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Sample records for adaptive attention processes

  1. Effects of Crowding and Attention on High-Levels of Motion Processing and Motion Adaptation

    PubMed Central

    Pavan, Andrea; Greenlee, Mark W.

    2015-01-01

    The motion after-effect (MAE) persists in crowding conditions, i.e., when the adaptation direction cannot be reliably perceived. The MAE originating from complex moving patterns spreads into non-adapted sectors of a multi-sector adapting display (i.e., phantom MAE). In the present study we used global rotating patterns to measure the strength of the conventional and phantom MAEs in crowded and non-crowded conditions, and when attention was directed to the adapting stimulus and when it was diverted away from the adapting stimulus. The results show that: (i) the phantom MAE is weaker than the conventional MAE, for both non-crowded and crowded conditions, and when attention was focused on the adapting stimulus and when it was diverted from it, (ii) conventional and phantom MAEs in the crowded condition are weaker than in the non-crowded condition. Analysis conducted to assess the effect of crowding on high-level of motion adaptation suggests that crowding is likely to affect the awareness of the adapting stimulus rather than degrading its sensory representation, (iii) for high-level of motion processing the attentional manipulation does not affect the strength of either conventional or phantom MAEs, neither in the non-crowded nor in the crowded conditions. These results suggest that high-level MAEs do not depend on attention and that at high-level of motion adaptation the effects of crowding are not modulated by attention. PMID:25615577

  2. Effects of crowding and attention on high-levels of motion processing and motion adaptation.

    PubMed

    Pavan, Andrea; Greenlee, Mark W

    2015-01-01

    The motion after-effect (MAE) persists in crowding conditions, i.e., when the adaptation direction cannot be reliably perceived. The MAE originating from complex moving patterns spreads into non-adapted sectors of a multi-sector adapting display (i.e., phantom MAE). In the present study we used global rotating patterns to measure the strength of the conventional and phantom MAEs in crowded and non-crowded conditions, and when attention was directed to the adapting stimulus and when it was diverted away from the adapting stimulus. The results show that: (i) the phantom MAE is weaker than the conventional MAE, for both non-crowded and crowded conditions, and when attention was focused on the adapting stimulus and when it was diverted from it, (ii) conventional and phantom MAEs in the crowded condition are weaker than in the non-crowded condition. Analysis conducted to assess the effect of crowding on high-level of motion adaptation suggests that crowding is likely to affect the awareness of the adapting stimulus rather than degrading its sensory representation, (iii) for high-level of motion processing the attentional manipulation does not affect the strength of either conventional or phantom MAEs, neither in the non-crowded nor in the crowded conditions. These results suggest that high-level MAEs do not depend on attention and that at high-level of motion adaptation the effects of crowding are not modulated by attention.

  3. Attention modulates visual size adaptation.

    PubMed

    Kreutzer, Sylvia; Fink, Gereon R; Weidner, Ralph

    2015-01-01

    The current study determined in healthy subjects (n = 16) whether size adaptation occurs at early, i.e., preattentive, levels of processing or whether higher cognitive processes such as attention can modulate the illusion. To investigate this issue, bottom-up stimulation was kept constant across conditions by using a single adaptation display containing both small and large adapter stimuli. Subjects' attention was directed to either the large or small adapter stimulus by means of a luminance detection task. When attention was directed toward the small as compared to the large adapter, the perceived size of the subsequent target was significantly increased. Data suggest that different size adaptation effects can be induced by one and the same stimulus depending on the current allocation of attention. This indicates that size adaptation is subject to attentional modulation. These findings are in line with previous research showing that transient as well as sustained attention modulates visual features, such as contrast sensitivity and spatial frequency, and influences adaptation in other contexts, such as motion adaptation (Alais & Blake, 1999; Lankheet & Verstraten, 1995). Based on a recently suggested model (Pooresmaeili, Arrighi, Biagi, & Morrone, 2013), according to which perceptual adaptation is based on local excitation and inhibition in V1, we conclude that guiding attention can boost these local processes in one or the other direction by increasing the weight of the attended adapter. In sum, perceptual adaptation, although reflected in changes of neural activity at early levels (as shown in the aforementioned study), is nevertheless subject to higher-order modulation.

  4. Cognitive adaptation: spatial memory or attentional processing. a comment on Furley and Memmert (2010).

    PubMed

    Allen, R; Fioratou, E; McGeorge, P

    2011-02-01

    This commentary considers the paper by Furley and Memmert (2010) who sought to test the respective validities of the specific processing and cognitive adaptation hypotheses. That they found no evidence of a difference between experienced basketball players and nonathletes on the Corsi block task, a measure of spatial memory, led them to infer support for the specific processing hypothesis, namely that differences between experts and novices manifest themselves only in processes related specifically to the domain of expertise. An alternative interpretation is offered, indicating possible confounds and referring to recent research that suggests Corsi block and dynamic spatial tasks depend upon different neuronal networks.

  5. Attentional processes and meditation.

    PubMed

    Hodgins, Holley S; Adair, Kathryn C

    2010-12-01

    Visual attentional processing was examined in adult meditators and non-meditators on behavioral measures of change blindness, concentration, perspective-shifting, selective attention, and sustained inattentional blindness. Results showed that meditators (1) noticed more changes in flickering scenes and noticed them more quickly, (2) counted more accurately in a challenging concentration task, (3) identified a greater number of alternative perspectives in multiple perspectives images, and (4) showed less interference from invalid cues in a visual selective attention task, but (5) did not differ on a measure of sustained inattentional blindness. Together, results show that regular meditation is associated with more accurate, efficient, and flexible visual attentional processing across diverse tasks that have high face validity outside of the laboratory. Furthermore, effects were assessed in a context separate from actual meditation practice, suggesting that meditators' better visual attention is not just immediate, but extends to contexts separate from meditation practice.

  6. Adaptive allocation of attentional gain

    PubMed Central

    Scolari, Miranda; Serences, John T.

    2009-01-01

    Humans are adept at distinguishing between stimuli that are very similar, an ability that is particularly crucial when the outcome is of serious consequence (e.g. for a surgeon or air traffic controller). Traditionally, selective attention was thought to facilitate perception by increasing the gain of sensory neurons tuned to the defining features of a behaviorally relevant object (e.g. color, orientation, etc.). In contrast, recent mathematical models counter-intuitively suggest that in many cases attentional gain should be applied to neurons that are tuned away from relevant features, especially when discriminating highly similar stimuli. Here we used psychophysical methods to critically evaluate these ‘ideal observer’ models. The data demonstrate that attention enhances the gain of the most informative sensory neurons, even when these neurons are tuned away from the behaviorally relevant target feature. Moreover, the degree to which an individual adopted optimal attentional gain settings by the end of testing predicted success rates on a difficult visual discrimination task, as well as the amount of task improvement that occurred across repeated testing sessions (learning). Contrary to most traditional accounts, these observations suggest that the primary function of attentional gain is not simply to enhance the representation of target features, but to optimize performance on the current perceptual task. Additionally, individual differences in gain suggest that the operating characteristics of low-level attentional phenomena are not stable trait-like attributes and that variability in how attention is deployed may play an important role in determining perceptual abilities. PMID:19776279

  7. Encoding attentional states during visuomotor adaptation

    PubMed Central

    Im, Hee Yeon; Bédard, Patrick; Song, Joo-Hyun

    2015-01-01

    We recently showed that visuomotor adaptation acquired under attentional distraction is better recalled under a similar level of distraction compared to no distraction. This paradoxical effect suggests that attentional state (e.g., divided or undivided) is encoded as an internal context during visuomotor learning and should be reinstated for successful recall (Song & Bédard, 2015). To investigate if there is a critical temporal window for encoding attentional state in visuomotor memory, we manipulated whether participants performed the secondary attention-demanding task concurrently in the early or late phase of visuomotor learning. Recall performance was enhanced when the attentional states between recall and the early phase of visuomotor learning were consistent. However, it reverted to untrained levels when tested under the attentional state of the late-phase learning. This suggests that attentional state is primarily encoded during the early phase of learning before motor errors decrease and reach an asymptote. Furthermore, we demonstrate that when divided and undivided attentional states were mixed during visuomotor adaptation, only divided attention was encoded as an internal cue for memory retrieval. Therefore, a single attentional state appears to be primarily integrated with visuomotor memory while motor error reduction is in progress during learning. PMID:26114683

  8. Reward valence modulates conflict-driven attentional adaptation: electrophysiological evidence.

    PubMed

    van Steenbergen, Henk; Band, Guido P H; Hommel, Bernhard

    2012-07-01

    Recent findings suggest that, relative to negative feedback, positive feedback counteracts conflict processing and subsequent attentional adaptation. Here we hypothesize that this interaction may direct adjustments in perception and action via the anterior cingulate cortex (ACC). We recorded EEG while participants performed an arrow flanker task with monetary gain or loss as arbitrary reward feedback between trials. As predicted, we found a reduction in conflict-driven adaptation for trials in which conflict was followed by monetary gain (vs. monetary loss), a behavioral effect accompanied by a modulation in early visual processing related to the processing of the distracters. Moreover, time-frequency analyses showed that ongoing fronto-central theta oscillations induced by previous conflict sustained longer after loss than after gain, an interaction presumably reflecting ACC modulation. These data provide a first important step toward understanding the neural mechanism underlying the affective regulation of conflict-driven behavior.

  9. Reward valence modulates conflict-driven attentional adaptation: electrophysiological evidence.

    PubMed

    van Steenbergen, Henk; Band, Guido P H; Hommel, Bernhard

    2012-07-01

    Recent findings suggest that, relative to negative feedback, positive feedback counteracts conflict processing and subsequent attentional adaptation. Here we hypothesize that this interaction may direct adjustments in perception and action via the anterior cingulate cortex (ACC). We recorded EEG while participants performed an arrow flanker task with monetary gain or loss as arbitrary reward feedback between trials. As predicted, we found a reduction in conflict-driven adaptation for trials in which conflict was followed by monetary gain (vs. monetary loss), a behavioral effect accompanied by a modulation in early visual processing related to the processing of the distracters. Moreover, time-frequency analyses showed that ongoing fronto-central theta oscillations induced by previous conflict sustained longer after loss than after gain, an interaction presumably reflecting ACC modulation. These data provide a first important step toward understanding the neural mechanism underlying the affective regulation of conflict-driven behavior. PMID:22504294

  10. Microscopic cell nuclei segmentation based on adaptive attention window.

    PubMed

    Ko, ByoungChul; Seo, MiSuk; Nam, Jae-Yeal

    2009-06-01

    This paper presents an adaptive attention window (AAW)-based microscopic cell nuclei segmentation method. For semantic AAW detection, a luminance map is used to create an initial attention window, which is then reduced close to the size of the real region of interest (ROI) using a quad-tree. The purpose of the AAW is to facilitate background removal and reduce the ROI segmentation processing time. Region segmentation is performed within the AAW, followed by region clustering and removal to produce segmentation of only ROIs. Experimental results demonstrate that the proposed method can efficiently segment one or more ROIs and produce similar segmentation results to human perception. In future work, the proposed method will be used for supporting a region-based medical image retrieval system that can generate a combined feature vector of segmented ROIs based on extraction and patient data.

  11. Reliance on visual attention during visuomotor adaptation: an SSVEP study.

    PubMed

    Reuter, Eva-Maria; Bednark, Jeffery; Cunnington, Ross

    2015-07-01

    Visuomotor adaptation involves the learning of a new mapping between a spatial goal and well-learned movements. In order to learn a new visuomotor transformation, visual attention is needed to monitor movements and their visual consequences. Once a transformation is learnt, it can be executed automatically without attentional control. Using steady-state visual evoked potentials (SSVEPs) measured from EEG activity, we examined how visual attention changes during the early phase of visuomotor adaptation. SSVEPs were elicited by a green disc flickering at 15 Hz which was either the movement target or the cursor that participants controlled. Participants performed an adapted continuous visuomotor adaptation task with either 60° or 120° screen cursor rotation, and changes in 15-Hz SSVEP power were examined. Participants' performance improved over time in all conditions, with the rate of learning significantly influenced by the degree of rotation. SSVEPs at 15 Hz showed a significant change over time with adaptation for 60° rotations, but not for 120° rotations, such that SSVEPs elicited by the stimuli were significantly lower for 60° compared with 120° rotation conditions over the last adaptation blocks. This suggests that visual attention to the movement target and feedback reduces over time as performance improves during visuomotor adaptation for easier rotations, but must be maintained throughout the task for more difficult 120° rotations that might require more strategic control.

  12. Holistic processing from learned attention to parts.

    PubMed

    Chua, Kao-Wei; Richler, Jennifer J; Gauthier, Isabel

    2015-08-01

    Attention helps us focus on what is most relevant to our goals, and prior work has shown that aspects of attention can be learned. Learned inattention to parts can abolish holistic processing of faces, but it is unknown whether learned attention to parts is sufficient to cause a change from part-based to holistic processing with objects. We trained subjects to individuate nonface objects (Greebles) from 2 categories: Ploks and Glips. Diagnostic information was in complementary halves for the 2 categories. Holistic processing was then tested with Plok-Glip composites that combined the kind of part that was diagnostic or nondiagnostic during training. Exposure to Greeble parts resulted in general failures of selective attention for nondiagnostic composites, but face-like holistic processing was only observed for diagnostic composites. These results demonstrated a novel link between learned attentional control and the acquisition of holistic processing.

  13. Adaptive passive fathometer processing.

    PubMed

    Siderius, Martin; Song, Heechun; Gerstoft, Peter; Hodgkiss, William S; Hursky, Paul; Harrison, Chris

    2010-04-01

    Recently, a technique has been developed to image seabed layers using the ocean ambient noise field as the sound source. This so called passive fathometer technique exploits the naturally occurring acoustic sounds generated on the sea-surface, primarily from breaking waves. The method is based on the cross-correlation of noise from the ocean surface with its echo from the seabed, which recovers travel times to significant seabed reflectors. To limit averaging time and make this practical, beamforming is used with a vertical array of hydrophones to reduce interference from horizontally propagating noise. The initial development used conventional beamforming, but significant improvements have been realized using adaptive techniques. In this paper, adaptive methods for this process are described and applied to several data sets to demonstrate improvements possible as compared to conventional processing.

  14. Adaptive Signal Processing Testbed

    NASA Astrophysics Data System (ADS)

    Parliament, Hugh A.

    1991-09-01

    The design and implementation of a system for the acquisition, processing, and analysis of signal data is described. The initial application for the system is the development and analysis of algorithms for excision of interfering tones from direct sequence spread spectrum communication systems. The system is called the Adaptive Signal Processing Testbed (ASPT) and is an integrated hardware and software system built around the TMS320C30 chip. The hardware consists of a radio frequency data source, digital receiver, and an adaptive signal processor implemented on a Sun workstation. The software components of the ASPT consists of a number of packages including the Sun driver package; UNIX programs that support software development on the TMS320C30 boards; UNIX programs that provide the control, user interaction, and display capabilities for the data acquisition, processing, and analysis components of the ASPT; and programs that perform the ASPT functions including data acquisition, despreading, and adaptive filtering. The performance of the ASPT system is evaluated by comparing actual data rates against their desired values. A number of system limitations are identified and recommendations are made for improvements.

  15. Accuracy of Information Processing under Focused Attention.

    ERIC Educational Resources Information Center

    Bastick, Tony

    This paper reports the results of an experiment on the accuracy of information processing during attention focused arousal under two conditions: single estimation and double estimation. The attention of 187 college students was focused by a task requiring high level competition for a monetary prize ($10) under severely limited time conditions. The…

  16. Temporal Processing, Attention, and Learning Disorders

    ERIC Educational Resources Information Center

    Landerl, Karin; Willburger, Edith

    2010-01-01

    In a large sample (N = 439) of literacy impaired and unimpaired elementary school children the predictions of the temporal processing theory of dyslexia were tested while controlling for (sub)clininal attentional deficits. Visual and Auditory Temporal Order Judgement were administered as well as three subtests of a standardized attention test. The…

  17. Attentional processes and choking under pressure.

    PubMed

    Schücker, Linda; Hagemann, Norbert; Strauss, Bernd

    2013-04-01

    The self-focus theory of choking under pressure explains decreases in performance of well-learned motor tasks with an increase in skill-focused attention. This shift in attentional focus has been demonstrated; however, specific propositions about the processes in pressure-induced attentional shift are yet to be developed. This study assesses whether specific aspects of movement execution attract more attention than others when movements are executed under pressure. Such elements are important in conscious movement control before execution becomes automated through practice; under pressure, attention may be redirected to these elements. Basketball free throws were executed by 22 junior national team members in a low and high pressure situation. Two dual task/focus conditions (related to different aspects of the movement) were implemented in each pressure condition. This dual task paradigm was used as a direct and detailed measure of skill focused attention, suitable to show specific pressure induced shifts of attention that lead to performance decrements. Pressure was induced by telling players that their performance would be evaluated by coaches. Players were defined as chokers if their performance decreased under this pressure. Chokers showed differences with regard to their attentional focus on movement execution in the pressure conditions compared to the players defined as non-chokers. The findings suggest that attentional shifts during choking can be related to specific aspects of movement execution.

  18. Do social utility judgments influence attentional processing?

    PubMed

    Shore, Danielle M; Heerey, Erin A

    2013-10-01

    Research shows that social judgments influence decision-making in social environments. For example, judgments about an interaction partners' trustworthiness affect a variety of social behaviors and decisions. One mechanism by which social judgments may influence social decisions is by biasing the automatic allocation of attention toward certain social partners, thereby shaping the information people acquire. Using an attentional blink paradigm, we investigate how trustworthiness judgments alter the allocation of attention to social stimuli in a set of two experiments. The first experiment investigates trustworthiness judgments based solely on a social partner's facial appearance. The second experiment examines the effect of trustworthiness judgments based on experienced behavior. In the first, strong appearance-based judgments (positive and negative) enhanced stimulus recognizability but did not alter the size of the attentional blink, suggesting that appearance-based social judgments enhance face memory but do not affect pre-attentive processing. However, in the second experiment, in which judgments were based on behavioral experience rather than appearance, positive judgments enhanced pre-attentive processing of trustworthy faces. This suggests that a stimulus's potential benefits, rather than its disadvantages, shape the automatic distribution of attentional resources. These results have implications for understanding how appearance- and behavior-based social cues shape attention distribution in social environments. PMID:23887150

  19. Does Involuntary Attentional Capture Curtail Stimulus Processing

    NASA Technical Reports Server (NTRS)

    Remington, Roger W.; McLean, John P.; Folk, Charles L.; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    Under certain conditions uninformative visual cues at non-target locations increase target RTs. The typical explanation is that visual attention has been involuntarily summoned to the cued location and is unavailable when needed at the target location. Here we present evidence that capture has not just oriented attention away from the target location, but has lead to the processing of stimuli at the location of the uninformative cue.

  20. Attentional Processing of Letter Strings by Children.

    PubMed

    Leclercq, Virginie; Siéroff, Eric

    2016-01-01

    Reading a letter string requires attentional orienting toward the beginning of the string (left-dominant orientation), followed by orienting along the string. These attentional-orienting processes differ according to the lexicality of the letter string: Sequential processes apply when reading nonwords or pseudowords, while words can be processed more globally. The aim of this study was to evaluate the development of these attentional processes involved in reading. We conducted two experiments in 6- (first grade), 7- (second grade), and 9-year-old (fourth grade) children, using a procedure that required the detection of a letter (Experiment 1) or a nonletter (Experiment 2) target in a string of five characters. The target character could occur in the second (left) or fourth (right) position in the string. Results showed an advantage for left nonletter targets as early as age 6 and of left letter targets as early as age 7. In 6-year-olds, only good readers detected a left letter target faster than a right letter target; others detected a right letter target faster. Thus, dominant orienting toward the beginning of the letter string is not fully developed in children before the second year of reading. A possibility is that beginning readers have difficulties inhibiting an attention-orienting bias toward the right visual field in linguistic tasks. The results also showed that the lexicality effect on these attentional processes develops gradually until the fourth year of reading. We believe that the procedure used in this study will be very valuable for evaluating attentional difficulties during reading acquisition. PMID:25386702

  1. Errors Disrupt Subsequent Early Attentional Processes

    PubMed Central

    Van der Borght, Liesbet; Schevernels, Hanne; Burle, Boris; Notebaert, Wim

    2016-01-01

    It has been demonstrated that target detection is impaired following an error in an unrelated flanker task. These findings support the idea that the occurrence or processing of unexpected error-like events interfere with subsequent information processing. In the present study, we investigated the effect of errors on early visual ERP components. We therefore combined a flanker task and a visual discrimination task. Additionally, the intertrial interval between both tasks was manipulated in order to investigate the duration of these negative after-effects. The results of the visual discrimination task indicated that the amplitude of the N1 component, which is related to endogenous attention, was significantly decreased following an error, irrespective of the intertrial interval. Additionally, P3 amplitude was attenuated after an erroneous trial, but only in the long-interval condition. These results indicate that low-level attentional processes are impaired after errors. PMID:27050303

  2. Adaptations of motor neural structures' activity to lapses in attention.

    PubMed

    Derosière, Gérard; Billot, Maxime; Ward, E Tomas; Perrey, Stéphane

    2015-01-01

    Sustained attention is fundamental for cognition and when impaired, impacts negatively on important contemporary living skills. Degradation in sustained attention is characterized by the time-on-task (TOT) effect, which manifests as a gradual increase in reaction time (RT). The TOT effect is accompanied by changes in relative brain activity patterns in attention-related areas, most noticeably in the prefrontal cortex (PFC) and the right parietal areas. However, activity changes in task-relevant motor structures have not been confirmed to date. This article describes an investigation of such motor-related activity changes as measured with 1) the time course of corticospinal excitability (CSE) through single-pulse transcranial magnetic stimulation; and 2) the changes in activity of premotor (PMC), primary motor (M1), PFC, and right parietal areas by means of near-infrared spectroscopy, during a sustained attention RT task exhibiting the TOT effect. Our results corroborate established findings such as a significant increase (P < 0.05) in lateral prefrontal and right parietal areas activity after the emergence of the TOT effect but also reveal adaptations in the form of motor activity changes--in particular, a significant increase in CSE (P < 0.01) and in primary motor area (M1) activity (P < 0.05).

  3. Motion-guided attention promotes adaptive communications during social navigation

    PubMed Central

    Lemasson, B. H.; Anderson, J. J.; Goodwin, R. A.

    2013-01-01

    Animals are capable of enhanced decision making through cooperation, whereby accurate decisions can occur quickly through decentralized consensus. These interactions often depend upon reliable social cues, which can result in highly coordinated activities in uncertain environments. Yet information within a crowd may be lost in translation, generating confusion and enhancing individual risk. As quantitative data detailing animal social interactions accumulate, the mechanisms enabling individuals to rapidly and accurately process competing social cues remain unresolved. Here, we model how motion-guided attention influences the exchange of visual information during social navigation. We also compare the performance of this mechanism to the hypothesis that robust social coordination requires individuals to numerically limit their attention to a set of n-nearest neighbours. While we find that such numerically limited attention does not generate robust social navigation across ecological contexts, several notable qualities arise from selective attention to motion cues. First, individuals can instantly become a local information hub when startled into action, without requiring changes in neighbour attention level. Second, individuals can circumvent speed–accuracy trade-offs by tuning their motion thresholds. In turn, these properties enable groups to collectively dampen or amplify social information. Lastly, the minority required to sway a group's short-term directional decisions can change substantially with social context. Our findings suggest that motion-guided attention is a fundamental and efficient mechanism underlying collaborative decision making during social navigation. PMID:23325772

  4. Motion-guided attention promotes adaptive communications during social navigation.

    PubMed

    Lemasson, B H; Anderson, J J; Goodwin, R A

    2013-03-01

    Animals are capable of enhanced decision making through cooperation, whereby accurate decisions can occur quickly through decentralized consensus. These interactions often depend upon reliable social cues, which can result in highly coordinated activities in uncertain environments. Yet information within a crowd may be lost in translation, generating confusion and enhancing individual risk. As quantitative data detailing animal social interactions accumulate, the mechanisms enabling individuals to rapidly and accurately process competing social cues remain unresolved. Here, we model how motion-guided attention influences the exchange of visual information during social navigation. We also compare the performance of this mechanism to the hypothesis that robust social coordination requires individuals to numerically limit their attention to a set of n-nearest neighbours. While we find that such numerically limited attention does not generate robust social navigation across ecological contexts, several notable qualities arise from selective attention to motion cues. First, individuals can instantly become a local information hub when startled into action, without requiring changes in neighbour attention level. Second, individuals can circumvent speed-accuracy trade-offs by tuning their motion thresholds. In turn, these properties enable groups to collectively dampen or amplify social information. Lastly, the minority required to sway a group's short-term directional decisions can change substantially with social context. Our findings suggest that motion-guided attention is a fundamental and efficient mechanism underlying collaborative decision making during social navigation.

  5. Adaptive processing for LANDSAT data

    NASA Technical Reports Server (NTRS)

    Crane, R. B.; Reyer, J. F.

    1975-01-01

    Analytical and test results on the use of adaptive processing on LANDSAT data are presented. The Kalman filter was used as a framework to contain different adapting techniques. When LANDSAT MSS data were used all of the modifications made to the Kalman filter performed the functions for which they were designed. It was found that adaptive processing could provide compensation for incorrect signature means, within limits. However, if the data were such that poor classification accuracy would be obtained when the correct means were used, then adaptive processing would not improve the accuracy and might well lower it even further.

  6. A new adaptive videogame for training attention and executive functions: design principles and initial validation.

    PubMed

    Montani, Veronica; De Filippo De Grazia, Michele; Zorzi, Marco

    2014-01-01

    A growing body of evidence suggests that action videogames could enhance a variety of cognitive skills and more specifically attention skills. The aim of this study was to develop a novel adaptive videogame to support the rehabilitation of the most common consequences of traumatic brain injury (TBI), that is the impairment of attention and executive functions. TBI patients can be affected by psychomotor slowness and by difficulties in dealing with distraction, maintain a cognitive set for a long time, processing different simultaneously presented stimuli, and planning purposeful behavior. Accordingly, we designed a videogame that was specifically conceived to activate those functions. Playing involves visuospatial planning and selective attention, active maintenance of the cognitive set representing the goal, and error monitoring. Moreover, different game trials require to alternate between two tasks (i.e., task switching) or to perform the two tasks simultaneously (i.e., divided attention/dual-tasking). The videogame is controlled by a multidimensional adaptive algorithm that calibrates task difficulty on-line based on a model of user performance that is updated on a trial-by-trial basis. We report simulations of user performance designed to test the adaptive game as well as a validation study with healthy participants engaged in a training protocol. The results confirmed the involvement of the cognitive abilities that the game is supposed to enhance and suggested that training improved attentional control during play.

  7. A new adaptive videogame for training attention and executive functions: design principles and initial validation

    PubMed Central

    Montani, Veronica; De Filippo De Grazia, Michele; Zorzi, Marco

    2014-01-01

    A growing body of evidence suggests that action videogames could enhance a variety of cognitive skills and more specifically attention skills. The aim of this study was to develop a novel adaptive videogame to support the rehabilitation of the most common consequences of traumatic brain injury (TBI), that is the impairment of attention and executive functions. TBI patients can be affected by psychomotor slowness and by difficulties in dealing with distraction, maintain a cognitive set for a long time, processing different simultaneously presented stimuli, and planning purposeful behavior. Accordingly, we designed a videogame that was specifically conceived to activate those functions. Playing involves visuospatial planning and selective attention, active maintenance of the cognitive set representing the goal, and error monitoring. Moreover, different game trials require to alternate between two tasks (i.e., task switching) or to perform the two tasks simultaneously (i.e., divided attention/dual-tasking). The videogame is controlled by a multidimensional adaptive algorithm that calibrates task difficulty on-line based on a model of user performance that is updated on a trial-by-trial basis. We report simulations of user performance designed to test the adaptive game as well as a validation study with healthy participants engaged in a training protocol. The results confirmed the involvement of the cognitive abilities that the game is supposed to enhance and suggested that training improved attentional control during play. PMID:24860529

  8. Habituation of attentional networks during emotion processing.

    PubMed

    Feinstein, Justin S; Goldin, Philippe R; Stein, Murray B; Brown, Gregory G; Paulus, Martin P

    2002-07-19

    Dysfunctional emotion processing is a key aspect of many neuropsychiatric disorders. This dysfunction may be due to an abnormal magnitude of neural substrate activation during emotion processing or due to an altered time course of the neural substrate response. To better understand the temporal characteristics of the neural substrate activation underlying implicit emotion processing, nine healthy female controls were repeatedly exposed to pictures of affective faces while performing a gender identification task in an fMRI. As the salience of the stimuli decreased with repeated exposure, brain areas implicated in a right hemispheric spatial attention network (including the posterior parietal cortex (BA 40) and the frontal eye fields (BA 6)) habituated while brain areas lateralized to the left hemisphere (including the angular gyrus (BA 39), posterior superior temporal gyrus (BA 39) and insula (BA 13)) sensitized. These results provide strong evidence that the time course of activation is a critical component when assessing the function of neural substrates underlying emotion processing (specifically whether habituation is altered) in neuro-psychiatric patients. PMID:12151781

  9. Treating Attention in Mild Aphasia: Evaluation of Attention Process Training-II

    ERIC Educational Resources Information Center

    Murray, Laura L.; Keeton, R. Jessica; Karcher, Laura

    2006-01-01

    This study examined whether attention processing training-II [Sohlberg, M. M., Johnson, L., Paule, L., Raskin, S. A., & Mateer, C. A. (2001). "Attention Process Training-II: A program to address attentional deficits for persons with mild cognitive dysfunction" (2nd ed.). Wake Forest, NC: Lash & Associates.; APT-II], when applied in the context of…

  10. The role of attention in visual processing.

    PubMed Central

    Maunsell, John H R; Cook, Erik P

    2002-01-01

    Attention to a visual stimulus typically increases the responses of cortical neurons to that stimulus. Because many studies have shown a close relationship between the performance of individual neurons and behavioural performance of animal subjects, it is important to consider how attention affects this relationship. Measurements of behavioural and neuronal performance taken from rhesus monkeys while they performed a motion detection task with two attentional states show that attention alters the relationship between behaviour and neuronal response. Notably, attention affects the relationship differently in different cortical visual areas. This indicates that a close relationship between neuronal and behavioural performance on a given task persists over changes in attentional state only within limited regions of visual cortex. PMID:12217174

  11. Greater efficiency in attentional processing related to mindfulness meditation.

    PubMed

    van den Hurk, Paul A M; Giommi, Fabio; Gielen, Stan C; Speckens, Anne E M; Barendregt, Henk P

    2010-06-01

    In this study, attentional processing in relation to mindfulness meditation was investigated. Since recent studies have suggested that mindfulness meditation may induce improvements in attentional processing, we have tested 20 expert mindfulness meditators in the attention network test. Their performance was compared to that of 20 age- and gender-matched controls. In addition to attentional network analyses, overall attentional processing was analysed by means of efficiency scores (i.e., accuracy controlled for reaction time). Better orienting and executive attention (reflected by smaller differences in either reaction time or error score, respectively) were observed in the mindfulness meditation group. Furthermore, extensive mindfulness meditation appeared to be related to a reduction of the fraction of errors for responses with the same reaction time. These results provide new insights into differences in attentional processing related to mindfulness meditation and suggest the possibility of increasing the efficiency in attentional processing by extensive mental training.

  12. Adaptive memory: animacy processing produces mnemonic advantages.

    PubMed

    VanArsdall, Joshua E; Nairne, James S; Pandeirada, Josefa N S; Blunt, Janell R

    2013-01-01

    It is adaptive to remember animates, particularly animate agents, because they play an important role in survival and reproduction. Yet, surprisingly, the role of animacy in mnemonic processing has received little direct attention in the literature. In two experiments, participants were presented with pronounceable nonwords and properties characteristic of either living (animate) or nonliving (inanimate) things. The task was to rate the likelihood that each nonword-property pair represented a living thing or a nonliving object. In Experiment 1, a subsequent recognition memory test for the nonwords revealed a significant advantage for the nonwords paired with properties of living things. To generalize this finding, Experiment 2 replicated the animate advantage using free recall. These data demonstrate a new phenomenon in the memory literature - a possible mnemonic tuning for animacy - and add to growing data supporting adaptive memory theory. PMID:23261948

  13. Attentional processes link perception and action.

    PubMed Central

    Anderson, Stephen J; Yamagishi, Noriko; Karavia, Vivian

    2002-01-01

    Behavioural studies on normal and brain-damaged individuals provide convincing evidence that the perception of objects results in the generation of both visual and motor signals in the brain, irrespective of whether or not there is an intention to act upon the object. In this paper we sought to determine the basis of the motor signals generated by visual objects. By examining how the properties of an object affect an observer's reaction time for judging its orientation, we provide evidence to indicate that directed visual attention is responsible for the automatic generation of motor signals associated with the spatial characteristics of perceived objects. PMID:12065038

  14. Baseline Shifts do not Predict Attentional Modulation of Target Processing During Feature-Based Visual Attention

    PubMed Central

    Fannon, Sean P.; Saron, Clifford D.; Mangun, George R.

    2007-01-01

    Cues that direct selective attention to a spatial location have been observed to increase baseline neural activity in visual areas that represent a to-be-attended stimulus location. Analogous attention-related baseline shifts have also been observed in response to attention-directing cues for non-spatial stimulus features. It has been proposed that baseline shifts with preparatory attention may serve as the mechanism by which attention modulates the responses to subsequent visual targets that match the attended location or feature. Using functional MRI, we localized color- and motion-sensitive visual areas in individual subjects and investigated the relationship between cue-induced baseline shifts and the subsequent attentional modulation of task-relevant target stimuli. Although attention-directing cues often led to increased background neural activity in feature specific visual areas, these increases were not correlated with either behavior in the task or subsequent attentional modulation of the visual targets. These findings cast doubt on the hypothesis that attention-related shifts in baseline neural activity result in selective sensory processing of visual targets during feature-based selective attention. PMID:18958221

  15. Attentional Modulation of Emotional Conflict Processing with Flanker Tasks

    PubMed Central

    Zhou, Pingyan; Liu, Xun

    2013-01-01

    Emotion processing has been shown to acquire priority by biasing allocation of attentional resources. Aversive images or fearful expressions are processed quickly and automatically. Many existing findings suggested that processing of emotional information was pre-attentive, largely immune from attentional control. Other studies argued that attention gated the processing of emotion. To tackle this controversy, the current study examined whether and to what degrees attention modulated processing of emotion using a stimulus-response-compatibility (SRC) paradigm. We conducted two flanker experiments using color scale faces in neutral expressions or gray scale faces in emotional expressions. We found SRC effects for all three dimensions (color, gender, and emotion) and SRC effects were larger when the conflicts were task relevant than when they were task irrelevant, suggesting that conflict processing of emotion was modulated by attention, similar to those of color and face identity (gender). However, task modulation on color SRC effect was significantly greater than that on gender or emotion SRC effect, indicating that processing of salient information was modulated by attention to a lesser degree than processing of non-emotional stimuli. We proposed that emotion processing can be influenced by attentional control, but at the same time salience of emotional information may bias toward bottom-up processing, rendering less top-down modulation than that on non-emotional stimuli. PMID:23544155

  16. Spatial Attention Enhances Perceptual Processing of Single-Element Displays

    NASA Technical Reports Server (NTRS)

    Bacon, William; Johnston, James C.; Remington, Roger W.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    Shiu and Pashler (1993) reported that precueing masked, single-element displays had negligible effects on identification accuracy. They argued that spatial attention does not actually enhance stimulus perceptibility, but only reduces decision noise. Alternatively, such negative results may arise if cues are sub-optimal, or if masks place an insufficient premium on timely deployment of attention. We report results showing that valid cueing enhances processing of even single-element displays. Spatial attention does indeed enhance perceptual processes.

  17. Attentional modulation of reward processing in the human brain.

    PubMed

    Rothkirch, Marcus; Schmack, Katharina; Deserno, Lorenz; Darmohray, Dana; Sterzer, Philipp

    2014-07-01

    Although neural signals of reward anticipation have been studied extensively, the functional relationship between reward and attention has remained unclear: Neural signals implicated in reward processing could either reflect attentional biases towards motivationally salient stimuli, or proceed independently of attentional processes. Here, we sought to disentangle reward and attention-related neural processes by independently modulating reward value and attentional task demands in a functional magnetic resonance imaging study in healthy human participants. During presentation of a visual reward cue that indicated whether monetary reward could be obtained in a subsequent reaction time task, participants either attended to the reward cue or performed an unrelated attention-demanding task at two different levels of difficulty. In ventral striatum and ventral tegmental area, neural responses were modulated by reward anticipation irrespective of attentional demands, thus indicating attention-independent processing of reward cues. By contrast, additive effects of reward and attention were observed in visual cortex. Critically, reward-related activations in right anterior insula strongly depended on attention to the reward cue. Dynamic causal modelling revealed that the attentional modulation of reward processing in insular cortex was mediated by enhanced effective connectivity from ventral striatum to anterior insula. Our results provide evidence for distinct functional roles of the brain regions involved in the processing of reward-indicating information: While subcortical structures signal the motivational salience of reward cues even when attention is fully engaged elsewhere, reward-related responses in anterior insula depend on available attentional resources, likely reflecting the conscious evaluation of sensory information with respect to motivational value. PMID:24307490

  18. Study Of Adaptive-Array Signal Processing

    NASA Technical Reports Server (NTRS)

    Satorius, Edgar H.; Griffiths, Lloyd

    1990-01-01

    Report describes study of adaptive signal-processing techniques for suppression of mutual satellite interference in mobile (on ground)/satellite communication system. Presents analyses and numerical simulations of performances of two approaches to signal processing for suppression of interference. One approach, known as "adaptive side lobe canceling", second called "adaptive temporal processing".

  19. Effects of valence and divided attention on cognitive reappraisal processes

    PubMed Central

    Leclerc, Christina M.; Kensinger, Elizabeth A.

    2014-01-01

    Numerous studies have investigated the neural substrates supporting cognitive reappraisal, identifying the importance of cognitive control processes implemented by prefrontal cortex (PFC). This study examined how valence and attention affect the processes used for cognitive reappraisal by asking participants to passively view or to cognitively reappraise positive and negative images with full or divided attention. When participants simply viewed these images, results revealed few effects of valence or attention. However, when participants engaged in reappraisal, there was a robust effect of valence, with the reappraisal of negative relative to positive images associated with more widespread activation, including within regions of medial and lateral PFC. There also was an effect of attention, with more lateral PFC recruitment when regulating with full attention and more medial PFC recruitment when regulating with divided attention. Within two regions of medial PFC and one region of ventrolateral PFC, there was an interaction between valence and attention: in these regions, divided attention reduced activity during reappraisal of positive but not negative images. Critically, participants continued to report reappraisal success even during the Divided Attention condition. These results suggest multiple routes to successful cognitive reappraisal, depending upon image valence and the availability of attentional resources. PMID:24493837

  20. Listeners modulate temporally selective attention during natural speech processing

    PubMed Central

    Astheimer, Lori B.; Sanders, Lisa D.

    2009-01-01

    Spatially selective attention allows for the preferential processing of relevant stimuli when more information than can be processed in detail is presented simultaneously at distinct locations. Temporally selective attention may serve a similar function during speech perception by allowing listeners to allocate attentional resources to time windows that contain highly relevant acoustic information. To test this hypothesis, event-related potentials were compared in response to attention probes presented in six conditions during a narrative: concurrently with word onsets, beginning 50 and 100 ms before and after word onsets, and at random control intervals. Times for probe presentation were selected such that the acoustic environments of the narrative were matched for all conditions. Linguistic attention probes presented at and immediately following word onsets elicited larger amplitude N1s than control probes over medial and anterior regions. These results indicate that native speakers selectively process sounds presented at specific times during normal speech perception. PMID:18395316

  1. Attentional Processes in Young Children with Congenital Visual Impairment

    ERIC Educational Resources Information Center

    Tadic, Valerie; Pring, Linda; Dale, Naomi

    2009-01-01

    The study investigated attentional processes of 32 preschool children with congenital visual impairment (VI). Children with profound visual impairment (PVI) and severe visual impairment (SVI) were compared to a group of typically developing sighted children in their ability to respond to adult directed attention in terms of establishing,…

  2. Shallow Processing and Attention Capture in Written and Spoken Discourse

    ERIC Educational Resources Information Center

    Sanford, Alison J. S.; Sanford, Anthony J.; Molle, Jo; Emmott, Catherine

    2006-01-01

    Processing of discourse seems to be far from uniform with much evidence indicating that it can be quite shallow. The question is then what modulates depth of processing? A range of discourse devices exist that we believe may lead to more detailed processing of language input (Attention Capturers), thus serving as modulators of processing enabling…

  3. Deployment of spatial attention without moving the eyes is boosted by oculomotor adaptation

    PubMed Central

    Habchi, Ouazna; Rey, Elodie; Mathieu, Romain; Urquizar, Christian; Farnè, Alessandro; Pélisson, Denis

    2015-01-01

    Vertebrates developed sophisticated solutions to select environmental visual information, being capable of moving attention without moving the eyes. A large body of behavioral and neuroimaging studies indicate a tight coupling between eye movements and spatial attention. The nature of this link, however, remains highly debated. Here, we demonstrate that deployment of human covert attention, measured in stationary eye conditions, can be boosted across space by changing the size of ocular saccades to a single position via a specific adaptation paradigm. These findings indicate that spatial attention is more widely affected by oculomotor plasticity than previously thought. PMID:26300755

  4. Thalamic Circuit Mechanisms Link Sensory Processing in Sleep and Attention

    PubMed Central

    Chen, Zhe; Wimmer, Ralf D.; Wilson, Matthew A.; Halassa, Michael M.

