purkinje cell degeneration mutant mice.

PubMed

Le Marec, N; Lalonde, R

1998-02-01

The purpose of this study was to evaluate the sensorimotor skills of a spontaneous mouse mutant, Purkinje cell degeneration (PCD), marked by selective cerebellar cortical atrophy on a treadmill activated at 1 of 2 speeds and at 1 of 3 slopes, requiring forward movements to avoid footshocks. There was no difference in latencies before falling from the belt between PCD mutants and controls during acquisition. However, PCD mutants were impaired on the fast treadmill during retention, implicating the cerebellum in the memory of a motor skill. During acquisition of the slow treadmill task at the 2 lowest slopes of inclination, PCD mutants spent more time walking than controls, an indication of a decreased ability of coordinating whole body movements. The same pattern of higher walking time on the slow treadmill in PCD mutants was evident during retention. These results indicate that the cerebellar cortex is involved in the acquisition and the retention of a task requiring equilibrium.

Recovering task fMRI signals from highly under-sampled data with low-rank and temporal subspace constraints.

PubMed

Chiew, Mark; Graedel, Nadine N; Miller, Karla L

2018-07-01

Recent developments in highly accelerated fMRI data acquisition have employed low-rank and/or sparsity constraints for image reconstruction, as an alternative to conventional, time-independent parallel imaging. When under-sampling factors are high or the signals of interest are low-variance, however, functional data recovery can be poor or incomplete. We introduce a method for improving reconstruction fidelity using external constraints, like an experimental design matrix, to partially orient the estimated fMRI temporal subspace. Combining these external constraints with low-rank constraints introduces a new image reconstruction model that is analogous to using a mixture of subspace-decomposition (PCA/ICA) and regression (GLM) models in fMRI analysis. We show that this approach improves fMRI reconstruction quality in simulations and experimental data, focusing on the model problem of detecting subtle 1-s latency shifts between brain regions in a block-design task-fMRI experiment. Successful latency discrimination is shown at acceleration factors up to R = 16 in a radial-Cartesian acquisition. We show that this approach works with approximate, or not perfectly informative constraints, where the derived benefit is commensurate with the information content contained in the constraints. The proposed method extends low-rank approximation methods for under-sampled fMRI data acquisition by leveraging knowledge of expected task-based variance in the data, enabling improvements in the speed and efficiency of fMRI data acquisition without the loss of subtle features. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

What Top-Down Task Sets Do for Us: An ERP Study on the Benefits of Advance Preparation in Visual Search

ERIC Educational Resources Information Center

Eimer, Martin; Kiss, Monika; Nicholas, Susan

2011-01-01

When target-defining features are specified in advance, attentional target selection in visual search is controlled by preparatory top-down task sets. We used ERP measures to study voluntary target selection in the absence of such feature-specific task sets, and to compare it to selection that is guided by advance knowledge about target features.…

Increased experience amplifies the activation of task-irrelevant category representations.

PubMed

Wu, Rachel; Pruitt, Zoe; Zinszer, Benjamin D; Cheung, Olivia S

2017-02-01

Prior research has demonstrated the benefits (i.e., task-relevant attentional selection) and costs (i.e., task-irrelevant attentional capture) of prior knowledge on search for an individual target or multiple targets from a category. This study investigated whether the level of experience with particular categories predicts the degree of task-relevant and task-irrelevant activation of item and category representations. Adults with varying levels of dieting experience (measured via 3 subscales of Disinhibition, Restraint, Hunger; Stunkard & Messick, Journal of Psychosomatic Research, 29(1), 71-83, 1985) searched for targets defined as either a specific food item (e.g., carrots), or a category (i.e., any healthy or unhealthy food item). Apart from the target-present trials, in the target-absent "foil" trials, when searching for a specific item (e.g., carrots), irrelevant items from the target's category (e.g., squash) were presented. The ERP (N2pc) results revealed that the activation of task-relevant representations (measured via Exemplar and Category N2pc amplitudes) did not differ based on the degree of experience. Critically, however, increased dieting experience, as revealed by lower Disinhibition scores, predicted activation of task-irrelevant representations (i.e., attentional capture of foils from the target item category). Our results suggest that increased experience with particular categories encourages the rapid activation of category representations even when category information is task irrelevant, and that the N2pc in foil trials could potentially serve as an indication of experience level in future studies on categorization.

The course of visual searching to a target in a fixed location: electrophysiological evidence from an emotional flanker task.

PubMed

Dong, Guangheng; Yang, Lizhu; Shen, Yue

2009-08-21

The present study investigated the course of visual searching to a target in a fixed location, using an emotional flanker task. Event-related potentials (ERPs) were recorded while participants performed the task. Emotional facial expressions were used as emotion-eliciting triggers. The course of visual searching was analyzed through the emotional effects arising from these emotion-eliciting stimuli. The flanker stimuli showed effects at about 150-250 ms following the stimulus onset, while the effect of target stimuli showed effects at about 300-400 ms. The visual search sequence in an emotional flanker task moved from a whole overview to a specific target, even if the target always appeared at a known location. The processing sequence was "parallel" in this task. The results supported the feature integration theory of visual search.

The effect of a robot-assisted surgical system on the kinematics of user movements.

PubMed

Nisky, Ilana; Hsieh, Michael H; Okamura, Allison M

2013-01-01

Teleoperated robot-assisted surgery (RAS) offers many advantages over traditional minimally invasive surgery. However, RAS has not yet realized its full potential, and it is not clear how to optimally train surgeons to use these systems. We hypothesize that the dynamics of the master manipulator impact the ability of users to make desired movements with the robot. We compared freehand and teleoperated movements of novices and experienced surgeons. To isolate the effects of dynamics from procedural knowledge, we chose simple movements rather than surgical tasks. We found statistically significant effects of teleoperation and user expertise in several aspects of motion, including target acquisition error, movement speed, and movement smoothness. Such quantitative assessment of human motor performance in RAS can impact the design of surgical robots, their control, and surgeon training methods, and eventually, improve patient outcomes.

The proper treatment of language acquisition and change in a population setting.

PubMed

Niyogi, Partha; Berwick, Robert C

2009-06-23

Language acquisition maps linguistic experience, primary linguistic data (PLD), onto linguistic knowledge, a grammar. Classically, computational models of language acquisition assume a single target grammar and one PLD source, the central question being whether the target grammar can be acquired from the PLD. However, real-world learners confront populations with variation, i.e., multiple target grammars and PLDs. Removing this idealization has inspired a new class of population-based language acquisition models. This paper contrasts 2 such models. In the first, iterated learning (IL), each learner receives PLD from one target grammar but different learners can have different targets. In the second, social learning (SL), each learner receives PLD from possibly multiple targets, e.g., from 2 parents. We demonstrate that these 2 models have radically different evolutionary consequences. The IL model is dynamically deficient in 2 key respects. First, the IL model admits only linear dynamics and so cannot describe phase transitions, attested rapid changes in languages over time. Second, the IL model cannot properly describe the stability of languages over time. In contrast, the SL model leads to nonlinear dynamics, bifurcations, and possibly multiple equilibria and so suffices to model both the case of stable language populations, mixtures of more than 1 language, as well as rapid language change. The 2 models also make distinct, empirically testable predictions about language change. Using historical data, we show that the SL model more faithfully replicates the dynamics of the evolution of Middle English.