    2016-01-01

    The correlation between sleep integrity and attentional performance is normally interpreted as poor sleep causing impaired attention. Here, we provide an alternative explanation for this correlation: common thalamic circuits regulate sensory processing across sleep and attention, and their disruption may lead to correlated dysfunction. Using multi-electrode recordings in mice, we find that rate and rhythmicity of thalamic reticular nucleus (TRN) neurons are predictive of their functional organization in sleep and suggestive of their participation in sensory processing across states. Surprisingly, TRN neurons associated with spindles in sleep are also associated with alpha oscillations during attention. As such, we propose that common thalamic circuit principles regulate sensory processing in a state-invariant manner and that in certain disorders, targeting these circuits may be a more viable therapeutic strategy than considering individual states in isolation. PMID:26778969

  5. Self-Referenced Processing, Neurodevelopment and Joint Attention in Autism

    ERIC Educational Resources Information Center

    Mundy, Peter; Gwaltney, Mary; Henderson, Heather

    2010-01-01

    This article describes a parallel and distributed processing model (PDPM) of joint attention, self-referenced processing and autism. According to this model, autism involves early impairments in the capacity for rapid, integrated processing of self-referenced (proprioceptive and interoceptive) and other-referenced (exteroceptive) information.…

  6. Attention as reward-driven optimization of sensory processing.

    PubMed

    Chalk, Matthew; Murray, Iain; Seriès, Peggy

    2013-11-01

    Attention causes diverse changes to visual neuron responses, including alterations in receptive field structure, and firing rates. A common theoretical approach to investigate why sensory neurons behave as they do is based on the efficient coding hypothesis: that sensory processing is optimized toward the statistics of the received input. We extend this approach to account for the influence of task demands, hypothesizing that the brain learns a probabilistic model of both the sensory input and reward received for performing different actions. Attention-dependent changes to neural responses reflect optimization of this internal model to deal with changes in the sensory environment (stimulus statistics) and behavioral demands (reward statistics). We use this framework to construct a simple model of visual processing that is able to replicate a number of attention-dependent changes to the responses of neurons in the midlevel visual cortices. The model is consistent with and provides a normative explanation for recent divisive normalization models of attention (Reynolds & Heeger, 2009).

  7. Attentional Processes in Children's Overt and Relational Aggression

    ERIC Educational Resources Information Center

    Arsenault, Darin J.; Foster, Sharon L.

    2012-01-01

    This study examined attention and memory processes assumed by the social information-processing model to be biased in aggressive children. We also explored whether similar biases were associated with overt and relational aggression. A total of 96 fourth through sixth graders saw videos of overtly and relationally aggressive child actors and…

  8. Investigations in adaptive processing of multispectral data

    NASA Technical Reports Server (NTRS)

    Kriegler, F. J.; Horwitz, H. M.

    1973-01-01

    Adaptive data processing procedures are applied to the problem of classifying objects in a scene scanned by multispectral sensor. These procedures show a performance improvement over standard nonadaptive techniques. Some sources of error in classification are identified and those correctable by adaptive processing are discussed. Experiments in adaptation of signature means by decision-directed methods are described. Some of these methods assume correlation between the trajectories of different signature means; for others this assumption is not made.

  9. An adaptive signal-processing approach to online adaptive tutoring.

    PubMed

    Bergeron, Bryan; Cline, Andrew

    2011-01-01

    Conventional intelligent or adaptive tutoring online systems rely on domain-specific models of learner behavior based on rules, deep domain knowledge, and other resource-intensive methods. We have developed and studied a domain-independent methodology of adaptive tutoring based on domain-independent signal-processing approaches that obviate the need for the construction of explicit expert and student models. A key advantage of our method over conventional approaches is a lower barrier to entry for educators who want to develop adaptive online learning materials.

  10. Photoreceptor processes in visual adaptation.

    PubMed

    Ripps, H; Pepperberg, D R

    1987-01-01

    In this paper we have stressed two experimental results in need of explanation: (i) the reduced efficacy with which (remaining, abundant) rhodopsin in the light-adapted receptor mediates the flash response; and (ii) the disparity in conditions of irradiation (weak background vs. extensive bleaching) leading to equivalent conditions of threshold. The model discussed above suggests, in molecular terms, a possible basis for both properties of receptor adaptation. On the view developed here, property (i) derives from the ability of photoactivated or bleached pigment (R or B) to restrict dramatically the availability of a substance required for phototransduction. Property (ii) derives in large part from the pronounced disparity in the effectiveness of R (during illumination) and B (remaining after illumination) in reducing the availability of this substance. On this view, the "equivalence" of threshold elevation in states of light- vs. dark-adaptation derives from an overall equality of a product of factors (Q, Etot/Es, and J of equation 2). Under all but extreme conditions, this aggregate of factors is dominated by the term Etot/Es, reflecting the functional state of E. PMID:3317149

  11. Understanding Attention to Adaptive Hints in Educational Games: An Eye-Tracking Study

    ERIC Educational Resources Information Center

    Conati, Cristina; Jaques, Natasha; Muir, Mary

    2013-01-01

    This paper presents a user study that investigates the factors affecting student attention to user-adaptive hints during interaction with an educational computer game. The study focuses on Prime Climb, an educational game designed to provide individualized support for learning number factorization skills in the form of textual hints based on a…

  12. Towards incorporating affective computing to virtual rehabilitation; surrogating attributed attention from posture for boosting therapy adaptation

    NASA Astrophysics Data System (ADS)

    Rivas, Jesús J.; Heyer, Patrick; Orihuela-Espina, Felipe; Sucar, Luis Enrique

    2015-01-01

    Virtual rehabilitation (VR) is a novel motor rehabilitation therapy in which the rehabilitation exercises occurs through interaction with bespoken virtual environments. These virtual environments dynamically adapt their activity to match the therapy progress. Adaptation should be guided by the cognitive and emotional state of the patient, none of which are directly observable. Here, we present our first steps towards inferring non-observable attentional state from unobtrusively observable seated posture, so that this knowledge can later be exploited by a VR platform to modulate its behaviour. The space of seated postures was discretized and 648 pictures of acted representations were exposed to crowd-evaluation to determine attributed state of attention. A semi-supervised classifier based on Na¨ıve Bayes with structural improvement was learnt to unfold a predictive relation between posture and attributed attention. Internal validity was established following a 2×5 cross-fold strategy. Following 4959 votes from crowd, classification accuracy reached a promissory 96.29% (µ±σ = 87.59±6.59) and F-measure reached 82.35% (µ ± σ = 69.72 ± 10.50). With the afforded rate of classification, we believe it is safe to claim posture as a reliable proxy for attributed attentional state. It follows that unobtrusively monitoring posture can be exploited for guiding an intelligent adaptation in a virtual rehabilitation platform. This study further helps to identify critical aspects of posture permitting inference of attention.

  13. Optical Profilometers Using Adaptive Signal Processing

    NASA Technical Reports Server (NTRS)

    Hall, Gregory A.; Youngquist, Robert; Mikhael, Wasfy

    2006-01-01

    A method of adaptive signal processing has been proposed as the basis of a new generation of interferometric optical profilometers for measuring surfaces. The proposed profilometers would be portable, hand-held units. Sizes could be thus reduced because the adaptive-signal-processing method would make it possible to substitute lower-power coherent light sources (e.g., laser diodes) for white light sources and would eliminate the need for most of the optical components of current white-light profilometers. The adaptive-signal-processing method would make it possible to attain scanning ranges of the order of decimeters in the proposed profilometers.

  14. Spatiotopic perceptual learning mediated by retinotopic processing and attentional remapping.

    PubMed

    Zhang, En; Zhang, Gong-Liang; Li, Wu

    2013-12-01

    Visual processing takes place in both retinotopic and spatiotopic frames of reference. Whereas visual perceptual learning is usually specific to the trained retinotopic location, our recent study has shown spatiotopic specificity of learning in motion direction discrimination. To explore the mechanisms underlying spatiotopic processing and learning, and to examine whether similar mechanisms also exist in visual form processing, we trained human subjects to discriminate an orientation difference between two successively displayed stimuli, with a gaze shift in between to manipulate their positional relation in the spatiotopic frame of reference without changing their retinal locations. Training resulted in better orientation discriminability for the trained than for the untrained spatial relation of the two stimuli. This learning-induced spatiotopic preference was seen only at the trained retinal location and orientation, suggesting experience-dependent spatiotopic form processing directly based on a retinotopic map. Moreover, a similar but weaker learning-induced spatiotopic preference was still present even if the first stimulus was rendered irrelevant to the orientation discrimination task by having the subjects judge the orientation of the second stimulus relative to its mean orientation in a block of trials. However, if the first stimulus was absent, and thus no attention was captured before the gaze shift, the learning produced no significant spatiotopic preference, suggesting an important role of attentional remapping in spatiotopic processing and learning. Taken together, our results suggest that spatiotopic visual representation can be mediated by interactions between retinotopic processing and attentional remapping, and can be modified by perceptual training.

  15. Surprise? Early visual novelty processing is not modulated by attention

    PubMed Central

    Tarbi, Elise C.; Sun, Xue; Holcomb, Phillip J.; Daffner, Kirk R.

    2010-01-01

    This study investigated the influence of direction of attention on the early detection of visual novelty, as indexed by the anterior N2. The anterior N2 was measured in young subjects (n=32) under an Attend and Ignore condition. Subjects were presented standard, target/rare, and perceptually novel visual stimuli under both conditions, but under the Ignore condition, attention was directed towards an auditory n-back task. The size of the anterior N2 to novel stimuli did not differ between conditions and was significantly larger than the anterior N2 to all other stimulus types. Furthermore, under the Ignore condition, the anterior N2 to visual novel stimuli was not affected by the level of difficulty of the auditory n-back task (3-back vs. 2-back). Our findings suggest that the early processing of visual novelty, as measured by the size of the anterior N2, is not strongly modulated by direction of attention. PMID:20880260

  16. Visual attention in reading: Eye movements reflect cognitive processes.

    PubMed

    Rayner, K

    1977-07-01

    Two hypotheses regarding the nature of fixation durations in reading were discussed. One position suggests that semantic processing lags behind the perceptual input of information. The other position suggests that semantic processing is more rapid and immediate. Eye movement data of skilled readers reading passages of text were analyzed. It was found that the main verb of the sentence received more visual attention than other key grammatical elements within a sentence. On the basis of the overall result pattern, it was argued that eye movements are affected by cognitive processes occurring at the time of the fixations.

  17. Evolution of attention mechanisms for early visual processing

    NASA Astrophysics Data System (ADS)

    Müller, Thomas; Knoll, Alois

    2011-03-01

    Early visual processing as a method to speed up computations on visual input data has long been discussed in the computer vision community. The general target of a such approaches is to filter nonrelevant information from the costly higher-level visual processing algorithms. By insertion of this additional filter layer the overall approach can be speeded up without actually changing the visual processing methodology. Being inspired by the layered architecture of the human visual processing apparatus, several approaches for early visual processing have been recently proposed. Most promising in this field is the extraction of a saliency map to determine regions of current attention in the visual field. Such saliency can be computed in a bottom-up manner, i.e. the theory claims that static regions of attention emerge from a certain color footprint, and dynamic regions of attention emerge from connected blobs of textures moving in a uniform way in the visual field. Top-down saliency effects are either unconscious through inherent mechanisms like inhibition-of-return, i.e. within a period of time the attention level paid to a certain region automatically decreases if the properties of that region do not change, or volitional through cognitive feedback, e.g. if an object moves consistently in the visual field. These bottom-up and top-down saliency effects have been implemented and evaluated in a previous computer vision system for the project JAST. In this paper an extension applying evolutionary processes is proposed. The prior vision system utilized multiple threads to analyze the regions of attention delivered from the early processing mechanism. Here, in addition, multiple saliency units are used to produce these regions of attention. All of these saliency units have different parameter-sets. The idea is to let the population of saliency units create regions of attention, then evaluate the results with cognitive feedback and finally apply the genetic mechanism

  18. Oscillatory synchrony as a mechanism of attentional processing.

    PubMed

    Gregoriou, Georgia G; Paneri, Sofia; Sapountzis, Panagiotis

    2015-11-11

    The question of how the brain selects which stimuli in our visual field will be given priority to enter into perception, to guide our actions and to form our memories has been a matter of intense research in studies of visual attention. Work in humans and animal models has revealed an extended network of areas involved in the control and maintenance of attention. For many years, imaging studies in humans constituted the main source of a systems level approach, while electrophysiological recordings in non-human primates provided insight into the cellular mechanisms of visual attention. Recent technological advances and the development of sophisticated analytical tools have allowed us to bridge the gap between the two approaches and assess how neuronal ensembles across a distributed network of areas interact in visual attention tasks. A growing body of evidence suggests that oscillatory synchrony plays a crucial role in the selective communication of neuronal populations that encode the attended stimuli. Here, we discuss data from theoretical and electrophysiological studies, with more emphasis on findings from humans and non-human primates that point to the relevance of oscillatory activity and synchrony for attentional processing and behavior. These findings suggest that oscillatory synchrony in specific frequencies reflects the biophysical properties of specific cell types and local circuits and allows the brain to dynamically switch between different spatio-temporal patterns of activity to achieve flexible integration and selective routing of information along selected neuronal populations according to behavioral demands. This article is part of a Special Issue entitled SI: Prediction and Attention.

  19. Selective visual attention based clutter metric with human visual system adaptability.

    PubMed

    Zheng, Bo; Wang, Xiao-Dong; Huang, Jing-Tao; Wang, Jian; Jiang, Yang

    2016-09-20

    Most existing clutter metrics are proposed based on fixed structural features and experienced weight measures. In this paper, we identify the clutter as selective visual attention effects and propose a type of clutter metric. First, adaptive structural features are extracted from the blocks with an edge-structure similarity to the target. Next, the confusing blocks are selected by the similarity threshold based on the attention guidance map. The clutter is estimated by quantifying the effects of confusing blocks on target acquisition performance. The comparative field experiments, with a Search_2 dataset, show that the proposed metric is consistent with the adaptability of the human visual system (HVS) and outperforms other metrics. PMID:27661600

  20. The influence of scopolamine on motor control and attentional processes

    PubMed Central

    Bestaven, Emma; Kambrun, Charline; Guehl, Dominique; Cazalets, Jean-René

    2016-01-01

    Background: Motion sickness may be caused by a sensory conflict between the visual and the vestibular systems. Scopolamine, known to be the most effective therapy to control the vegetative symptoms of motion sickness, acts on the vestibular nucleus and potentially the vestibulospinal pathway, which may affect balance and motor tasks requiring both attentional process and motor balance. The aim of this study was to explore the effect of scopolamine on motor control and attentional processes. Methods: Seven subjects were evaluated on four different tasks before and after a subcutaneous injection of scopolamine (0.2 mg): a one-minute balance test, a subjective visual vertical test, a pointing task and a galvanic vestibular stimulation with EMG recordings. Results: The results showed that the reaction time and the movement duration were not modified after the injection of scopolamine. However, there was an increase in the center of pressure displacement during the balance test, a decrease in EMG muscle response after galvanic vestibular stimulation and an alteration in the perception of verticality. Discussion: These results confirm that low doses of scopolamine such as those prescribed to avoid motion sickness have no effect on attentional processes, but that it is essential to consider the responsiveness of each subject. However, scopolamine did affect postural control and the perception of verticality. In conclusion, the use of scopolamine to prevent motion sickness must be considered carefully because it could increase imbalances in situations when individuals are already at risk of falling (e.g., sailing, parabolic flight). PMID:27169000

  1. Adaptive filtering in biological signal processing.

    PubMed

    Iyer, V K; Ploysongsang, Y; Ramamoorthy, P A

    1990-01-01

    The high dependence of conventional optimal filtering methods on the a priori knowledge of the signal and noise statistics render them ineffective in dealing with signals whose statistics cannot be predetermined accurately. Adaptive filtering methods offer a better alternative, since the a priori knowledge of statistics is less critical, real time processing is possible, and the computations are less expensive for this approach. Adaptive filtering methods compute the filter coefficients "on-line", converging to the optimal values in the least-mean square (LMS) error sense. Adaptive filtering is therefore apt for dealing with the "unknown" statistics situation and has been applied extensively in areas like communication, speech, radar, sonar, seismology, and biological signal processing and analysis for channel equalization, interference and echo canceling, line enhancement, signal detection, system identification, spectral analysis, beamforming, modeling, control, etc. In this review article adaptive filtering in the context of biological signals is reviewed. An intuitive approach to the underlying theory of adaptive filters and its applicability are presented. Applications of the principles in biological signal processing are discussed in a manner that brings out the key ideas involved. Current and potential future directions in adaptive biological signal processing are also discussed.

  2. The role of spatial attention in visual word processing

    NASA Technical Reports Server (NTRS)

    Mccann, Robert S.; Folk, Charles L.; Johnston, James C.

    1992-01-01

    Subjects made lexical decisions on a target letter string presented above or below fixation. In Experiments 1 and 2, target location was cued 100 ms in advance of target onset. Responses were faster on validly than on invalidly cued trials. In Experiment 3, the target was sometimes accompanied by irrelevant stimuli on the other side of fixation; in such cases, responses were slowed (a spatial filtering effect). Both cuing and filtering effects on response time were additive with effects of word frequency and lexical status (words vs. nonwords). These findings are difficult to reconcile with claims that spatial attention is less involved in processing familiar words than in unfamiliar words and nonwords. The results can be reconciled with a late-selection locus of spatial attention only with difficulty, but are easily explained by early-selection models.

  3. Divided Attention and Processes Underlying Sense of Agency

    PubMed Central

    Wen, Wen; Yamashita, Atsushi; Asama, Hajime

    2016-01-01

    Sense of agency refers to the subjective feeling of controlling events through one’s behavior or will. Sense of agency results from matching predictions of one’s own actions with actual feedback regarding the action. Furthermore, when an action involves a cued goal, performance-based inference contributes to sense of agency. That is, if people achieve their goal, they would believe themselves to be in control. Previous studies have shown that both action-effect comparison and performance-based inference contribute to sense of agency; however, the dominance of one process over the other may shift based on task conditions such as the presence or absence of specific goals. In this study, we examined the influence of divided attention on these two processes underlying sense of agency in two conditions. In the experimental task, participants continuously controlled a moving dot for 10 s while maintaining a string of three or seven digits in working memory. We found that when there was no cued goal (no-cued-goal condition), sense of agency was impaired by high cognitive load. Contrastingly, when participants controlled the dot based on a cued goal (cued-goal-directed condition), their sense of agency was lower than in the no-cued-goal condition and was not affected by cognitive load. The results suggest that the action-effect comparison process underlying sense of agency requires attention. On the other hand, the weaker influence of divided attention in the cued-goal-directed condition could be attributed to the dominance of performance-based inference, which is probably automatic. PMID:26858680

  4. Neural Adaptation Effects in Conceptual Processing

    PubMed Central

    Marino, Barbara F. M.; Borghi, Anna M.; Gemmi, Luca; Cacciari, Cristina; Riggio, Lucia

    2015-01-01

    We investigated the conceptual processing of nouns referring to objects characterized by a highly typical color and orientation. We used a go/no-go task in which we asked participants to categorize each noun as referring or not to natural entities (e.g., animals) after a selective adaptation of color-edge neurons in the posterior LV4 region of the visual cortex was induced by means of a McCollough effect procedure. This manipulation affected categorization: the green-vertical adaptation led to slower responses than the green-horizontal adaptation, regardless of the specific color and orientation of the to-be-categorized noun. This result suggests that the conceptual processing of natural entities may entail the activation of modality-specific neural channels with weights proportional to the reliability of the signals produced by these channels during actual perception. This finding is discussed with reference to the debate about the grounded cognition view. PMID:26264031

  5. Bayesian nonparametric adaptive control using Gaussian processes.

    PubMed

    Chowdhary, Girish; Kingravi, Hassan A; How, Jonathan P; Vela, Patricio A

    2015-03-01

    Most current model reference adaptive control (MRAC) methods rely on parametric adaptive elements, in which the number of parameters of the adaptive element are fixed a priori, often through expert judgment. An example of such an adaptive element is radial basis function networks (RBFNs), with RBF centers preallocated based on the expected operating domain. If the system operates outside of the expected operating domain, this adaptive element can become noneffective in capturing and canceling the uncertainty, thus rendering the adaptive controller only semiglobal in nature. This paper investigates a Gaussian process-based Bayesian MRAC architecture (GP-MRAC), which leverages the power and flexibility of GP Bayesian nonparametric models of uncertainty. The GP-MRAC does not require the centers to be preallocated, can inherently handle measurement noise, and enables MRAC to handle a broader set of uncertainties, including those that are defined as distributions over functions. We use stochastic stability arguments to show that GP-MRAC guarantees good closed-loop performance with no prior domain knowledge of the uncertainty. Online implementable GP inference methods are compared in numerical simulations against RBFN-MRAC with preallocated centers and are shown to provide better tracking and improved long-term learning.

  6. Word semantics is processed even without attentional effort.

    PubMed

    Relander, Kristiina; Rämä, Pia; Kujala, Teija

    2009-08-01

    We examined the attentional modulation of semantic priming and the N400 effect for spoken words. The aim was to find out how the semantics of spoken language is processed when attention is directed to another modality (passive task), to the phonetics of spoken words (phonological task), or to the semantics of spoken words (word task). Equally strong behavioral priming effects were obtained in the phonological and the word tasks. A significant N400 effect was found in all tasks. The effect was stronger in the word and the phonological tasks than in the passive task, but there was no difference in the magnitude of the effect between the phonological and the word tasks. The latency of the N400 effect did not differ between the tasks. Although the N400 effect had a centroparietal maximum in the phonological and the word tasks, it was largest at the parietal recording sites in the passive task. The effect was more pronounced at the left than right recording sites in the phonological task, but there was no laterality effect in the other tasks. The N400 effect in the passive task indicates that semantic priming occurs even when spoken words are not actively attended. However, stronger N400 effect in the phonological and the word tasks than in the passive task suggests that controlled processes modulate the N400 effect. The finding that there were no differences in the N400 effect between the phonological and the word tasks indicates that the semantics of attended spoken words is processed regardless of whether semantic processing is relevant for task performance.

  7. The conflict adaptation is affected by attentional strategies: evidence from the arrow flanker task.

    PubMed

    Chen, Jia; Li, Chang; He, ChunHong; Chen, AnTao

    2009-10-01

    Recently, several studies have considered factors affecting the occurrence of congruency sequence effect (CSE) in the arrow flanker task. In the present study, the influence of the following factors was examined: the presentation of a fixation and the intertrial interval (ITI) were considered. Results of the study showed that the CSE was significant when there was no fixation and when the ITI was long for response repetitions and response changes, but disappeared for response change trials in other conditions. These results showed that, even in the arrow flanker task, the conflict adaptation effect did contribute to the CSE. The current results suggested that the conflict adaptation effect in the arrow flanker task was based on the appropriate application of attention strategies.

  8. Adoption: biological and social processes linked to adaptation.

    PubMed

    Grotevant, Harold D; McDermott, Jennifer M

    2014-01-01

    Children join adoptive families through domestic adoption from the public child welfare system, infant adoption through private agencies, and international adoption. Each pathway presents distinctive developmental opportunities and challenges. Adopted children are at higher risk than the general population for problems with adaptation, especially externalizing, internalizing, and attention problems. This review moves beyond the field's emphasis on adoptee-nonadoptee differences to highlight biological and social processes that affect adaptation of adoptees across time. The experience of stress, whether prenatal, postnatal/preadoption, or during the adoption transition, can have significant impacts on the developing neuroendocrine system. These effects can contribute to problems with physical growth, brain development, and sleep, activating cascading effects on social, emotional, and cognitive development. Family processes involving contact between adoptive and birth family members, co-parenting in gay and lesbian adoptive families, and racial socialization in transracially adoptive families affect social development of adopted children into adulthood.

  9. Low-latency adaptive optics system processing electronics

    NASA Astrophysics Data System (ADS)

    Duncan, Terry S.; Voas, Joshua K.; Eager, Robert J.; Newey, Scott C.; Wynia, John L.

    2003-02-01

    Extensive system modeling and analysis clearly shows that system latency is a primary performance driver in closed loop adaptive optical systems. With careful attention to all sensing, processing, and controlling components, system latency can be significantly reduced. Upgrades to the Starfire Optical Range (SOR) 3.5-meter telescope facility adaptive optical system have resulted in a reduction in overall latency from 660 μsec to 297 μsec. Future efforts will reduce the system latency even more to the 170 msec range. The changes improve system bandwidth significantly by reducing the "age" of the correction that is applied to the deformable mirror. Latency reductions have been achieved by increasing the pixel readout pattern and rate on the wavefront sensor, utilizing a new high-speed field programmable gate array (FPGA) based wavefront processor, doubling the processing rate of the real-time reconstructor, and streamlining the operation of the deformable mirror drivers.

  10. Saccade adaptation in young people diagnosed with Attention Deficit Hyperactivity Disorder Combined Type.

    PubMed

    Connolly, Amanda J; Rinehart, Nicole J; Fielding, Joanne

    2016-10-01

    Growing evidence suggests Attention Deficit Hyperactivity Disorder (ADHD) often co-occurs with Autism Spectrum Disorder (ASD), and a better understanding of the nature of their overlap, including at a neurobiological level, is needed. Research has implicated cerebellar-networks as part of the neural-circuitry disrupted in ASD, but little research has been carried out to investigate this in ADHD. We investigated cerebellar integrity using a double-step saccade adaptation paradigm in a group of male children age 8-15 (n=12) diagnosed with ADHD-Combined Type (-CT). Their performance was compared to a group of age and IQ-matched typically developing (TD) controls (n=12). Parent reported symptoms of ADHD-CT and ASD were measured, along with motor proficiency (Movement ABC-2). We found, on average, the adaptation of saccade gain was reduced for the ADHD-CT group compared to the TD group. Greater saccadic gain change (adaptation) was also positively correlated with higher Movement ABC-2 total and balance scores among the ADHD-CT participants. These differences suggest cerebellar networks underlying saccade adaptation may be disrupted in young people with ADHD-CT. Though our findings require further replication with larger samples, they suggest further research into cerebellar dysfunction in ADHD-CT, and as a point of neurobiological overlap with ASD, may be warranted.

  11. Adaptive deployment of spatial and feature-based attention before saccades

    PubMed Central

    White, Alex L.; Rolfs, Martin; Carrasco, Marisa

    2012-01-01

    What you see depends not only on where you are looking but also on where you will look next. The pre-saccadic attention shift is an automatic enhancement of visual sensitivity at the target of the next saccade. We investigated whether and how perceptual factors independent of the oculomotor plan modulate pre-saccadic attention within and across trials. Observers made saccades to one (the target) of six patches of moving dots and discriminated a brief luminance pulse (the probe) that appeared at an unpredictable location. Sensitivity to the probe was always higher at the target’s location (spatial attention), and this attention effect was stronger if the previous probe appeared at the previous target’s location. Furthermore, sensitivity was higher for probes moving in directions similar to the target’s direction (feature-based attention), but only when the previous probe moved in the same direction as the previous target. Therefore, implicit cognitive processes permeate pre-saccadic attention, so that–contingent on recent experience–it flexibly distributes resources to potentially relevant locations and features. PMID:23147690

  12. Post-perceptual processing during the attentional blink is modulated by inter-trial task expectancies

    PubMed Central

    Sy, Jocelyn L.; Elliott, James C.; Giesbrecht, Barry

    2013-01-01

    The selective processing of goal-relevant information depends on an attention system that can flexibly adapt to changing task demands and expectations. Evidence from visual search tasks indicates that the perceptual selectivity of attention increases when the bottom-up demands of the task increase and when the expectations about task demands engendered by trial history are violated. Evidence from studies of the attentional blink (AB), which measures the temporal dynamics of attention, also indicates that perceptual selectivity during the AB is increased if the bottom-up task demands are increased. The present work tested whether expectations about task demands engendered by trial history also modulate perceptual selectivity during the AB. Two experiments tested the extent to which inter-trial switches in task demands reduced post-perceptual processing of targets presented during the AB. Experiment 1 indexed post-perceptual processing using the event-related potential (ERP) technique to isolate the context sensitive N400 ERP component evoked by words presented during the AB. Experiment 2 indexed post-perceptual processing using behavioral performance to determine the extent to which personal names survive the AB. The results of both experiments revealed that both electrophysiological (Exp. 1) and behavioral (Exp. 2) indices of post-perceptual processing were attenuated when consecutive trials differed in terms of their perceptual demands. The results are consistent with the notion that the selectivity of attention during the AB is modulated not only by within-trial task demands, but also can be flexibly determined by trial-by-trial expectations. PMID:24115924

  13. A Novel Approach for Adaptive Signal Processing

    NASA Technical Reports Server (NTRS)

    Chen, Ya-Chin; Juang, Jer-Nan

    1998-01-01

    Adaptive linear predictors have been used extensively in practice in a wide variety of forms. In the main, their theoretical development is based upon the assumption of stationarity of the signals involved, particularly with respect to the second order statistics. On this basis, the well-known normal equations can be formulated. If high- order statistical stationarity is assumed, then the equivalent normal equations involve high-order signal moments. In either case, the cross moments (second or higher) are needed. This renders the adaptive prediction procedure non-blind. A novel procedure for blind adaptive prediction has been proposed and considerable implementation has been made in our contributions in the past year. The approach is based upon a suitable interpretation of blind equalization methods that satisfy the constant modulus property and offers significant deviations from the standard prediction methods. These blind adaptive algorithms are derived by formulating Lagrange equivalents from mechanisms of constrained optimization. In this report, other new update algorithms are derived from the fundamental concepts of advanced system identification to carry out the proposed blind adaptive prediction. The results of the work can be extended to a number of control-related problems, such as disturbance identification. The basic principles are outlined in this report and differences from other existing methods are discussed. The applications implemented are speech processing, such as coding and synthesis. Simulations are included to verify the novel modelling method.

  14. Adaptive processing for enhanced target acquisition

    NASA Astrophysics Data System (ADS)

    Page, Scott F.; Smith, Moira I.; Hickman, Duncan; Bernhardt, Mark; Oxford, William; Watson, Norman; Beath, F.

    2009-05-01

    Conventional air-to-ground target acquisition processes treat the image stream in isolation from external data sources. This ignores information that may be available through modern mission management systems which could be fused into the detection process in order to provide enhanced performance. By way of an example relating to target detection, this paper explores the use of a-priori knowledge and other sensor information in an adaptive architecture with the aim of enhancing performance in decision making. The approach taken here is to use knowledge of target size, terrain elevation, sensor geometry, solar geometry and atmospheric conditions to characterise the expected spatial and radiometric characteristics of a target in terms of probability density functions. An important consideration in the construction of the target probability density functions are the known errors in the a-priori knowledge. Potential targets are identified in the imagery and their spatial and expected radiometric characteristics are used to compute the target likelihood. The adaptive architecture is evaluated alongside a conventional non-adaptive algorithm using synthetic imagery representative of an air-to-ground target acquisition scenario. Lastly, future enhancements to the adaptive scheme are discussed as well as strategies for managing poor quality or absent a-priori information.

  15. Photorefractive processing for large adaptive phased arrays.

    PubMed

    Weverka, R T; Wagner, K; Sarto, A

    1996-03-10

    An adaptive null-steering phased-array optical processor that utilizes a photorefractive crystal to time integrate the adaptive weights and null out correlated jammers is described. This is a beam-steering processor in which the temporal waveform of the desired signal is known but the look direction is not. The processor computes the angle(s) of arrival of the desired signal and steers the array to look in that direction while rotating the nulls of the antenna pattern toward any narrow-band jammers that may be present. We have experimentally demonstrated a simplified version of this adaptive phased-array-radar processor that nulls out the narrow-band jammers by using feedback-correlation detection. In this processor it is assumed that we know a priori only that the signal is broadband and the jammers are narrow band. These are examples of a class of optical processors that use the angular selectivity of volume holograms to form the nulls and look directions in an adaptive phased-array-radar pattern and thereby to harness the computational abilities of three-dimensional parallelism in the volume of photorefractive crystals. The development of this processing in volume holographic system has led to a new algorithm for phased-array-radar processing that uses fewer tapped-delay lines than does the classic time-domain beam former. The optical implementation of the new algorithm has the further advantage of utilization of a single photorefractive crystal to implement as many as a million adaptive weights, allowing the radar system to scale to large size with no increase in processing hardware.

  16. Contrast Adaptation Implies Two Spatiotemporal Channels but Three Adapting Processes

    ERIC Educational Resources Information Center

    Langley, Keith; Bex, Peter J.

    2007-01-01

    The contrast gain control model of adaptation predicts that the effects of contrast adaptation correlate with contrast sensitivity. This article reports that the effects of high contrast spatiotemporal adaptors are maximum when adapting around 19 Hz, which is a factor of two or more greater than the peak in contrast sensitivity. To explain the…

  17. Attentional Resource Allocation in Visuotactile Processing Depends on the Task, But Optimal Visuotactile Integration Does Not Depend on Attentional Resources

    PubMed Central

    Wahn, Basil; König, Peter

    2016-01-01

    Humans constantly process and integrate sensory input from multiple sensory modalities. However, the amount of input that can be processed is constrained by limited attentional resources. A matter of ongoing debate is whether attentional resources are shared across sensory modalities, and whether multisensory integration is dependent on attentional resources. Previous research suggested that the distribution of attentional resources across sensory modalities depends on the the type of tasks. Here, we tested a novel task combination in a dual task paradigm: Participants performed a self-terminated visual search task and a localization task in either separate sensory modalities (i.e., haptics and vision) or both within the visual modality. Tasks considerably interfered. However, participants performed the visual search task faster when the localization task was performed in the tactile modality in comparison to performing both tasks within the visual modality. This finding indicates that tasks performed in separate sensory modalities rely in part on distinct attentional resources. Nevertheless, participants integrated visuotactile information optimally in the localization task even when attentional resources were diverted to the visual search task. Overall, our findings suggest that visual search and tactile localization partly rely on distinct attentional resources, and that optimal visuotactile integration is not dependent on attentional resources. PMID:27013994

  18. Coping and adaptation process during puerperium

    PubMed Central

    Muñoz de Rodríguez, Lucy; Ruiz de Cárdenas, Carmen Helena

    2012-01-01

    Introduction: The puerperium is a stage that produces changes and adaptations in women, couples and family. Effective coping, during this stage, depends on the relationship between the demands of stressful or difficult situations and the recourses that the puerperal individual has. Roy (2004), in her Middle Range Theory about the Coping and Adaptation Processing, defines Coping as the ''behavioral and cognitive efforts that a person makes to meet the environment demands''. For the puerperal individual, the correct coping is necessary to maintain her physical and mental well being, especially against situations that can be stressful like breastfeeding and return to work. According to Lazarus and Folkman (1986), a resource for coping is to have someone who receives emotional support, informative and / or tangible. Objective: To review the issue of women coping and adaptation during the puerperium stage and the strategies that enhance this adaptation. Methods: search and selection of database articles: Cochrane, Medline, Ovid, ProQuest, Scielo, and Blackwell Synergy. Other sources: unpublished documents by Roy, published books on Roy´s Model, Websites from of international health organizations. Results: the need to recognize the puerperium as a stage that requires comprehensive care is evident, where nurses must be protagonist with the care offered to women and their families, considering the specific demands of this situation and recourses that promote effective coping and the family, education and health services. PMID:24893059

  19. Alerting enhances attentional bias for salient stimuli: evidence from a global/local processing task.

    PubMed

    Weinbach, Noam; Henik, Avishai

    2014-11-01

    The present study examined the role of alerting in modulating attentional bias to salient events. In a global/local processing task, participants were presented with a large arrow (global level) comprised of smaller arrows (local level) pointing in the same or opposite directions and had to indicate the direction of the large or small arrows in different blocks. Saliency of the global and local levels was manipulated, creating global-salient and local-salient conditions. Alerting signals were presented in half of the trials prior to the target. Results revealed a double dissociation in the effects of alerting on global/local interference effects. In a global salient condition, alerting increased global interference and decreased local interference. In a local salient condition, alerting reduced global interference and increased local interference. We demonstrate that within a single task, alerting can increase and reduce conflict based on perceptual saliency. These findings help to better understand disorders like hemispatial neglect in which both arousal and attention to salient events are impaired. These results also challenge previous theories suggesting that alerting acts to increase conflict interference. We argue that alerting is an adaptive mechanism that diverts attention to salient events, but comes at a cost when selective attention to less salient details is required.

  20. Visual Tracking Based on the Adaptive Color Attention Tuned Sparse Generative Object Model.

    PubMed

    Tian, Chunna; Gao, Xinbo; Wei, Wei; Zheng, Hong

    2015-12-01

    This paper presents a new visual tracking framework based on an adaptive color attention tuned local sparse model. The histograms of sparse coefficients of all patches in an object are pooled together according to their spatial distribution. A particle filter methodology is used as the location model to predict candidates for object verification during tracking. Since color is an important visual clue to distinguish objects from background, we calculate the color similarity between objects in the previous frames and the candidates in current frame, which is adopted as color attention to tune the local sparse representation-based appearance similarity measurement between the object template and candidates. The color similarity can be calculated efficiently with hash coded color names, which helps the tracker find more reliable objects during tracking. We use a flexible local sparse coding of the object to evaluate the degeneration degree of the appearance model, based on which we build a model updating mechanism to alleviate drifting caused by temporal varying multi-factors. Experiments on 76 challenging benchmark color sequences and the evaluation under the object tracking benchmark protocol demonstrate the superiority of the proposed tracker over the state-of-the-art methods in accuracy. PMID:26390460

  1. Topography of somatosensory processing: cerebral lateralization and focused attention.

    PubMed

    Meador, K J; Allison, J D; Loring, D W; Lavin, T B; Pillai, J J

    2002-03-01

    Healthy dextrals underwent fMRI during a task of graphesthesia requiring detection of any number written consecutively from an otherwise random number sequence. Test conditions included (1) focus on unilateral right hand stimuli, (2) focus on unilateral left hand stimuli, (3) focus on right hand only during bilateral hand stimulation, (4) focus on left hand only during bilateral hand stimulation, and (5) rest. Attention to unilateral hand stimulation produced bihemispheric activation with minimal or no activation of ipsilateral primary sensorimotor region. Attention to unilateral left hand stimuli resulted in more activation than attention to unilateral right hand stimuli. Stimulation of the nonattended hand activated the contralateral somatosensory area, but to a lesser spatial extent than attended stimuli. Comparing focused attention to the left versus right side during identical sensory inputs (i.e., bilateral hand stimulation), focused attention to the right hand increased activation in the left somatosensory region, but focused attention to the left hand increased activation in both cerebral hemispheres. Thus, focused attention to unilateral somatosensory stimuli produces bilateral cerebral activation, but the increase in blood flow is greater in the contralateral hemisphere. Unattended stimuli activate the contralateral primary somatosensory area. Left/right asymmetries were demonstrated consistent with cerebral lateralization.

  2. Less Efficient Neural Processing Related to Irregular Sleep and Less Sustained Attention in Toddlers

    PubMed Central

    Hoyniak, Caroline P.; Petersen, Isaac T.; McQuillan, Maureen E.; Staples, Angela D.; Bates, John E.

    2015-01-01

    The current study used event-related potentials to examine a candidate process through which sleep difficulties affect attentional processing in toddlers. Fifteen toddlers participated in an auditory Oddball Task while neurophysiological data were collected. Sleep deficits were assessed using actigraphs, and attention was examined with a sustained attention task. A P3-like component was elicited from the toddlers, and longer target P3 latencies were associated with poorer sustained attention and irregular sleep. Findings suggest that irregular sleep is associated with less efficient attentional processing as reflected by the P3 component, and that longer target P3 latencies are associated with poorer sustained attention. PMID:26151613

  3. Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS)

    NASA Technical Reports Server (NTRS)

    Masek, Jeffrey G.

    2006-01-01

    The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) project is creating a record of forest disturbance and regrowth for North America from the Landsat satellite record, in support of the carbon modeling activities. LEDAPS relies on the decadal Landsat GeoCover data set supplemented by dense image time series for selected locations. Imagery is first atmospherically corrected to surface reflectance, and then change detection algorithms are used to extract disturbance area, type, and frequency. Reuse of the MODIS Land processing system (MODAPS) architecture allows rapid throughput of over 2200 MSS, TM, and ETM+ scenes. Initial ("Beta") surface reflectance products are currently available for testing, and initial continental disturbance products will be available by the middle of 2006.

  4. Parameter adaptive estimation of random processes

    NASA Technical Reports Server (NTRS)

    Caglayan, A. K.; Vanlandingham, H. F.

    1975-01-01

    This paper is concerned with the parameter adaptive least squares estimation of random processes. The main result is a general representation theorem for the conditional expectation of a random variable on a product probability space. Using this theorem along with the general likelihood ratio expression, the least squares estimate of the process is found in terms of the parameter conditioned estimates. The stochastic differential for the a posteriori probability and the stochastic differential equation for the a posteriori density are found by using simple stochastic calculus on the representations obtained. The results are specialized to the case when the parameter has a discrete distribution. The results can be used to construct an implementable recursive estimator for certain types of nonlinear filtering problems. This is illustrated by some simple examples.

  5. Irrelevant stimulus processing in ADHD: catecholamine dynamics and attentional networks.

    PubMed

    Aboitiz, Francisco; Ossandón, Tomás; Zamorano, Francisco; Palma, Bárbara; Carrasco, Ximena

    2014-01-01

    A cardinal symptom of attention deficit and hyperactivity disorder (ADHD) is a general distractibility where children and adults shift their attentional focus to stimuli that are irrelevant to the ongoing behavior. This has been attributed to a deficit in dopaminergic signaling in cortico-striatal networks that regulate goal-directed behavior. Furthermore, recent imaging evidence points to an impairment of large scale, antagonistic brain networks that normally contribute to attentional engagement and disengagement, such as the task-positive networks and the default mode network (DMN). Related networks are the ventral attentional network (VAN) involved in attentional shifting, and the salience network (SN) related to task expectancy. Here we discuss the tonic-phasic dynamics of catecholaminergic signaling in the brain, and attempt to provide a link between this and the activities of the large-scale cortical networks that regulate behavior. More specifically, we propose that a disbalance of tonic catecholamine levels during task performance produces an emphasis of phasic signaling and increased excitability of the VAN, yielding distractibility symptoms. Likewise, immaturity of the SN may relate to abnormal tonic signaling and an incapacity to build up a proper executive system during task performance. We discuss different lines of evidence including pharmacology, brain imaging and electrophysiology, that are consistent with our proposal. Finally, restoring the pharmacodynamics of catecholaminergic signaling seems crucial to alleviate ADHD symptoms; however, the possibility is open to explore cognitive rehabilitation strategies to top-down modulate network dynamics compensating the pharmacological deficits.

  6. Irrelevant stimulus processing in ADHD: catecholamine dynamics and attentional networks

    PubMed Central

    Aboitiz, Francisco; Ossandón, Tomás; Zamorano, Francisco; Palma, Bárbara; Carrasco, Ximena

    2014-01-01

    A cardinal symptom of attention deficit and hyperactivity disorder (ADHD) is a general distractibility where children and adults shift their attentional focus to stimuli that are irrelevant to the ongoing behavior. This has been attributed to a deficit in dopaminergic signaling in cortico-striatal networks that regulate goal-directed behavior. Furthermore, recent imaging evidence points to an impairment of large scale, antagonistic brain networks that normally contribute to attentional engagement and disengagement, such as the task-positive networks and the default mode network (DMN). Related networks are the ventral attentional network (VAN) involved in attentional shifting, and the salience network (SN) related to task expectancy. Here we discuss the tonic–phasic dynamics of catecholaminergic signaling in the brain, and attempt to provide a link between this and the activities of the large-scale cortical networks that regulate behavior. More specifically, we propose that a disbalance of tonic catecholamine levels during task performance produces an emphasis of phasic signaling and increased excitability of the VAN, yielding distractibility symptoms. Likewise, immaturity of the SN may relate to abnormal tonic signaling and an incapacity to build up a proper executive system during task performance. We discuss different lines of evidence including pharmacology, brain imaging and electrophysiology, that are consistent with our proposal. Finally, restoring the pharmacodynamics of catecholaminergic signaling seems crucial to alleviate ADHD symptoms; however, the possibility is open to explore cognitive rehabilitation strategies to top-down modulate network dynamics compensating the pharmacological deficits. PMID:24723897

  7. Irrelevant stimulus processing in ADHD: catecholamine dynamics and attentional networks.

    PubMed

    Aboitiz, Francisco; Ossandón, Tomás; Zamorano, Francisco; Palma, Bárbara; Carrasco, Ximena

    2014-01-01

    A cardinal symptom of attention deficit and hyperactivity disorder (ADHD) is a general distractibility where children and adults shift their attentional focus to stimuli that are irrelevant to the ongoing behavior. This has been attributed to a deficit in dopaminergic signaling in cortico-striatal networks that regulate goal-directed behavior. Furthermore, recent imaging evidence points to an impairment of large scale, antagonistic brain networks that normally contribute to attentional engagement and disengagement, such as the task-positive networks and the default mode network (DMN). Related networks are the ventral attentional network (VAN) involved in attentional shifting, and the salience network (SN) related to task expectancy. Here we discuss the tonic-phasic dynamics of catecholaminergic signaling in the brain, and attempt to provide a link between this and the activities of the large-scale cortical networks that regulate behavior. More specifically, we propose that a disbalance of tonic catecholamine levels during task performance produces an emphasis of phasic signaling and increased excitability of the VAN, yielding distractibility symptoms. Likewise, immaturity of the SN may relate to abnormal tonic signaling and an incapacity to build up a proper executive system during task performance. We discuss different lines of evidence including pharmacology, brain imaging and electrophysiology, that are consistent with our proposal. Finally, restoring the pharmacodynamics of catecholaminergic signaling seems crucial to alleviate ADHD symptoms; however, the possibility is open to explore cognitive rehabilitation strategies to top-down modulate network dynamics compensating the pharmacological deficits. PMID:24723897

  8. Finding Relevant Items: Attentional Guidance Improves Visual Selection Processes

    NASA Astrophysics Data System (ADS)

    Stork, Sonja; Hild, Isabella; Wiesbeck, Mathey; Zaeh, Michael F.; Schubö, Anna

    In daily life and at work people are confronted with complex information. Especially elderly or disabled users might be overburdened by the amount of information and distracted by irrelevant items. Due to this, they possibly fail to find and select relevant items in visual search. This could be demotivating for the use of media like the internet or could result in an inability to achieve certain job requirements. A method for supporting performance in visual search tasks is the guidance of attention. The present study compares different methods for attentional guidance. Results show a benefit for peripheral exogenous cues realized as luminance changes in comparison to endogenous central cues. Possible applications for the proposed attentional guidance method are discussed.

  9. Masking T1 Difficulty: Processing Time and the Attentional Blink

    ERIC Educational Resources Information Center

    Visser, Troy A. W.

    2007-01-01

    When observers are presented with 2 targets in rapid succession, identification of the 1st is highly accurate, whereas identification of the 2nd is impaired at brief intertarget intervals (i.e., 200-500 ms). This 2nd-target deficit is known as the attentional blink (AB). According to bottleneck models, the AB arises because attending to the 1st…

  10. The role of spatial attention in nonconscious processing: a comparison of face and nonface stimuli.

    PubMed

    Finkbeiner, Matthew; Palermo, Romina

    2009-01-01

    Recent findings from the masked priming paradigm have revealed a surprising influence of higher-level cognitive systems (i.e., attention) on nonconscious cognitive processes. These data have effectively undermined the long-standing assumption in cognitive science that nonconscious processes are carried out independently of attention and have quickly led to the opposite view that attention is a prerequisite for nonconscious processes. Here we present evidence for a middle position by showing that the dependence of nonconscious processes on attention varies with the type of information to be processed. Specifically, we found that nonconsciously perceived faces engaged cognitive processes regardless of attention, whereas nonface stimuli engaged cognitive processes only when attended. These qualitatively different patterns suggest two distinct processing routes: one that is modulated by visual attention and one that is not.

  11. The Urban Adaptation and Adaptation Process of Urban Migrant Children: A Qualitative Study

    ERIC Educational Resources Information Center

    Liu, Yang; Fang, Xiaoyi; Cai, Rong; Wu, Yang; Zhang, Yaofang

    2009-01-01

    This article employs qualitative research methods to explore the urban adaptation and adaptation processes of Chinese migrant children. Through twenty-one in-depth interviews with migrant children, the researchers discovered: The participant migrant children showed a fairly high level of adaptation to the city; their process of urban adaptation…

  12. Linearly-Constrained Adaptive Signal Processing Methods

    NASA Astrophysics Data System (ADS)

    Griffiths, Lloyd J.

    1988-01-01

    In adaptive least-squares estimation problems, a desired signal d(n) is estimated using a linear combination of L observation values samples xi (n), x2(n), . . . , xL-1(n) and denoted by the vector X(n). The estimate is formed as the inner product of this vector with a corresponding L-dimensional weight vector W. One particular weight vector of interest is Wopt which minimizes the mean-square between d(n) and the estimate. In this context, the term `mean-square difference' is a quadratic measure such as statistical expectation or time average. The specific value of W which achieves the minimum is given by the prod-uct of the inverse data covariance matrix and the cross-correlation between the data vector and the desired signal. The latter is often referred to as the P-vector. For those cases in which time samples of both the desired and data vector signals are available, a variety of adaptive methods have been proposed which will guarantee that an iterative weight vector Wa(n) converges (in some sense) to the op-timal solution. Two which have been extensively studied are the recursive least-squares (RLS) method and the LMS gradient approximation approach. There are several problems of interest in the communication and radar environment in which the optimal least-squares weight set is of interest and in which time samples of the desired signal are not available. Examples can be found in array processing in which only the direction of arrival of the desired signal is known and in single channel filtering where the spectrum of the desired response is known a priori. One approach to these problems which has been suggested is the P-vector algorithm which is an LMS-like approximate gradient method. Although it is easy to derive the mean and variance of the weights which result with this algorithm, there has never been an identification of the corresponding underlying error surface which the procedure searches. The purpose of this paper is to suggest an alternative

  13. A Unique Role of Endogenous Visual-Spatial Attention in Rapid Processing of Multiple Targets

    ERIC Educational Resources Information Center

    Guzman-Martinez, Emmanuel; Grabowecky, Marcia; Palafox, German; Suzuki, Satoru

    2011-01-01

    Visual spatial attention can be exogenously captured by a salient stimulus or can be endogenously allocated by voluntary effort. Whether these two attention modes serve distinctive functions is debated, but for processing of single targets the literature suggests superiority of exogenous attention (it is faster acting and serves more functions).…

  14. Dynamic Motivational Processing of Antimarijuana Messages: Coactivation Begets Attention

    ERIC Educational Resources Information Center

    Wang, Zheng; Solloway, Tyler; Tchernev, John M.; Barker, Bethany

    2012-01-01

    In the theoretical framework of dynamic motivational activation, this study reveals the dynamics of antimarijuana public service announcement (PSA) processing, especially the processing of co-occurring positive and negative content. It specifies the important role of endogenous feedback dynamics of the information processing system and teases them…

  15. Not so different after all: The same oscillatory processes support different types of attention.

    PubMed

    Frey, Julia Natascha; Ruhnau, Philipp; Weisz, Nathan

    2015-11-11

    Scientific research from the last two decades has provided a vast amount of evidence that brain oscillations reflect physiological activity enabling diverse cognitive processes. The goal of this review is to give a broad empirical and conceptual overview of how ongoing oscillatory activity may support attention processes. Keeping in mind that definitions of cognitive constructs like attention are prone to being blurry and ambiguous, the present review focuses mainly on the neural correlates of 'top-down' attention deployment. In particular, we will discuss modulations of (ongoing) oscillatory activity during spatial, temporal, selective, and internal attention. Across these seemingly distinct attentional domains, we will summarize studies showing the involvement of two oscillatory processes observed during attention deployment: power modulations mainly in the alpha band, and phase modulations in lower frequency bands. This article is part of a Special Issue entitled SI: Prediction and Attention.

  16. Not so different after all: The same oscillatory processes support different types of attention.

    PubMed

    Frey, Julia Natascha; Ruhnau, Philipp; Weisz, Nathan

    2015-11-11

    Scientific research from the last two decades has provided a vast amount of evidence that brain oscillations reflect physiological activity enabling diverse cognitive processes. The goal of this review is to give a broad empirical and conceptual overview of how ongoing oscillatory activity may support attention processes. Keeping in mind that definitions of cognitive constructs like attention are prone to being blurry and ambiguous, the present review focuses mainly on the neural correlates of 'top-down' attention deployment. In particular, we will discuss modulations of (ongoing) oscillatory activity during spatial, temporal, selective, and internal attention. Across these seemingly distinct attentional domains, we will summarize studies showing the involvement of two oscillatory processes observed during attention deployment: power modulations mainly in the alpha band, and phase modulations in lower frequency bands. This article is part of a Special Issue entitled SI: Prediction and Attention. PMID:25721788

  17. Flood adaptive traits and processes: an overview.

    PubMed

    Voesenek, Laurentius A C J; Bailey-Serres, Julia

    2015-04-01

    Unanticipated flooding challenges plant growth and fitness in natural and agricultural ecosystems. Here we describe mechanisms of developmental plasticity and metabolic modulation that underpin adaptive traits and acclimation responses to waterlogging of root systems and submergence of aerial tissues. This includes insights into processes that enhance ventilation of submerged organs. At the intersection between metabolism and growth, submergence survival strategies have evolved involving an ethylene-driven and gibberellin-enhanced module that regulates growth of submerged organs. Opposing regulation of this pathway is facilitated by a subgroup of ethylene-response transcription factors (ERFs), which include members that require low O₂ or low nitric oxide (NO) conditions for their stabilization. These transcription factors control genes encoding enzymes required for anaerobic metabolism as well as proteins that fine-tune their function in transcription and turnover. Other mechanisms that control metabolism and growth at seed, seedling and mature stages under flooding conditions are reviewed, as well as findings demonstrating that true endurance of submergence includes an ability to restore growth following the deluge. Finally, we highlight molecular insights obtained from natural variation of domesticated and wild species that occupy different hydrological niches, emphasizing the value of understanding natural flooding survival strategies in efforts to stabilize crop yields in flood-prone environments.

  18. Demand and Modality of Directed Attention Modulate “Pre-attentive” Sensory Processes in Schizophrenia Patients and Nonpsychiatric Controls

    PubMed Central

    Rissling, Anthony J.; Park, Sung-Hyouk; Young, Jared W.; Rissling, Michelle B.; Sugar, Catherine A.; Sprock, Joyce; Mathias, Daniel J.; Pela, Marlena; Sharp, Richard F.; Braff, David L.; Light, Gregory A.

    2013-01-01

    Background Mismatch negativity (MNN) and P3a are event related potential (ERP) measures of early sensory information processing. These components are usually conceptualized as being “pre-attentive” and therefore immune to changes with variations in attentional functioning. This study aimed to determine whether manipulations of attention influence the amplitudes and latencies of MMN and P3a and, if so, the extent to which these early sensory processes govern concurrent behavioral vigilance performance in schizophrenia patients and normal subjects. Methods Schizophrenia patients (SZ; n=20) and Nonpsychiatric Control Subjects (NCS; n=20) underwent auditory ERP testing to assess MMN and P3a across 4 EEG recording sessions in which attentional demand (low vs. high) and sensory modality of directed attention (visual vs. auditory) were experimentally varied. Results Across conditions, SZ patients exhibited deficits in MMN and P3a amplitudes. Significant amplitude and latency modulation were observed in both SZ and NCS but there were no group-by- condition interactions. The amount of MMN amplitude attenuation from low- to-high-demand tasks was significantly associated with increased vigilance performance in both SZ and NCS groups (r=-0.67 and r=-0.60). Conclusions Attentional demand and modality of directed attention significantly influence the amplitude and latencies of “pre-attentive” ERP components in both SZ and NCS. Deficits in MMN and P3a were not “normalized” when attention was directed to the auditory stimuli in schizophrenia patients. The adaptive modulation of early sensory information processing appears to govern concurrent attentional task performance. MMN and P3a may serve as a gateway to some higher order cognitive operations necessary for psychosocial functioning. PMID:23490760

  19. Attentional Processes in Children's Learning. Appendix A: Project Papers.

    ERIC Educational Resources Information Center

    White, Sheldon H.

    This appendix includes seven papers which focus on various aspects of the learning processes of children ages 5-7: (1) S. Thompson, "Transitions to concrete operations: A survey of Piaget's writings" (in outline form); (2) S. H. White, "Changes in learning processes in the late preschool years," an examination of cross-cultural evidence of…

  20. Adaptive, predictive controller for optimal process control

    SciTech Connect

    Brown, S.K.; Baum, C.C.; Bowling, P.S.; Buescher, K.L.; Hanagandi, V.M.; Hinde, R.F. Jr.; Jones, R.D.; Parkinson, W.J.

    1995-12-01

    One can derive a model for use in a Model Predictive Controller (MPC) from first principles or from experimental data. Until recently, both methods failed for all but the simplest processes. First principles are almost always incomplete and fitting to experimental data fails for dimensions greater than one as well as for non-linear cases. Several authors have suggested the use of a neural network to fit the experimental data to a multi-dimensional and/or non-linear model. Most networks, however, use simple sigmoid functions and backpropagation for fitting. Training of these networks generally requires large amounts of data and, consequently, very long training times. In 1993 we reported on the tuning and optimization of a negative ion source using a special neural network[2]. One of the properties of this network (CNLSnet), a modified radial basis function network, is that it is able to fit data with few basis functions. Another is that its training is linear resulting in guaranteed convergence and rapid training. We found the training to be rapid enough to support real-time control. This work has been extended to incorporate this network into an MPC using the model built by the network for predictive control. This controller has shown some remarkable capabilities in such non-linear applications as continuous stirred exothermic tank reactors and high-purity fractional distillation columns[3]. The controller is able not only to build an appropriate model from operating data but also to thin the network continuously so that the model adapts to changing plant conditions. The controller is discussed as well as its possible use in various of the difficult control problems that face this community.

  1. [Cyclic interactions in the processes of adaptation regulation].

    PubMed

    Vasilevskiĭ, N N; Aleksandrova, Zh G; Suvorov, N B

    1989-01-01

    Human adaptation is characterised by essential changes of functional systems biorhythms which appears in the changes of their components' sequence and in the dynamics of biorhythmological cycles. These objective laws, having been described for human EEG, allow to discern clearly the individual-typological peculiarities in man with different stages of adaptation, the same as the adaptive shifts during long-term influence of external factors. The cyclic course of adaptative processes is regarded as a measure of adaptability. With the help of biorhythmic multitude the memory is constantly satiated from the brain by discrete portions of adaptogenic information, which prevents the natural processes of the memory disintegration. PMID:2816008

  2. Reduced attentional capacity, but normal processing speed and shifting of attention in developmental dyslexia: evidence from a serial task.

    PubMed

    Romani, Cristina; Tsouknida, Effie; di Betta, Anna M; Olson, Andrew

    2011-06-01

    We report the performance of a group of adult dyslexics and matched controls in an array-matching task where two strings of either consonants or symbols are presented side by side and have to be judged to be the same or different. The arrays may differ either in the order or identity of two adjacent characters. This task does not require naming - which has been argued to be the cause of dyslexics' difficulty in processing visual arrays - but, instead, has a strong serial component as demonstrated by the fact that, in both groups, Reaction times (RTs) increase monotonically with position of a mismatch. The dyslexics are clearly impaired in all conditions and performance in the identity conditions predicts performance across orthographic tasks even after age, performance IQ and phonology are partialled out. Moreover, the shapes of serial position curves are revealing of the underlying impairment. In the dyslexics, RTs increase with position at the same rate as in the controls (lines are parallel) ruling out reduced processing speed or difficulties in shifting attention. Instead, error rates show a catastrophic increase for positions which are either searched later or more subject to interference. These results are consistent with a reduction in the attentional capacity needed in a serial task to bind together identity and positional information. This capacity is best seen as a reduction in the number of spotlights into which attention can be split to process information at different locations rather than as a more generic reduction of resources which would also affect processing the details of single objects.

  3. A Parallel and Distributed Processing Model of Joint Attention, Social-Cognition and Autism

    PubMed Central

    Mundy, Peter; Sullivan, Lisa; Mastergeorge, Ann M.

    2009-01-01

    Scientific Abstract The impaired development of joint attention is a cardinal feature of autism. Therefore, understanding the nature of joint attention is a central to research on this disorder. Joint attention may be best defined in terms of an information processing system that begins to develop by 4–6 months of age. This system integrates the parallel processing of internal information about one’s own visual attention with external information about the visual attention of other people. This type of joint encoding of information about self and other attention requires the activation of a distributed anterior and posterior cortical attention network. Genetic regulation, in conjunction with self-organizing behavioral activity guides the development of functional connectivity in this network. With practice in infancy the joint processing of self-other attention becomes automatically engaged as an executive function. It can be argued that this executive joint-attention is fundamental to human learning, as well as the development of symbolic thought, social-cognition and social-competence throughout the life span. One advantage of this parallel and distributed processing model of joint attention (PDPM) is that it directly connects theory on social pathology to a range of phenomenon in autism associated with neural connectivity, constructivist and connectionist models of cognitive development, early intervention, activity-dependent gene expression, and atypical ocular motor control. PMID:19358304

  4. Modular and Adaptive Control of Sound Processing

    NASA Astrophysics Data System (ADS)

    van Nort, Douglas

    parameters. In this view, desired gestural dynamics and sonic response are achieved through modular construction of mapping layers that are themselves subject to parametric control. Complementing this view of the design process, the work concludes with an approach in which the creation of gestural control/sound dynamics are considered in the low-level of the underlying sound model. The result is an adaptive system that is specialized to noise-based transformations that are particularly relevant in an electroacoustic music context. Taken together, these different approaches to design and evaluation result in a unified framework for creation of an instrumental system. The key point is that this framework addresses the influence that mapping structure and control dynamics have on the perceived feel of the instrument. Each of the results illustrate this using either top-down or bottom-up approaches that consider musical control context, thereby pointing to the greater potential for refined sonic articulation that can be had by combining them in the design process.

  5. Is There a Common Linkage among Reading Comprehension, Visual Attention, and Magnocellular Processing?

    ERIC Educational Resources Information Center

    Solan, Harold A.; Shelley-Tremblay, John F.; Hansen, Peter C.; Larson, Steven

    2007-01-01

    The authors examined the relationships between reading comprehension, visual attention, and magnocellular processing in 42 Grade 7 students. The goal was to quantify the sensitivity of visual attention and magnocellular visual processing as concomitants of poor reading comprehension in the absence of either vision therapy or cognitive…

  6. Cueing Complex Animations: Does Direction of Attention Foster Learning Processes?

    ERIC Educational Resources Information Center

    Lowe, Richard; Boucheix, Jean-Michel

    2011-01-01

    The time course of learners' processing of a complex animation was studied using a dynamic diagram of a piano mechanism. Over successive repetitions of the material, two forms of cueing (standard colour cueing and anti-cueing) were administered either before or during the animated segment of the presentation. An uncued group and two other control…

  7. Quantitative genetic study of the adaptive process.

    PubMed

    Shaw, R G; Shaw, F H

    2014-01-01

    The additive genetic variance with respect to absolute fitness, VA(W), divided by mean absolute fitness, , sets the rate of ongoing adaptation. Fisher's key insight yielding this quantitative prediction of adaptive evolution, known as the Fundamental Theorem of Natural Selection, is well appreciated by evolutionists. Nevertheless, extremely scant information about VA(W) is available for natural populations. Consequently, the capacity for fitness increase via natural selection is unknown. Particularly in the current context of rapid environmental change, which is likely to reduce fitness directly and, consequently, the size and persistence of populations, the urgency of advancing understanding of immediate adaptive capacity is extreme. We here explore reasons for the dearth of empirical information about VA(W), despite its theoretical renown and critical evolutionary role. Of these reasons, we suggest that expectations that VA(W) is negligible, in general, together with severe statistical challenges of estimating it, may largely account for the limited empirical emphasis on it. To develop insight into the dynamics of VA(W) in a changing environment, we have conducted individual-based genetically explicit simulations. We show that, as optimizing selection on a trait changes steadily over generations, VA(W) can grow considerably, supporting more rapid adaptation than would the VA(W) of the base population. We call for direct evaluation of VA(W) and in support of prediction of rates adaptive evolution, and we advocate for the use of aster modeling as a rigorous basis for achieving this goal.

  8. Differentiating allocation of resources and conflict detection within attentional control processing.

    PubMed

    Blasi, Giuseppe; Goldberg, Terry E; Elvevåg, Brita; Rasetti, Roberta; Bertolino, Alessandro; Cohen, Jessica; Alce, Guilna; Zoltick, Brad; Weinberger, Daniel R; Mattay, Venkata S

    2007-01-01

    Increasing demands for conflict detection and for allocation of attentional resources increase the need for attentional control. While prior evidence suggests that different cortical regions are preferentially engaged by these two attentional processes, the effect of increasing demand for conflict detection and/or allocation of attentional resources has been relatively unexplored. We designed a novel task (the 'variable attentional control'--VAC--task) that varies the demand for attentional control by increasing conflict detection and allocation of attentional resources within the same stimuli. We studied 34 subjects who underwent event-related functional magnetic resonance imaging while performing the VAC task. Increasing demand for attentional control, as reflected by longer reaction time and reduced accuracy, was associated with greater activation in the dorsolateral prefrontal cortex, parietal cortex and dorsal cingulate. Furthermore, an increase in conflict detection was associated with greater dorsal cingulate activity, whereas an increase in demand for allocation of attentional resources implied greater activation in the dorsolateral prefrontal and parietal cortices. In essence, in addition to allowing the exploration of the overall effects of increasing demand for attentional control, our novel task also allowed parsing of the neural components of attentional control into those related to allocation of attentional resources and those related to conflict detection.

  9. Electroencephalograph (EEG) signal processing method of motor imaginary potential for attention level classification.

    PubMed

    Ming, Dong; Xi, Youyuan; Zhang, Mingming; Qi, Hongzhi; Cheng, Longlong; Wan, Baikun; Li, Liyong

    2009-01-01

    Research of visual attention is one of the important domains of psychology and neurophysiology. In this study, an attention related electroencephalograph (EEG) signal processing method was proposed to distinguish the different levels of people's attention during the imaginary limbs motor. There were two EEG feedback experiments (playing tennis and walking) to measure the different levels of visual attention. Three imaginary motor tasks (attention, inattention, and rest task) were performed with the flash stimulus displayed on the screen in the experiments. A nonlinear dynamics parameter of multi-scale entropy (MSE) was extracted from those EEG data recorded. According to the statistics analysis of 14 subjects, there was an obvious declining tendency of MSE with the level of attention declining, which validated the effectiveness of the proposed method to classify the visual attention level.

  10. Anxiety modulates the degree of attentive resources required to process emotional faces.

    PubMed

    Fox, Elaine; Russo, Riccardo; Georgiou, George A

    2005-12-01

    The present study contributes to the ongoing debate over the extent to which attentive resources are required for emotion perception. Although fearful facial expressions are strong competitors for attention, we predict that the magnitude of this effect may be modulated by anxiety. To test this hypothesis, healthy volunteers who varied in their self-reported levels of trait and state anxiety underwent an attentional blink task. Both fearful and happy facial expressions were subject to a strong attentional blink effect for low-anxious individuals. For those reporting high anxiety, a blink occurred for both fearful and happy facial expressions, but the magnitude of the attentional blink was significantly reduced for the fearful expressions. This supports the proposals that emotion perception is not fully automatic and that anxiety is related to a reduced ability to inhibit the processing of threat-related stimuli. Thus, individual differences in self-reported anxiety are an important determinant of the attentional control of emotional processing.

  11. A systematic process for adaptive concept exploration

    NASA Astrophysics Data System (ADS)

    Nixon, Janel Nicole

    several common challenges to the creation of quantitative modeling and simulation environments. Namely, a greater number of alternative solutions imply a greater number of design variables as well as larger ranges on those variables. This translates to a high-dimension combinatorial problem. As the size and dimensionality of the solution space gets larger, the number of physically impossible solutions within that space greatly increases. Thus, the ratio of feasible design space to infeasible space decreases, making it much harder to not only obtain a good quantitative sample of the space, but to also make sense of that data. This is especially the case in the early stages of design, where it is not practical to dedicate a great deal of resources to performing thorough, high-fidelity analyses on all the potential solutions. To make quantitative analyses feasible in these early stages of design, a method is needed that allows for a relatively sparse set of information to be collected quickly and efficiently, and yet, that information needs to be meaningful enough with which to base a decision. The method developed to address this need uses a Systematic Process for Adaptive Concept Exploration (SPACE). In the SPACE method, design space exploration occurs in a sequential fashion; as data is acquired, the sampling scheme adapts to the specific problem at hand. Previously gathered data is used to make inferences about the nature of the problem so that future samples can be taken from the more interesting portions of the design space. Furthermore, the SPACE method identifies those analyses that have significant impacts on the relationships being modeled, so that effort can be focused on acquiring only the most pertinent information. The SPACE method uses a four-part sampling scheme to efficiently uncover the parametric relationships between the design variables and responses. Step 1 aims to identify the location of infeasible space within the region of interest using an initial

  12. Adaptive mesh refinement for stochastic reaction-diffusion processes

    SciTech Connect

    Bayati, Basil; Chatelain, Philippe; Koumoutsakos, Petros

    2011-01-01

    We present an algorithm for adaptive mesh refinement applied to mesoscopic stochastic simulations of spatially evolving reaction-diffusion processes. The transition rates for the diffusion process are derived on adaptive, locally refined structured meshes. Convergence of the diffusion process is presented and the fluctuations of the stochastic process are verified. Furthermore, a refinement criterion is proposed for the evolution of the adaptive mesh. The method is validated in simulations of reaction-diffusion processes as described by the Fisher-Kolmogorov and Gray-Scott equations.

  13. [Molecular genetic bases of adaptation processes and approaches to their analysis].

    PubMed

    Salmenkova, E A

    2013-01-01

    Great interest in studying the molecular genetic bases of the adaptation processes is explained by their importance in understanding evolutionary changes, in the development ofintraspecific and interspecific genetic diversity, and in the creation of approaches and programs for maintaining and restoring the population. The article examines the sources and conditions for generating adaptive genetic variability and contribution of neutral and adaptive genetic variability to the population structure of the species; methods for identifying the adaptive genetic variability on the genome level are also described. Considerable attention is paid to the potential of new technologies of genome analysis, including next-generation sequencing and some accompanying methods. In conclusion, the important role of the joint use of genomics and proteomics approaches in understanding the molecular genetic bases of adaptation is emphasized.

  14. The pupil response is sensitive to divided attention during speech processing.

    PubMed

    Koelewijn, Thomas; Shinn-Cunningham, Barbara G; Zekveld, Adriana A; Kramer, Sophia E

    2014-06-01

    Dividing attention over two streams of speech strongly decreases performance compared to focusing on only one. How divided attention affects cognitive processing load as indexed with pupillometry during speech recognition has so far not been investigated. In 12 young adults the pupil response was recorded while they focused on either one or both of two sentences that were presented dichotically and masked by fluctuating noise across a range of signal-to-noise ratios. In line with previous studies, the performance decreases when processing two target sentences instead of one. Additionally, dividing attention to process two sentences caused larger pupil dilation and later peak pupil latency than processing only one. This suggests an effect of attention on cognitive processing load (pupil dilation) during speech processing in noise. PMID:24709275

  15. Processing of masked and unmasked emotional faces under different attentional conditions: an electrophysiological investigation

    PubMed Central

    Zotto, Marzia Del; Pegna, Alan J.

    2015-01-01

    In order to investigate the interactions between non-spatial selective attention, awareness and emotion processing, we carried out an ERP study using a backward masking paradigm, in which angry, fearful, happy, and neutral facial expressions were presented, while participants attempted to detect the presence of one or the other category of facial expressions in the different experimental blocks. ERP results showed that negative emotions enhanced an early N170 response over temporal-occipital leads in both masked and unmasked conditions, independently of selective attention. A later effect arising at the P2 was linked to awareness. Finally, selective attention was found to affect the N2 and N3 components over occipito-parietal leads. Our findings reveal that (i) the initial processing of facial expressions arises prior to attention and awareness; (ii) attention and awareness give rise to temporally distinct periods of activation independently of the type of emotion with only a partial degree of overlap; and (iii) selective attention appears to be influenced by the emotional nature of the stimuli, which in turn impinges on unconscious processing at a very early stage. This study confirms previous reports that negative facial expressions can be processed rapidly, in absence of visual awareness and independently of selective attention. On the other hand, attention and awareness may operate in a synergistic way, depending on task demand. PMID:26583003

  16. Auditory Working Memory Load Impairs Visual Ventral Stream Processing: Toward a Unified Model of Attentional Load

    ERIC Educational Resources Information Center

    Klemen, Jane; Buchel, Christian; Buhler, Mira; Menz, Mareike M.; Rose, Michael

    2010-01-01

    Attentional interference between tasks performed in parallel is known to have strong and often undesired effects. As yet, however, the mechanisms by which interference operates remain elusive. A better knowledge of these processes may facilitate our understanding of the effects of attention on human performance and the debilitating consequences…

  17. Selective and divided attention modulates auditory-vocal integration in the processing of pitch feedback errors.

    PubMed

    Liu, Ying; Hu, Huijing; Jones, Jeffery A; Guo, Zhiqiang; Li, Weifeng; Chen, Xi; Liu, Peng; Liu, Hanjun

    2015-08-01

    Speakers rapidly adjust their ongoing vocal productions to compensate for errors they hear in their auditory feedback. It is currently unclear what role attention plays in these vocal compensations. This event-related potential (ERP) study examined the influence of selective and divided attention on the vocal and cortical responses to pitch errors heard in auditory feedback regarding ongoing vocalisations. During the production of a sustained vowel, participants briefly heard their vocal pitch shifted up two semitones while they actively attended to auditory or visual events (selective attention), or both auditory and visual events (divided attention), or were not told to attend to either modality (control condition). The behavioral results showed that attending to the pitch perturbations elicited larger vocal compensations than attending to the visual stimuli. Moreover, ERPs were likewise sensitive to the attentional manipulations: P2 responses to pitch perturbations were larger when participants attended to the auditory stimuli compared to when they attended to the visual stimuli, and compared to when they were not explicitly told to attend to either the visual or auditory stimuli. By contrast, dividing attention between the auditory and visual modalities caused suppressed P2 responses relative to all the other conditions and caused enhanced N1 responses relative to the control condition. These findings provide strong evidence for the influence of attention on the mechanisms underlying the auditory-vocal integration in the processing of pitch feedback errors. In addition, selective attention and divided attention appear to modulate the neurobehavioral processing of pitch feedback errors in different ways.

  18. Acute physical exercise affected processing efficiency in an auditory attention task more than processing effectiveness.

    PubMed

    Dutke, Stephan; Jaitner, Thomas; Berse, Timo; Barenberg, Jonathan

    2014-02-01

    Research on effects of acute physical exercise on performance in a concurrent cognitive task has generated equivocal evidence. Processing efficiency theory predicts that concurrent physical exercise can increase resource requirements for sustaining cognitive performance even when the level of performance is unaffected. This hypothesis was tested in a dual-task experiment. Sixty young adults worked on a primary auditory attention task and a secondary interval production task while cycling on a bicycle ergometer. Physical load (cycling) and cognitive load of the primary task were manipulated. Neither physical nor cognitive load affected primary task performance, but both factors interacted on secondary task performance. Sustaining primary task performance under increased physical and/or cognitive load increased resource consumption as indicated by decreased secondary task performance. Results demonstrated that physical exercise effects on cognition might be underestimated when only single task performance is the focus.

  19. Adaptation to Leftward-shifting Prisms Enhances Local Processing in Healthy Individuals

    PubMed Central

    Reed, Scott A.; Dassonville, Paul

    2014-01-01

    In healthy individuals, adaptation to left-shifting prisms has been shown to simulate the symptoms of hemispatial neglect, including a reduction in global processing that approximates the local bias observed in neglect patients. The current study tested whether leftward prism adaptation can more specifically enhance local processing abilities. In three experiments, the impact of local and global processing was assessed through tasks that measure susceptibility to illusions that are known to be driven by local or global contextual effects. Susceptibility to the rod-and-frame illusion – an illusion disproportionately driven by both local and global effects depending on frame size – was measured before and after adaptation to left- and right-shifting prisms. A significant increase in rod-and-frame susceptibility was found for the left-shifting prism group, suggesting that adaptation caused an increase in local processing effects. The results of a second experiment confirmed that leftward prism adaptation enhances local processing, as assessed with susceptibility to the simultaneous-tilt illusion. A final experiment employed a more specific measure of the global effect typically associated with the rod-andframe illusion, and found that although the global effect was somewhat diminished after leftward prism adaptation, the trend failed to reach significance (p = .078). Rightward prism adaptation had no significant effects on performance in any of the experiments. Combined, these findings indicate that leftward prism adaptation in healthy individuals can simulate the local processing bias of neglect patients primarily through an increased sensitivity to local visual cues, and confirm that prism adaptation not only modulates lateral shifts of attention, but also prompts shifts from one level of processing to another. PMID:24560913

  20. Adaptation to leftward-shifting prisms enhances local processing in healthy individuals.

    PubMed

    Reed, Scott A; Dassonville, Paul

    2014-04-01

    In healthy individuals, adaptation to left-shifting prisms has been shown to simulate the symptoms of hemispatial neglect, including a reduction in global processing that approximates the local bias observed in neglect patients. The current study tested whether leftward prism adaptation can more specifically enhance local processing abilities. In three experiments, the impact of local and global processing was assessed through tasks that measure susceptibility to illusions that are known to be driven by local or global contextual effects. Susceptibility to the rod-and-frame illusion - an illusion disproportionately driven by both local and global effects depending on frame size - was measured before and after adaptation to left- and right-shifting prisms. A significant increase in rod-and-frame susceptibility was found for the left-shifting prism group, suggesting that adaptation caused an increase in local processing effects. The results of a second experiment confirmed that leftward prism adaptation enhances local processing, as assessed with susceptibility to the simultaneous-tilt illusion. A final experiment employed a more specific measure of the global effect typically associated with the rod-and-frame illusion, and found that although the global effect was somewhat diminished after leftward prism adaptation, the trend failed to reach significance (p=.078). Rightward prism adaptation had no significant effects on performance in any of the experiments. Combined, these findings indicate that leftward prism adaptation in healthy individuals can simulate the local processing bias of neglect patients primarily through an increased sensitivity to local visual cues, and confirm that prism adaptation not only modulates lateral shifts of attention, but also prompts shifts from one level of processing to another.

  1. Independent Sampling vs Interitem Dependencies in Whole Report Processing: Contributions of Processing Architecture and Variable Attention.

    PubMed

    Busey, Thomas A.; Townsend, James T.

    2001-04-01

    All current models of visual whole report processing assume perceptual independence among the displayed items in which the perceptual processing of individual items is not affected by other items in the display. However, models proposed by Townsend (1981, Acta Psychologica 47, 149-173), Shibuya and Bundesen (1988, Journal of Experimental Psychology: Human Perception and Performance 14, 591-600), and Bundesen (1990, Psychological Review 97, 523-547) contain postperceptual buffers that must predict negative dependencies. The perceptual-independence assumption forms what we term the modal model class. A recent example of a model that assumes perceptual independence is the Independent Sampling Model of Loftus, Busey, and Senders (1993, Perception and Psychophysics 54, 535-554). The fundamental independence assumption has only been directly tested once before, where tests revealed no dependencies except those produced by guessing. The present study tests the independence assumption using several different statistics and, contrary to most extant models of whole report, finds significant positive dependence. Poisson models do predict a positive dependence and we develop a succinctly parameterized version, the Weighted Path Poisson Model, which allows the finishing order to be a weighted probabilistic mechanism. However, it does not predict the data quite as well as a new model, the Variable Attention Model, which allows independence within trials (unlike the Poisson models). This model assumes that attention (or, potentially, other aspects such as signal quality) varies widely across trials, thus predicting an overall positive dependence. Intuitions for and against the competing models are discussed. In addition, we show, through mimicking formulae, that models which contain the proper qualitative type of dependence structure can be cast in either serial or parallel form. Copyright 2001 Academic Press.

  2. Adaptive Diagrams: Handing Control over to the Learner to Manage Split-Attention Online

    ERIC Educational Resources Information Center

    Agostinho, Shirley; Tindall-Ford, Sharon; Roodenrys, Kylie

    2013-01-01

    Based on cognitive load theory, it is well known that when studying a diagram that includes explanatory text, optimal learning occurs when the text is physically positioned close to the diagram as it eliminates the need for learners to split their attention between the two sources of information. What is not known is the effect on learning when…

  3. Deficits in attentional processing of fearful facial expressions in schizophrenic patients.

    PubMed

    Liu, Yunzhe; Zhang, Dandan; Zhao, Yanli; Tan, Shuping; Luo, Yuejia

    2016-01-01

    Impaired attentional processing of negative facial expressions is prominent in schizophrenia and has been shown to be associated with patients' social dysfunctions. However, little is known about when and which specific attention deficits influence social functions. Given the dynamic feature of attention, it is necessary to investigate the attention deficits in negative emotional processing unfolding in time. The current study used event-related potentials (ERPs) to investigate the temporal dynamics of attention deficits in emotion perception and their potential relationship with emotional/social impairments in neuroleptic naive schizophrenic patients. Two specific attention deficits were identified and were found to be associated with emotional/social impairments. More specifically, the deficit in orienting attention (evidenced with the reduced P1 amplitude) was correlated with expressive deficits, while the deficit in executive control of attention (evidenced with the reduced P3 amplitude) was correlated with avolition/asociality. Together, these findings may provide novel insights into the core pathophysiological processes and offer objective biomarkers for specific emotional/social impairments in schizophrenia. It is also hoped that this study helps to bridge the gap between basic cognitive deficits and relative high-level social dysfunctions in schizophrenic patients. PMID:27586404

  4. Deficits in attentional processing of fearful facial expressions in schizophrenic patients

    PubMed Central

    Liu, Yunzhe; Zhang, Dandan; Zhao, Yanli; Tan, Shuping; Luo, Yuejia

    2016-01-01

    Impaired attentional processing of negative facial expressions is prominent in schizophrenia and has been shown to be associated with patients’ social dysfunctions. However, little is known about when and which specific attention deficits influence social functions. Given the dynamic feature of attention, it is necessary to investigate the attention deficits in negative emotional processing unfolding in time. The current study used event-related potentials (ERPs) to investigate the temporal dynamics of attention deficits in emotion perception and their potential relationship with emotional/social impairments in neuroleptic naive schizophrenic patients. Two specific attention deficits were identified and were found to be associated with emotional/social impairments. More specifically, the deficit in orienting attention (evidenced with the reduced P1 amplitude) was correlated with expressive deficits, while the deficit in executive control of attention (evidenced with the reduced P3 amplitude) was correlated with avolition/asociality. Together, these findings may provide novel insights into the core pathophysiological processes and offer objective biomarkers for specific emotional/social impairments in schizophrenia. It is also hoped that this study helps to bridge the gap between basic cognitive deficits and relative high-level social dysfunctions in schizophrenic patients. PMID:27586404

  5. Adaptive Processes in Thalamus and Cortex Revealed by Silencing of Primary Visual Cortex during Contrast Adaptation.

    PubMed

    King, Jillian L; Lowe, Matthew P; Stover, Kurt R; Wong, Aimee A; Crowder, Nathan A

    2016-05-23

    Visual adaptation illusions indicate that our perception is influenced not only by the current stimulus but also by what we have seen in the recent past. Adaptation to stimulus contrast (the relative luminance created by edges or contours in a scene) induces the perception of the stimulus fading away and increases the contrast detection threshold in psychophysical tests [1, 2]. Neural correlates of contrast adaptation have been described throughout the visual system including the retina [3], dorsal lateral geniculate nucleus (dLGN) [4, 5], primary visual cortex (V1) [6], and parietal cortex [7]. The apparent ubiquity of adaptation at all stages raises the question of how this process cascades across brain regions [8]. Focusing on V1, adaptation could be inherited from pre-cortical stages, arise from synaptic depression at the thalamo-cortical synapse [9], or develop locally, but what is the weighting of these contributions? Because contrast adaptation in mouse V1 is similar to classical animal models [10, 11], we took advantage of the optogenetic tools available in mice to disentangle the processes contributing to adaptation in V1. We disrupted cortical adaptation by optogenetically silencing V1 and found that adaptation measured in V1 now resembled that observed in dLGN. Thus, the majority of adaptation seen in V1 neurons arises through local activity-dependent processes, with smaller contributions from dLGN inheritance and synaptic depression at the thalamo-cortical synapse. Furthermore, modeling indicates that divisive scaling of the weakly adapted dLGN input can predict some of the emerging features of V1 adaptation.

  6. Adaptive Constructive Processes and the Future of Memory

    ERIC Educational Resources Information Center

    Schacter, Daniel L.

    2012-01-01

    Memory serves critical functions in everyday life but is also prone to error. This article examines adaptive constructive processes, which play a functional role in memory and cognition but can also produce distortions, errors, and illusions. The article describes several types of memory errors that are produced by adaptive constructive processes…

  7. Adaptive Noise Suppression Using Digital Signal Processing

    NASA Technical Reports Server (NTRS)

    Kozel, David; Nelson, Richard

    1996-01-01

    A signal to noise ratio dependent adaptive spectral subtraction algorithm is developed to eliminate noise from noise corrupted speech signals. The algorithm determines the signal to noise ratio and adjusts the spectral subtraction proportion appropriately. After spectra subtraction low amplitude signals are squelched. A single microphone is used to obtain both eh noise corrupted speech and the average noise estimate. This is done by determining if the frame of data being sampled is a voiced or unvoiced frame. During unvoice frames an estimate of the noise is obtained. A running average of the noise is used to approximate the expected value of the noise. Applications include the emergency egress vehicle and the crawler transporter.

  8. Adaptive Memory: Is Survival Processing Special?

    ERIC Educational Resources Information Center

    Nairne, James S.; Pandeirada, Josefa N. S.

    2008-01-01

    Do the operating characteristics of memory continue to bear the imprints of ancestral selection pressures? Previous work in our laboratory has shown that human memory may be specially tuned to retain information processed in terms of its survival relevance. A few seconds of survival processing in an incidental learning context can produce recall…

  9. The Role of Attention in Somatosensory Processing: A Multi-trait, Multi-method Analysis.

    PubMed

    Wodka, Ericka L; Puts, Nicolaas A J; Mahone, E Mark; Edden, Richard A E; Tommerdahl, Mark; Mostofsky, Stewart H

    2016-10-01

    Sensory processing abnormalities in autism have largely been described by parent report. This study used a multi-method (parent-report and measurement), multi-trait (tactile sensitivity and attention) design to evaluate somatosensory processing in ASD. Results showed multiple significant within-method (e.g., parent report of different traits)/cross-trait (e.g., attention and tactile sensitivity) correlations, suggesting that parent-reported tactile sensory dysfunction and performance-based tactile sensitivity describe different behavioral phenomena. Additionally, both parent-reported tactile functioning and performance-based tactile sensitivity measures were significantly associated with measures of attention. Findings suggest that sensory (tactile) processing abnormalities in ASD are multifaceted, and may partially reflect a more global deficit in behavioral regulation (including attention). Challenges of relying solely on parent-report to describe sensory difficulties faced by children/families with ASD are also highlighted.

  10. The Role of Attention in Somatosensory Processing: A Multi-trait, Multi-method Analysis

    PubMed Central

    Puts, Nicolaas A. J.; Mahone, E. Mark; Edden, Richard A. E.; Tommerdahl, Mark; Mostofsky, Stewart H.

    2016-01-01

    Sensory processing abnormalities in autism have largely been described by parent report. This study used a multi-method (parent-report and measurement), multi-trait (tactile sensitivity and attention) design to evaluate somatosensory processing in ASD. Results showed multiple significant within-method (e.g., parent report of different traits)/cross-trait (e.g., attention and tactile sensitivity) correlations, suggesting that parent-reported tactile sensory dysfunction and performance-based tactile sensitivity describe different behavioral phenomena. Additionally, both parent-reported tactile functioning and performance-based tactile sensitivity measures were significantly associated with measures of attention. Findings suggest that sensory (tactile) processing abnormalities in ASD are multifaceted, and may partially reflect a more global deficit in behavioral regulation (including attention). Challenges of relying solely on parent-report to describe sensory difficulties faced by children/families with ASD are also highlighted. PMID:27448580

  11. The Role of Attention in Somatosensory Processing: A Multi-trait, Multi-method Analysis.

    PubMed

    Wodka, Ericka L; Puts, Nicolaas A J; Mahone, E Mark; Edden, Richard A E; Tommerdahl, Mark; Mostofsky, Stewart H

    2016-10-01

    Sensory processing abnormalities in autism have largely been described by parent report. This study used a multi-method (parent-report and measurement), multi-trait (tactile sensitivity and attention) design to evaluate somatosensory processing in ASD. Results showed multiple significant within-method (e.g., parent report of different traits)/cross-trait (e.g., attention and tactile sensitivity) correlations, suggesting that parent-reported tactile sensory dysfunction and performance-based tactile sensitivity describe different behavioral phenomena. Additionally, both parent-reported tactile functioning and performance-based tactile sensitivity measures were significantly associated with measures of attention. Findings suggest that sensory (tactile) processing abnormalities in ASD are multifaceted, and may partially reflect a more global deficit in behavioral regulation (including attention). Challenges of relying solely on parent-report to describe sensory difficulties faced by children/families with ASD are also highlighted. PMID:27448580

  12. Revisiting attentional processing of non-emotional cues in social anxiety: A specific impairment for the orienting network of attention.

    PubMed

    Heeren, Alexandre; Maurage, Pierre; Philippot, Pierre

    2015-07-30

    People with social anxiety disorder (SAD) exhibit an attentional bias for threat (AB). Nevertheless, the focus on AB for emotional stimuli has led to neglect the exploration of basic attention deficits for non-emotional material among SAD patients. This study aimed to investigate the integrity of the attentional system in SAD. The Attention Network Test was used to precisely explore attentional deficits, and centrally the differential deficit across the three attentional networks, namely alerting (allowing to achieve and maintain a state of alertness), orienting (allowing to select information from sensory input by engaging or disengaging attention to one stimulus among others and/or shifting the attentional resources from one stimulation to another), and executive control (involving the top-down control of attention and allowing to resolve response conflicts). Twenty-five patients with SAD were compared to 25 matched controls. SAD patients exhibited a specific impairment for the orienting network (p < 0.001) but preserved performance for the alerting and executive networks. Complementary analyses revealed that this impairment may result from a faster attentional engagement to task-irrelevant material. The orienting impairment was highly correlated with the intensity of the social anxiety symptoms, but did not correlate either with trait-anxiety, state-anxiety, or depressive symptoms. PMID:25957649

  13. Effects of Methylphenidate (Ritalin) on Auditory Performance in Children with Attention and Auditory Processing Disorders.

    ERIC Educational Resources Information Center

    Tillery, Kim L.; Katz, Jack; Keller, Warren D.

    2000-01-01

    A double-blind, placebo-controlled study examined effects of methylphenidate (Ritalin) on auditory processing in 32 children with both attention deficit hyperactivity disorder and central auditory processing (CAP) disorder. Analyses revealed that Ritalin did not have a significant effect on any of the central auditory processing measures, although…

  14. Attention to language: novel MEG paradigm for registering involuntary language processing in the brain.

    PubMed

    Shtyrov, Yury; Smith, Marie L; Horner, Aidan J; Henson, Richard; Nathan, Pradeep J; Bullmore, Edward T; Pulvermüller, Friedemann

    2012-09-01

    Previous research indicates that, under explicit instructions to listen to spoken stimuli or in speech-oriented behavioural tasks, the brain's responses to senseless pseudowords are larger than those to meaningful words; the reverse is true in non-attended conditions. These differential responses could be used as a tool to trace linguistic processes in the brain and their interaction with attention. However, as previous studies relied on explicit instructions to attend or ignore the stimuli, a technique for automatic attention modulation (i.e., not dependent on explicit instruction) would be more advantageous, especially when cooperation with instructions may not be guaranteed (e.g., neurological patients, children etc). Here we present a novel paradigm in which the stimulus context automatically draws attention to speech. In a non-attend passive auditory oddball sequence, rare words and pseudowords were presented among frequent non-speech tones of variable frequency and length. The low percentage of spoken stimuli guarantees an involuntary attention switch to them. The speech stimuli, in turn, could be disambiguated as words or pseudowords only in their end, at the last phoneme, after the attention switch would have already occurred. Our results confirmed that this paradigm can indeed be used to induce automatic shifts of attention to spoken input. At ~250ms after the stimulus onset, a P3a-like neuromagnetic deflection was registered to spoken (but not tone) stimuli indicating an involuntary attention shift. Later, after the word-pseudoword divergence point, we found a larger oddball response to pseudowords than words, best explained by neural processes of lexical search facilitated through increased attention. Furthermore, we demonstrate a breakdown of this orderly pattern of neurocognitive processes as a result of sleep deprivation. The new paradigm may thus be an efficient way to assess language comprehension processes and their dynamic interaction with those

  15. Attention to language: novel MEG paradigm for registering involuntary language processing in the brain.

    PubMed

    Shtyrov, Yury; Smith, Marie L; Horner, Aidan J; Henson, Richard; Nathan, Pradeep J; Bullmore, Edward T; Pulvermüller, Friedemann

    2012-09-01

    Previous research indicates that, under explicit instructions to listen to spoken stimuli or in speech-oriented behavioural tasks, the brain's responses to senseless pseudowords are larger than those to meaningful words; the reverse is true in non-attended conditions. These differential responses could be used as a tool to trace linguistic processes in the brain and their interaction with attention. However, as previous studies relied on explicit instructions to attend or ignore the stimuli, a technique for automatic attention modulation (i.e., not dependent on explicit instruction) would be more advantageous, especially when cooperation with instructions may not be guaranteed (e.g., neurological patients, children etc). Here we present a novel paradigm in which the stimulus context automatically draws attention to speech. In a non-attend passive auditory oddball sequence, rare words and pseudowords were presented among frequent non-speech tones of variable frequency and length. The low percentage of spoken stimuli guarantees an involuntary attention switch to them. The speech stimuli, in turn, could be disambiguated as words or pseudowords only in their end, at the last phoneme, after the attention switch would have already occurred. Our results confirmed that this paradigm can indeed be used to induce automatic shifts of attention to spoken input. At ~250ms after the stimulus onset, a P3a-like neuromagnetic deflection was registered to spoken (but not tone) stimuli indicating an involuntary attention shift. Later, after the word-pseudoword divergence point, we found a larger oddball response to pseudowords than words, best explained by neural processes of lexical search facilitated through increased attention. Furthermore, we demonstrate a breakdown of this orderly pattern of neurocognitive processes as a result of sleep deprivation. The new paradigm may thus be an efficient way to assess language comprehension processes and their dynamic interaction with those

  16. Selective attentional processing to fall-relevant stimuli among older adults who fear falling.

    PubMed

    Brown, Lesley A; White, Patti; Doan, Jonathan B; de Bruin, Natalie

    2011-05-01

    Fear of falling is known to affect more than half of community-dwelling older adults over 60 years of age. This fear is associated with physical and psychological effects that increase the risk of falling. The authors' theory is that attentional processing biases may exist in this population that serve to perpetuate fear of falling and subsequently increase fall risk. As a starting point in testing this proposition, the authors examined selective attentional processing bias to fall-relevant stimuli among older adults. Thirty older adult participants (M(age) = 70.8 ± 5.8), self-categorized to be Fearful of Falling (FF, n = 15) or Non-Fearful of Falling (NF, n = 15) completed a visual dot-probe paradigm to determine detection latencies to fall-threatening and general-threat stimuli. Attentional processing was defined using three index scores: attentional bias, congruency index, and incongruency index. Bias indicates capture of attention, whereas congruency and incongruency imply vigilance and disengagement difficulty, respectively. Both groups showed an attentional bias to fall-threat words but those who were fearful of falling also showed an incongruency effect for fall-threat words. These findings confirm that selective attentional processing profiles for fall-relevant stimuli differ between older adults who exhibit fear of falling and those who do not have this fear. Moreover, in accordance with current interpretations of selective attentional processing, the incongruency effect noted among fall-fearful older adults presents a possibility for a difficulty disengaging from fall-threatening stimuli.

  17. Spatial attention does not modulate holistic face processing, even when multiple faces are present.

    PubMed

    Norman, Liam J; Tokarev, Alexander

    2014-01-01

    The perception of faces is often considered to be unique in comparison with that of other objects in the world. The fact that faces are processed not by their constituent components but by the spatial configuration between those components (holistic face processing--HFP) is often used to support this. Despite two decades of research, however, there is no consensus as to whether or not HFP is a process that is subject to attentional modulation. Here, in two experiments, we used a method to direct spatial attention not previously used in studies of HFP--an exogenous spatial cue--as it offers a robust, rapid, and involuntary method of directing attention. In one experiment we demonstrate that the degree of HFP afforded to a face is not reduced when attention is directed away from that face. In a second experiment we replicate this finding even when the face is simultaneously flanked by other faces--a condition under which a face-specific processing module would, hypothetically, be more sensitive to attentional guidance. These results add to the argument that HFP is carried out independently of attention.

  18. Sensory Processing Subtypes in Autism: Association with Adaptive Behavior

    ERIC Educational Resources Information Center

    Lane, Alison E.; Young, Robyn L.; Baker, Amy E. Z.; Angley, Manya T.

    2010-01-01

    Children with autism are frequently observed to experience difficulties in sensory processing. This study examined specific patterns of sensory processing in 54 children with autistic disorder and their association with adaptive behavior. Model-based cluster analysis revealed three distinct sensory processing subtypes in autism. These subtypes…

  19. Brief Report: Joint Attention and Information Processing in Children with Higher Functioning Autism Spectrum Disorders.

    PubMed

    Mundy, Peter; Kim, Kwanguk; McIntyre, Nancy; Lerro, Lindsay; Jarrold, William

    2016-07-01

    Theory suggests that information processing during joint attention may be atypical in children with Autism Spectrum Disorder (ASD). This hypothesis was tested in a study of school-aged children with higher functioning ASD and groups of children with symptoms of ADHD or typical development. The results indicated that the control groups displayed significantly better recognition memory for pictures studied in an initiating joint attention (IJA) rather than responding to joint attention (RJA) condition. This effect was not evident in the ASD group. The ASD group also recognized fewer pictures from the IJA condition than controls, but not the RJA condition. Atypical information processing may be a marker of the continued effects of joint attention disturbance in school aged children with ASD. PMID:27062035

  20. Positive Affect Processing and Joint Attention in Infants at High Risk for Autism: An Exploratory Study.

    PubMed

    Key, Alexandra P; Ibanez, Lisa V; Henderson, Heather A; Warren, Zachary; Messinger, Daniel S; Stone, Wendy L

    2015-12-01

    Few behavioral indices of risk for autism spectrum disorders (ASD) are present before 12 months, and potential biomarkers remain largely unexamined. This prospective study of infant siblings of children with ASD (n = 16) and low-risk comparison infants (n = 15) examined group differences in event-related potentials (ERPs) indexing processing of facial positive affect (N290/P400, Nc) at 9 months and their relation to joint attention at 15 months. Group differences were most pronounced for subtle facial expressions, in that the low-risk group exhibited relatively longer processing (P400 latency) and greater attention resource allocation (Nc amplitude). Exploratory analyses found associations between ERP responses and later joint attention, suggesting that attention to positive affect cues may support the development of other social competencies.

  1. Attentional modulation of neural processing of shape, color, and velocity in humans

    SciTech Connect

    Corbetta, M.; Miezin, F.M.; Dobmeyer, S.; Shulman, G.L.; Petersen, S.E. )

    1990-06-22

    Positron emission tomography (PET) was used to measure changes in regional cerebral blood flow of normal subjects, while they were discriminating different attributes (shape, color, and velocity) of the same set of visual stimuli. Psychophysical evidence indicated that the sensitivity for discriminating subtle stimulus changes was higher when subjects focused attention on one attribute than when they divided attention among several attributes. Correspondingly, attention enhanced the activity of different regions of extrastriate visual cortex that appear to be specialized for processing information related to the selected attribute.

  2. Sleep deprivation influences some but not all processes of supervisory attention

    NASA Technical Reports Server (NTRS)

    Jennings, J. R.; Monk, T. H.; van der Molen, M. W.

    2003-01-01

    Does one night of sleep deprivation alter processes of supervisory attention in general or only a specific subset of such processes? Twenty college-aged volunteers, half female, performed a choice reaction time task. A cue indicated that compatible (e.g., right button, right-pointing arrow) or incompatible (e.g., left button, right-pointing arrow) responses were to be given to a stimulus that followed 50 or 500 ms later. The paradigm assessed response inhibition, task-shifting skill, and task strategy-processes inherent in supervisory attention. Performance, along with heart rate, was assessed for 12 hr following normal sleep or a night of complete sleep deprivation. Sleep deprivation altered neither preparation for task shifting nor response inhibition. The ability to use preparatory bias to speed performance did decrease with sleep deprivation. Sleep deprivation appears to selectively affect this supervisory attention process, which is perceived as an active effort to cope with a challenging task.

  3. Perception in the absence of attention: perceptual processing in the Roelofs effect during inattentional blindness.

    PubMed

    Lathrop, William B; Bridgeman, Bruce; Tseng, Philip

    2011-01-01

    We present two experiments that examine sensory processing during conditions of inattentional blindness. A large rectangular frame that normally induces a Roelofs effect can go unreported due to inattentional blindness. Even when participants fail to report the frame, they mislocalize an attended target in a way consistent with having processed the frame. A more demanding visuospatial distractor task can increase inattentional blindness during conditions of divided attention, but has no effect on the spatial mislocalization illusion. Our results support theories that postulate a significant amount of perceptual processing in the absence of attention. PMID:22208130

  4. Action video games and improved attentional control: Disentangling selection- and response-based processes.

    PubMed

    Chisholm, Joseph D; Kingstone, Alan

    2015-10-01

    Research has demonstrated that experience with action video games is associated with improvements in a host of cognitive tasks. Evidence from paradigms that assess aspects of attention has suggested that action video game players (AVGPs) possess greater control over the allocation of attentional resources than do non-video-game players (NVGPs). Using a compound search task that teased apart selection- and response-based processes (Duncan, 1985), we required participants to perform an oculomotor capture task in which they made saccades to a uniquely colored target (selection-based process) and then produced a manual directional response based on information within the target (response-based process). We replicated the finding that AVGPs are less susceptible to attentional distraction and, critically, revealed that AVGPs outperform NVGPs on both selection-based and response-based processes. These results not only are consistent with the improved-attentional-control account of AVGP benefits, but they suggest that the benefit of action video game playing extends across the full breadth of attention-mediated stimulus-response processes that impact human performance. PMID:25772554

  5. Action video games and improved attentional control: Disentangling selection- and response-based processes.

    PubMed

    Chisholm, Joseph D; Kingstone, Alan

    2015-10-01

    Research has demonstrated that experience with action video games is associated with improvements in a host of cognitive tasks. Evidence from paradigms that assess aspects of attention has suggested that action video game players (AVGPs) possess greater control over the allocation of attentional resources than do non-video-game players (NVGPs). Using a compound search task that teased apart selection- and response-based processes (Duncan, 1985), we required participants to perform an oculomotor capture task in which they made saccades to a uniquely colored target (selection-based process) and then produced a manual directional response based on information within the target (response-based process). We replicated the finding that AVGPs are less susceptible to attentional distraction and, critically, revealed that AVGPs outperform NVGPs on both selection-based and response-based processes. These results not only are consistent with the improved-attentional-control account of AVGP benefits, but they suggest that the benefit of action video game playing extends across the full breadth of attention-mediated stimulus-response processes that impact human performance.

  6. On adaptive robustness approach to Anti-Jam signal processing

    NASA Astrophysics Data System (ADS)

    Poberezhskiy, Y. S.; Poberezhskiy, G. Y.

    An effective approach to exploiting statistical differences between desired and jamming signals named adaptive robustness is proposed and analyzed in this paper. It combines conventional Bayesian, adaptive, and robust approaches that are complementary to each other. This combining strengthens the advantages and mitigates the drawbacks of the conventional approaches. Adaptive robustness is equally applicable to both jammers and their victim systems. The capabilities required for realization of adaptive robustness in jammers and victim systems are determined. The employment of a specific nonlinear robust algorithm for anti-jam (AJ) processing is described and analyzed. Its effectiveness in practical situations has been proven analytically and confirmed by simulation. Since adaptive robustness can be used by both sides in electronic warfare, it is more advantageous for the fastest and most intelligent side. Many results obtained and discussed in this paper are also applicable to commercial applications such as communications in unregulated or poorly regulated frequency ranges and systems with cognitive capabilities.

  7. The Role of Attention in Somatosensory Processing: A Multi-Trait, Multi-Method Analysis

    ERIC Educational Resources Information Center

    Wodka, Ericka L.; Puts, Nicolaas A. J.; Mahone, E. Mark; Edden, Richard A. E.; Tommerdahl, Mark; Mostofsky, Stewart H.

    2016-01-01

    Sensory processing abnormalities in autism have largely been described by parent report. This study used a multi-method (parent-report and measurement), multi-trait (tactile sensitivity and attention) design to evaluate somatosensory processing in ASD. Results showed multiple significant within-method (e.g., parent report of different…

  8. Spatial Attention Effects during Conscious and Nonconscious Processing of Visual Features and Objects

    ERIC Educational Resources Information Center

    Tapia, Evelina; Breitmeyer, Bruno G.; Jacob, Jane; Broyles, Elizabeth C.

    2013-01-01

    Flanker congruency effects were measured in a masked flanker task to assess the properties of spatial attention during conscious and nonconscious processing of form, color, and conjunctions of these features. We found that (1) consciously and nonconsciously processed colored shape distractors (i.e., flankers) produce flanker congruency effects;…

  9. An Exploratory Study of Planning, Attention, Simultaneous, and Successive Cognitive Processes.

    ERIC Educational Resources Information Center

    Naglieri, Jack A.; And Others

    1989-01-01

    Examined factorial validity of tasks designed to measure cognitive processing in each of Luria's three functional units. Fourth and fifth graders (N=112) were administered nine experimental tasks chosen or developed according to theoretical components of planning, attention, simultaneous, and successive processes. Obtained general support for…

  10. Temporal Processing Impairment in Children with Attention-Deficit-Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Huang, Jia; Yang, Bin-rang; Zou, Xiao-bing; Jing, Jin; Pen, Gang; McAlonan, Grainne M.; Chan, Raymond C. K.

    2012-01-01

    The current study aimed to investigate temporal processing in Chinese children with Attention-Deficit-Hyperactivity Disorder(ADHD) using time production, time reproduction paradigm and duration discrimination tasks. A battery of tests specifically designed to measure temporal processing was administered to 94 children with ADHD and 100…

  11. Establishment of Joint Attention in Dyads Involving Hearing Mothers of Deaf and Hearing Children, and Its Relation to Adaptive Social Behavior

    ERIC Educational Resources Information Center

    Nowakowski, Matilda E.; Tasker, Susan L.; Schmidt, Louis A.

    2009-01-01

    Mounting evidence points to joint attention as a mediating variable in children's adaptive behavior. Joint attention in interactions between hearing mothers and congenitally deaf (n = 27) and hearing (n = 29) children, ages 18-36 months, was examined. All deaf children had severe to profound hearing loss. Mother-child interactions were coded for…

  12. Adaptation to leftward-shifting prisms reduces the global processing bias of healthy individuals.

    PubMed

    Bultitude, Janet H; Woods, Jill M

    2010-05-01

    When healthy individuals are presented with peripheral figures in which small letters are arranged to form a large letter, they are faster to identify the global- than the local-level information, and have difficulty ignoring global information when identifying the local level. The global reaction time (RT) advantage and global interference effect imply preferential processing of global-level information in the normal brain. This contrasts with the local processing bias demonstrated following lesions to the right temporo-parietal junction (TPJ), such as those that lead to hemispatial neglect (neglect). Recent research from our lab demonstrated that visuo-motor adaptation to rightward-shifting prisms, which ameliorates many leftward performance deficits of neglect patients, improved the local processing bias of patients with right TPJ lesions (Bultitude, Rafal, & List, 2009). Here we demonstrate that adaptation to leftward-shifting prisms, which can induce neglect-like performance in neurologically healthy individuals, also reduces the normal global processing bias. Forty-eight healthy participants were asked to identify the global or local forms of hierarchical figures before and after adaptation to leftward- or rightward-shifting prisms. Prior to prism adaptation, both groups had greater difficulty ignoring irrelevant global information when identifying the local level (global interference) compared to their ability to ignore irrelevant local-level information when identifying the global level (local interference). Participants who adapted to leftward-shifting prisms showed a significant reduction in global interference, but there was no change in the performance of the rightward-shifting Prism Group. These results show, for the first time, that in addition to previously demonstrated effects on lateralised attention, prism adaptation can influence non-lateralised spatial attention in healthy individuals.

  13. Do I have my attention? Speed of processing advantages for the self-face are not driven by automatic attention capture.

    PubMed

    Keyes, Helen; Dlugokencka, Aleksandra

    2014-01-01

    We respond more quickly to our own face than to other faces, but there is debate over whether this is connected to attention-grabbing properties of the self-face. In two experiments, we investigate whether the self-face selectively captures attention, and the attentional conditions under which this might occur. In both experiments, we examined whether different types of face (self, friend, stranger) provide differential levels of distraction when processing self, friend and stranger names. In Experiment 1, an image of a distractor face appeared centrally - inside the focus of attention - behind a target name, with the faces either upright or inverted. In Experiment 2, distractor faces appeared peripherally - outside the focus of attention - in the left or right visual field, or bilaterally. In both experiments, self-name recognition was faster than other name recognition, suggesting a self-referential processing advantage. The presence of the self-face did not cause more distraction in the naming task compared to other types of face, either when presented inside (Experiment 1) or outside (Experiment 2) the focus of attention. Distractor faces had different effects across the two experiments: when presented inside the focus of attention (Experiment 1), self and friend images facilitated self and friend naming, respectively. This was not true for stranger stimuli, suggesting that faces must be robustly represented to facilitate name recognition. When presented outside the focus of attention (Experiment 2), no facilitation occurred. Instead, we report an interesting distraction effect caused by friend faces when processing strangers' names. We interpret this as a "social importance" effect, whereby we may be tuned to pick out and pay attention to familiar friend faces in a crowd. We conclude that any speed of processing advantages observed in the self-face processing literature are not driven by automatic attention capture.

  14. Do I Have My Attention? Speed of Processing Advantages for the Self-Face Are Not Driven by Automatic Attention Capture

    PubMed Central

    Keyes, Helen; Dlugokencka, Aleksandra

    2014-01-01

    We respond more quickly to our own face than to other faces, but there is debate over whether this is connected to attention-grabbing properties of the self-face. In two experiments, we investigate whether the self-face selectively captures attention, and the attentional conditions under which this might occur. In both experiments, we examined whether different types of face (self, friend, stranger) provide differential levels of distraction when processing self, friend and stranger names. In Experiment 1, an image of a distractor face appeared centrally – inside the focus of attention – behind a target name, with the faces either upright or inverted. In Experiment 2, distractor faces appeared peripherally – outside the focus of attention – in the left or right visual field, or bilaterally. In both experiments, self-name recognition was faster than other name recognition, suggesting a self-referential processing advantage. The presence of the self-face did not cause more distraction in the naming task compared to other types of face, either when presented inside (Experiment 1) or outside (Experiment 2) the focus of attention. Distractor faces had different effects across the two experiments: when presented inside the focus of attention (Experiment 1), self and friend images facilitated self and friend naming, respectively. This was not true for stranger stimuli, suggesting that faces must be robustly represented to facilitate name recognition. When presented outside the focus of attention (Experiment 2), no facilitation occurred. Instead, we report an interesting distraction effect caused by friend faces when processing strangers’ names. We interpret this as a “social importance” effect, whereby we may be tuned to pick out and pay attention to familiar friend faces in a crowd. We conclude that any speed of processing advantages observed in the self-face processing literature are not driven by automatic attention capture. PMID:25338170

  15. Auditory global-local processing: effects of attention and musical experience.

    PubMed

    Ouimet, Tia; Foster, Nicholas E V; Hyde, Krista L

    2012-10-01

    In vision, global (whole) features are typically processed before local (detail) features ("global precedence effect"). However, the distinction between global and local processing is less clear in the auditory domain. The aims of the present study were to investigate: (i) the effects of directed versus divided attention, and (ii) the effect musical training on auditory global-local processing in 16 adult musicians and 16 non-musicians. Participants were presented with short nine-tone melodies, each comprised of three triplet sequences (three-tone units). In a "directed attention" task, participants were asked to focus on either the global or local pitch pattern and had to determine if the pitch pattern went up or down. In a "divided attention" task, participants judged whether the target pattern (up or down) was present or absent. Overall, global structure was perceived faster and more accurately than local structure. The global precedence effect was observed regardless of whether attention was directed to a specific level or divided between levels. Musicians performed more accurately than non-musicians overall, but non-musicians showed a more pronounced global advantage. This study provides evidence for an auditory global precedence effect across attention tasks, and for differences in auditory global-local processing associated with musical experience. PMID:23039447

  16. Auditory global-local processing: effects of attention and musical experience.

    PubMed

    Ouimet, Tia; Foster, Nicholas E V; Hyde, Krista L

    2012-10-01

    In vision, global (whole) features are typically processed before local (detail) features ("global precedence effect"). However, the distinction between global and local processing is less clear in the auditory domain. The aims of the present study were to investigate: (i) the effects of directed versus divided attention, and (ii) the effect musical training on auditory global-local processing in 16 adult musicians and 16 non-musicians. Participants were presented with short nine-tone melodies, each comprised of three triplet sequences (three-tone units). In a "directed attention" task, participants were asked to focus on either the global or local pitch pattern and had to determine if the pitch pattern went up or down. In a "divided attention" task, participants judged whether the target pattern (up or down) was present or absent. Overall, global structure was perceived faster and more accurately than local structure. The global precedence effect was observed regardless of whether attention was directed to a specific level or divided between levels. Musicians performed more accurately than non-musicians overall, but non-musicians showed a more pronounced global advantage. This study provides evidence for an auditory global precedence effect across attention tasks, and for differences in auditory global-local processing associated with musical experience.

  17. Adaptive constructive processes and the future of memory

    PubMed Central

    Schacter, Daniel L.

    2013-01-01

    Memory serves critical functions in everyday life, but is also prone to error. This article examines adaptive constructive processes, which play a functional role in memory and cognition but can also produce distortions, errors, or illusions. The article describes several types of memory errors that are produced by adaptive constructive processes, and focuses in particular on the process of imagining or simulating events that might occur in one’s personal future. Simulating future events relies on many of the same cognitive and neural processes as remembering past events, which may help to explain why imagination and memory can be easily confused. The article considers both pitfalls and adaptive aspects of future event simulation in the context of research on planning, prediction, problem solving, mind-wandering, prospective and retrospective memory, coping and positivity bias, and the interconnected set of brain regions known as the default network. PMID:23163437

  18. The Automatic Conservative: Ideology-Based Attentional Asymmetries in the Processing of Valenced Information

    PubMed Central

    Carraro, Luciana; Castelli, Luigi; Macchiella, Claudia

    2011-01-01

    Research has widely explored the differences between conservatives and liberals, and it has been also recently demonstrated that conservatives display different reactions toward valenced stimuli. However, previous studies have not yet fully illuminated the cognitive underpinnings of these differences. In the current work, we argued that political ideology is related to selective attention processes, so that negative stimuli are more likely to automatically grab the attention of conservatives as compared to liberals. In Experiment 1, we demonstrated that negative (vs. positive) information impaired the performance of conservatives, more than liberals, in an Emotional Stroop Task. This finding was confirmed in Experiment 2 and in Experiment 3 employing a Dot-Probe Task, demonstrating that threatening stimuli were more likely to attract the attention of conservatives. Overall, results support the conclusion that people embracing conservative views of the world display an automatic selective attention for negative stimuli. PMID:22096486

  19. True-Time-Delay Adaptive Array Processing Using Photorefractive Crystals

    NASA Astrophysics Data System (ADS)

    Kriehn, G. R.; Wagner, K.

    Radio frequency (RF) signal processing has proven to be a fertile application area when using photorefractive-based, optical processing techniques. This is due to a photorefractive material's capability to record gratings and diffract off these gratings with optically modulated beams that contain a wide RF bandwidth, and include applications such as the bias-free time-integrating correlator [1], adaptive signal processing, and jammer excision, [2, 3, 4]. Photorefractive processing of signals from RF antenna arrays is especially appropriate because of the massive parallelism that is readily achievable in a photorefractive crystal (in which many resolvable beams can be incident on a single crystal simultaneously—each coming from an optical modulator driven by a separate RF antenna element), and because a number of approaches for adaptive array processing using photorefractive crystals have been successfully investigated [5, 6]. In these types of applications, the adaptive weight coefficients are represented by the amplitude and phase of the holographic gratings, and many millions of such adaptive weights can be multiplexed within the volume of a photorefractive crystal. RF modulated optical signals from each array element are diffracted from the adaptively recorded photorefractive gratings (which can be multiplexed either angularly or spatially), and are then coherently combined with the appropriate amplitude weights and phase shifts to effectively steer the angular receptivity pattern of the antenna array toward the desired arriving signal. Likewise, the antenna nulls can also be rotated toward unwanted narrowband jammers for extinction, thereby optimizing the signal-to-interference-plus-noise ratio.

  20. Sequential sampling model for multiattribute choice alternatives with random attention time and processing order.

    PubMed

    Diederich, Adele; Oswald, Peter

    2014-01-01

    A sequential sampling model for multiattribute binary choice options, called multiattribute attention switching (MAAS) model, assumes a separate sampling process for each attribute. During the deliberation process attention switches from one attribute consideration to the next. The order in which attributes are considered as well for how long each attribute is considered-the attention time-influences the predicted choice probabilities and choice response times. Several probability distributions for the attention time with different variances are investigated. Depending on the time and order schedule the model predicts a rich choice probability/choice response time pattern including preference reversals and fast errors. Furthermore, the difference between finite and infinite decision horizons for the attribute considered last is investigated. For the former case the model predicts a probability p 0 > 0 of not deciding within the available time. The underlying stochastic process for each attribute is an Ornstein-Uhlenbeck process approximated by a discrete birth-death process. All predictions are also true for the widely applied Wiener process. PMID:25249963

  1. Does Attention Play a Role in Dynamic Receptive Field Adaptation to Changing Acoustic Salience in A1?

    PubMed Central

    Fritz, Jonathan; Elhilali, Mounya; David, Stephen; Shamma, Shihab

    2007-01-01

    Acoustic filter properties of A1 neurons can dynamically adapt to stimulus statistics, classical conditioning, instrumental learning and the changing auditory attentional focus. We have recently developed an experimental paradigm that allows us to view cortical receptive field plasticity on-line as the animal meets different behavioral challenges by attending to salient acoustic cues and changing its cortical filters to enhance performance. We propose that attention is the key trigger that initiates a cascade of events leading to the dynamic receptive field changes that we observe. In our paradigm, ferrets were initially trained, using conditioned avoidance training techniques, to discriminate between background noise stimuli (temporally orthogonal ripple combinations) and foreground tonal target stimuli. They learned to generalize the task for a wide variety of distinct background and foreground target stimuli. We recorded cortical activity in the awake behaving animal and computed on-line spectrotemporal receptive fields (STRFs) of single neurons in A1. We observed clear, predictable task-related changes in STRF shape while the animal performed spectral tasks (including single tone and multi-tone detection, and two-tone discrimination) with different tonal targets. A different set of task-related changes occurred when the animal performed temporal tasks (including gap detection and click-rate discrimination). Distinctive cortical STRF changes may constitute a “task-specific signature”. These spectral and temporal changes in cortical filters occur quite rapidly, within 2 minutes of task onset, and fade just as quickly after task completion, or in some cases, persisted for hours. The same cell could multiplex by differentially changing its receptive field in different task conditions. On-line dynamic task-related changes, as well as persistent plastic changes, were observed at a single-unit, multi-unit and population level. Auditory attention is likely to be

  2. Interests shape how adolescents pay attention: the interaction of motivation and top-down attentional processes in biasing sensory activations to anticipated events.

    PubMed

    Banerjee, Snigdha; Frey, Hans-Peter; Molholm, Sophie; Foxe, John J

    2015-03-01

    The voluntary allocation of attention to environmental inputs is a crucial mechanism of healthy cognitive functioning, and is probably influenced by an observer's level of interest in a stimulus. For example, an individual who is passionate about soccer but bored by botany will obviously be more attentive at a soccer match than an orchid show. The influence of monetary rewards on attention has been examined, but the impact of more common motivating factors (i.e. the level of interest in the materials under observation) remains unclear, especially during development. Here, stimulus sets were designed based on survey measures of the level of interest of adolescent participants in several item classes. High-density electroencephalography was recorded during a cued spatial attention task in which stimuli of high or low interest were presented in separate blocks. The motivational impact on performance of a spatial attention task was assessed, along with event-related potential measures of anticipatory top-down attention. As predicted, performance was improved for the spatial target detection of high interest items. Further, the impact of motivation was observed in parieto-occipital processes associated with anticipatory top-down spatial attention. The anticipatory activity over these regions was also increased for high vs. low interest stimuli, irrespective of the direction of spatial attention. The results also showed stronger anticipatory attentional and motivational modulations over the right vs. left parieto-occipital cortex. These data suggest that motivation enhances top-down attentional processes, and can independently shape activations in sensory regions in anticipation of events. They also suggest that attentional functions across hemispheres may not fully mature until late adolescence. PMID:25546318

  3. Emotional communication in the context of joint attention for food stimuli: effects on attentional and affective processing.

    PubMed

    Soussignan, Robert; Schaal, Benoist; Boulanger, Véronique; Garcia, Samuel; Jiang, Tao

    2015-01-01

    Guided by distinct theoretical frameworks (the embodiment theories, shared-signal hypothesis, and appraisal theories), we examined the effects of gaze direction and emotional expressions (joy, disgust, and neutral) of virtual characters on attention orienting and affective reactivity of participants while they were engaged in joint attention for food stimuli contrasted by preference (disliked, moderately liked, and liked). The participants were exposed to videos of avatars looking at food and displaying facial expressions with their gaze directed either toward the food only or toward the food and participants consecutively. We recorded eye-tracking responses, heart rate, facial electromyography (zygomatic, corrugator, and levator labii regions), and food wanting/liking. The avatars' joy faces increased the participants' zygomatic reactions and food liking, with mutual eye contact boosting attentional responses. Eye contact also fostered disgust reactions to disliked food, regardless of the avatars' expressions. The findings show that joint attention for food accompanied by face-to-face emotional communication elicits differential attentional and affective responses. The findings appear consistent with the appraisal theories of emotion.

  4. Stereotype Strength and Attentional Bias: Preference for Confirming versus Disconfirming Information Depends on Processing Capacity

    PubMed Central

    Allen, Thomas J.; Sherman, Jeffrey W.; Conrey, Frederica R.; Stroessner, Steven J.

    2009-01-01

    In two experiments, we investigated the relationships among stereotype strength, processing capacity, and the allocation of attention to stereotype-consistent versus stereotype-inconsistent information describing a target person. The results of both experiments showed that, with full capacity, greater stereotype strength was associated with increased attention toward stereotype-consistent versus stereotype-inconsistent information. However, when capacity was diminished, greater stereotype strength was associated with increased attention toward inconsistent versus consistent information. Thus, strong stereotypes may act as self-confirming filters when processing capacity is plentiful, but as efficient information gathering devices that maximize the acquisition of novel (disconfirming) information when capacity is depleted. Implications for models of stereotyping and stereotype change are discussed. PMID:20161043

  5. Attention allocation: Relationships to general working memory or specific language processing.

    PubMed

    Archibald, Lisa M D; Levee, Tyler; Olino, Thomas

    2015-11-01

    Attention allocation, updating working memory, and language processing are interdependent cognitive tasks related to the focused direction of limited resources, refreshing and substituting information in the current focus of attention, and receiving/sending verbal communication, respectively. The current study systematically examined the relationship among executive attention, working memory executive skills, and language abilities while adjusting for individual differences in short-term memory. School-age children completed a selective attention task requiring them to recall whether a presented shape was in the same place as a previous target shape shown in an array imposing a low or high working memory load. Results revealed a selective attention cost when working above but not within memory span capacity. Measures of general working memory were positively related to overall task performance, whereas language abilities were related to response time. In particular, higher language skills were associated with faster responses under low load conditions. These findings suggest that attentional control and storage demands have an additive impact on working memory resources but provide only limited evidence for a domain-general mechanism in language learning.

  6. Attentional effects on orientation judgements are dependent on memory consolidation processes.

    PubMed

    Haskell, Christie; Anderson, Britt

    2016-11-01

    Are the effects of memory and attention on perception synergistic, antagonistic, or independent? Tested separately, memory and attention have been shown to affect the accuracy of orientation judgements. When multiple stimuli are presented sequentially versus simultaneously, error variance is reduced. When a target is validly cued, precision is increased. What if they are manipulated together? We combined memory and attention manipulations in an orientation judgement task to answer this question. Two circular gratings were presented sequentially or simultaneously. On some trials a brief luminance cue preceded the stimuli. Participants were cued to report the orientation of one of the two gratings by rotating a response grating. We replicated the finding that error variance is reduced on sequential trials. Critically, we found interacting effects of memory and attention. Valid cueing reduced the median, absolute error only when two stimuli appeared together and improved it to the level of performance on uncued sequential trials, whereas invalid cueing always increased error. This effect was not mediated by cue predictiveness; however, predictive cues reduced the standard deviation of the error distribution, whereas nonpredictive cues reduced "guessing". Our results suggest that, when the demand on memory is greater than a single stimulus, attention is a bottom-up process that prioritizes stimuli for consolidation. Thus attention and memory are synergistic. PMID:26595533

  7. Acoustic noise alters selective attention processes as indicated by direct current (DC) brain potential changes.

    PubMed

    Trimmel, Karin; Schätzer, Julia; Trimmel, Michael

    2014-01-01

    Acoustic environmental noise, even of low to moderate intensity, is known to adversely affect information processing in animals and humans via attention mechanisms. In particular, facilitation and inhibition of information processing are basic functions of selective attention. Such mechanisms can be investigated by analyzing brain potentials under conditions of externally directed attention (intake of environmental information) versus internally directed attention (rejection of environmental stimuli and focusing on memory/planning processes). This study investigated brain direct current (DC) potential shifts-which are discussed to represent different states of cortical activation-of tasks that require intake and rejection of environmental information under noise. It was hypothesized that without background noise rejection tasks would show more positive DC potential changes compared to intake tasks and that under noise both kinds of tasks would show positive DC shifts as an expression of cortical inhibition caused by noise. DC potential shifts during intake and rejection tasks were analyzed at 16 standard locations in 45 persons during irrelevant speech or white noise vs. control condition. Without noise, rejection tasks were associated with more positive DC potential changes compared to intake tasks. During background noise, however, this difference disappeared and both kinds of tasks led to positive DC shifts. Results suggest-besides some limitations-that noise modulates selective attention mechanisms by switching to an environmental information processing and noise rejection mode, which could represent a suggested "attention shift". Implications for fMRI studies as well as for public health in learning and performance environments including susceptible persons are discussed.

  8. Acoustic Noise Alters Selective Attention Processes as Indicated by Direct Current (DC) Brain Potential Changes

    PubMed Central

    Trimmel, Karin; Schätzer, Julia; Trimmel, Michael

    2014-01-01

    Acoustic environmental noise, even of low to moderate intensity, is known to adversely affect information processing in animals and humans via attention mechanisms. In particular, facilitation and inhibition of information processing are basic functions of selective attention. Such mechanisms can be investigated by analyzing brain potentials under conditions of externally directed attention (intake of environmental information) versus internally directed attention (rejection of environmental stimuli and focusing on memory/planning processes). This study investigated brain direct current (DC) potential shifts—which are discussed to represent different states of cortical activation—of tasks that require intake and rejection of environmental information under noise. It was hypothesized that without background noise rejection tasks would show more positive DC potential changes compared to intake tasks and that under noise both kinds of tasks would show positive DC shifts as an expression of cortical inhibition caused by noise. DC potential shifts during intake and rejection tasks were analyzed at 16 standard locations in 45 persons during irrelevant speech or white noise vs. control condition. Without noise, rejection tasks were associated with more positive DC potential changes compared to intake tasks. During background noise, however, this difference disappeared and both kinds of tasks led to positive DC shifts. Results suggest—besides some limitations—that noise modulates selective attention mechanisms by switching to an environmental information processing and noise rejection mode, which could represent a suggested “attention shift”. Implications for fMRI studies as well as for public health in learning and performance environments including susceptible persons are discussed. PMID:25264675

  9. Dynamic oscillatory processes governing cued orienting and allocation of auditory attention

    PubMed Central

    Ahveninen, Jyrki; Huang, Samantha; Belliveau, John W.; Chang, Wei-Tang; Hämäläinen, Matti

    2013-01-01

    In everyday listening situations, we need to constantly switch between alternative sound sources and engage attention according to cues that match our goals and expectations. The exact neuronal bases of these processes are poorly understood. We investigated oscillatory brain networks controlling auditory attention using cortically constrained fMRI-weighted magnetoencephalography/ electroencephalography (MEG/EEG) source estimates. During consecutive trials, subjects were instructed to shift attention based on a cue, presented in the ear where a target was likely to follow. To promote audiospatial attention effects, the targets were embedded in streams of dichotically presented standard tones. Occasionally, an unexpected novel sound occurred opposite to the cued ear, to trigger involuntary orienting. According to our cortical power correlation analyses, increased frontoparietal/temporal 30–100 Hz gamma activity at 200–1400 ms after cued orienting predicted fast and accurate discrimination of subsequent targets. This sustained correlation effect, possibly reflecting voluntary engagement of attention after the initial cue-driven orienting, spread from the temporoparietal junction, anterior insula, and inferior frontal (IFC) cortices to the right frontal eye fields. Engagement of attention to one ear resulted in a significantly stronger increase of 7.5–15 Hz alpha in the ipsilateral than contralateral parieto-occipital cortices 200–600 ms after the cue onset, possibly reflecting crossmodal modulation of the dorsal visual pathway during audiospatial attention. Comparisons of cortical power patterns also revealed significant increases of sustained right medial frontal cortex theta power, right dorsolateral prefrontal cortex and anterior insula/IFC beta power, and medial parietal cortex and posterior cingulate cortex gamma activity after cued vs. novelty-triggered orienting (600–1400 ms). Our results reveal sustained oscillatory patterns associated with voluntary

  10. Applying statistical process control to the adaptive rate control problem

    NASA Astrophysics Data System (ADS)

    Manohar, Nelson R.; Willebeek-LeMair, Marc H.; Prakash, Atul

    1997-12-01

    Due to the heterogeneity and shared resource nature of today's computer network environments, the end-to-end delivery of multimedia requires adaptive mechanisms to be effective. We present a framework for the adaptive streaming of heterogeneous media. We introduce the application of online statistical process control (SPC) to the problem of dynamic rate control. In SPC, the goal is to establish (and preserve) a state of statistical quality control (i.e., controlled variability around a target mean) over a process. We consider the end-to-end streaming of multimedia content over the internet as the process to be controlled. First, at each client, we measure process performance and apply statistical quality control (SQC) with respect to application-level requirements. Then, we guide an adaptive rate control (ARC) problem at the server based on the statistical significance of trends and departures on these measurements. We show this scheme facilitates handling of heterogeneous media. Last, because SPC is designed to monitor long-term process performance, we show that our online SPC scheme could be used to adapt to various degrees of long-term (network) variability (i.e., statistically significant process shifts as opposed to short-term random fluctuations). We develop several examples and analyze its statistical behavior and guarantees.

  11. Shared and distinct factors driving attention and temporal processing across modalities

    PubMed Central

    Berry, Anne S.; Li, Xu; Lin, Ziyong; Lustig, Cindy

    2013-01-01

    In addition to the classic finding that “sounds are judged longer than lights,” the timing of auditory stimuli is often more precise and accurate than is the timing of visual stimuli. In cognitive models of temporal processing, these modality differences are explained by positing that auditory stimuli more automatically capture and hold attention, more efficiently closing an attentional switch that allows the accumulation of pulses marking the passage of time (Block & Zakay, 1997; Meck, 1991; Penney, 2003). However, attention is a multifaceted construct, and there has been little attempt to determine which aspects of attention may be related to modality effects. We used visual and auditory versions of the Continuous Temporal Expectancy Task (CTET; O'Connell et al., 2009) a timing task previously linked to behavioral and electrophysiological measures of mind-wandering and attention lapses, and tested participants with or without the presence of a video distractor. Performance in the auditory condition was generally superior to that in the visual condition, replicating standard results in the timing literature. The auditory modality was also less affected by declines in sustained attention indexed by declines in performance over time. In contrast, distraction had an equivalent impact on performance in the two modalities. Analysis of individual differences in performance revealed further differences between the two modalities: Poor performance in the auditory condition was primarily related to boredom whereas poor performance in the visual condition was primarily related to distractibility. These results suggest that: 1) challenges to different aspects of attention reveal both modality-specific and nonspecific effects on temporal processing, and 2) different factors drive individual differences when testing across modalities. PMID:23978664

  12. Orienting attention to points in time improves stimulus processing both within and across modalities.

    PubMed

    Lange, Kathrin; Röder, Brigitte

    2006-05-01

    Spatial attention affects the processing of stimuli of both a task-relevant and a task-irrelevant modality. The present study investigated if similar cross-modal effects exist when attention is oriented to a point in time. Short (600 msec) and long (1,200 msec) empty intervals, marked by a tactile onset and an auditory or a tactile offset marker, were presented. In each block, the participants had to attend one interval and one modality. Event-related potentials (ERPs) to auditory and tactile offset markers of attended as compared to unattended intervals were characterized by an enhancement of early negative deflections of the auditory and somatosensory ERPs (audition, 100-140 msec; touch, 130-180 msec) when audition or touch was task relevant, respectively. Similar effects were found for auditory stimuli when touch was task relevant. An additional reaction time experiment revealed faster responses to both auditory and tactile stimuli at the attended as compared to the unattended point in time, irrespective of which modality was primary. Both behavioral and ERP data show that attention can be focused on a point in time, which results in a more efficient processing of auditory and tactile stimuli. The ERP data further suggest that a relative enhancement at perceptual processing stages contributes to the processing advantage for temporally attended stimuli. The existence of cross-modal effects of temporal attention underlines the importance of time as a feature for binding input across different modalities.

  13. Using Hazard Functions to Assess Changes in Processing Capacity in an Attentional Cuing Paradigm

    ERIC Educational Resources Information Center

    Wenger, Michael J.; Gibson, Bradley S.

    2004-01-01

    Processing capacity-defined as the relative ability to perform mental work in a unit of time-is a critical construct in cognitive psychology and is central to theories of visual attention. The unambiguous use of the construct, experimentally and theoretically, has been hindered by both conceptual confusions and the use of measures that are at best…

  14. Temporal Context in Speech Processing and Attentional Stream Selection: A Behavioral and Neural Perspective

    ERIC Educational Resources Information Center

    Golumbic, Elana M. Zion; Poeppel, David; Schroeder, Charles E.

    2012-01-01

    The human capacity for processing speech is remarkable, especially given that information in speech unfolds over multiple time scales concurrently. Similarly notable is our ability to filter out of extraneous sounds and focus our attention on one conversation, epitomized by the "Cocktail Party" effect. Yet, the neural mechanisms underlying on-line…

  15. Brief Report: Joint Attention and Information Processing in Children with Higher Functioning Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Mundy, Peter; Kim, Kwanguk; McIntyre, Nancy; Lerro, Lindsay; Jarrold, William

    2016-01-01

    Theory suggests that information processing during joint attention may be atypical in children with Autism Spectrum Disorder (ASD). This hypothesis was tested in a study of school-aged children with higher functioning ASD and groups of children with symptoms of ADHD or typical development. The results indicated that the control groups displayed…

  16. Gender Differences in Planning, Attention, Simultaneous, and Successive (PASS) Cognitive Processes and Achievement.

    ERIC Educational Resources Information Center

    Naglieri, Jack A.; Rojahn, Johannes

    2001-01-01

    Examined 1,100 boys and 1,100 girls who matched the U.S. population using the Planning, Attention, Simultaneous, Successive (PASS) cognitive-processing theory, built on the neuropsychological work of A.R. Luria (1973). Results illustrate that the PASS theory offers a useful way to examine gender differences in cognitive performance. (BF)

  17. Attention and Semantic Processing during Speech: An fMRI Study

    ERIC Educational Resources Information Center

    Rama, Pia; Relander-Syrjanen, Kristiina; Carlson, Synnove; Salonen, Oili; Kujala, Teija

    2012-01-01

    This fMRI study was conducted to investigate whether language semantics is processed even when attention is not explicitly directed to word meanings. In the "unattended" condition, the subjects performed a visual detection task while hearing semantically related and unrelated word pairs. In the "phoneme" condition, the subjects made phoneme…

  18. Striatal Sensitivity during Reward Processing in Attention-Deficit/Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Paloyelis, Yannis; Mehta, Mitul A.; Faraone, Stephen V.; Asherson, Philip; Kuntsi, Jonna

    2012-01-01

    Objective: Attention-deficit/hyperactivity disorder (ADHD) has been linked to deficits in the dopaminergic reward-processing circuitry; yet, existing evidence is limited, and the influence of genetic variation affecting dopamine signaling remains unknown. We investigated striatal responsivity to rewards in ADHD combined type (ADHD-CT) using…

  19. Attention Processes in Children with Movement Difficulties, Reading Difficulties or Both

    ERIC Educational Resources Information Center

    Cruddace, S. A.; Riddell, P. M.

    2006-01-01

    Reading difficulties (RD) and movement difficulties (MD) co-occur more often in clinical populations than expected for independent disorders. In this study, we investigated the pattern of association between attentional processes, RD and MD in a population of 9 year old school children. Children were screened to identify index groups with RD, MD…

  20. Task-Set Reconfiguration Suspends Perceptual Processing: Evidence from Semantic Priming during the Attentional Blink

    ERIC Educational Resources Information Center

    Vachon, Francois; Tremblay, Sebastien; Jones, Dylan M.

    2007-01-01

    When two visual targets, Target 1 (T1) and Target 2 (T2), are presented among a rapid sequence of distractors, processing of T1 produces an attentional blink. Typically, processing of T2 is markedly impaired, except when T1 and T2 are adjacent (Lag 1 sparing). However, if a shift of task set--a change in task requirements from T1 to T2--occurs,…

  1. Becoming a Lunari or Taiyo expert: learned attention to parts drives holistic processing of faces.

    PubMed

    Chua, Kao-Wei; Richler, Jennifer J; Gauthier, Isabel

    2014-06-01

    Faces are processed holistically, but the locus of holistic processing remains unclear. We created two novel races of faces (Lunaris and Taiyos) to study how experience with face parts influences holistic processing. In Experiment 1, subjects individuated Lunaris wherein the top, bottom, or both face halves contained diagnostic information. Subjects who learned to attend to face parts exhibited no holistic processing. This suggests that individuation only leads to holistic processing when the whole face is attended. In Experiment 2, subjects individuated both Lunaris and Taiyos, with diagnostic information in complementary face halves of the two races. Holistic processing was measured with composites made of either diagnostic or nondiagnostic face parts. Holistic processing was only observed for composites made from diagnostic face parts, demonstrating that holistic processing can occur for diagnostic face parts that were never seen together. These results suggest that holistic processing is an expression of learned attention to diagnostic face parts.

  2. Audio-visual synchrony and feature-selective attention co-amplify early visual processing.

    PubMed

    Keitel, Christian; Müller, Matthias M

    2016-05-01

    Our brain relies on neural mechanisms of selective attention and converging sensory processing to efficiently cope with rich and unceasing multisensory inputs. One prominent assumption holds that audio-visual synchrony can act as a strong attractor for spatial attention. Here, we tested for a similar effect of audio-visual synchrony on feature-selective attention. We presented two superimposed Gabor patches that differed in colour and orientation. On each trial, participants were cued to selectively attend to one of the two patches. Over time, spatial frequencies of both patches varied sinusoidally at distinct rates (3.14 and 3.63 Hz), giving rise to pulse-like percepts. A simultaneously presented pure tone carried a frequency modulation at the pulse rate of one of the two visual stimuli to introduce audio-visual synchrony. Pulsed stimulation elicited distinct time-locked oscillatory electrophysiological brain responses. These steady-state responses were quantified in the spectral domain to examine individual stimulus processing under conditions of synchronous versus asynchronous tone presentation and when respective stimuli were attended versus unattended. We found that both, attending to the colour of a stimulus and its synchrony with the tone, enhanced its processing. Moreover, both gain effects combined linearly for attended in-sync stimuli. Our results suggest that audio-visual synchrony can attract attention to specific stimulus features when stimuli overlap in space. PMID:26226930

  3. Temporal context in speech processing and attentional stream selection: a behavioral and neural perspective.

    PubMed

    Zion Golumbic, Elana M; Poeppel, David; Schroeder, Charles E

    2012-09-01

    The human capacity for processing speech is remarkable, especially given that information in speech unfolds over multiple time scales concurrently. Similarly notable is our ability to filter out of extraneous sounds and focus our attention on one conversation, epitomized by the 'Cocktail Party' effect. Yet, the neural mechanisms underlying on-line speech decoding and attentional stream selection are not well understood. We review findings from behavioral and neurophysiological investigations that underscore the importance of the temporal structure of speech for achieving these perceptual feats. We discuss the hypothesis that entrainment of ambient neuronal oscillations to speech's temporal structure, across multiple time-scales, serves to facilitate its decoding and underlies the selection of an attended speech stream over other competing input. In this regard, speech decoding and attentional stream selection are examples of 'Active Sensing', emphasizing an interaction between proactive and predictive top-down modulation of neuronal dynamics and bottom-up sensory input. PMID:22285024

  4. Adapting the Transtheoretical Model of Change to the Bereavement Process

    ERIC Educational Resources Information Center

    Calderwood, Kimberly A.

    2011-01-01

    Theorists currently believe that bereaved people undergo some transformation of self rather than returning to their original state. To advance our understanding of this process, this article presents an adaptation of Prochaska and DiClemente's transtheoretical model of change as it could be applied to the journey that bereaved individuals…

  5. Motivational influences on impression formation: outcome dependency, accuracy-driven attention, and individuating processes.

    PubMed

    Neuberg, S L; Fiske, S T

    1987-09-01

    How might being outcome dependent on another person influence the processes that one uses to form impressions of that person? We designed three experiments to investigate this question with respect to short-term, task-oriented outcome dependency. In all three experiments, subjects expected to interact with a young man formerly hospitalized as a schizophrenic, and they received information about the person's attributes in either written profiles or videotapes. In Experiment 1, short-term, task-oriented outcome dependency led subjects to use relatively individuating processes (i.e., to base their impressions of the patient on his particular attributes), even under conditions that typically lead subjects to use relatively category-based processes (i.e., to base their impressions on the patient's schizophrenic label). Moreover, in the conditions that elicited individuating processes, subjects spent more time attending to the patient's particular attribute information. Experiment 2 demonstrated that the attention effects in Experiment 1 were not merely a function of impression positivity and that outcome dependency did not influence the impression formation process when attribute information in addition to category-level information was unavailable. Finally, Experiment 3 manipulated not outcome dependency but the attentional goal of forming an accurate impression. We found that accuracy-driven attention to attribute information also led to individuating processes. The results of the three experiments indicate that there are important influences of outcome dependency on impression formation. These results are consistent with a model in which the tendency for short-term, task-oriented outcome dependency to facilitate individuating impression formation processes is mediated by an increase in accuracy-driven attention to attribute information.

  6. Motivational influences on impression formation: outcome dependency, accuracy-driven attention, and individuating processes.

    PubMed

    Neuberg, S L; Fiske, S T

    1987-09-01

    How might being outcome dependent on another person influence the processes that one uses to form impressions of that person? We designed three experiments to investigate this question with respect to short-term, task-oriented outcome dependency. In all three experiments, subjects expected to interact with a young man formerly hospitalized as a schizophrenic, and they received information about the person's attributes in either written profiles or videotapes. In Experiment 1, short-term, task-oriented outcome dependency led subjects to use relatively individuating processes (i.e., to base their impressions of the patient on his particular attributes), even under conditions that typically lead subjects to use relatively category-based processes (i.e., to base their impressions on the patient's schizophrenic label). Moreover, in the conditions that elicited individuating processes, subjects spent more time attending to the patient's particular attribute information. Experiment 2 demonstrated that the attention effects in Experiment 1 were not merely a function of impression positivity and that outcome dependency did not influence the impression formation process when attribute information in addition to category-level information was unavailable. Finally, Experiment 3 manipulated not outcome dependency but the attentional goal of forming an accurate impression. We found that accuracy-driven attention to attribute information also led to individuating processes. The results of the three experiments indicate that there are important influences of outcome dependency on impression formation. These results are consistent with a model in which the tendency for short-term, task-oriented outcome dependency to facilitate individuating impression formation processes is mediated by an increase in accuracy-driven attention to attribute information. PMID:3656080

  7. Behavioral training promotes multiple adaptive processes following acute hearing loss

    PubMed Central

    Keating, Peter; Rosenior-Patten, Onayomi; Dahmen, Johannes C; Bell, Olivia; King, Andrew J

    2016-01-01

    The brain possesses a remarkable capacity to compensate for changes in inputs resulting from a range of sensory impairments. Developmental studies of sound localization have shown that adaptation to asymmetric hearing loss can be achieved either by reinterpreting altered spatial cues or by relying more on those cues that remain intact. Adaptation to monaural deprivation in adulthood is also possible, but appears to lack such flexibility. Here we show, however, that appropriate behavioral training enables monaurally-deprived adult humans to exploit both of these adaptive processes. Moreover, cortical recordings in ferrets reared with asymmetric hearing loss suggest that these forms of plasticity have distinct neural substrates. An ability to adapt to asymmetric hearing loss using multiple adaptive processes is therefore shared by different species and may persist throughout the lifespan. This highlights the fundamental flexibility of neural systems, and may also point toward novel therapeutic strategies for treating sensory disorders. DOI: http://dx.doi.org/10.7554/eLife.12264.001 PMID:27008181

  8. Adaptive beamforming for array signal processing in aeroacoustic measurements.

    PubMed

    Huang, Xun; Bai, Long; Vinogradov, Igor; Peers, Edward

    2012-03-01

    Phased microphone arrays have become an important tool in the localization of noise sources for aeroacoustic applications. In most practical aerospace cases the conventional beamforming algorithm of the delay-and-sum type has been adopted. Conventional beamforming cannot take advantage of knowledge of the noise field, and thus has poorer resolution in the presence of noise and interference. Adaptive beamforming has been used for more than three decades to address these issues and has already achieved various degrees of success in areas of communication and sonar. In this work an adaptive beamforming algorithm designed specifically for aeroacoustic applications is discussed and applied to practical experimental data. It shows that the adaptive beamforming method could save significant amounts of post-processing time for a deconvolution method. For example, the adaptive beamforming method is able to reduce the DAMAS computation time by at least 60% for the practical case considered in this work. Therefore, adaptive beamforming can be considered as a promising signal processing method for aeroacoustic measurements.

  9. Topographical Organization of Attentional, Social, and Memory Processes in the Human Temporoparietal Cortex.

    PubMed

    Igelström, Kajsa M; Webb, Taylor W; Kelly, Yin T; Graziano, Michael S A

    2016-01-01

    The temporoparietal junction (TPJ) is activated in association with a large range of functions, including social cognition, episodic memory retrieval, and attentional reorienting. An ongoing debate is whether the TPJ performs an overarching, domain-general computation, or whether functions reside in domain-specific subdivisions. We scanned subjects with fMRI during five tasks known to activate the TPJ, probing social, attentional, and memory functions, and used data-driven parcellation (independent component analysis) to isolate task-related functional processes in the bilateral TPJ. We found that one dorsal component in the right TPJ, which was connected with the frontoparietal control network, was activated in all of the tasks. Other TPJ subregions were specific for attentional reorienting, oddball target detection, or social attribution of belief. The TPJ components that participated in attentional reorienting and oddball target detection appeared spatially separated, but both were connected with the ventral attention network. The TPJ component that participated in the theory-of-mind task was part of the default-mode network. Further, we found that the BOLD response in the domain-general dorsal component had a longer latency than responses in the domain-specific components, suggesting an involvement in distinct, perhaps postperceptual, computations. These findings suggest that the TPJ performs both domain-general and domain-specific computations that reside within spatially distinct functional components. PMID:27280153

  10. Attention modulates cortical processing of pitch feedback errors in voice control.

    PubMed

    Hu, Huijing; Liu, Ying; Guo, Zhiqiang; Li, Weifeng; Liu, Peng; Chen, Shaozhen; Liu, Hanjun

    2015-01-01

    Considerable evidence has shown that unexpected alterations in auditory feedback elicit fast compensatory adjustments in vocal production. Although generally thought to be involuntary in nature, whether these adjustments can be influenced by attention remains unknown. The present event-related potential (ERP) study aimed to examine whether neurobehavioral processing of auditory-vocal integration can be affected by attention. While sustaining a vowel phonation and hearing pitch-shifted feedback, participants were required to either ignore the pitch perturbations, or attend to them with low (counting the number of perturbations) or high attentional load (counting the type of perturbations). Behavioral results revealed no systematic change of vocal response to pitch perturbations irrespective of whether they were attended or not. At the level of cortex, there was an enhancement of P2 response to attended pitch perturbations in the low-load condition as compared to when they were ignored. In the high-load condition, however, P2 response did not differ from that in the ignored condition. These findings provide the first neurophysiological evidence that auditory-motor integration in voice control can be modulated as a function of attention at the level of cortex. Furthermore, this modulatory effect does not lead to a general enhancement but is subject to attentional load.

  11. Topographical Organization of Attentional, Social, and Memory Processes in the Human Temporoparietal Cortex123

    PubMed Central

    Webb, Taylor W.; Kelly, Yin T.; Graziano, Michael S. A.

    2016-01-01

    Abstract The temporoparietal junction (TPJ) is activated in association with a large range of functions, including social cognition, episodic memory retrieval, and attentional reorienting. An ongoing debate is whether the TPJ performs an overarching, domain-general computation, or whether functions reside in domain-specific subdivisions. We scanned subjects with fMRI during five tasks known to activate the TPJ, probing social, attentional, and memory functions, and used data-driven parcellation (independent component analysis) to isolate task-related functional processes in the bilateral TPJ. We found that one dorsal component in the right TPJ, which was connected with the frontoparietal control network, was activated in all of the tasks. Other TPJ subregions were specific for attentional reorienting, oddball target detection, or social attribution of belief. The TPJ components that participated in attentional reorienting and oddball target detection appeared spatially separated, but both were connected with the ventral attention network. The TPJ component that participated in the theory-of-mind task was part of the default-mode network. Further, we found that the BOLD response in the domain-general dorsal component had a longer latency than responses in the domain-specific components, suggesting an involvement in distinct, perhaps postperceptual, computations. These findings suggest that the TPJ performs both domain-general and domain-specific computations that reside within spatially distinct functional components. PMID:27280153

  12. Unraveling the sub-processes of selective attention: insights from dynamic modeling and continuous behavior.

    PubMed

    Frisch, Simon; Dshemuchadse, Maja; Görner, Max; Goschke, Thomas; Scherbaum, Stefan

    2015-11-01

    Selective attention biases information processing toward stimuli that are relevant for achieving our goals. However, the nature of this bias is under debate: Does it solely rely on the amplification of goal-relevant information or is there a need for additional inhibitory processes that selectively suppress currently distracting information? Here, we explored the processes underlying selective attention with a dynamic, modeling-based approach that focuses on the continuous evolution of behavior over time. We present two dynamic neural field models incorporating the diverging theoretical assumptions. Simulations with both models showed that they make similar predictions with regard to response times but differ markedly with regard to their continuous behavior. Human data observed via mouse tracking as a continuous measure of performance revealed evidence for the model solely based on amplification but no indication of persisting selective distracter inhibition. PMID:26232190

  13. Newly-formed emotional memories guide selective attention processes: Evidence from event-related potentials

    PubMed Central

    Schupp, Harald T.; Kirmse, Ursula; Schmälzle, Ralf; Flaisch, Tobias; Renner, Britta

    2016-01-01

    Emotional cues can guide selective attention processes. However, emotional stimuli can both activate long-term memory representations reflecting general world knowledge and engage newly formed memory representations representing specific knowledge from the immediate past. Here, the self-completion feature of associative memory was utilized to assess the regulation of attention processes by newly-formed emotional memory. First, new memory representations were formed by presenting pictures depicting a person either in an erotic pose or as a portrait. Afterwards, to activate newly-built memory traces, edited pictures were presented showing only the head region of the person. ERP recordings revealed the emotional regulation of attention by newly-formed memories. Specifically, edited pictures from the erotic compared to the portrait category elicited an early posterior negativity and late positive potential, similar to the findings observed for the original pictures. A control condition showed that the effect was dependent on newly-formed memory traces. Given the large number of new memories formed each day, they presumably make an important contribution to the regulation of attention in everyday life. PMID:27321471

  14. Newly-formed emotional memories guide selective attention processes: Evidence from event-related potentials.

    PubMed

    Schupp, Harald T; Kirmse, Ursula; Schmälzle, Ralf; Flaisch, Tobias; Renner, Britta

    2016-01-01

    Emotional cues can guide selective attention processes. However, emotional stimuli can both activate long-term memory representations reflecting general world knowledge and engage newly formed memory representations representing specific knowledge from the immediate past. Here, the self-completion feature of associative memory was utilized to assess the regulation of attention processes by newly-formed emotional memory. First, new memory representations were formed by presenting pictures depicting a person either in an erotic pose or as a portrait. Afterwards, to activate newly-built memory traces, edited pictures were presented showing only the head region of the person. ERP recordings revealed the emotional regulation of attention by newly-formed memories. Specifically, edited pictures from the erotic compared to the portrait category elicited an early posterior negativity and late positive potential, similar to the findings observed for the original pictures. A control condition showed that the effect was dependent on newly-formed memory traces. Given the large number of new memories formed each day, they presumably make an important contribution to the regulation of attention in everyday life. PMID:27321471

  15. Stress and selective attention: the interplay of mood, cortisol levels, and emotional information processing.

    PubMed

    Ellenbogen, Mark A; Schwartzman, Alex E; Stewart, Jane; Walker, Claire-Dominique

    2002-11-01

    The effects of a stressful challenge on the processing of emotional words were examined in college students. Stress induction was achieved using a competitive computer task, where the individual either repeatedly lost or won against a confederate. Mood, attention, and cortisol were recorded during the study. There were four findings: (1) Participants in the negative stressor condition were faster to shift attention away from negative words than positive or neutral words; (2) attentional shifts away from negative words were associated with stress-induced mood lowering; (3) participants in the negative stress condition with elevated scores on the Beck Depression Inventory were slow to disengage attention from all stimuli; and (4) elevated depression scores were associated with lower cortisol change from baseline during the experimental phase, and with higher cortisol levels during the recovery phase. These findings point to information-processing strategies as a means to regulate emotion, and to atypical features of cognitive and adrenocortical function that may serve as putative risk markers of depression.

  16. Sustained and transient attentional processes modulate neural predictors of memory encoding in consecutive time periods.

    PubMed

    Padovani, Tullia; Koenig, Thomas; Eckstein, Doris; Perrig, Walter J

    2013-07-01

    Memory formation is commonly thought to rely on brain activity following an event. Yet, recent research has shown that even brain activity previous to an event can predict later recollection (subsequent memory effect, SME). In order to investigate the attentional sources of the SME, event-related potentials (ERPs) elicited by task cues preceding target words were recorded in a switched task paradigm that was followed by a surprise recognition test. Stay trials, that is, those with the same task as the previous trial, were contrasted with switch trials, which included a task switch compared to the previous trial. The underlying assumption was that sustained attention would be dominant in stay trials and that transient attentional reconfiguration processes would be dominant in switch trials. To determine the SME, local and global statistics of scalp electric fields were used to identify differences between subsequently remembered and forgotten items. Results showed that the SME in stay trials occurred in a time window from 2 to 1 sec before target onset, whereas the SME in switch trials occurred subsequently, in a time window from 1 to 0 sec before target onset. Both SMEs showed a frontal negativity resembling the topography of previously reported effects, which suggests that sustained and transient attentional processes contribute to the prestimulus SME in consecutive time periods. PMID:24381815

  17. Selective Attention to Semantic and Syntactic Features Modulates Sentence Processing Networks in Anterior Temporal Cortex

    PubMed Central

    Rogalsky, Corianne

    2009-01-01

    Numerous studies have identified an anterior temporal lobe (ATL) region that responds preferentially to sentence-level stimuli. It is unclear, however, whether this activity reflects a response to syntactic computations or some form of semantic integration. This distinction is difficult to investigate with the stimulus manipulations and anomaly detection paradigms traditionally implemented. The present functional magnetic resonance imaging study addresses this question via a selective attention paradigm. Subjects monitored for occasional semantic anomalies or occasional syntactic errors, thus directing their attention to semantic integration, or syntactic properties of the sentences. The hemodynamic response in the sentence-selective ATL region (defined with a localizer scan) was examined during anomaly/error-free sentences only, to avoid confounds due to error detection. The majority of the sentence-specific region of interest was equally modulated by attention to syntactic or compositional semantic features, whereas a smaller subregion was only modulated by the semantic task. We suggest that the sentence-specific ATL region is sensitive to both syntactic and integrative semantic functions during sentence processing, with a smaller portion of this area preferentially involved in the later. This study also suggests that selective attention paradigms may be effective tools to investigate the functional diversity of networks involved in sentence processing. PMID:18669589

  18. Quantum state and process tomography via adaptive measurements

    NASA Astrophysics Data System (ADS)

    Wang, HengYan; Zheng, WenQiang; Yu, NengKun; Li, KeRen; Lu, DaWei; Xin, Tao; Li, Carson; Ji, ZhengFeng; Kribs, David; Zeng, Bei; Peng, XinHua; Du, JiangFeng

    2016-10-01

    We investigate quantum state tomography (QST) for pure states and quantum process tomography (QPT) for unitary channels via adaptive measurements. For a quantum system with a d-dimensional Hilbert space, we first propose an adaptive protocol where only 2 d - 1 measurement outcomes are used to accomplish the QST for all pure states. This idea is then extended to study QPT for unitary channels, where an adaptive unitary process tomography (AUPT) protocol of d 2+ d-1 measurement outcomes is constructed for any unitary channel. We experimentally implement the AUPT protocol in a 2-qubit nuclear magnetic resonance system. We examine the performance of the AUPT protocol when applied to Hadamard gate, T gate ( π/8 phase gate), and controlled-NOT gate, respectively, as these gates form the universal gate set for quantum information processing purpose. As a comparison, standard QPT is also implemented for each gate. Our experimental results show that the AUPT protocol that reconstructing unitary channels via adaptive measurements significantly reduce the number of experiments required by standard QPT without considerable loss of fidelity.

  19. Adaptive Process Control with Fuzzy Logic and Genetic Algorithms

    NASA Technical Reports Server (NTRS)

    Karr, C. L.

    1993-01-01

    Researchers at the U.S. Bureau of Mines have developed adaptive process control systems in which genetic algorithms (GA's) are used to augment fuzzy logic controllers (FLC's). GA's are search algorithms that rapidly locate near-optimum solutions to a wide spectrum of problems by modeling the search procedures of natural genetics. FLC's are rule based systems that efficiently manipulate a problem environment by modeling the 'rule-of-thumb' strategy used in human decision-making. Together, GA's and FLC's possess the capabilities necessary to produce powerful, efficient, and robust adaptive control systems. To perform efficiently, such control systems require a control element to manipulate the problem environment, an analysis element to recognize changes in the problem environment, and a learning element to adjust to the changes in the problem environment. Details of an overall adaptive control system are discussed. A specific laboratory acid-base pH system is used to demonstrate the ideas presented.

  20. Adaptive process control using fuzzy logic and genetic algorithms

    NASA Technical Reports Server (NTRS)

    Karr, C. L.

    1993-01-01

    Researchers at the U.S. Bureau of Mines have developed adaptive process control systems in which genetic algorithms (GA's) are used to augment fuzzy logic controllers (FLC's). GA's are search algorithms that rapidly locate near-optimum solutions to a wide spectrum of problems by modeling the search procedures of natural genetics. FLC's are rule based systems that efficiently manipulate a problem environment by modeling the 'rule-of-thumb' strategy used in human decision making. Together, GA's and FLC's possess the capabilities necessary to produce powerful, efficient, and robust adaptive control systems. To perform efficiently, such control systems require a control element to manipulate the problem environment, and a learning element to adjust to the changes in the problem environment. Details of an overall adaptive control system are discussed. A specific laboratory acid-base pH system is used to demonstrate the ideas presented.

  1. Peripheral Visual Cues: Their Fate in Processing and Effects on Attention and Temporal-Order Perception

    PubMed Central

    Tünnermann, Jan; Scharlau, Ingrid

    2016-01-01

    Peripheral visual cues lead to large shifts in psychometric distributions of temporal-order judgments. In one view, such shifts are attributed to attention speeding up processing of the cued stimulus, so-called prior entry. However, sometimes these shifts are so large that it is unlikely that they are caused by attention alone. Here we tested the prevalent alternative explanation that the cue is sometimes confused with the target on a perceptual level, bolstering the shift of the psychometric function. We applied a novel model of cued temporal-order judgments, derived from Bundesen's Theory of Visual Attention. We found that cue–target confusions indeed contribute to shifting psychometric functions. However, cue-induced changes in the processing rates of the target stimuli play an important role, too. At smaller cueing intervals, the cue increased the processing speed of the target. At larger intervals, inhibition of return was predominant. Earlier studies of cued TOJs were insensitive to these effects because in psychometric distributions they are concealed by the conjoint effects of cue–target confusions and processing rate changes. PMID:27766086

  2. I Can Read It in Your Eyes: What Eye Movements Tell Us about Visuo-Attentional Processes in Developmental Dyslexia

    ERIC Educational Resources Information Center

    Bellocchi, Stephanie; Muneaux, Mathilde; Bastien-Toniazzo, Mireille; Ducrot, Stephanie

    2013-01-01

    Most studies today agree about the link between visual-attention and oculomotor control during reading: attention seems to affect saccadic programming, that is, the position where the eyes land in a word. Moreover, recent studies show that visuo-attentional processes are strictly linked to normal and impaired reading. In particular, a large body…

  3. Epidemic processes over adaptive state-dependent networks

    NASA Astrophysics Data System (ADS)

    Ogura, Masaki; Preciado, Victor M.

    2016-06-01

    In this paper we study the dynamics of epidemic processes taking place in adaptive networks of arbitrary topology. We focus our study on the adaptive susceptible-infected-susceptible (ASIS) model, where healthy individuals are allowed to temporarily cut edges connecting them to infected nodes in order to prevent the spread of the infection. In this paper we derive a closed-form expression for a lower bound on the epidemic threshold of the ASIS model in arbitrary networks with heterogeneous node and edge dynamics. For networks with homogeneous node and edge dynamics, we show that the resulting lower bound is proportional to the epidemic threshold of the standard SIS model over static networks, with a proportionality constant that depends on the adaptation rates. Furthermore, based on our results, we propose an efficient algorithm to optimally tune the adaptation rates in order to eradicate epidemic outbreaks in arbitrary networks. We confirm the tightness of the proposed lower bounds with several numerical simulations and compare our optimal adaptation rates with popular centrality measures.

  4. Efficient true-time-delay adaptive array processing

    NASA Astrophysics Data System (ADS)

    Wagner, Kelvin H.; Kraut, Shawn; Griffiths, Lloyd J.; Weaver, Samuel P.; Weverka, Robert T.; Sarto, Anthony W.

    1996-11-01

    We present a novel and efficient approach to true-time-delay (TTD) beamforming for large adaptive phased arrays with N elements, for application in radar, sonar, and communication. This broadband and efficient adaptive method for time-delay array processing algorithm decreases the number of tapped delay lines required for N-element arrays form N to only 2, producing an enormous savings in optical hardware, especially for large arrays. This new adaptive system provides the full NM degrees of freedom of a conventional N element time delay beamformer with M taps, each, enabling it to fully and optimally adapt to an arbitrary complex spatio-temporal signal environment that can contain broadband signals, noise, and narrowband and broadband jammers, all of which can arrive from arbitrary angles onto an arbitrarily shaped array. The photonic implementation of this algorithm uses index gratings produce in the volume of photorefractive crystals as the adaptive weights in a TTD beamforming network, 1 or 2 acousto-optic devices for signal injection, and 1 or 2 time-delay-and- integrate detectors for signal extraction. This approach achieves significant reduction in hardware complexity when compared to systems employing discrete RF hardware for the weights or when compared to alternative optical systems that typically use N channel acousto-optic deflectors.

  5. A pox on the mind: Disjunction of attention and memory in the processing of physical disfigurement

    PubMed Central

    Ackerman, Joshua M.; Becker, D. Vaughn; Mortensen, Chad R.; Sasaki, Takao; Neuberg, Steven L.; Kenrick, Douglas T.

    2009-01-01

    The unfavorable treatment of people with physical disfigurements is well-documented, yet little is known about basic perceptual and cognitive responses to disfigurement. Here, we identify a specialized pattern of cognitive processing consistent with the hypothesis that disfigurements act as heuristic cues to contagious disease. Disfigurements are often invariant across time and difficult to conceal, and thus observers can detect the presence of such cues without necessarily remembering the particular individuals bearing these cues. Indeed, despite the fact that disfigured faces were especially likely to hold disease-sensitive perceivers’ attention (Study 1), disfigured individuals were often confused with one another and thus not well remembered later (Study 2), revealing a disjunction of the typical relationship between elevated attention and elevated memory. We discuss the implications of our results for stigmatization of people with and without physical abnormalities and suggest the possibility that cognitive mechanisms for processing social information may be functionally tuned to the variant nature of important cues. PMID:19578547

  6. Thermodynamic Costs of Information Processing in Sensory Adaptation

    PubMed Central

    Sartori, Pablo; Granger, Léo; Lee, Chiu Fan; Horowitz, Jordan M.

    2014-01-01

    Biological sensory systems react to changes in their surroundings. They are characterized by fast response and slow adaptation to varying environmental cues. Insofar as sensory adaptive systems map environmental changes to changes of their internal degrees of freedom, they can be regarded as computational devices manipulating information. Landauer established that information is ultimately physical, and its manipulation subject to the entropic and energetic bounds of thermodynamics. Thus the fundamental costs of biological sensory adaptation can be elucidated by tracking how the information the system has about its environment is altered. These bounds are particularly relevant for small organisms, which unlike everyday computers, operate at very low energies. In this paper, we establish a general framework for the thermodynamics of information processing in sensing. With it, we quantify how during sensory adaptation information about the past is erased, while information about the present is gathered. This process produces entropy larger than the amount of old information erased and has an energetic cost bounded by the amount of new information written to memory. We apply these principles to the E. coli's chemotaxis pathway during binary ligand concentration changes. In this regime, we quantify the amount of information stored by each methyl group and show that receptors consume energy in the range of the information-theoretic minimum. Our work provides a basis for further inquiries into more complex phenomena, such as gradient sensing and frequency response. PMID:25503948

  7. Small sample properties of an adaptive filter with application to low volume statistical process control

    SciTech Connect

    Crowder, S.V.; Eshleman, L.

    1998-08-01

    In many manufacturing environments such as the nuclear weapons complex, emphasis has shifted from the regular production and delivery of large orders to infrequent small orders. However, the challenge to maintain the same high quality and reliability standards white building much smaller lot sizes remains. To meet this challenge, specific areas need more attention, including fast and on-target process start-up, low volume statistical process control, process characterization with small experiments, and estimating reliability given few actual performance tests of the product. In this paper the authors address the issue of low volume statistical process control. They investigate an adaptive filtering approach to process monitoring with a relatively short time series of autocorrelated data. The emphasis is on estimation and minimization of mean squared error rather than the traditional hypothesis testing and run length analyses associated with process control charting. The authors develop an adaptive filtering technique that assumes initial process parameters are unknown, and updates the parameters as more data become available. Using simulation techniques, they study the data requirements (the length of a time series of autocorrelated data) necessary to adequately estimate process parameters. They show that far fewer data values are needed than is typically recommended for process control applications. And they demonstrate the techniques with a case study from the nuclear weapons manufacturing complex.

  8. Small Sample Properties of an Adaptive Filter with Application to Low Volume Statistical Process Control

    SciTech Connect

    CROWDER, STEPHEN V.

    1999-09-01

    In many manufacturing environments such as the nuclear weapons complex, emphasis has shifted from the regular production and delivery of large orders to infrequent small orders. However, the challenge to maintain the same high quality and reliability standards while building much smaller lot sizes remains. To meet this challenge, specific areas need more attention, including fast and on-target process start-up, low volume statistical process control, process characterization with small experiments, and estimating reliability given few actual performance tests of the product. In this paper we address the issue of low volume statistical process control. We investigate an adaptive filtering approach to process monitoring with a relatively short time series of autocorrelated data. The emphasis is on estimation and minimization of mean squared error rather than the traditional hypothesis testing and run length analyses associated with process control charting. We develop an adaptive filtering technique that assumes initial process parameters are unknown, and updates the parameters as more data become available. Using simulation techniques, we study the data requirements (the length of a time series of autocorrelated data) necessary to adequately estimate process parameters. We show that far fewer data values are needed than is typically recommended for process control applications. We also demonstrate the techniques with a case study from the nuclear weapons manufacturing complex.

  9. Beat processing is pre-attentive for metrically simple rhythms with clear accents: an ERP study.

    PubMed

    Bouwer, Fleur L; Van Zuijen, Titia L; Honing, Henkjan

    2014-01-01

    The perception of a regular beat is fundamental to music processing. Here we examine whether the detection of a regular beat is pre-attentive for metrically simple, acoustically varying stimuli using the mismatch negativity (MMN), an ERP response elicited by violations of acoustic regularity irrespective of whether subjects are attending to the stimuli. Both musicians and non-musicians were presented with a varying rhythm with a clear accent structure in which occasionally a sound was omitted. We compared the MMN response to the omission of identical sounds in different metrical positions. Most importantly, we found that omissions in strong metrical positions, on the beat, elicited higher amplitude MMN responses than omissions in weak metrical positions, not on the beat. This suggests that the detection of a beat is pre-attentive when highly beat inducing stimuli are used. No effects of musical expertise were found. Our results suggest that for metrically simple rhythms with clear accents beat processing does not require attention or musical expertise. In addition, we discuss how the use of acoustically varying stimuli may influence ERP results when studying beat processing.

  10. Beyond pleasure and arousal: appetitive erotic stimuli modulate electrophysiological brain correlates of early attentional processing.

    PubMed

    Kuhr, Benjamin; Schomberg, Jessica; Gruber, Thomas; Quirin, Markus

    2013-03-27

    Previous studies investigating affective reactions to pictures that elicit a specific effect have mainly focused on the dimensions valence and arousal. Using an event-related picture-viewing paradigm in electroencephalography, we investigated whether erotica - that is appetitive, evolutionarily relevant stimuli - have effects on early stages of attentional processing that are distinct from those of other positive and arousing stimuli. Seventeen male students viewed arousing photos of erotic, nude women or pictures of extreme sport scenes, as well as control pictures of attractive, dressed women or daily activities. Erotic pictures differed from extreme sport pictures not only in late but also in early attentional processes, as indicated by event-related potentials appearing from 130 ms after stimulus onset (P1). The findings suggest (a) that the dimension of appetence should be considered in addition to valence and arousal when investigating psychophysiological reactions to affective-motivational stimuli and (b) that early attentional processing as mirrored by the P1 can be influenced by motivational systems. PMID:23426107

  11. The role of automaticity and attention in neural processes underlying empathy for happiness, sadness, and anxiety

    PubMed Central

    Morelli, Sylvia A.; Lieberman, Matthew D.

    2013-01-01

    Although many studies have examined the neural basis of empathy, relatively little is known about how empathic processes are affected by different attentional conditions. Thus, we examined whether instructions to empathize might amplify responses in empathy-related regions and whether cognitive load would diminish the involvement of these regions. Thirty-two participants completed a functional magnetic resonance imaging session assessing empathic responses to individuals experiencing happy, sad, and anxious events. Stimuli were presented under three conditions: watching naturally, actively empathizing, and under cognitive load. Across analyses, we found evidence for a core set of neural regions that support empathic processes (dorsomedial prefrontal cortex, DMPFC; medial prefrontal cortex, MPFC; temporoparietal junction, TPJ; amygdala; ventral anterior insula, AI; and septal area, SA). Two key regions—the ventral AI and SA—were consistently active across all attentional conditions, suggesting that they are automatically engaged during empathy. In addition, watching vs. empathizing with targets was not markedly different and instead led to similar subjective and neural responses to others' emotional experiences. In contrast, cognitive load reduced the subjective experience of empathy and diminished neural responses in several regions related to empathy and social cognition (DMPFC, MPFC, TPJ, and amygdala). The results reveal how attention impacts empathic processes and provides insight into how empathy may unfold in everyday interactions. PMID:23658538

  12. Beat Processing Is Pre-Attentive for Metrically Simple Rhythms with Clear Accents: An ERP Study

    PubMed Central

    Bouwer, Fleur L.; Van Zuijen, Titia L.; Honing, Henkjan

    2014-01-01

    The perception of a regular beat is fundamental to music processing. Here we examine whether the detection of a regular beat is pre-attentive for metrically simple, acoustically varying stimuli using the mismatch negativity (MMN), an ERP response elicited by violations of acoustic regularity irrespective of whether subjects are attending to the stimuli. Both musicians and non-musicians were presented with a varying rhythm with a clear accent structure in which occasionally a sound was omitted. We compared the MMN response to the omission of identical sounds in different metrical positions. Most importantly, we found that omissions in strong metrical positions, on the beat, elicited higher amplitude MMN responses than omissions in weak metrical positions, not on the beat. This suggests that the detection of a beat is pre-attentive when highly beat inducing stimuli are used. No effects of musical expertise were found. Our results suggest that for metrically simple rhythms with clear accents beat processing does not require attention or musical expertise. In addition, we discuss how the use of acoustically varying stimuli may influence ERP results when studying beat processing. PMID:24870123

  13. Effects of selective attention on syntax processing in music and language.

    PubMed

    Maidhof, Clemens; Koelsch, Stefan

    2011-09-01

    The present study investigated the effects of auditory selective attention on the processing of syntactic information in music and speech using event-related potentials. Spoken sentences or musical chord sequences were either presented in isolation, or simultaneously. When presented simultaneously, participants had to focus their attention either on speech, or on music. Final words of sentences and final harmonies of chord sequences were syntactically either correct or incorrect. Irregular chords elicited an early right anterior negativity (ERAN), whose amplitude was decreased when music was simultaneously presented with speech, compared to when only music was presented. However, the amplitude of the ERAN-like waveform elicited when music was ignored did not differ from the conditions in which participants attended the chord sequences. Irregular sentences elicited an early left anterior negativity (ELAN), regardless of whether speech was presented in isolation, was attended, or was to be ignored. These findings suggest that the neural mechanisms underlying the processing of syntactic structure of music and speech operate partially automatically, and, in the case of music, are influenced by different attentional conditions. Moreover, the ERAN was slightly reduced when irregular sentences were presented, but only when music was ignored. Therefore, these findings provide no clear support for an interaction of neural resources for syntactic processing already at these early stages.

  14. Age-related decline in bottom-up processing and selective attention in the very old.

    PubMed

    Zhuravleva, Tatyana Y; Alperin, Brittany R; Haring, Anna E; Rentz, Dorene M; Holcomb, Philip J; Daffner, Kirk R

    2014-06-01

    Previous research demonstrating age-related deficits in selective attention have not included old-old adults, an increasingly important group to study. The current investigation compared event-related potentials in 15 young-old (65-79 years old) and 23 old-old (80-99 years old) subjects during a color-selective attention task. Subjects responded to target letters in a specified color (Attend) while ignoring letters in a different color (Ignore) under both low and high loads. There were no group differences in visual acuity, accuracy, reaction time, or latency of early event-related potential components. The old-old group showed a disruption in bottom-up processing, indexed by a substantially diminished posterior N1 (smaller amplitude). They also demonstrated markedly decreased modulation of bottom-up processing based on selected visual features, indexed by the posterior selection negativity (SN), with similar attenuation under both loads. In contrast, there were no group differences in frontally mediated attentional selection, measured by the anterior selection positivity (SP). There was a robust inverse relationship between the size of the SN and SP (the smaller the SN, the larger the SP), which may represent an anteriorly supported compensatory mechanism. In the absence of a decline in top-down modulation indexed by the SP, the diminished SN may reflect age-related degradation of early bottom-up visual processing in old-old adults.

  15. How attentional systems process conflicting cues. The superiority of social over symbolic orienting revisited.

    PubMed

    Nummenmaa, Lauri; Hietanen, Jari K

    2009-12-01

    We investigated orienting of attention by social and symbolic cues presented inside/outside the locus of attention. Participants responded to laterally presented targets preceded by simultaneously presented gaze and arrow cues. Participants' attention was allocated to either of the cues and the other cue served as a distractor. In Experiments 1-4 nonpredictive cues were employed. The validity of the attended cue and distractor were varied orthogonally. Valid cues and distractors produced additive facilitation to reaction times when compared to invalid cues and distractors. The effects of gaze and arrow distractors were similar. When the cue was 100% valid and the distractor 50% valid (Experiment 5), distractor validity had no effect on reaction times. When realistic gaze and arrow cues were employed (Experiment 6), arrow but not gaze distractors influenced the reaction times. The results suggest that social and symbolic directional information can be integrated for attention orienting. The processing of social and symbolic directional information can be modulated by top-down control, but the efficiency of the control depends on the visual saliency of the cues. PMID:19968432

  16. Rapid processing of letters, digits and symbols: what purely visual-attentional deficit in developmental dyslexia?

    PubMed

    Ziegler, Johannes C; Pech-Georgel, Catherine; Dufau, Stéphane; Grainger, Jonathan

    2010-07-01

    Visual-attentional theories of dyslexia predict deficits for dyslexic children not only for the perception of letter strings but also for non-alphanumeric symbol strings. This prediction was tested in a two-alternative forced-choice paradigm with letters, digits, and symbols. Children with dyslexia showed significant deficits for letter and digit strings but not for symbol strings. This finding is difficult to explain for visual-attentional theories of dyslexia which postulate identical deficits for letters, digits and symbols. Moreover, dyslexics showed normal W-shaped serial position functions for letter and digit strings, which suggests that their deficit is not due to an abnormally small attentional window. Finally, the size of the deficit was identical for letters and digits, which suggests that poor letter perception is not just a consequence of the lack of reading. Together then, our results show that symbols that map onto phonological codes are impaired (i.e. letters and digits), whereas symbols that do not map onto phonological codes are not impaired. This dissociation suggests that impaired symbol-sound mapping rather than impaired visual-attentional processing is the key to understanding dyslexia. PMID:20590718

  17. Adaptive Sampling for Learning Gaussian Processes Using Mobile Sensor Networks

    PubMed Central

    Xu, Yunfei; Choi, Jongeun

    2011-01-01

    This paper presents a novel class of self-organizing sensing agents that adaptively learn an anisotropic, spatio-temporal Gaussian process using noisy measurements and move in order to improve the quality of the estimated covariance function. This approach is based on a class of anisotropic covariance functions of Gaussian processes introduced to model a broad range of spatio-temporal physical phenomena. The covariance function is assumed to be unknown a priori. Hence, it is estimated by the maximum a posteriori probability (MAP) estimator. The prediction of the field of interest is then obtained based on the MAP estimate of the covariance function. An optimal sampling strategy is proposed to minimize the information-theoretic cost function of the Fisher Information Matrix. Simulation results demonstrate the effectiveness and the adaptability of the proposed scheme. PMID:22163785

  18. Asymmetry in infants' selective attention to facial features during visual processing of infant-directed speech

    PubMed Central

    Smith, Nicholas A.; Gibilisco, Colleen R.; Meisinger, Rachel E.; Hankey, Maren

    2013-01-01

    Two experiments used eye tracking to examine how infant and adult observers distribute their eye gaze on videos of a mother producing infant- and adult-directed speech. Both groups showed greater attention to the eyes than to the nose and mouth, as well as an asymmetrical focus on the talker's right eye for infant-directed speech stimuli. Observers continued to look more at the talker's apparent right eye when the video stimuli were mirror flipped, suggesting that the asymmetry reflects a perceptual processing bias rather than a stimulus artifact, which may be related to cerebral lateralization of emotion processing. PMID:24062705

  19. [Formula: see text] and [Formula: see text] Spoken Word Processing: Evidence from Divided Attention Paradigm.

    PubMed

    Shafiee Nahrkhalaji, Saeedeh; Lotfi, Ahmad Reza; Koosha, Mansour

    2016-10-01

    The present study aims to reveal some facts concerning first language ([Formula: see text] and second language ([Formula: see text] spoken-word processing in unbalanced proficient bilinguals using behavioral measures. The intention here is to examine the effects of auditory repetition word priming and semantic priming in first and second languages of these bilinguals. The other goal is to explore the effects of attention manipulation on implicit retrieval of perceptual and conceptual properties of spoken [Formula: see text] and [Formula: see text] words. In so doing, the participants performed auditory word priming and semantic priming as memory tests in their [Formula: see text] and [Formula: see text]. In a half of the trials of each experiment, they carried out the memory test while simultaneously performing a secondary task in visual modality. The results revealed that effects of auditory word priming and semantic priming were present when participants processed [Formula: see text] and [Formula: see text] words in full attention condition. Attention manipulation could reduce priming magnitude in both experiments in [Formula: see text]. Moreover, [Formula: see text] word retrieval increases the reaction times and reduces accuracy on the simultaneous secondary task to protect its own accuracy and speed.

  20. Electrophysiological evidence of multitasking impairment of attentional deployment reflects target-specific processing, not distractor inhibition.

    PubMed

    Corriveau, Isabelle; Fortier-Gauthier, Ulysse; Pomerleau, Vincent Jetté; McDonald, John; Dell'acqua, Roberto; Jolicoeur, Pierre

    2012-11-01

    We studied the interaction between the control mechanisms subserving spatial attention and central attention using the psychological refractory period (PRP) paradigm. Two stimuli, a pure tone (T(1)) and a circular visual array (T(2)), including a salient target and a salient distractor, were presented at varying stimulus onset asynchronies, each requiring a speeded response. Target-specific and distractor-specific lateralized event-related potentials were isolated by placing one of them at a lateral position and the other on the vertical midline. As SOA was decreased, a progressive reduction and postponement of a T(2)-locked N2pc component was observed with a lateral target and a central distractor. No lateralized potentials were associated with a lateral distractor and a central target. The sustained posterior contralateral negativity (SPCN) was observed independently of SOA modulation, only with a lateral target. We also observed an earlier positive deflection, the Ppc (positivity posterior contralateral), that was contralateral to both lateral targets and distractors, whose amplitude and latency were not affected by SOA variations. We conclude that central processing interferes specifically with target processing reflected by the N2pc and SPCN. We propose that the Ppc reflects an initial, bottom-up response to the presence of a salient stimulus, whereas the N2pc and SPCN reflect the controlled deployment of spatial attention to targets and maintenance of target information in visual short-term memory, respectively.

  1. Basic processes in reading aloud and colour naming: towards a better understanding of the role of spatial attention.

    PubMed

    Robidoux, Serje; Rauwerda, Derek; Besner, Derek

    2014-05-01

    Whether or not lexical access from print requires spatial attention has been debated intensively for the last 30 years. Studies involving colour naming generally find evidence that "unattended" words are processed. In contrast, reading-based experiments do not find evidence of distractor processing. One theory ascribes the discrepancy to weaker attentional demands for colour identification. If colour naming does not capture all of a subject's attention, the remaining attentional resources can be deployed to process the distractor word. The present study combined exogenous spatial cueing with colour naming and reading aloud separately and found that colour naming is less sensitive to the validity of a spatial cue than is reading words aloud. Based on these results, we argue that colour naming studies do not effectively control attention so that no conclusions about unattended distractor processing can be drawn from them. Thus we reiterate the consistent conclusion drawn from reading aloud and lexical decision studies: There is no word identification without (spatial) attention.

  2. Negative attention bias and processing deficits during the cognitive reappraisal of unpleasant emotions in HIV+ women.

    PubMed

    McIntosh, Roger C; Tartar, Jaime L; Widmayer, Susan; Rosselli, Monica

    2015-01-01

    Deficits in emotional processing may be attributed to HIV disease or comorbid psychiatric disorders. Electrocortical markers of emotional attention, i.e., amplitude of the P2 and late positive potential (LPP), were compared between 26 HIV+ women and 25 healthy controls during an emotional regulation paradigm. HIV+ women showed early attention bias to negative stimuli indexed by greater P2 amplitude. In contrast, compared with the passive viewing of unpleasant images, HIV+ women demonstrated attenuation of the early and late LPP during positive reappraisal. This interaction remained significant after adjusting for individual differences in apathy, anxiety, and depression. Post hoc analyses implicated time since HIV diagnosis with LPP attenuation during positive reappraisal. Advancing HIV disease may disrupt neural generators associated with the cognitive reappraisal of emotions independent of psychiatric function. PMID:25541865

  3. Human feature-based attention consists of two distinct spatiotemporal processes.

    PubMed

    Gledhill, Daniela; Grimsen, Cathleen; Fahle, Manfred; Wegener, Detlef

    2015-01-01

    In human and nonhuman primates, goal-directed behavior requires the selection of relevant pieces of information from the multitude of simultaneous sensory inputs. Feature-based attention (FBA) plays a crucial role in this selection by improving the neuronal representation of an attended stimulus feature. Of particular interest for understanding the neuronal mechanisms behind FBA is the processing fate of spatially unattended stimuli, either sharing the attended feature attribute or belonging to the attended or to a nonattended feature dimension. Using a wide range of cue/stimulus combinations, we investigated event-related potentials from the human brain, recorded under conditions of different feature attention but constant visual stimulation. We found that neural processing of visual stimuli sharing the dimension or the attribute of the attended target is associated with two distinct spatiotemporal processes, particularly prominent during the selection negativity period. Dimension-based modulation of neural signals first emerged over frontal electrode sites, and temporally preceded and accompanied attribute-specific FBA effects at occipital, parieto-occipital, and parietal electrodes. The findings suggest a process of FBA that not only increases responses of those neurons particularly tuned to the attended attribute but also modulates activity in the cortical module that is selective for the feature dimension to which the attended attribute belongs.

  4. Attentional strategic control over nonlexical and lexical processing in written spelling to dictation in adults.

    PubMed

    Bonin, Patrick; Collay, Sandra; Fayol, Michel; Méot, Alain

    2005-01-01

    We conducted four experiments to investigate whether adults can exert attentional strategic control over nonlexical and lexical processing in written spelling to dictation. In Experiment 1, regular and irregular words were produced either in a nonword context (regular and irregular nonwords) or in a word context (high-frequency regular and irregular words), whereas in Experiment 2, the same set of words was produced either in a regular nonword or in an irregular low-frequency word context. Experiment 3 was a replication of Experiment 2 but with increased manipulation of the context. In Experiment 4, participants had to produce either under time pressure or in response to standard written spelling instructions. Regularity effects were found in all the experiments, but their size was not reliably affected by manipulations intended to increase or decrease reliance on nonlexical processing. More particularly, the results from Experiment 4 show that adults can speed up the initialization of their writing responses to a substantial degree without altering regularity effects on either latencies or spelling errors. Our findings suggest that, although adults are able to generate an internal deadline criterion of when to initialize the writing responses, nonlexical processing is a mandatory process that is not subject to attentional strategic control in written spelling to dictation. PMID:15915793

  5. Reactive recruitment of attentional control in math anxiety: an ERP study of numeric conflict monitoring and adaptation.

    PubMed

    Suárez-Pellicioni, Macarena; Núñez-Peña, María Isabel; Colomé, Àngels

    2014-01-01

    This study uses event-related brain potentials (ERPs) to investigate the electrophysiological correlates of numeric conflict monitoring in math-anxious individuals, by analyzing whether math anxiety is related to abnormal processing in early conflict detection (as shown by the N450 component) and/or in a later, response-related stage of processing (as shown by the conflict sustained potential; Conflict-SP). Conflict adaptation effects were also studied by analyzing the effect of the previous trial's congruence in current interference. To this end, 17 low math-anxious (LMA) and 17 high math-anxious (HMA) individuals were presented with a numerical Stroop task. Groups were extreme in math anxiety but did not differ in trait or state anxiety or in simple math ability. The interference effect of the current trial (incongruent-congruent) and the interference effect preceded by congruence and by incongruity were analyzed both for behavioral measures and for ERPs. A greater interference effect was found for response times in the HMA group than in the LMA one. Regarding ERPs, the LMA group showed a greater N450 component for the interference effect preceded by congruence than when preceded by incongruity, while the HMA group showed greater Conflict-SP amplitude for the interference effect preceded by congruence than when preceded by incongruity. Our study showed that the electrophysiological correlates of numeric interference in HMA individuals comprise the absence of a conflict adaptation effect in the first stage of conflict processing (N450) and an abnormal subsequent up-regulation of cognitive control in order to overcome the conflict (Conflict-SP). More concretely, our study shows that math anxiety is related to a reactive and compensatory recruitment of control resources that is implemented only when previously exposed to a stimuli presenting conflicting information.

  6. Adaptive processes drive ecomorphological convergent evolution in antwrens (Thamnophilidae).

    PubMed

    Bravo, Gustavo A; Remsen, J V; Brumfield, Robb T

    2014-10-01

    Phylogenetic niche conservatism (PNC) and convergence are contrasting evolutionary patterns that describe phenotypic similarity across independent lineages. Assessing whether and how adaptive processes give origin to these patterns represent a fundamental step toward understanding phenotypic evolution. Phylogenetic model-based approaches offer the opportunity not only to distinguish between PNC and convergence, but also to determine the extent that adaptive processes explain phenotypic similarity. The Myrmotherula complex in the Neotropical family Thamnophilidae is a polyphyletic group of sexually dimorphic small insectivorous forest birds that are relatively homogeneous in size and shape. Here, we integrate a comprehensive species-level molecular phylogeny of the Myrmotherula complex with morphometric and ecological data within a comparative framework to test whether phenotypic similarity is described by a pattern of PNC or convergence, and to identify evolutionary mechanisms underlying body size and shape evolution. We show that antwrens in the Myrmotherula complex represent distantly related clades that exhibit adaptive convergent evolution in body size and divergent evolution in body shape. Phenotypic similarity in the group is primarily driven by their tendency to converge toward smaller body sizes. Differences in body size and shape across lineages are associated to ecological and behavioral factors.

  7. Contrasting emotion processing and executive functioning in attention-deficit/hyperactivity disorder and bipolar disorder.

    PubMed

    Soncin, Stephen; Brien, Donald C; Coe, Brian C; Marin, Alina; Munoz, Douglas P

    2016-10-01

    Attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder (BD) are highly comorbid and share executive function and emotion processing deficits, complicating diagnoses despite distinct clinical features. We compared performance on an oculomotor task that assessed these processes to capture subtle differences between ADHD and BD. The interaction between emotion processing and executive functioning may be informative because, although these processes overlap anatomically, certain regions that are compromised in each network are different in ADHD and BD. Adults, aged 18-62, with ADHD (n = 22), BD (n = 20), and healthy controls (n = 21) performed an interleaved pro- and antisaccade task (looking toward vs. looking away from a visual target, respectively). Task irrelevant emotional faces (fear, happy, sad, neutral) were presented on a subset of trials either before or with the target. The ADHD group made more direction errors (looked in the wrong direction) than controls. Presentation of negatively valenced (fear, sad) and ambiguous (neutral) emotional faces increased saccadic reaction time in BD only compared to controls, whereas longer presentation of sad faces modestly increased group differences. The antisaccade task differentiated ADHD from controls. Emotional processing further impaired processing speed in BD. We propose that the dorsolateral prefrontal cortex is critical in both processing systems, but the inhibitory signal this region generates is impacted by dysfunction in the emotion processing network, possibly at the orbitofrontal cortex, in BD. These results suggest there are differences in how emotion processing and executive functioning interact, which could be utilized to improve diagnostic specificity. (PsycINFO Database Record

  8. Optimal and adaptive methods of processing hydroacoustic signals (review)

    NASA Astrophysics Data System (ADS)

    Malyshkin, G. S.; Sidel'nikov, G. B.

    2014-09-01

    Different methods of optimal and adaptive processing of hydroacoustic signals for multipath propagation and scattering are considered. Advantages and drawbacks of the classical adaptive (Capon, MUSIC, and Johnson) algorithms and "fast" projection algorithms are analyzed for the case of multipath propagation and scattering of strong signals. The classical optimal approaches to detecting multipath signals are presented. A mechanism of controlled normalization of strong signals is proposed to automatically detect weak signals. The results of simulating the operation of different detection algorithms for a linear equidistant array under multipath propagation and scattering are presented. An automatic detector is analyzed, which is based on classical or fast projection algorithms, which estimates the background proceeding from median filtering or the method of bilateral spatial contrast.

  9. Parallel Processing of Adaptive Meshes with Load Balancing

    NASA Technical Reports Server (NTRS)

    Das, Sajal K.; Harvey, Daniel J.; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

    2001-01-01

    Many scientific applications involve grids that lack a uniform underlying structure. These applications are often also dynamic in nature in that the grid structure significantly changes between successive phases of execution. In parallel computing environments, mesh adaptation of unstructured grids through selective refinement/coarsening has proven to be an effective approach. However, achieving load balance while minimizing interprocessor communication and redistribution costs is a difficult problem. Traditional dynamic load balancers are mostly inadequate because they lack a global view of system loads across processors. In this paper, we propose a novel and general-purpose load balancer that utilizes symmetric broadcast networks (SBN) as the underlying communication topology, and compare its performance with a successful global load balancing environment, called PLUM, specifically created to handle adaptive unstructured applications. Our experimental results on an IBM SP2 demonstrate that the SBN-based load balancer achieves lower redistribution costs than that under PLUM by overlapping processing and data migration.

  10. Attention-like processes underlying optomotor performance in a Drosophila choice maze.

    PubMed

    van Swinderen, Bruno; Flores, Kristopher A

    2007-02-01

    The authors present a novel paradigm for studying visual responses in Drosophila. An eight-level choice maze was found to reliably segregate fly populations according to their responses to moving stripes displayed on a computer screen. Visual responsiveness was robust in wild-type flies, and performance depended on salience effects such as stimulus color and speed. Analysis of individual fly choices in the maze revealed that stereotypy, or choice persistence, contributed significantly to a strain's performance. On the basis of these observations, the authors bred wild-type flies for divergent visual phenotypes by selecting individual flies displaying extreme stereotypy. Selected flies alternated less often in the sequential choice maze than unselected flies, showing that stereotypy could evolve across generations. The authors found that selection for increased stereotypy impaired flies' responsiveness to competing stimuli in tests for attention-like behavior in the maze. Visual selective attention was further investigated by electrophysiology, and it was found that increased stereotypy also impaired responsiveness to competing stimuli at the level of brain activity. Combined results present a comprehensive approach to studying visual responses in Drosophila, and show that behavioral performance involves attention-like processes that are variable among individuals and thus sensitive to artificial selection.

  11. Self make-up: the influence of self-referential processing on attention orienting

    PubMed Central

    Zhao, Shuo; Uono, Shota; Yoshimura, Sayaka; Toichi, Motomi

    2015-01-01

    For humans, both eye gaze and arrows serve as powerful signals for orienting attention. Recent studies have shown important differences between gaze and arrows in attention orienting; however, the mechanisms underlying these differences are not known. One such mechanism may be self-referential processing. To investigate this possibility, we trained participants to associate two cues (a red and green arrow in Experiment 1A and two different faces in Experiment 1B) with distinct words (“self” and “other”). Then, we manipulated two types of sound (voice and tone) as targets to investigate whether the cueing effect to self- and other-referential cues differs in a manner similar to that reported for gaze and arrows. We found that self-, but not other-, referential cues induced an enhanced cueing effect to the voice target relative to the tone target regardless of the cue characteristic (i.e., biological or non-biological). Our results suggest that the difference between gaze and arrows in orienting attention can be explained, at least in part, by the self-referentiality of gaze. Furthermore, in Experiment 2, we found a reverse cueing pattern between gaze and arrow cues by manipulating subjects’ experiences, suggesting that differences in the self-referentiality of gaze and arrow cues are not inherent. PMID:26391177

  12. Temporal Context in Speech Processing and Attentional Stream Selection: A Behavioral and Neural perspective

    PubMed Central

    Zion Golumbic, Elana M.; Poeppel, David; Schroeder, Charles E.

    2012-01-01

    The human capacity for processing speech is remarkable, especially given that information in speech unfolds over multiple time scales concurrently. Similarly notable is our ability to filter out of extraneous sounds and focus our attention on one conversation, epitomized by the ‘Cocktail Party’ effect. Yet, the neural mechanisms underlying on-line speech decoding and attentional stream selection are not well understood. We review findings from behavioral and neurophysiological investigations that underscore the importance of the temporal structure of speech for achieving these perceptual feats. We discuss the hypothesis that entrainment of ambient neuronal oscillations to speech’s temporal structure, across multiple time-scales, serves to facilitate its decoding and underlies the selection of an attended speech stream over other competing input. In this regard, speech decoding and attentional stream selection are examples of ‘active sensing’, emphasizing an interaction between proactive and predictive top-down modulation of neuronal dynamics and bottom-up sensory input. PMID:22285024

  13. Effects of attention on the neural processing of harmonic syntax in Western music.

    PubMed

    Loui, Psyche; Grent-'t-Jong, Tineke; Torpey, Dana; Woldorff, Marty

    2005-12-01

    The effects of selective attention on the neural response to the violation of musical syntax were investigated in the present study. Musical chord progressions were played to nonmusicians while Event-Related Potentials (ERPs) were recorded. The five-chord progressions included 61% harmonically expected cadences (I-I(6)-IV-V-I), 26% harmonically unexpected cadences (I-I(6)-IV-V-N(6)), and 13% with one of the five chords having an intensity fadeout across its duration. During the attended condition, subjects responded by pressing a button upon detecting a fadeout in volume; during the unattended condition, subjects were given reading comprehension materials and instructed to ignore all auditory stimuli. In response to the harmonic deviant, an Early Anterior Negativity (EAN) was observed at 150-300 ms in both attention conditions, but it was much larger in amplitude in the attended condition. A second scalp-negative deflection was also identified at 380-600 ms following the harmonic deviants; this Late Negativity onset earlier during the attended condition. These results suggest strong effects of attention on the neural processing of harmonic syntax.

  14. Salience and Attention in Surprisal-Based Accounts of Language Processing

    PubMed Central

    Zarcone, Alessandra; van Schijndel, Marten; Vogels, Jorrig; Demberg, Vera

    2016-01-01

    The notion of salience has been singled out as the explanatory factor for a diverse range of linguistic phenomena. In particular, perceptual salience (e.g., visual salience of objects in the world, acoustic prominence of linguistic sounds) and semantic-pragmatic salience (e.g., prominence of recently mentioned or topical referents) have been shown to influence language comprehension and production. A different line of research has sought to account for behavioral correlates of cognitive load during comprehension as well as for certain patterns in language usage using information-theoretic notions, such as surprisal. Surprisal and salience both affect language processing at different levels, but the relationship between the two has not been adequately elucidated, and the question of whether salience can be reduced to surprisal / predictability is still open. Our review identifies two main challenges in addressing this question: terminological inconsistency and lack of integration between high and low levels of representations in salience-based accounts and surprisal-based accounts. We capitalize upon work in visual cognition in order to orient ourselves in surveying the different facets of the notion of salience in linguistics and their relation with models of surprisal. We find that work on salience highlights aspects of linguistic communication that models of surprisal tend to overlook, namely the role of attention and relevance to current goals, and we argue that the Predictive Coding framework provides a unified view which can account for the role played by attention and predictability at different levels of processing and which can clarify the interplay between low and high levels of processes and between predictability-driven expectation and attention-driven focus. PMID:27375525

  15. Impaired processing speed and attention in first-episode drug naive schizophrenia with deficit syndrome.

    PubMed

    Chen, Ce; Jiang, Wenhui; Zhong, Na; Wu, Jin; Jiang, Haifeng; Du, Jiang; Li, Ye; Ma, Xiancang; Zhao, Min; Hashimoto, Kenji; Gao, Chengge

    2014-11-01

    Although first-episode drug naive patients with schizophrenia are known to show cognitive impairment, the cognitive performances of these patients, who suffer deficit syndrome, compared with those who suffer non-deficit syndrome is undetermined. The aim of this study was to compare cognitive performances in first-episode drug-naive schizophrenia with deficit syndrome or non-deficit syndrome. First-episode drug naive patients (n=49) and medicated patients (n=108) with schizophrenia, and age, sex, and education matched healthy controls (n=57 for the first-episode group, and n=128 for the medicated group) were enrolled. Patients were divided into deficit or non-deficit syndrome groups, using the Schedule for Deficit Syndrome. Cognitive performance was assessed using the CogState computerized cognitive battery. All cognitive domains in first-episode drug naive and medicated patients showed significant impairment compared with their respective control groups. Furthermore, cognitive performance in first-episode drug naive patients was significantly worse than in medicated patients. Interestingly, the cognitive performance markers of processing speed and attention, in first-episode drug naive patients with deficit syndrome, were both significantly worse than in equivalent patients without deficit syndrome. In contrast, no differences in cognitive performance were found between the two groups of medicated patients. In conclusion, this study found that first-episode drug naive schizophrenia with deficit syndrome showed significantly impaired processing speed and attention, compared with patients with non-deficit syndrome. These findings highlight processing speed and attention as potential targets for pharmacological and psychosocial interventions in first-episode schizophrenia with deficit syndrome, since these domains are associated with social outcomes.

  16. Salience and Attention in Surprisal-Based Accounts of Language Processing.

    PubMed

    Zarcone, Alessandra; van Schijndel, Marten; Vogels, Jorrig; Demberg, Vera

    2016-01-01

    The notion of salience has been singled out as the explanatory factor for a diverse range of linguistic phenomena. In particular, perceptual salience (e.g., visual salience of objects in the world, acoustic prominence of linguistic sounds) and semantic-pragmatic salience (e.g., prominence of recently mentioned or topical referents) have been shown to influence language comprehension and production. A different line of research has sought to account for behavioral correlates of cognitive load during comprehension as well as for certain patterns in language usage using information-theoretic notions, such as surprisal. Surprisal and salience both affect language processing at different levels, but the relationship between the two has not been adequately elucidated, and the question of whether salience can be reduced to surprisal / predictability is still open. Our review identifies two main challenges in addressing this question: terminological inconsistency and lack of integration between high and low levels of representations in salience-based accounts and surprisal-based accounts. We capitalize upon work in visual cognition in order to orient ourselves in surveying the different facets of the notion of salience in linguistics and their relation with models of surprisal. We find that work on salience highlights aspects of linguistic communication that models of surprisal tend to overlook, namely the role of attention and relevance to current goals, and we argue that the Predictive Coding framework provides a unified view which can account for the role played by attention and predictability at different levels of processing and which can clarify the interplay between low and high levels of processes and between predictability-driven expectation and attention-driven focus. PMID:27375525

  17. The processing of emotional stimuli during periods of limited attentional resources in schizophrenia.

    PubMed

    Strauss, Gregory P; Catalano, Lauren T; Llerena, Katiah; Gold, James M

    2013-05-01

    When participants are asked to attend to two target stimuli in a rapid serial visual presentation sequence, the successful identification of the 1st target (T1) leads to transient impairment in reporting the 2nd target (T2)--this effect is known as the attentional blink (AB). In healthy individuals, this AB effect is either diminished or accentuated when emotional stimuli are presented in the T2 or T1 positions, respectively, suggesting that affective content influences bottom-up (i.e., exogenous) attention. In the current study, we conducted two separate experiments using the Emotional Attentional Blink paradigm where emotional words were presented in the T2 or T1 position to determine whether schizophrenia patients with high and low negative symptoms differ from controls in the extent to which emotional stimuli influence bottom-up attentional processes. Participants included 33 schizophrenia patients and 28 controls in Experiment 1 (T2 Task), and 30 schizophrenia patients and 24 controls in Experiment 2 (T1 Task). In both experiments, patients were divided into high (HI-NEG) and low (LOW-NEG) negative symptom subgroups using the Scale for the Assessment of Negative Symptoms. Results of Experiment 1 indicated that controls and LOW-NEG patients displayed the typical pattern of AB sparing at early lags for emotional relative to neutral words; however, HI-NEG patients showed no difference in T2 accuracy between emotional and neutral stimuli. Results of Experiment 2 indicated that controls and LOW-NEG patients displayed reduced T2 accuracy following unpleasant T1 stimuli, while HI-NEG patients showed no decrement in T2 accuracy after emotional T1s. Across both experiments, findings suggest that emotional stimuli have a bottom-up competitive advantage in LOW-NEG patients and controls; however, this bottom-up advantage is absent in HI-NEG patients.

  18. The Processing of Emotional Stimuli During Periods of Limited Attentional Resources in Schizophrenia

    PubMed Central

    Strauss, Gregory P.; Catalano, Lauren T.; Llerena, Katiah; Gold, James M.

    2013-01-01

    When participants are asked to attend to two target stimuli in a rapid serial visual presentation sequence the successful identification of the 1st target (T1) leads to transient impairment in reporting the 2nd target (T2)- this effect is known as the attentional blink (AB). In healthy individuals, this AB effect is either diminished or accentuated when emotional stimuli are presented in the T2 or T1 positions, respectively, suggesting that affective content influences bottom-up (i.e., exogenous) attention. In the current study, we conducted two separate experiments using the Emotional Attentional Blink paradigm where emotional words were presented in the T2 or T1 position to determine whether schizophrenia patients with high and low negative symptoms differ from controls in the extent to which emotional stimuli influence bottom-up attentional processes. Participants included 33 schizophrenia patients and 28 controls in Experiment 1 (T2 Task), and 30 schizophrenia patients and 24 controls in Experiment 2 (T1 Task). In both experiments, patients were divided into high (HI-NEG) and low (LOW-NEG) negative symptom sub-groups using the Scale for the Assessment of Negative Symptoms. Results of Experiment 1 indicated that controls and LOW-NEG patients displayed the typical pattern of AB sparing at early lags for emotional relative to neutral words; however, HI-NEG patients showed no difference in T2 accuracy between emotional and neutral stimuli. Results of Experiment 2 indicated that controls and LOW-NEG patients displayed reduced T2 accuracy following unpleasant T1 stimuli, while HI-NEG patients showed no decrement in T2 accuracy following emotional T1s. Across both experiments, findings suggest that emotional stimuli have a bottom-up competitive advantage in LOW-NEG patients and controls; however, this bottom-up advantage is absent in HI-NEG patients. PMID:23421529

  19. Text-speak processing and the sustained attention to response task.

    PubMed

    Head, James; Russell, Paul N; Dorahy, Martin J; Neumann, Ewald; Helton, William S

    2012-01-01

    We examined performance in a sustained attention to response task (SART) (Experiment 1) and a more traditionally formatted vigilance task (Experiment 2) using novel word stimuli (text-speak) and normally spelt words. This enabled us to address whether the SART is a better measure of sustained attention or of response strategy, and to investigate the cognitive demands of text-speak processing. In Experiment 1, 72 participants completed a subset (text-speak) and a word SART, as well as a self-reported text experience questionnaire. Those who reported more proficiency and experience with text-speak made more errors on the subset SART, but this appeared to be due to their increase in response speed. This did not occur in the word SART. In Experiment 2, 14 participants completed high No-Go, low-Go (more traditional response format) versions of these tasks to further investigate the cognitive demands of text-speak processing. Response latency increased over periods of watch only for the text-speak task, not for the word task. The results of Experiment 1 support the perspective that the SART is highly sensitive to response strategy, and the results of both experiments together indicate target detection tasks may be a novel way of investigating the cognitive demands of text-speak processing.

  20. Mental workload prediction based on attentional resource allocation and information processing.

    PubMed

    Xiao, Xu; Wanyan, Xiaoru; Zhuang, Damin

    2015-01-01

    Mental workload is an important component in complex human-machine systems. The limited applicability of empirical workload measures produces the need for workload modeling and prediction methods. In the present study, a mental workload prediction model is built on the basis of attentional resource allocation and information processing to ensure pilots' accuracy and speed in understanding large amounts of flight information on the cockpit display interface. Validation with an empirical study of an abnormal attitude recovery task showed that this model's prediction of mental workload highly correlated with experimental results. This mental workload prediction model provides a new tool for optimizing human factors interface design and reducing human errors. PMID:26406085

  1. On Cognition, Structured Sequence Processing, and Adaptive Dynamical Systems

    NASA Astrophysics Data System (ADS)

    Petersson, Karl Magnus

    2008-11-01

    Cognitive neuroscience approaches the brain as a cognitive system: a system that functionally is conceptualized in terms of information processing. We outline some aspects of this concept and consider a physical system to be an information processing device when a subclass of its physical states can be viewed as representational/cognitive and transitions between these can be conceptualized as a process operating on these states by implementing operations on the corresponding representational structures. We identify a generic and fundamental problem in cognition: sequentially organized structured processing. Structured sequence processing provides the brain, in an essential sense, with its processing logic. In an approach addressing this problem, we illustrate how to integrate levels of analysis within a framework of adaptive dynamical systems. We note that the dynamical system framework lends itself to a description of asynchronous event-driven devices, which is likely to be important in cognition because the brain appears to be an asynchronous processing system. We use the human language faculty and natural language processing as a concrete example through out.

  2. Adaptive ocean acoustic processing for a shallow ocean experiment

    SciTech Connect

    Candy, J.V.; Sullivan, E.J.

    1995-07-19

    A model-based approach is developed to solve an adaptive ocean acoustic signal processing problem. Here we investigate the design of model-based identifier (MBID) for a normal-mode model developed from a shallow water ocean experiment and then apply it to a set of experimental data demonstrating the feasibility of this approach. In this problem we show how the processor can be structured to estimate the horizontal wave numbers directly from measured pressure sound speed thereby eliminating the need for synthetic aperture processing or a propagation model solution. Ocean acoustic signal processing has made great strides over the past decade necessitated by the development of quieter submarines and the recent proliferation of diesel powered vessels.

  3. Adaptive PCA based fault diagnosis scheme in imperial smelting process.

    PubMed

    Hu, Zhikun; Chen, Zhiwen; Gui, Weihua; Jiang, Bin

    2014-09-01

    In this paper, an adaptive fault detection scheme based on a recursive principal component analysis (PCA) is proposed to deal with the problem of false alarm due to normal process changes in real process. Our further study is also dedicated to develop a fault isolation approach based on Generalized Likelihood Ratio (GLR) test and Singular Value Decomposition (SVD) which is one of general techniques of PCA, on which the off-set and scaling fault can be easily isolated with explicit off-set fault direction and scaling fault classification. The identification of off-set and scaling fault is also applied. The complete scheme of PCA-based fault diagnosis procedure is proposed. The proposed scheme is first applied to Imperial Smelting Process, and the results show that the proposed strategies can be able to mitigate false alarms and isolate faults efficiently.

  4. Independent effects of eye gaze and spatial attention on the processing of tactile events: Evidence from event-related potentials.

    PubMed

    Gherri, Elena; Forster, Bettina

    2015-07-01

    Directing one's gaze at a body part reduces detection speed and enhances the processing of tactile stimuli presented at the gazed location. Given the close links between spatial attention and the oculomotor system it is possible that these gaze- dependent modulations of touch are mediated by attentional mechanisms. To investigate this possibility, gaze direction and sustained tactile attention were orthogonally manipulated in the present study. Participants covertly attended to one hand to perform a tactile target-nontarget discrimination while they gazed at the same or opposite hand. Spatial attention resulted in enhancements of the somatosensory P100 and Nd components. In contrast, gaze resulted in modulations of the N140 component with more positive ERPs for gazed than non gazed stimuli. This dissociation in the pattern and timing of the effects of gaze and attention on somatosensory processing reveals that gaze and attention have independent effects on touch. PMID:26101088

  5. A general framework for adaptive processing of data structures.

    PubMed

    Frasconi, P; Gori, M; Sperduti, A

    1998-01-01

    A structured organization of information is typically required by symbolic processing. On the other hand, most connectionist models assume that data are organized according to relatively poor structures, like arrays or sequences. The framework described in this paper is an attempt to unify adaptive models like artificial neural nets and belief nets for the problem of processing structured information. In particular, relations between data variables are expressed by directed acyclic graphs, where both numerical and categorical values coexist. The general framework proposed in this paper can be regarded as an extension of both recurrent neural networks and hidden Markov models to the case of acyclic graphs. In particular we study the supervised learning problem as the problem of learning transductions from an input structured space to an output structured space, where transductions are assumed to admit a recursive hidden statespace representation. We introduce a graphical formalism for representing this class of adaptive transductions by means of recursive networks, i.e., cyclic graphs where nodes are labeled by variables and edges are labeled by generalized delay elements. This representation makes it possible to incorporate the symbolic and subsymbolic nature of data. Structures are processed by unfolding the recursive network into an acyclic graph called encoding network. In so doing, inference and learning algorithms can be easily inherited from the corresponding algorithms for artificial neural networks or probabilistic graphical model.

  6. [Super sweet corn hybrids adaptability for industrial processing. I freezing].

    PubMed

    Alfonzo, Braunnier; Camacho, Candelario; Ortiz de Bertorelli, Ligia; De Venanzi, Frank

    2002-09-01

    With the purpose of evaluating adaptability to the freezing process of super sweet corn sh2 hybrids Krispy King, Victor and 324, 100 cobs of each type were frozen at -18 degrees C. After 120 days of storage, their chemical, microbiological and sensorial characteristics were compared with a sweet corn su. Industrial quality of the process of freezing and length and number of rows in cobs were also determined. Results revealed yields above 60% in frozen corns. Length and number of rows in cobs were acceptable. Most of the chemical characteristics of super sweet hybrids were not different from the sweet corn assayed at the 5% significance level. Moisture content and soluble solids of hybrid Victor, as well as total sugars of hybrid 324 were statistically different. All sh2 corns had higher pH values. During freezing, soluble solids concentration, sugars and acids decreased whereas pH increased. Frozen cobs exhibited acceptable microbiological rank, with low activities of mesophiles and total coliforms, absence of psychrophiles and fecal coliforms, and an appreciable amount of molds. In conclusion, sh2 hybrids adapted with no problems to the freezing process, they had lower contents of soluble solids and higher contents of total sugars, which almost doubled the amount of su corn; flavor, texture, sweetness and appearance of kernels were also better. Hybrid Victor was preferred by the evaluating panel and had an outstanding performance due to its yield and sensorial characteristics. PMID:12448345

  7. Landsat ecosystem disturbance adaptive processing system (LEDAPS) algorithm description

    USGS Publications Warehouse

    Schmidt, Gail; Jenkerson, Calli; Masek, Jeffrey; Vermote, Eric; Gao, Feng

    2013-01-01

    The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) software was originally developed by the National Aeronautics and Space Administration–Goddard Space Flight Center and the University of Maryland to produce top-of-atmosphere reflectance from LandsatThematic Mapper and Enhanced Thematic Mapper Plus Level 1 digital numbers and to apply atmospheric corrections to generate a surface-reflectance product.The U.S. Geological Survey (USGS) has adopted the LEDAPS algorithm for producing the Landsat Surface Reflectance Climate Data Record.This report discusses the LEDAPS algorithm, which was implemented by the USGS.

  8. Prediction and control of chaotic processes using nonlinear adaptive networks

    SciTech Connect

    Jones, R.D.; Barnes, C.W.; Flake, G.W.; Lee, K.; Lewis, P.S.; O'Rouke, M.K.; Qian, S.

    1990-01-01

    We present the theory of nonlinear adaptive networks and discuss a few applications. In particular, we review the theory of feedforward backpropagation networks. We then present the theory of the Connectionist Normalized Linear Spline network in both its feedforward and iterated modes. Also, we briefly discuss the theory of stochastic cellular automata. We then discuss applications to chaotic time series, tidal prediction in Venice lagoon, finite differencing, sonar transient detection, control of nonlinear processes, control of a negative ion source, balancing a double inverted pendulum and design advice for free electron lasers and laser fusion targets.

  9. Selective attention modulates the effect of target location probability on redundant signal processing.

    PubMed

    Chang, Ting-Yun; Little, Daniel R; Yang, Cheng-Ta

    2016-08-01

    We investigated the decision process underlying the detection of targets at multiple locations. In three experiments using the same observers, target location probability and attentional instructions were manipulated. A redundant-target detection task was conducted in which participants were required to detect a dot presented at one of two locations. When the dot appeared at the two locations with equal frequency (Experiment 1), those participants who were found to have limited to unlimited capacity were shown to adopt a parallel, self-terminating strategy. By contrast, those participants who had supercapacity were shown to process redundant targets in a coactive manner. When targets were presented with unequal probability, two participants adopted a parallel, self-terminating strategy regardless of whether they were informed the target location probability (Experiment 3) or not (Experiment 2). For the remaining two participants, the strategy changed from parallel, self-terminating to serial, self-terminating as a result of the probability instructions. In Experiments 2 and 3, all the participants were of unlimited to limited capacity. Taken together, these results suggest that target location probability differently affects the selection of a decision strategy and highlight the role of controlled attention in selecting a decision strategy.

  10. Temporal processing impairment in children with attention-deficit-hyperactivity disorder.

    PubMed

    Huang, Jia; Yang, Bin-rang; Zou, Xiao-bing; Jing, Jin; Pen, Gang; McAlonan, Gráinne M; Chan, Raymond C K

    2012-01-01

    The current study aimed to investigate temporal processing in Chinese children with Attention-Deficit-Hyperactivity Disorder(ADHD) using time production, time reproduction paradigm and duration discrimination tasks. A battery of tests specifically designed to measure temporal processing was administered to 94 children with ADHD and 100 demographically matched healthy children. A multivariate analysis of variance (MANOVA) and a repeated measure MANOVA indicated that children with ADHD were impaired in time processing functions. The results of pairwise comparisons showed that the probands with a family history of ADHD performed significantly worse than those without family history in the time production tasks and the time reproduction task. Logistic regression analysis showed duration discrimination had a significant role in predicting whether the children were suffering from ADHD or not, while temporal processing had a significant role in predicting whether the ADHD children had a family history or not. This study provides further support for the existence of a generic temporal processing impairment in ADHD children and suggests that abnormalities in time processing and ADHD share some common genetic factors. PMID:22119703

  11. [Evenly floating attention, models and theories of the cognitive process of the psychoanalyst].

    PubMed

    König, H

    1996-04-01

    The perception process taking place in the mind of the analyst in the psycho-analytic situation is a constant oscillation between the temptation to be guided too much by theory and the dangers of trusting to feelings and intuition alone. In order to avoid the pitfalls of this Scylla and Charybdis situation and with a view to reconciling empathy and knowledge in such a way as to provide optimal access to the patient's unconscious, the author draws upon a model devised by W.R. Bion. The author claims that Bion's model, an intermedium between affect and cognition, achieves the integration of evenly suspended attention and theory-guided perception by taking account of patient's experiential objects while at the same time allowing scope for cognitive activity, a process which Bion calls "intervening phase" König then briefly recounts a case study illustrating the possibility of achieving interpretations that combine both empathy and knowledge. PMID:8685384

  12. [Evenly floating attention, models and theories of the cognitive process of the psychoanalyst].

    PubMed

    König, H

    1996-04-01

    The perception process taking place in the mind of the analyst in the psycho-analytic situation is a constant oscillation between the temptation to be guided too much by theory and the dangers of trusting to feelings and intuition alone. In order to avoid the pitfalls of this Scylla and Charybdis situation and with a view to reconciling empathy and knowledge in such a way as to provide optimal access to the patient's unconscious, the author draws upon a model devised by W.R. Bion. The author claims that Bion's model, an intermedium between affect and cognition, achieves the integration of evenly suspended attention and theory-guided perception by taking account of patient's experiential objects while at the same time allowing scope for cognitive activity, a process which Bion calls "intervening phase" König then briefly recounts a case study illustrating the possibility of achieving interpretations that combine both empathy and knowledge.

  13. Polymer Solidification and Stabilization: Adaptable Processes for Atypical Wastes

    SciTech Connect

    Jensen, C.

    2007-07-01

    Vinyl Ester Styrene (VES) and Advanced Polymer Solidification (APS{sup TM}) processes are used to solidify, stabilize, and immobilize radioactive, pyrophoric and hazardous wastes at US Department of Energy (DOE) and Department of Defense (DOD) sites, and commercial nuclear facilities. A wide range of projects have been accomplished, including in situ immobilization of ion exchange resin and carbon filter media in decommissioned submarines; underwater solidification of zirconium and hafnium machining swarf; solidification of uranium chips; impregnation of depth filters; immobilization of mercury, lead and other hazardous wastes (including paint chips and blasting media); and in situ solidification of submerged demineralizers. Discussion of the adaptability of the VES and APS{sup TM} processes is timely, given the decommissioning work at government sites, and efforts by commercial nuclear plants to reduce inventories of one-of-a-kind wastes. The VES and APS{sup TM} media and processes are highly adaptable to a wide range of waste forms, including liquids, slurries, bead and granular media; as well as metal fines, particles and larger pieces. With the ability to solidify/stabilize liquid wastes using high-speed mixing; wet sludges and solids by low-speed mixing; or bead and granular materials through in situ processing, these polymer will produce a stable, rock-hard product that has the ability to sequester many hazardous waste components and create Class B and C stabilized waste forms for disposal. Technical assessment and approval of these solidification processes and final waste forms have been greatly simplified by exhaustive waste form testing, as well as multiple NRC and CRCPD waste form approvals. (authors)

  14. Attention Modulates the Auditory Cortical Processing of Spatial and Category Cues in Naturalistic Auditory Scenes

    PubMed Central

    Renvall, Hanna; Staeren, Noël; Barz, Claudia S.; Ley, Anke; Formisano, Elia

    2016-01-01

    This combined fMRI and MEG study investigated brain activations during listening and attending to natural auditory scenes. We first recorded, using in-ear microphones, vocal non-speech sounds, and environmental sounds that were mixed to construct auditory scenes containing two concurrent sound streams. During the brain measurements, subjects attended to one of the streams while spatial acoustic information of the scene was either preserved (stereophonic sounds) or removed (monophonic sounds). Compared to monophonic sounds, stereophonic sounds evoked larger blood-oxygenation-level-dependent (BOLD) fMRI responses in the bilateral posterior superior temporal areas, independent of which stimulus attribute the subject was attending to. This finding is consistent with the functional role of these regions in the (automatic) processing of auditory spatial cues. Additionally, significant differences in the cortical activation patterns depending on the target of attention were observed. Bilateral planum temporale and inferior frontal gyrus were preferentially activated when attending to stereophonic environmental sounds, whereas when subjects attended to stereophonic voice sounds, the BOLD responses were larger at the bilateral middle superior temporal gyrus and sulcus, previously reported to show voice sensitivity. In contrast, the time-resolved MEG responses were stronger for mono- than stereophonic sounds in the bilateral auditory cortices at ~360 ms after the stimulus onset when attending to the voice excerpts within the combined sounds. The observed effects suggest that during the segregation of auditory objects from the auditory background, spatial sound cues together with other relevant temporal and spectral cues are processed in an attention-dependent manner at the cortical locations generally involved in sound recognition. More synchronous neuronal activation during monophonic than stereophonic sound processing, as well as (local) neuronal inhibitory mechanisms in

  15. Altered attentional and perceptual processes as indexed by N170 during gaze perception in schizophrenia: Relationship with perceived threat and paranoid delusions.

    PubMed

    Tso, Ivy F; Calwas, Anita M; Chun, Jinsoo; Mueller, Savanna A; Taylor, Stephan F; Deldin, Patricia J

    2015-08-01

    Using gaze information to orient attention and guide behavior is critical to social adaptation. Previous studies have suggested that abnormal gaze perception in schizophrenia (SCZ) may originate in abnormal early attentional and perceptual processes and may be related to paranoid symptoms. Using event-related brain potentials (ERPs), this study investigated altered early attentional and perceptual processes during gaze perception and their relationship to paranoid delusions in SCZ. Twenty-eight individuals with SCZ or schizoaffective disorder and 32 demographically matched healthy controls (HCs) completed a gaze-discrimination task with face stimuli varying in gaze direction (direct, averted), head orientation (forward, deviated), and emotion (neutral, fearful). ERPs were recorded during the task. Participants rated experienced threat from each face after the task. Participants with SCZ were as accurate as, though slower than, HCs on the task. Participants with SCZ displayed enlarged N170 responses over the left hemisphere to averted gaze presented in fearful relative to neutral faces, indicating a heightened encoding sensitivity to faces signaling external threat. This abnormality was correlated with increased perceived threat and paranoid delusions. Participants with SCZ also showed a reduction of N170 modulation by head orientation (normally increased amplitude to deviated faces relative to forward faces), suggesting less integration of contextual cues of head orientation in gaze perception. The psychophysiological deviations observed during gaze discrimination in SCZ underscore the role of early attentional and perceptual abnormalities in social information processing and paranoid symptoms of SCZ. PMID:25894438

  16. Contrasting emotion processing and executive functioning in attention-deficit/hyperactivity disorder and bipolar disorder.

    PubMed

    Soncin, Stephen; Brien, Donald C; Coe, Brian C; Marin, Alina; Munoz, Douglas P

    2016-10-01

    Attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder (BD) are highly comorbid and share executive function and emotion processing deficits, complicating diagnoses despite distinct clinical features. We compared performance on an oculomotor task that assessed these processes to capture subtle differences between ADHD and BD. The interaction between emotion processing and executive functioning may be informative because, although these processes overlap anatomically, certain regions that are compromised in each network are different in ADHD and BD. Adults, aged 18-62, with ADHD (n = 22), BD (n = 20), and healthy controls (n = 21) performed an interleaved pro- and antisaccade task (looking toward vs. looking away from a visual target, respectively). Task irrelevant emotional faces (fear, happy, sad, neutral) were presented on a subset of trials either before or with the target. The ADHD group made more direction errors (looked in the wrong direction) than controls. Presentation of negatively valenced (fear, sad) and ambiguous (neutral) emotional faces increased saccadic reaction time in BD only compared to controls, whereas longer presentation of sad faces modestly increased group differences. The antisaccade task differentiated ADHD from controls. Emotional processing further impaired processing speed in BD. We propose that the dorsolateral prefrontal cortex is critical in both processing systems, but the inhibitory signal this region generates is impacted by dysfunction in the emotion processing network, possibly at the orbitofrontal cortex, in BD. These results suggest there are differences in how emotion processing and executive functioning interact, which could be utilized to improve diagnostic specificity. (PsycINFO Database Record PMID:27537826

  17. Adaptation as process: the future of Darwinism and the legacy of Theodosius Dobzhansky.

    PubMed

    Depew, David J

    2011-03-01

    Conceptions of adaptation have varied in the history of genetic Darwinism depending on whether what is taken to be focal is the process of adaptation, adapted states of populations, or discrete adaptations in individual organisms. I argue that Theodosius Dobzhansky's view of adaptation as a dynamical process contrasts with so-called "adaptationist" views of natural selection figured as "design-without-a-designer" of relatively discrete, enumerable adaptations. Correlated with these respectively process and product oriented approaches to adaptive natural selection are divergent pictures of organisms themselves as developmental wholes or as "bundles" of adaptations. While even process versions of genetical Darwinism are insufficiently sensitive to the fact much of the variation on which adaptive selection works consists of changes in the timing, rate, or location of ontogenetic events, I argue that articulations of the Modern Synthesis influenced by Dobzhansky are more easily reconciled with the recent shift to evolutionary developmentalism than are versions that make discrete adaptations central.

  18. Attentional gain and processing capacity limits predict the propensity to neglect unexpected visual stimuli.

    PubMed

    Papera, Massimiliano; Richards, Anne

    2016-05-01

    Exogenous allocation of attentional resources allows the visual system to encode and maintain representations of stimuli in visual working memory (VWM). However, limits in the processing capacity to allocate resources can prevent unexpected visual stimuli from gaining access to VWM and thereby to consciousness. Using a novel approach to create unbiased stimuli of increasing saliency, we investigated visual processing during a visual search task in individuals who show a high or low propensity to neglect unexpected stimuli. When propensity to inattention is high, ERP recordings show a diminished amplification concomitantly with a decrease in theta band power during the N1 latency, followed by a poor target enhancement during the N2 latency. Furthermore, a later modulation in the P3 latency was also found in individuals showing propensity to visual neglect, suggesting that more effort is required for conscious maintenance of visual information in VWM. Effects during early stages of processing (N80 and P1) were also observed suggesting that sensitivity to contrasts and medium-to-high spatial frequencies may be modulated by low-level saliency (albeit no statistical group differences were found). In accordance with the Global Workplace Model, our data indicate that a lack of resources in low-level processors and visual attention may be responsible for the failure to "ignite" a state of high-level activity spread across several brain areas that is necessary for stimuli to access awareness. These findings may aid in the development of diagnostic tests and intervention to detect/reduce inattention propensity to visual neglect of unexpected stimuli. PMID:26849023

  19. Attentional gain and processing capacity limits predict the propensity to neglect unexpected visual stimuli.

    PubMed

    Papera, Massimiliano; Richards, Anne

    2016-05-01

    Exogenous allocation of attentional resources allows the visual system to encode and maintain representations of stimuli in visual working memory (VWM). However, limits in the processing capacity to allocate resources can prevent unexpected visual stimuli from gaining access to VWM and thereby to consciousness. Using a novel approach to create unbiased stimuli of increasing saliency, we investigated visual processing during a visual search task in individuals who show a high or low propensity to neglect unexpected stimuli. When propensity to inattention is high, ERP recordings show a diminished amplification concomitantly with a decrease in theta band power during the N1 latency, followed by a poor target enhancement during the N2 latency. Furthermore, a later modulation in the P3 latency was also found in individuals showing propensity to visual neglect, suggesting that more effort is required for conscious maintenance of visual information in VWM. Effects during early stages of processing (N80 and P1) were also observed suggesting that sensitivity to contrasts and medium-to-high spatial frequencies may be modulated by low-level saliency (albeit no statistical group differences were found). In accordance with the Global Workplace Model, our data indicate that a lack of resources in low-level processors and visual attention may be responsible for the failure to "ignite" a state of high-level activity spread across several brain areas that is necessary for stimuli to access awareness. These findings may aid in the development of diagnostic tests and intervention to detect/reduce inattention propensity to visual neglect of unexpected stimuli.

  20. Processing speed training increases the efficiency of attentional resource allocation in young adults.

    PubMed

    Burge, Wesley K; Ross, Lesley A; Amthor, Franklin R; Mitchell, William G; Zotov, Alexander; Visscher, Kristina M

    2013-01-01

    Cognitive training has been shown to improve performance on a range of tasks. However, the mechanisms underlying these improvements are still unclear. Given the wide range of transfer effects, it is likely that these effects are due to a factor common to a wide range of tasks. One such factor is a participant's efficiency in allocating limited cognitive resources. The impact of a cognitive training program, Processing Speed Training (PST), on the allocation of resources to a set of visual tasks was measured using pupillometry in 10 young adults as compared to a control group of a 10 young adults (n = 20). PST is a well-studied computerized training program that involves identifying simultaneously presented central and peripheral stimuli. As training progresses, the task becomes increasingly more difficult, by including peripheral distracting stimuli and decreasing the duration of stimulus presentation. Analysis of baseline data confirmed that pupil diameter reflected cognitive effort. After training, participants randomized to PST used fewer attentional resources to perform complex visual tasks as compared to the control group. These pupil diameter data indicated that PST appears to increase the efficiency of attentional resource allocation. Increases in cognitive efficiency have been hypothesized to underlie improvements following experience with action video games, and improved cognitive efficiency has been hypothesized to underlie the benefits of PST in older adults. These data reveal that these training schemes may share a common underlying mechanism of increasing cognitive efficiency in younger adults. PMID:24151461

  1. How do selective attentional processes contribute to maintenance and recall in children's working memory capacity?

    PubMed

    Roome, Hannah E; Towse, John N; Jarrold, Chris

    2014-01-01

    The development of working memory capacity is considered from the perspective of the active maintenance of items in primary memory (PM) and a cue-dependent search component, secondary memory (SM). Using free recall, plus a more novel serial interleaved items task, age-related increases in PM estimates were evident in both paradigms. In addition to this, age-related improvements in attentional selectivity were observed, indexed by the recall of target and non-target information respectively. To further characterize PM, presentation modality was varied in the serial interleaved items task (auditory, visual and dual presentation). Developmental differences were found in the effectiveness of presentation formats. Older children's recall was enhanced by the combination of labeled visual items and enduring auditory information, whilst the same format was detrimental to younger children's recall of target information. The present results show how estimates of PM and SM in children relate to the development of working memory capacity, but measurement of these constructs in children is not straightforward. Data also points to age-related changes in selective attention, which in turn contributes to children's ability to process and maintain information in working memory.

  2. How do selective attentional processes contribute to maintenance and recall in children's working memory capacity?

    PubMed

    Roome, Hannah E; Towse, John N; Jarrold, Chris

    2014-01-01

    The development of working memory capacity is considered from the perspective of the active maintenance of items in primary memory (PM) and a cue-dependent search component, secondary memory (SM). Using free recall, plus a more novel serial interleaved items task, age-related increases in PM estimates were evident in both paradigms. In addition to this, age-related improvements in attentional selectivity were observed, indexed by the recall of target and non-target information respectively. To further characterize PM, presentation modality was varied in the serial interleaved items task (auditory, visual and dual presentation). Developmental differences were found in the effectiveness of presentation formats. Older children's recall was enhanced by the combination of labeled visual items and enduring auditory information, whilst the same format was detrimental to younger children's recall of target information. The present results show how estimates of PM and SM in children relate to the development of working memory capacity, but measurement of these constructs in children is not straightforward. Data also points to age-related changes in selective attention, which in turn contributes to children's ability to process and maintain information in working memory. PMID:25566031

  3. Holistic processing of musical notation: Dissociating failures of selective attention in experts and novices.

    PubMed

    Wong, Yetta Kwailing; Gauthier, Isabel

    2010-12-01

    Holistic processing (i.e., the tendency to process objects as wholes) is associated with face perception and also with expertise individuating novel objects. Surprisingly, recent work also reveals holistic effects in novice observers. It is unclear whether the same mechanisms support holistic effects in experts and in novices. In the present study, we measured holistic processing of music sequences using a selective attention task in participants who vary in music-reading expertise. We found that holistic effects were strategic in novices but were relatively automatic in experts. Correlational analyses revealed that individual holistic effects were predicted by both individual music-reading ability and neural responses for musical notation in the right fusiform face area (rFFA), but in opposite directions for experts and novices, suggesting that holistic effects in the two groups may be of different natures. To characterize expert perception, it is important not only to measure the tendency to process objects as wholes, but also to test whether this effect is dependent on task constraints.

  4. On being peripheral and paying attention: prototypicality and information processing in intergroup conflict.

    PubMed

    Van Kleef, Gerben A; Steinel, Wolfgang; Homan, Astrid C

    2013-01-01

    Intergroup conflicts are ubiquitous-they occur, for instance, between (work)groups, departments, organizations, political parties, or nations. Such conflicts are commonly addressed through negotiations, in which representatives negotiate on behalf of their constituency. Intergroup negotiations are complex, as representatives need to navigate between the interests of their own constituency and the other party. This implies that negotiation success requires careful processing of information about both parties' interests. Here, we examine how representative negotiators' motivation to engage in such thorough information processing is influenced by their position in the group. Whereas prototypical representatives feel secure about their membership, peripheral representatives have a less certain position. We propose that peripheral representatives are therefore more attentive and responsive to information that may be relevant to the negotiation than prototypical representatives, but only when they are accountable to their constituents. Data from 4 experiments showed that peripheral representatives reported higher information-processing motivation (Experiment 1), bought and recalled more information (Experiment 2), exhibited greater sensitivity to emotional expressions of the outgroup representative (Experiment 3), and attained more integrative ("win-win") agreements (Experiment 4) than prototypical representatives, but only when they were accountable. The findings are discussed in relation to theorizing on group dynamics, motivated information processing, emotion, and intergroup conflict, and practical implications are considered.

  5. Transfer of Training between Music and Speech: Common Processing, Attention, and Memory

    PubMed Central

    Besson, Mireille; Chobert, Julie; Marie, Céline

    2011-01-01

    After a brief historical perspective of the relationship between language and music, we review our work on transfer of training from music to speech that aimed at testing the general hypothesis that musicians should be more sensitive than non-musicians to speech sounds. In light of recent results in the literature, we argue that when long-term experience in one domain influences acoustic processing in the other domain, results can be interpreted as common acoustic processing. But when long-term experience in one domain influences the building-up of abstract and specific percepts in another domain, results are taken as evidence for transfer of training effects. Moreover, we also discuss the influence of attention and working memory on transfer effects and we highlight the usefulness of the event-related potentials method to disentangle the different processes that unfold in the course of music and speech perception. Finally, we give an overview of an on-going longitudinal project with children aimed at testing transfer effects from music to different levels and aspects of speech processing. PMID:21738519

  6. How Attentional Systems Process Conflicting Cues. The Superiority of Social over Symbolic Orienting Revisited

    ERIC Educational Resources Information Center

    Nummenmaa, Lauri; Hietanen, Jari K.

    2009-01-01

    We investigated orienting of attention by social and symbolic cues presented inside/outside the locus of attention. Participants responded to laterally presented targets preceded by simultaneously presented gaze and arrow cues. Participants' attention was allocated to either of the cues and the other cue served as a distractor. In Experiments 1-4…

  7. Attentional Processes in Interactions between People with Profound Intellectual and Multiple Disabilities and Direct Support Staff

    ERIC Educational Resources Information Center

    Ine, Hostyn; Heleen, Neerinckx; Bea, Maes

    2011-01-01

    Few studies have examined joint attention in interactions with persons with profound intellectual and multiple disabilities (PIMD), despite its important role in high-quality interaction. The purpose of this study is to describe the attention-directing behaviours of persons with PIMD and their direct support staff and the attention episodes…

  8. Adaptive random renormalization group classification of multiscale dispersive processes

    NASA Astrophysics Data System (ADS)

    Cushman, John; O'Malley, Dan

    2013-04-01

    Renormalization group operators provide a detailed classification tool for dispersive processes. We begin by reviewing a two-scale renormalization group classification scheme. Repeated application of one operator is associated with long time behavior of the process while repeated application of the other is associated with short time behavior. This approach is shown to be robust even in the presence of non-stationary increments and/or infinite second moments. Fixed points of the operators can be used for further sub classification of the processes when appropriate limits exist. As an example we look at advective dispersion in an ergodic velocity field. Let X(t) be a fixed point of the long-time renormalization group operator (RGO) RX(t)=X(rt)/r^p. Scaling laws for the probability density, mean first passage times, and finite-size Lyapunov exponents of such fixed points are reviewed in anticipation of more general results. A generalized RGO, Rp, where the exponent in R above is now a random variable is introduced. Scaling laws associated with these random RGOs (RRGOs) are demonstrated numerically and applied to a process modeling the transition from sub-dispersion to Fickian dispersion. The scaling laws for the RRGO are not simple power laws, but instead are a weighted average of power laws. The weighting in the scaling laws can be determined adaptively via Bayes' theorem.

  9. Shifting Attention

    ERIC Educational Resources Information Center

    Ingram, Jenni

    2014-01-01

    This article examines the shifts in attention and focus as one teacher introduces and explains an image that represents the processes involved in a numeric problem that his students have been working on. This paper takes a micro-analytic approach to examine how the focus of attention shifts through what the teacher and students do and say in the…

  10. Adaptive model predictive process control using neural networks

    DOEpatents

    Buescher, Kevin L.; Baum, Christopher C.; Jones, Roger D.

    1997-01-01

    A control system for controlling the output of at least one plant process output parameter is implemented by adaptive model predictive control using a neural network. An improved method and apparatus provides for sampling plant output and control input at a first sampling rate to provide control inputs at the fast rate. The MPC system is, however, provided with a network state vector that is constructed at a second, slower rate so that the input control values used by the MPC system are averaged over a gapped time period. Another improvement is a provision for on-line training that may include difference training, curvature training, and basis center adjustment to maintain the weights and basis centers of the neural in an updated state that can follow changes in the plant operation apart from initial off-line training data.

  11. Adaptive model predictive process control using neural networks

    DOEpatents

    Buescher, K.L.; Baum, C.C.; Jones, R.D.

    1997-08-19

    A control system for controlling the output of at least one plant process output parameter is implemented by adaptive model predictive control using a neural network. An improved method and apparatus provides for sampling plant output and control input at a first sampling rate to provide control inputs at the fast rate. The MPC system is, however, provided with a network state vector that is constructed at a second, slower rate so that the input control values used by the MPC system are averaged over a gapped time period. Another improvement is a provision for on-line training that may include difference training, curvature training, and basis center adjustment to maintain the weights and basis centers of the neural in an updated state that can follow changes in the plant operation apart from initial off-line training data. 46 figs.

  12. Non-linear, adaptive array processing for acoustic interference suppression.

    PubMed

    Hoppe, Elizabeth; Roan, Michael

    2009-06-01

    A method is introduced where blind source separation of acoustical sources is combined with spatial processing to remove non-Gaussian, broadband interferers from space-time displays such as bearing track recorder displays. This differs from most standard techniques such as generalized sidelobe cancellers in that the separation of signals is not done spatially. The algorithm performance is compared to adaptive beamforming techniques such as minimum variance distortionless response beamforming. Simulations and experiments using two acoustic sources were used to verify the performance of the algorithm. Simulations were also used to determine the effectiveness of the algorithm under various signal to interference, signal to noise, and array geometry conditions. A voice activity detection algorithm was used to benchmark the performance of the source isolation.

  13. Cortical State and Attention

    PubMed Central

    Harris, Kenneth D.; Thiele, Alexander

    2012-01-01

    Preface The brain continuously adapts its processing machinery to behavioural demands. To achieve this it rapidly modulates the operating mode of cortical circuits, controlling the way information is transformed and routed. This article will focus on two experimental approaches by which the control of cortical information processing has been investigated: the study of state-dependent cortical processing in rodents, and attention in the primate visual system. Both processes involve a modulation of low-frequency activity fluctuations and spiking correlation, and are mediated by common receptor systems. We suggest that selective attention involves processes similar to state change, operating at a local columnar level to enhance the representation of otherwise nonsalient features while suppressing internally generated activity patterns. PMID:21829219

  14. Attentional processes and their remediation in children treated for cancer: a literature review and the development of a therapeutic approach.

    PubMed

    Butler, Robert W; Copeland, Donna R

    2002-01-01

    It is now generally accepted that central nervous system treatments for childhood cancer can result in significant cognitive impairment, most commonly in the areas of attention/concentration. We review the literature on attentional and neurocognitive deficits in this population, and also efforts to remediate attentional deficits in other brain injured populations. It was our goal to develop an innovative, psychologically based outpatient rehabilitation program that would improve dysfunctional attentional processes and associated neuropsychological deficits. The characteristics of this program and a pilot study of its effectiveness are described. Participants were 31 off-therapy cancer survivors with documented attention deficits. Twenty-one completed the cognitive remediation program (CRP) and 10 served as comparisons. All participants completed a test of vigilance attention, 2 tests with an attentional component, and an arithmetic academic achievement measure. When the scores of the 2 groups were compared, the CRP group exhibited statistically significant improvement on all attentional measures. In contrast, the comparison group did not manifest any significant changes. Neither group demonstrated statistically significant changes on the arithmetic achievement test. We believe that the CRP has potential for improving attention/concentration, but generalization to academic achievement remains unproven. Phase 3 clinical trials and the documentation of long-term treatment gains are needed. Furthermore, it will be necessary to demonstrate the ecological validity of the CRP. With these caveats, this therapeutic approach may be helpful in other populations of cognitively impaired children and young adults, such as patients who have suffered traumatic brain injury.

  15. Dissociating effects of movement preparation and spatial attention on visual processing: evidence from event-related potentials.

    PubMed

    Ley, Pia; Röder, Brigitte

    2014-01-01

    The present study investigated whether effects of movement preparation and visual spatial attention on visual processing can be dissociated. Movement preparation and visual spatial attention were manipulated orthogonally in a dual-task design. Ten participants covertly prepared unimanual lateral arm movements to one hemifield, while attending to visual stimuli presented either in the same or in the hemifield opposite to the movement goal. Event-related potentials to task-irrelevant visual stimuli were analysed. Both joint and distinct modulations of visual ERPs by visual spatial attention and movement preparation were observed: The latencies of all analysed peaks (P1, N1, P2) were shorter for matching (in terms of direction of attention and movement) versus non-matching sensory-motor conditions. The P1 amplitude, as well, depended on the sensory-motor matching: The P1 was larger for non-matching compared to matching conditions. By contrast, the N1 amplitude showed additive effects of sensory attention and movement preparation: with attention and movement preparation directed towards the visual stimulus the N1 was largest, with both directed opposite to the stimulus the N1 was smallest. P2 amplitudes, instead, were only modulated by sensory attention. The present data show that movement preparation and sensory spatial attention are tightly linked and interrelated, showing joint modulations throughout stimulus processing. At the same time, however, our data argue against the idea of identity of the two systems. Instead, sensory spatial attention and movement preparation seem to be processed at least partially independently, though still exerting a combined influence on visual stimulus processing.

  16. [Transcranial magnetic stimulation (TMS), inhibition processes and attention deficit/hyperactivity disorder (ADHD) - an overview].

    PubMed

    Hoegl, Thomas; Bender, Stephan; Buchmann, Johannes; Kratz, Oliver; Moll, Gunther H; Heinrich, Hartmut

    2014-11-01

    Motor system excitability can be tested by transcranial magnetic stimulation CFMS). In this article, an overview of recent methodological developments and research findings related to attention deficit/hyperactivity disorder (ADHD) is provided. Different TMS parameters that reflect the function of interneurons in the motor cortex may represent neurophysiological markers of inhibition in ADHD, particularly the so-called intracortical inhibition. In children with a high level of hyperactivity and impulsivity, intracortical inhibition was comparably low at rest as shortly before the execution of a movement. TMS-evoked potentials can also be measured in the EEG so that investigating processes of excitability is not restricted to motor areas in future studies. The effects of methylphenidate on motor system excitability may be interpreted in the sense of a 'fine-tuning' with these mainly dopaminergic effects also depending on genetic parameters (DAT1 transporter). A differentiated view on the organization of motor control can be achieved by a combined analysis of TMS parameters and event-related potentials. Applying this bimodal approach, strong evidence for a deviant implementation of motor control in children with ADHD and probably compensatory mechanisms (with involvement of the prefrontal cortex) was obtained. These findings, which contribute to a better understanding of hyperactivity/impulsivity, inhibitory processes and motor control in ADHD as well as the mechanisms of medication, underline the relevance of TMS as a neurophysiological method in ADHD research.

  17. The process of auditory distraction: disrupted attention and impaired recall in a simulated lecture environment.

    PubMed

    Zeamer, Charlotte; Fox Tree, Jean E

    2013-09-01

    Literature on auditory distraction has generally focused on the effects of particular kinds of sounds on attention to target stimuli. In support of extensive previous findings that have demonstrated the special role of language as an auditory distractor, we found that a concurrent speech stream impaired recall of a short lecture, especially for verbatim language. But impaired recall effects were also found with a variety of nonlinguistic noises, suggesting that neither type of noise nor amplitude and duration of noise are adequate predictors of distraction. Rather, distraction occurred when it was difficult for a listener to process sounds and assemble coherent, differentiable streams of input, one task-salient and attended and the other task-irrelevant and inhibited. In 3 experiments, the effects of auditory distractors during a short spoken lecture were tested. Participants recalled details of the lecture and also reported their opinions of the sound quality. Our findings suggest that distractors that are difficult to designate as either task related or environment related (and therefore irrelevant) draw cognitive processing resources away from a target speech stream during a listening task, impairing recall.

  18. Feature processing and attention in the human visual system: an overview.

    PubMed

    Heslenfeld, D J; Kenemans, J L; Kok, A; Molenaar, P C

    1997-03-21

    A recent development in the cognitive modelling of visual selective attention is the incorporation of design principles derived from the neuroanatomy and neurophysiology of the primate visual system. In this paper, we describe these recent 'neurocognitive' models in more detail, point out the underlying neurobiological principles, and show that in all cases attention is implemented as an energetical resource which can be directed to representations and pathways in the system. In the second part of the paper, we specify the predictions derived from this 'energy hypothesis', and evaluate available data pertaining to this issue. We present new analyses of electrophysiological data in order to directly test the hypothesis that attention modulates feature-specific representations. It will be shown that in the case of sustained spatial attention, the data are in agreement with this hypothesis, whereas in the case of nonspatial attention, there is no evidence of a modulation of feature-specific pathways by attention. PMID:9083650

  19. The effect of fear on attentional processing in a sample of healthy females.

    PubMed

    Finucane, Anne M; Power, Mick J

    2010-01-01

    The present experiment examines the effect of fear on efficiency of three attention networks: executive attention, orienting and alerting, in a healthy female sample. International Affective Picture System (IAPS) images were used to elicit both a fear response and a non-emotional response in 100 participants. During the emotion manipulation, participants performed a modified version of the Attention Network Test (ANT). Results showed enhanced executive attention in the fear condition compared to the control condition. Specifically, during a fear experience participants were better able to inhibit irrelevant information resulting in faster response times to a target. There was no effect of fear on orienting while the effect of fear on alerting was inconclusive. It is suggested that enhanced executive attention in fear-eliciting situations may function to focus attention on a potentially threat-related target, thus facilitating subsequent rapid responding.

  20. Recasting Hope: a process of adaptation following fetal anomaly diagnosis.

    PubMed

    Lalor, Joan; Begley, Cecily M; Galavan, Eoin

    2009-02-01

    Recent decades have seen ultrasound revolutionise the management of pregnancy and its possible complications. However, somewhat less consideration has been given to the psychosocial consequences of mass screening resulting in fetal anomaly detection in low-risk populations, particularly in contexts where termination of pregnancy services are not readily accessible. A grounded theory study was conducted exploring forty-one women's experiences of ultrasound diagnosis of fetal abnormality up to and beyond the birth in the Republic of Ireland. Thirty-one women chose to continue the pregnancy and ten women accessed termination of pregnancy services outside the state. Data were collected using repeated in-depth individual interviews pre- and post-birth and analysed using the constant comparative method. Recasting Hope, the process of adaptation following diagnosis is represented temporally as four phases: 'Assume Normal', 'Shock', 'Gaining Meaning' and 'Rebuilding'. Some mothers expressed a sense of incredulity when informed of the anomaly and the 'Assume Normal' phase provides an improved understanding as to why women remain unprepared for an adverse diagnosis. Transition to phase 2, 'Shock,' is characterised by receiving the diagnosis and makes explicit women's initial reactions. Once the diagnosis is confirmed, a process of 'Gaining Meaning' commences, whereby an attempt to make sense of this ostensibly negative event begins. 'Rebuilding', the final stage in the process, is concerned with the extent to which women recover from the loss and resolve the inconsistency between their experience and their previous expectations of pregnancy in particular and beliefs in the world in general. This theory contributes to the theoretical field of thanatology as applied to the process of grieving associated with the loss of an ideal child. The framework of Recasting Hope is intended for use as a tool to assist health professionals through offering simple yet effective

  1. Augmenting synthetic aperture radar with space time adaptive processing

    NASA Astrophysics Data System (ADS)

    Riedl, Michael; Potter, Lee C.; Ertin, Emre

    2013-05-01

    Wide-area persistent radar video offers the ability to track moving targets. A shortcoming of the current technology is an inability to maintain track when Doppler shift places moving target returns co-located with strong clutter. Further, the high down-link data rate required for wide-area imaging presents a stringent system bottleneck. We present a multi-channel approach to augment the synthetic aperture radar (SAR) modality with space time adaptive processing (STAP) while constraining the down-link data rate to that of a single antenna SAR system. To this end, we adopt a multiple transmit, single receive (MISO) architecture. A frequency division design for orthogonal transmit waveforms is presented; the approach maintains coherence on clutter, achieves the maximal unaliased band of radial velocities, retains full resolution SAR images, and requires no increase in receiver data rate vis-a-vis the wide-area SAR modality. For Nt transmit antennas and N samples per pulse, the enhanced sensing provides a STAP capability with Nt times larger range bins than the SAR mode, at the cost of O(log N) more computations per pulse. The proposed MISO system and the associated signal processing are detailed, and the approach is numerically demonstrated via simulation of an airborne X-band system.

  2. Emotional Processing and Attention Control Impairments in Children with Anxiety: An Integrative Review of Event-Related Potentials Findings.

    PubMed

    Wauthia, Erika; Rossignol, Mandy

    2016-01-01

    Anxiety disorders in adults have been associated with biased processing of emotional information which may be due to a deficit in attentional control. This deficit leads to an hypervigilance and a selective attention toward threatening information. Event-related potentials (ERPs) have been used to study this topic in anxious adults. Similar biases have been reported in children with anxiety but researches investigating the ERPs components underpinning these biases are more scarce. However, the understanding of the neural correlates of attentional biases in anxious children seem quite important since they could play a role in the etiology and the maintenance of this disorder. This review summarizes the results of researches having used ERPs to index emotional processing and attention control in children suffering from anxiety. We will focus on the P1, indexing basic visual perceptual processing, the N2, thought to reflect cognitive control process, the P3 typically associated with response inhibition, and the late positive potential (LPP) that indicates sustained attention toward motivationally salient stimuli. We will also examine the error-related negativity (ERN) that indexes monitoring system for detecting errors. Electro-physiological studies generally reported increased amplitudes of these components in anxious children, even when they did not differ from typically developing children at a behavioral level. These results suggest diminished cognitive control that influences children's selective attention mechanisms toward threatening information. Theoretical perspectives and implications for future researches will be discussed in the framework of current models of childhood anxiety. PMID:27199802

  3. Basic processes in reading aloud and colour naming: towards a better understanding of the role of spatial attention.

    PubMed

    Robidoux, Serje; Rauwerda, Derek; Besner, Derek

    2014-05-01

    Whether or not lexical access from print requires spatial attention has been debated intensively for the last 30 years. Studies involving colour naming generally find evidence that "unattended" words are processed. In contrast, reading-based experiments do not find evidence of distractor processing. One theory ascribes the discrepancy to weaker attentional demands for colour identification. If colour naming does not capture all of a subject's attention, the remaining attentional resources can be deployed to process the distractor word. The present study combined exogenous spatial cueing with colour naming and reading aloud separately and found that colour naming is less sensitive to the validity of a spatial cue than is reading words aloud. Based on these results, we argue that colour naming studies do not effectively control attention so that no conclusions about unattended distractor processing can be drawn from them. Thus we reiterate the consistent conclusion drawn from reading aloud and lexical decision studies: There is no word identification without (spatial) attention. PMID:24224499

  4. A Comparative Study of Sustained Attentional Bias on Emotional Processing in ADHD Children to Pictures with Eye-Tracking

    PubMed Central

    PISHYAREH, Ebrahim; TEHRANI-DOOST, Mehdi; MAHMOODI-GHARAIE, Javad; KHORRAMI, Anahita; RAHMDAR, Saeid Reza

    2015-01-01

    Objective ADHD children have anomalous and negative behavior especially in emotionally related fields when compared to other. Evidence indicates that attention has an impact on emotional processing. The present study evaluates the effect of emotional processing on the sustained attention of children with ADHD type C. Materials & Methods Sixty participants form two equal groups (each with 30 children) of normal and ADHD children) and each subject met the required selected criterion as either a normal or an ADHD child. Both groups were aged from 6–11-years-old. All pictures were chosen from the International Affective Picture System (IAPS) and presented paired emotional and neutral scenes in the following categories: pleasant-neutral; pleasant-unpleasant; unpleasant-neutral; and neutral–neutral. Sustained attention was evaluated based on the number and duration of total fixation and was compared between the groups with MANOVA analysis. Results The duration of sustained attention on pleasant in the pleasant-unpleasant pair was significant. Bias in duration of sustained attention on pleasant scenes in pleasant-neutral pairs is significantly different between the groups. Conclusion Such significant differences might be indicative of ADHD children deficiencies in emotional processing. It seems that the highly deep effect of emotionally unpleasant scenes to gain the focus of ADHD children’s attention is responsible for impulsiveness and abnormal processing of emotional stimuli. PMID:25767541

  5. Emotional Processing and Attention Control Impairments in Children with Anxiety: An Integrative Review of Event-Related Potentials Findings

    PubMed Central

    Wauthia, Erika; Rossignol, Mandy

    2016-01-01

    Anxiety disorders in adults have been associated with biased processing of emotional information which may be due to a deficit in attentional control. This deficit leads to an hypervigilance and a selective attention toward threatening information. Event-related potentials (ERPs) have been used to study this topic in anxious adults. Similar biases have been reported in children with anxiety but researches investigating the ERPs components underpinning these biases are more scarce. However, the understanding of the neural correlates of attentional biases in anxious children seem quite important since they could play a role in the etiology and the maintenance of this disorder. This review summarizes the results of researches having used ERPs to index emotional processing and attention control in children suffering from anxiety. We will focus on the P1, indexing basic visual perceptual processing, the N2, thought to reflect cognitive control process, the P3 typically associated with response inhibition, and the late positive potential (LPP) that indicates sustained attention toward motivationally salient stimuli. We will also examine the error-related negativity (ERN) that indexes monitoring system for detecting errors. Electro-physiological studies generally reported increased amplitudes of these components in anxious children, even when they did not differ from typically developing children at a behavioral level. These results suggest diminished cognitive control that influences children's selective attention mechanisms toward threatening information. Theoretical perspectives and implications for future researches will be discussed in the framework of current models of childhood anxiety. PMID:27199802

  6. Selective visual processing across competition episodes: a theory of task-driven visual attention and working memory.

    PubMed

    Schneider, Werner X

    2013-10-19

    The goal of this review is to introduce a theory of task-driven visual attention and working memory (TRAM). Based on a specific biased competition model, the 'theory of visual attention' (TVA) and its neural interpretation (NTVA), TRAM introduces the following assumption. First, selective visual processing over time is structured in competition episodes. Within an episode, that is, during its first two phases, a limited number of proto-objects are competitively encoded-modulated by the current task-in activation-based visual working memory (VWM). In processing phase 3, relevant VWM objects are transferred via a short-term consolidation into passive VWM. Second, each time attentional priorities change (e.g. after an eye movement), a new competition episode is initiated. Third, if a phase 3 VWM process (e.g. short-term consolidation) is not finished, whereas a new episode is called, a protective maintenance process allows its completion. After a VWM object change, its protective maintenance process is followed by an encapsulation of the VWM object causing attentional resource costs in trailing competition episodes. Viewed from this perspective, a new explanation of key findings of the attentional blink will be offered. Finally, a new suggestion will be made as to how VWM items might interact with visual search processes. PMID:24018722

  7. Unraveling the anxious mind: anxiety, worry, and frontal engagement in sustained attention versus off-task processing.

    PubMed

    Forster, Sophie; Nunez Elizalde, Anwar O; Castle, Elizabeth; Bishop, Sonia J

    2015-03-01

    Much remains unknown regarding the relationship between anxiety, worry, sustained attention, and frontal function. Here, we addressed this using a sustained attention task adapted for functional magnetic resonance imaging. Participants responded to presentation of simple stimuli, withholding responses to an infrequent "No Go" stimulus. Dorsolateral prefrontal cortex (DLPFC) activity to "Go" trials, and dorsal anterior cingulate (dACC) activity to "No Go" trials were associated with faster error-free performance; consistent with DLPFC and dACC facilitating proactive and reactive control, respectively. Trait anxiety was linked to reduced recruitment of these regions, slower error-free performance, and decreased frontal-thalamo-striatal connectivity. This indicates an association between trait anxiety and impoverished frontal control of attention, even when external distractors are absent. In task blocks where commission errors were made, greater DLPFC-precuneus and DLPFC-posterior cingulate connectivity were associated with both trait anxiety and worry, indicative of increased off-task thought. Notably, unlike trait anxiety, worry was not linked to reduced frontal-striatal-thalamo connectivity, impoverished frontal recruitment, or slowed responding during blocks without commission errors, contrary to accounts proposing a direct causal link between worry and impoverished attentional control. This leads us to propose a new model of the relationship between anxiety, worry and frontal engagement in attentional control versus off-task thought.

  8. Blink and Shrink: The Effect of the Attentional Blink on Spatial Processing

    ERIC Educational Resources Information Center

    Olivers, Christian N. L.

    2004-01-01

    The detection or discrimination of the second of 2 targets in a rapid serial visual presentation (RSVP) task is often temporarily impaired-a phenomenon termed the attentional blink. This study demonstrated that the attentional blink also affects localization performance. Spatial cues pointed out the possible target positions in a subsequent visual…

  9. Electrophysiological Indices of Spatial Attention during Global/Local Processing in Good and Poor Phonological Decoders

    ERIC Educational Resources Information Center

    Matthews, Allison Jane; Martin, Frances Heritage

    2009-01-01

    Previous research suggests a relationship between spatial attention and phonological decoding in developmental dyslexia. The aim of this study was to examine differences between good and poor phonological decoders in the allocation of spatial attention to global and local levels of hierarchical stimuli. A further aim was to investigate the…

  10. Creating Joint Attentional Frames and Pointing to Evidence in the Reading and Writing Process

    ERIC Educational Resources Information Center

    Unger, John A.; Liu, Rong; Scullion, Vicki A.

    2015-01-01

    This theory-into-practice paper integrates Tomasello's concept of Joint Attentional Frames and well-known ideas related to the work of Russian psychologist, Lev Vygotsky, with more recent ideas from social semiotics. Classroom procedures for incorporating student-created Joint Attentional Frames into literacy lessons are explained by links to…

  11. A Computerized Task for Investigating the Relation between Attentional and Emotional Processes in Children

    ERIC Educational Resources Information Center

    Wilson, Beverly J.; Derryberry, Douglas; Kroeker, Rose

    2006-01-01

    The authors' goals in this article are to (a) describe a new task for the assessment of shifting attention between different affective stimuli, The Children's Attentional Shifting Task (CAST); (b) present the theoretical background for the development of the CAST; and (c) report initial information on the developmental appropriateness and validity…

  12. Different Attentional Blink Tasks Reflect Distinct Information Processing Limitations: An Individual Differences Approach

    ERIC Educational Resources Information Center

    Kelly, Ashleigh J.; Dux, Paul E.

    2011-01-01

    To study the temporal dynamics and capacity-limits of attentional selection and encoding, researchers often employ the attentional blink (AB) phenomenon: subjects' impaired ability to report the second of two targets in a rapid serial visual presentation (RSVP) stream that appear within 200-500 ms of one another. The AB has now been the subject of…

  13. Attentional Processing of Faces in ASD: A Dot-Probe Study

    ERIC Educational Resources Information Center

    Moore, David J.; Heavey, Lisa; Reidy, John

    2012-01-01

    The present study used the Dot-Probe paradigm to explore attentional allocation to faces compared with non-social images in high-functioning individuals with autism spectrum disorder (ASD) and typically developing controls. There was no evidence of attentional bias in either group when stimuli were presented at individually calculated…

  14. Attention and sentence processing deficits in Parkinson's disease: the role of anterior cingulate cortex.

    PubMed

    Grossman, M; Crino, P; Reivich, M; Stern, M B; Hurtig, H I

    1992-01-01

    Parkinson's disease (PD) is a complex neurodegenerative condition involving a motor disorder that is related to reduced dopaminergic input to the striatum. Intellectual deficits are also seen in PD, but the pathophysiology of these difficulties is poorly understood. Regional cerebral blood flow (rCBF) was studied in neurologically intact subjects during the performance of attention-demanding, sentence processing tasks using positron emission tomography (PET). The results demonstrated significantly increased rCBF in a distributed set of cerebral regions during the detection of an adjective or a particular agent in a sentence, including anterior cingulate cortex, left inferior and middle frontal cortex, left inferior temporo-occipital cortex, posterolateral temporal cortex, left caudate, and left thalamus. We identified defects in this cerebral network by studying PD patients with two PET techniques. Resting PET studies revealed a significant correlation between regional cerebral glucose metabolism in anterior cingulate cortex and deficits in attending to subtle grammatical aspects of sentences. Studies of PD patients with the PET activation technique revealed little change in anterior cingulate and left frontal CBF during performance of the adjective detection or agent detection tasks. These data suggest that a defect in anterior cingulate cortex contributes to the cognitive impairments observed in PD.

  15. The process of assisting behavior modification in a child with attention-deficit hyperactivity disorder.

    PubMed

    Chang, Hsin-Hsin; Chang, Ching-Sheng; Shih, Ying-Ling

    2007-06-01

    Attention Deficit Hyperactivity Disorder (ADHD) is a common psychological disease among children. The purpose of this study was to describe the process of assisting with behavior modification in a child with ADHD. The patient had undergone medical treatment for a year with no obvious effect. With the guidance of other professional people, the child's teachers and nursing instructors, the researchers proceeded with behavioral modification in conjunction with medication for another year. The medication treatment followed doctors' prescriptions, and, as regards the behavioral treatment, doctors and experts drafted and decided the content of the behavioral contract. The main basic techniques were skillful reinforcement and punishment. Then, via interviews with his parents and teachers, information was obtained that provided an understanding of the patient's condition and progress. It was found that the improvements were very significant. On the basis of the research results, the researchers submit that: (1) drug treatment combined with behavioral treatment apparently improves the daily behaviors of hyperactive children; (2) good communication with parents and psychological preparation are the most critical keys to the success of substantial behavioral improvement among hyperactive children; (3) establishment and integration of social resources, including provision of transitional parenting education solutions, and cooperation and sound interaction from school teachers, which fosters consolidated team work, are the critical factors to behavioral improvement among hyperactive children.

  16. The effect of emotional context on cognitive inhibition and attentional processing in dissociative identity disorder.

    PubMed

    Dorahy, Martin J; Middleton, Warwick; Irwin, Harvey J

    2005-05-01

    In light of previous research, the current study tested the hypothesis that dissociative identity disorder (DID) would be characterised by effective cognitive inhibitory functioning when tested in a neutral context, but weakened inhibition when tested in an emotionally negative context. Using a negative priming task (i.e. the flanker task) to assess inhibitory ability 11 DID, 11 depressed, and 11 general population participants were tested in the two differing experimental contexts. The contexts were manipulated by instructions and word stimuli, and following the completion of this task participants completed the Dissociative Experiences Scale and the Schizotypal Personality Scale. DID participants displayed a greater degree of self-reported anxiety in the negative context and as expected displayed a reduction in inhibition in this context but not in the neutral context. The degree of negative priming for the depressed and general population samples remained stable across contexts as did their anxiety levels. The DID sample displayed slower response times to negative compared to neutral words but this attentional bias was not evident for the two comparison groups. The relationship between increased arousal, inhibitory functioning, dissociation and information processing in DID is discussed.

  17. Disability and Sunshine: Can Hedonic Predictions Be Improved by Drawing Attention to Focusing Illusions or Emotional Adaptation?

    ERIC Educational Resources Information Center

    Ubel, Peter A.; Loewenstein, George; Jepson, Christopher

    2005-01-01

    People frequently mispredict the long-term emotional impact of circumstances. The authors examine 2 causes of such mispredictions--a focusing illusion and underappreciation of adaptation. In Experiment 1, the authors found, in 852 adults, that quality of life estimates (for living with disability) were not increased by reducing focusing illusions.…

  18. Developmental Dyslexia: Exploring How Much Phonological and Visual Attention Span Disorders Are Linked to Simultaneous Auditory Processing Deficits

    ERIC Educational Resources Information Center

    Lallier, Marie; Donnadieu, Sophie; Valdois, Sylviane

    2013-01-01

    The simultaneous auditory processing skills of 17 dyslexic children and 17 skilled readers were measured using a dichotic listening task. Results showed that the dyslexic children exhibited difficulties reporting syllabic material when presented simultaneously. As a measure of simultaneous visual processing, visual attention span skills were…

  19. Processing 3D form and 3D motion: respective contributions of attention-based and stimulus-driven activity.

    PubMed

    Paradis, A-L; Droulez, J; Cornilleau-Pérès, V; Poline, J-B

    2008-12-01

    This study aims at segregating the neural substrate for the 3D-form and 3D-motion attributes in structure-from-motion perception, and at disentangling the stimulus-driven and endogenous-attention-driven processing of these attributes. Attention and stimulus were manipulated independently: participants had to detect the transitions of one attribute--form, 3D motion or colour--while the visual stimulus underwent successive transitions of all attributes. We compared the BOLD activity related to form and 3D motion in three conditions: stimulus-driven processing (unattended transitions), endogenous attentional selection (task) or both stimulus-driven processing and attentional selection (attended transitions). In all conditions, the form versus 3D-motion contrasts revealed a clear dorsal/ventral segregation. However, while the form-related activity is consistent with previously described shape-selective areas, the activity related to 3D motion does not encompass the usual "visual motion" areas, but rather corresponds to a high-level motion system, including IPL and STS areas. Second, we found a dissociation between the neural processing of unattended attributes and that involved in endogenous attentional selection. Areas selective for 3D-motion and form showed either increased activity at transitions of these respective attributes or decreased activity when subjects' attention was directed to a competing attribute. We propose that both facilitatory and suppressive mechanisms of attribute selection are involved depending on the conditions driving this selection. Therefore, attentional selection is not limited to an increased activity in areas processing stimulus properties, and may unveil different functional localization from stimulus modulation.

  20. Threat/reward-sensitivity and hypomanic-personality modulate cognitive-control and attentional neural processes to emotional stimuli.

    PubMed

    Pornpattananangkul, Narun; Hu, Xiaoqing; Nusslock, Robin

    2015-11-01

    Temperamental-traits (e.g. threat/reward-sensitivity) are found to modulate cognitive-control and attentional-processes. Yet, it is unclear exactly how these traits interact with emotional-stimuli in the modulation of cognitive-control, as reflected by the N2 event-related potential (ERP), and attentional-processes, as reflected by the P2 and P3 ERPs. Here in an ERP emotional-Go/NoGo task, 36 participants were instructed to inhibit their response to Fearful- and Happy-faces. Individual-differences in threat-sensitivity, reward-sensitivity and hypomanic-personality were assessed through self-report. Hypomanic-personality was assessed, given its relationship with reward-sensitivity and relevance to mood-disorder symptoms. Concerning cognitive-control, individuals with elevated threat-sensitivity displayed more-negative N2s to Happy-NoGo (relative to Fearful-NoGo) faces, whereas both individuals with elevated reward-sensitivity and hypomanic-personality displayed more-negative N2s to Fearful-NoGo (relative to Happy-NoGo) faces. Accordingly, when cognitive-control is required (during Go/NoGo), a mismatch between one's temperament and the valence of the NoGo-stimulus elevates detection of the need for cognitive-control. Conversely, the modulation of attentional-processing was specific to threat-sensitivity, as there was no relationship between either reward-sensitivity or hypomanic-personality and attentional-processing. Elevated threat-sensitivity was associated with enhanced early (P2s) and later (P3s) attentional-processing to Fearful-NoGo (relative to Happy-NoGo) faces. These latter findings support the negative attentional-bias model relating elevated threat-sensitivity with attentional-biases toward negative-stimuli and away from positive-stimuli.

  1. The pharmacological characterization of attentional processes using a two-lever choice reaction time task in rats.

    PubMed

    Mishima, Kenichi; Fujii, Megumi; Aoo, Naoya; Yoshikawa, Tetsuya; Fukue, Yoshihiko; Honda, Yoko; Egashira, Nobuaki; Iwasaki, Katsunori; Shoyama, Yukihiro; Fujiwara, Michihiro

    2002-12-01

    Activating the noradrenergic and cholinergic systems is known to enhance attentional processes, while stimulating dopaminergic, serotonergic, and GABAergic systems suppresses them. The objective of the present study was to investigate the pharmacological characterization in the attentional processes of a two-lever choice reaction time (CRT) task using different centrally acting drugs. We designed seven parameters in this task: the correct response (CR) rate; error response rate; nonresponse (NR) rate; differential reinforcement of other behavior (DRO) responses; number of incorrect lever pressings during both the intertrial interval and DRO periods; the mean CRT of CR; and activity during 30 trials. The compounds produced different profiles at each dose. 1) Facilitative and disruptive effects on attentional processes occurred with changes in CRT alone. Scopolamine (0.1 mg/kg) and prazosin (0.3-1 mg/kg) prolonged the CRT, whereas methamphetamine (0.3 mg/kg) shortened the CRT. 2) Attentional deficits occurred with abnormal behavior showing premature response or perseverative behavior. Scopolamine (0.2-1 mg/kg), methamphetamine (3 mg/kg), delta(9)-tetrahydrocannabinol (10 mg/kg), and MK-801 (0.1-0.3 mg/kg) produced a marked increase in the number of total lever pressings. 3) Motor function deficits rather than attentional deficits occurred. 8-OH DPAT (1 mg/kg) and muscimol (1 mg/kg) produced a decrease in CR and an increase in NR with a marked decrease in activity and prolonged the CRT. Activating noradrenergic alpha(1) receptors was found to enhance the attentional processes, while blocking muscarinic receptors, alpha(1) receptors, and NMDA receptors, and stimulating cannabinoid receptors and the dopaminergic systems impaired the attentional processes in the two-lever CRT task.

  2. Cognition, emotion, and attention.

    PubMed

    Müller-Oehring, Eva M; Schulte, Tilman

    2014-01-01

    Deficits of attention, emotion, and cognition occur in individuals with alcohol abuse and addiction. This review elucidates the concepts of attention, emotion, and cognition and references research on the underlying neural networks and their compromise in alcohol use disorder. Neuroimaging research on adolescents with family history of alcoholism contributes to the understanding of pre-existing brain structural conditions and characterization of cognition and attention processes in high-risk individuals. Attention and cognition interact with other brain functions, including perceptual selection, salience, emotion, reward, and memory, through interconnected neural networks. Recent research reports compromised microstructural and functional network connectivity in alcoholism, which can have an effect on the dynamic tuning between brain systems, e.g., the frontally based executive control system, the limbic emotion system, and the midbrain-striatal reward system, thereby impeding cognitive flexibility and behavioral adaptation to changing environments. Finally, we introduce concepts of functional compensation, the capacity to generate attentional resources for performance enhancement, and brain structure recovery with abstinence. An understanding of the neural mechanisms of attention, emotion, and cognition will likely provide the basis for better treatment strategies for developing skills that enhance alcoholism therapy adherence and quality of life, and reduce the propensity for relapse. PMID:25307584

  3. Hyperactivity in boys with attention deficit/hyperactivity disorder (ADHD): the association between deficient behavioral inhibition, attentional processes, and objectively measured activity.

    PubMed

    Alderson, R Matt; Rapport, Mark D; Kasper, Lisa J; Sarver, Dustin E; Kofler, Michael J

    2012-01-01

    Contemporary models of ADHD hypothesize that hyperactivity reflects a byproduct of inhibition deficits. The current study investigated the relationship between children's motor activity and behavioral inhibition by experimentally manipulating demands placed on the limited-resource inhibition system. Twenty-two boys (ADHD = 11, TD = 11) between the ages of 8 and 12 years completed a conventional stop-signal task, two choice-task variants (no-tone, ignore-tone), and control tasks while their motor activity was measured objectively by actigraphs placed on their nondominant wrist and ankles. All children exhibited significantly higher activity rates under all three experimental tasks relative to control conditions, and children with ADHD moved significantly more than typically developing children across conditions. No differences in activity level were observed between the inhibition and noninhibition experimental tasks for either group, indicating that activity level was primarily associated with basic attentional rather than behavioral inhibition processes.

  4. Character Decomposition and Transposition Processes in Chinese Compound Words Modulates Attentional Blink

    PubMed Central

    Cao, Hongwen; Gao, Min; Yan, Hongmei

    2016-01-01

    The attentional blink (AB) is the phenomenon in which the identification of the second of two targets (T2) is attenuated if it is presented less than 500 ms after the first target (T1). Although the AB is eliminated in canonical word conditions, it remains unclear whether the character order in compound words affects the magnitude of the AB. Morpheme decomposition and transposition of Chinese two-character compound words can provide an effective means to examine AB priming and to assess combinations of the component representations inherent to visual word identification. In the present study, we examined the processing of consecutive targets in a rapid serial visual presentation (RSVP) paradigm using Chinese two-character compound words in which the two characters were transposed to form meaningful words or meaningless combinations (reversible, transposed, or canonical words). We found that when two Chinese characters that form a compound word, regardless of their order, are presented in an RSVP sequence, the likelihood of an AB for the second character is greatly reduced or eliminated compared to when the two characters constitute separate words rather than a compound word. Moreover, the order of the report for the two characters is more likely to be reversed when the normal order of the two characters in a compound word is reversed, especially when the interval between the presentation of the two characters is extremely short. These findings are more consistent with the cognitive strategy hypothesis than the resource-limited hypothesis during character decomposition and transposition of Chinese two-character compound words. These results suggest that compound characters are perceived as a unit, rather than two separate words. The data further suggest that readers could easily understand the text with character transpositions in compound words during Chinese reading. PMID:27379003

  5. Selective visual processing across competition episodes: a theory of task-driven visual attention and working memory

    PubMed Central

    Schneider, Werner X.

    2013-01-01

    The goal of this review is to introduce a theory of task-driven visual attention and working memory (TRAM). Based on a specific biased competition model, the ‘theory of visual attention’ (TVA) and its neural interpretation (NTVA), TRAM introduces the following assumption. First, selective visual processing over time is structured in competition episodes. Within an episode, that is, during its first two phases, a limited number of proto-objects are competitively encoded—modulated by the current task—in activation-based visual working memory (VWM). In processing phase 3, relevant VWM objects are transferred via a short-term consolidation into passive VWM. Second, each time attentional priorities change (e.g. after an eye movement), a new competition episode is initiated. Third, if a phase 3 VWM process (e.g. short-term consolidation) is not finished, whereas a new episode is called, a protective maintenance process allows its completion. After a VWM object change, its protective maintenance process is followed by an encapsulation of the VWM object causing attentional resource costs in trailing competition episodes. Viewed from this perspective, a new explanation of key findings of the attentional blink will be offered. Finally, a new suggestion will be made as to how VWM items might interact with visual search processes. PMID:24018722

  6. Attention and visual interference stimulation affect somatosensory processing: a magnetoencephalographic study.

    PubMed

    Lam, K; Kakigi, R; Mukai, T; Yamasaki, H

    2001-01-01

    In our previous study, continuous visual (cartoon and random dot motion) and auditory (music) stimulation changed the somatosensory evoked magnetic fields following electrical stimulation of the median nerve in human subjects. They enhanced the middle-latency components (3M and 4M) generated in the contralateral primary somatosensory cortex, and reduced the MI component generated in the ipsilateral secondary somatosensory cortex. We speculated that such interference effects were caused by activation of polymodal neurons in areas 5 and/or 7 of the parietal lobe as well as in the medial superior temporal region and superior temporal sulcus. However, we could not exclude the effect of attention on such interference effects. In the present study, to know the effect of attention on visual and auditory interference in these changes, we stimulated the bilateral median nerves unilaterally in a random order, and asked subjects to count the number of times the left median nerve was stimulated while visual or auditory interference was applied. Five components (1M-5M) were identified in the hemisphere contralateral to the stimulated nerve and only one component (MI) was found in the ipsilateral hemisphere. The 3M and 4M components (33-75 ms in latency) were enhanced by both attention and visual interference stimulation but not by auditory stimulation. The 5M component (70-115 ms) and MI component (70-133 ms) were enhanced by attention, but were not changed by attention together with visual or auditory interference. Summarizing the results of our previous study and the present study, (1) visual interference alone enhanced the 3M and 4M but reduced the MI, and (2) attention alone also enhanced the 3M and 4M, and enhanced the 5M and MI. As a result, (3) visual interference with attention enhanced the 3M and 4M more, and showed no significant change of the 5M and MI. This was compatible with a summation of the effects caused by visual interference alone and attention alone, but

  7. Analysis of dynamic deformation processes with adaptive KALMAN-filtering

    NASA Astrophysics Data System (ADS)

    Eichhorn, Andreas

    2007-05-01

    In this paper the approach of a full system analysis is shown quantifying a dynamic structural ("white-box"-) model for the calculation of thermal deformations of bar-shaped machine elements. The task was motivated from mechanical engineering searching new methods for the precise prediction and computational compensation of thermal influences in the heating and cooling phases of machine tools (i.e. robot arms, etc.). The quantification of thermal deformations under variable dynamic loads requires the modelling of the non-stationary spatial temperature distribution inside the object. Based upon FOURIERS law of heat flow the high-grade non-linear temperature gradient is represented by a system of partial differential equations within the framework of a dynamic Finite Element topology. It is shown that adaptive KALMAN-filtering is suitable to quantify relevant disturbance influences and to identify thermal parameters (i.e. thermal diffusivity) with a deviation of only 0,2%. As result an identified (and verified) parametric model for the realistic prediction respectively simulation of dynamic temperature processes is presented. Classifying the thermal bend as the main deformation quantity of bar-shaped machine tools, the temperature model is extended to a temperature deformation model. In lab tests thermal load steps are applied to an aluminum column. Independent control measurements show that the identified model can be used to predict the columns bend with a mean deviation (r.m.s.) smaller than 10 mgon. These results show that the deformation model is a precise predictor and suitable for realistic simulations of thermal deformations. Experiments with modified heat sources will be necessary to verify the model in further frequency spectra of dynamic thermal loads.

  8. Neuroscience of attentional processes for addiction medicine: from brain mechanisms to practical considerations.

    PubMed

    Fadardi, Javad Salehi; Cox, W Miles; Rahmani, Arash

    2016-01-01

    The present chapter first argues how having a goal for procuring alcohol or other substances leads to the development of a time-binding, dynamic, and goal oriented motivational state termed current concern, as the origin of substance-related attentional bias. Next, it discusses the importance of attentional bias in the development, continuation of, and relapsing to substance abuse. It further proceeds with a review of selective evidence from cognitive psychology that helps account for making decisions about using an addictive substance or refraining from using it. A discussion on the various brain loci that are involved in attentional bias and other kinds of cue reactivity is followed by presenting findings from neurocognitive research. Finally, from an interdisciplinary perspective, the chapter presents new trends and ideas that can be applied to addiction-related cognitive measurement and training. PMID:26806772

  9. The interference of local over global information processing in children with attention deficit hyperactivity disorder of the inattentive type.

    PubMed

    Song, Yongning; Hakoda, Yuji

    2012-04-01

    A classic finding in perception of compound patterns is normal individuals cannot skip global analysis in local-oriented processing, but they can successfully resist local analysis in global-oriented processing-the so-called global interference [1]. Recently, studies examining the role of brain hemisphere activity in the Navon task have indicated that the processing of global and local information can be, respectively, attributed to the right and left hemispheres. Moreover, many neuroimaging researches have revealed that certain core symptoms of attention deficit hyperactivity disorder (ADHD) are related to dysfunction of right hemisphere. These findings imply that global interference will be substantially less evident, and possibly even replaced by local interference in ADHD. The present study compared the performance of children with and without attention deficit hyperactivity disorder of the inattentive type (ADHD-I) in the processing of global and local information to examine the local interference hypothesis in ADHD. An ADHD-I group (n=15) and a paired control group (n=19) completed tasks using two versions of the Navon task, one requiring divided attention, in which no information was given to participants regarding the level at which a target would appear, and the other requiring selective attention, in which participants were instructed to attend to either the local or the global level. The results showed that children with ADHD-I exhibited local interference, regardless of which attention procedure was used. These results support the weak right hemisphere hypothesis in ADHD, and provide evidence against the deficit hypotheses for ADHD in the DSM-IV criteria [29], which postulates that inattention symptoms may manifest as a failure to provide close attention to details.

  10. Patellar tendinosis as an adaptive process: a new hypothesis

    PubMed Central

    Hamilton, B; Purdam, C

    2004-01-01

    Background: Patellar tendinosis (PT), or "jumper's knee" is a common condition in athletes participating in jumping sports, and is characterised by proximal patellar tendon pain and focal tenderness to palpation. Hypoechoic lesions observed in the proximal patellar tendon associated with the tendinosis are typically described as being a result of degenerative change or "failed healing". We propose a new model for the development of the hypoechoic lesion observed in PT, in which the aetiology is an adaptive response to differential forces within the tendon. Methods: We assessed the clinical, histopathological, and biomechanical literature surrounding the patellar tendon and integrated this with research into the response of tendons to differential forces. Results and conclusions: We propose that the hypoechoic lesion commonly described in PT is the result of adaptation or partial adaptation of the proximal patellar tendon to a compressive load. We postulate that the biomechanics of the patellar–patellar tendon interface creates this compressive environment. Secondary failure of the surrounding tensile adapted tendon tissue may result in tissue overload and failure, with resultant stimulation of nociceptors. We believe that this "adaptive model" of patellar tendinosis is consistent with the clinical and histological findings. PMID:15562176

  11. Time in Redox Adaptation Processes: From Evolution to Hormesis

    PubMed Central

    Sthijns, Mireille M. J. P. E.; Weseler, Antje R.; Bast, Aalt; Haenen, Guido R. M. M.

    2016-01-01

    Life on Earth has to adapt to the ever changing environment. For example, due to introduction of oxygen in the atmosphere, an antioxidant network evolved to cope with the exposure to oxygen. The adaptive mechanisms of the antioxidant network, specifically the glutathione (GSH) system, are reviewed with a special focus on the time. The quickest adaptive response to oxidative stress is direct enzyme modification, increasing the GSH levels or activating the GSH-dependent protective enzymes. After several hours, a hormetic response is seen at the transcriptional level by up-regulating Nrf2-mediated expression of enzymes involved in GSH synthesis. In the long run, adaptations occur at the epigenetic and genomic level; for example, the ability to synthesize GSH by phototrophic bacteria. Apparently, in an adaptive hormetic response not only the dose or the compound, but also time, should be considered. This is essential for targeted interventions aimed to prevent diseases by successfully coping with changes in the environment e.g., oxidative stress. PMID:27690013

  12. Memantine Improves Attentional Processes in Fragile X-Associated Tremor/Ataxia Syndrome: Electrophysiological Evidence from a Randomized Controlled Trial

    PubMed Central

    Yang, Jin-Chen; Rodriguez, Annette; Royston, Ashley; Niu, Yu-Qiong; Avar, Merve; Brill, Ryan; Simon, Christa; Grigsby, Jim; Hagerman, Randi J.; Olichney, John M.

    2016-01-01

    Progressive cognitive deficits are common in patients with fragile X-associated tremor/ataxia syndrome (FXTAS), with no targeted treatment yet established. In this substudy of the first randomized controlled trial for FXTAS, we examined the effects of NMDA antagonist memantine on attention and working memory. Data were analyzed for patients (24 in each arm) who completed both the primary memantine trial and two EEG recordings (at baseline and follow-up) using an auditory “oddball” task. Results demonstrated significantly improved attention/working memory performance after one year only for the memantine group. The event-related potential P2 amplitude elicited by non-targets was significantly enhanced in the treated group, indicating memantine-associated improvement in attentional processes at the stimulus identification/discrimination level. P2 amplitude increase was positively correlated with improvement on the behavioral measure of attention/working memory during target detection. Analysis also revealed that memantine treatment normalized the P2 habituation effect at the follow-up visit. These findings indicate that memantine may benefit attentional processes that represent fundamental components of executive function/dysfunction, thought to comprise the core cognitive deficit in FXTAS. The results provide evidence of target engagement of memantine, as well as therapeutically relevant information that could further the development of specific cognitive or disease-modifying therapies for FXTAS. PMID:26898832

  13. The control of visual attention and its influence on prioritized processing in a location negative priming paradigm.

    PubMed

    Fischer, Rico; Hagendorf, Herbert

    2006-07-01

    In a location-based negative priming paradigm, the possibility of a disengagement option of the underlying inhibitory mechanism was tested. Whereas in previous studies disengagement was observed when providing utility information about the probe trial structure, in the present study the allocation of visual attention to the stimuli was manipulated. In the first step an automatic deployment of visual attention was implemented by presenting all stimuli as abrupt onsets (Experiment 1), which demonstrated commonly observed negative priming effects. In further conditions of non-automatic allocation of visual attention in which target and distractor were presented as no-onset stimuli, negative priming effects were eliminated (Experiments 2 and 3). The preferred interpretation is that in conditions of automatic control of attention, target and distractor compete for control of action. A non-automatic control of visual attention, on the other hand, leads to a top-down modulated selection, which results in prioritized target encoding and a loss of distractor impact on the selection process. Alternative accounts and the role of no-onset distractor processing were investigated in Experiment 4.

  14. The impact of simulated MRI scanner background noise on visual attention processes as measured by the EEG.

    PubMed

    Kobald, S Oliver; Getzmann, Stephan; Beste, Christian; Wascher, Edmund

    2016-01-01

    Environmental noise is known to affect personal well-being as well as cognitive processes. Besides daily life, environmental noise can also occur in experimental research settings, e.g. when being in a magnetic resonance scanner. Scanner background noise (SBN) might pose serious confounds for experimental findings, even when non-auditory settings are examined. In the current experiment we tested if SBN alters bottom-up and top-down related processes of selective visual attention mechanisms. Participants completed two blocks of a visual change detection task, one block in silence and one block under SBN exposure. SBN was found to decrease accuracy in measures of visual attention. This effect was modulated by the temporal occurrence of SBN. When SBN was encountered in the first block, it prevented a significant improvement of accuracy in the second block. When SBN appeared in the second block, it significantly decreased accuracy. Neurophysiological findings showed a strong frontal positivity shift only when SBN was present in the first block, suggesting an inhibitory process to counteract the interfering SBN. Common correlates of both top-down and bottom-up processes of selective visual attention were not specifically affected by SBN exposure. Further research appears necessary to entirely rule out confounds of SBN in assessing visual attention. PMID:27324456

  15. Predictive Power of Attention and Reading Readiness Variables on Auditory Reasoning and Processing Skills of Six-Year-Old Children

    ERIC Educational Resources Information Center

    Erbay, Filiz

    2013-01-01

    The aim of present research was to describe the relation of six-year-old children's attention and reading readiness skills (general knowledge, word comprehension, sentences, and matching) with their auditory reasoning and processing skills. This was a quantitative study based on scanning model. Research sampling consisted of 204 kindergarten…

  16. The impact of simulated MRI scanner background noise on visual attention processes as measured by the EEG

    PubMed Central

    Kobald, S. Oliver; Getzmann, Stephan; Beste, Christian; Wascher, Edmund

    2016-01-01

    Environmental noise is known to affect personal well-being as well as cognitive processes. Besides daily life, environmental noise can also occur in experimental research settings, e.g. when being in a magnetic resonance scanner. Scanner background noise (SBN) might pose serious confounds for experimental findings, even when non-auditory settings are examined. In the current experiment we tested if SBN alters bottom-up and top-down related processes of selective visual attention mechanisms. Participants completed two blocks of a visual change detection task, one block in silence and one block under SBN exposure. SBN was found to decrease accuracy in measures of visual attention. This effect was modulated by the temporal occurrence of SBN. When SBN was encountered in the first block, it prevented a significant improvement of accuracy in the second block. When SBN appeared in the second block, it significantly decreased accuracy. Neurophysiological findings showed a strong frontal positivity shift only when SBN was present in the first block, suggesting an inhibitory process to counteract the interfering SBN. Common correlates of both top-down and bottom-up processes of selective visual attention were not specifically affected by SBN exposure. Further research appears necessary to entirely rule out confounds of SBN in assessing visual attention. PMID:27324456

  17. Electrophysiological Evidence of Atypical Motivation and Reward Processing in Children with Attention-Deficit Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Holroyd, Clay B.; Baker, Travis E.; Kerns, Kimberly A.; Muller, Ulrich

    2008-01-01

    Behavioral and neurophysiological evidence suggest that attention-deficit hyperactivity disorder (ADHD) is characterized by the impact of abnormal reward prediction error signals carried by the midbrain dopamine system on frontal brain areas that implement cognitive control. To investigate this issue, we recorded the event-related brain potential…

  18. Students with Learning Disabilities and Attention Disorders: Stories of the College Choice Process

    ERIC Educational Resources Information Center

    Mercer, Kerri A.

    2012-01-01

    Although there has been legislation that has improved access for students with disabilities, many students are choosing not to pursue postsecondary education. The rate of postsecondary attendance for students with learning disabilities and attention disorders has increased, but they are still enrolling in postsecondary education less frequently…

  19. The Influence of Strong Attentional Manipulations on the Processing of Dichotic Inputs in Right-Handers.

    ERIC Educational Resources Information Center

    Iaccino, James F.

    A study was conducted to investigate further the dichotic outcomes in right-handers as a function of sex, ear-side, and most especially stronger attentional bias. The derived prediction was: that increased focus time on the right side would produce a striking right ear advantage (REA) in either right-handed men or women, replicating the most…

  20. Translating Head Motion into Attention - Towards Processing of Student's Body-Language

    ERIC Educational Resources Information Center

    Raca, Mirko; Kidzinski, Lukasz; Dillenbourg, Pierre

    2015-01-01

    Evidence has shown that student's attention is a crucial factor for engagement and learning gain. Although it can be accurately assessed ad-hoc by an experienced teacher, continuous contact with all students in a large class is difficult to maintain and requires training for novice practitioners. We continue our previous work on investigating…

  1. Effects of Spatial Configuration on Visual Attention Processes. Umea Psychological Reports No. 154.

    ERIC Educational Resources Information Center

    Brannstrom, Lauritz

    The significance of spatial factors on an initial segmentation and an active attentional phase was demonstrated by briefly exposing spatial configurations of elements, and then asking the subjects to reproduce the patterns or to search them for a target letter. The stimulus displays consisted of small o's forming different spatial configurations,…

  2. Effects of Methylphenidate on the Auditory Processing Abilities of Children with Attention Deficit-Hyperactivity Disorder.

    ERIC Educational Resources Information Center

    Keith, Robert W.; Engineer, Parika

    1991-01-01

    Twenty subjects (ages 7-13) with attention deficit hyperactivity disorder were administered a battery of tests (including the Auditory Continuous Performance Test and the Token Test for Children) twice, first when not taking and then when taking methylphenidate. Results indicated significant improvement in performance on all measures when subjects…

  3. Attention Deficit/Hyperactivity Disorder: Perspectives of Participants in the Identification and Treatment Process.

    ERIC Educational Resources Information Center

    Davison, Judy C.

    2001-01-01

    Questions the rising incidence of Attention Deficit/Hyperactivity Disorder (AD/HD) diagnosis in the United States. Suggests that AD/HD is a socially constructed phenomenon rather than biologically based. Urges educators, medical personnel, and parents to take a holistic view of each child, with a serious examination of the wide range of causation…

  4. Electrophysiological Indices of Abnormal Error-Processing in Adolescents with Attention Deficit Hyperactivity Disorder (ADHD)

    ERIC Educational Resources Information Center

    Groom, Madeleine J.; Cahill, John D.; Bates, Alan T.; Jackson, Georgina M.; Calton, Timothy G.; Liddle, Peter F.; Hollis, Chris

    2010-01-01

    Background: Impaired cognitive control has been frequently observed in children and young people with attention deficit hyperactivity disorder (ADHD) and might underlie the excessive hyperactivity and impulsivity in this population. We investigated behavioural and electrophysiological indices relevant to one domain of cognitive control; namely…

  5. The Process of Auditory Distraction: Disrupted Attention and Impaired Recall in a Simulated Lecture Environment

    ERIC Educational Resources Information Center

    Zeamer, Charlotte; Fox Tree, Jean E.

    2013-01-01

    Literature on auditory distraction has generally focused on the effects of particular kinds of sounds on attention to target stimuli. In support of extensive previous findings that have demonstrated the special role of language as an auditory distractor, we found that a concurrent speech stream impaired recall of a short lecture, especially for…

  6. Basic Processes in Reading: On the Relation between Spatial Attention and Familiarity

    ERIC Educational Resources Information Center

    Risko, Evan F.; Stolz, Jennifer A.; Besner, Derek

    2011-01-01

    Two experiments combined a spatial cueing manipulation (valid vs. invalid spatial cues) with a stimulus repetition manipulation (repeated vs. nonrepeated) in order to assess the hypothesis that familiar items need less spatial attention than less familiar ones. The magnitude of the effect of cueing on reading aloud time for items that were…

  7. Comparing Perception of Stroop Stimuli in Focused versus Divided Attention Paradigms: Evidence for Dramatic Processing Differences

    ERIC Educational Resources Information Center

    Eidels, Ami; Townsend, James T.; Algom, Daniel

    2010-01-01

    A huge set of focused attention experiments show that when presented with color words printed in color, observers report the ink color faster if the carrier word is the name of the color rather than the name of an alternative color, the Stroop effect. There is also a large number (although not so numerous as the Stroop task) of so-called…

  8. Rapid Processing of Letters, Digits and Symbols: What Purely Visual-Attentional Deficit in Developmental Dyslexia?

    ERIC Educational Resources Information Center

    Ziegler, Johannes C.; Pech-Georgel, Catherine; Dufau, Stephane; Grainger, Jonathan

    2010-01-01

    Visual-attentional theories of dyslexia predict deficits for dyslexic children not only for the perception of letter strings but also for non-alphanumeric symbol strings. This prediction was tested in a two-alternative forced-choice paradigm with letters, digits, and symbols. Children with dyslexia showed significant deficits for letter and digit…

  9. Fixing our focus: Training attention to regulate emotion

    PubMed Central

    Wadlinger, Heather A.; Isaacowitz, Derek M.

    2010-01-01

    Empirical studies have frequently linked negative attentional biases with attentional dysfunction and negative moods; however, far less research has focused on how attentional deployment can be an adaptive strategy that regulates emotional experience. We argue that attention may be an invaluable tool for promoting emotion regulation. Accordingly, we present evidence that selective attention to positive information reflects emotion regulation, and that regulating attention is a critical component of the emotion regulatory process. Furthermore, attentional regulation can be successfully trained through repeated practice. We ultimately propose a model of attention training methodologies integrating attention-dependent emotion regulation strategies with attention networks. While additional interdisciplinary research is needed to bolster these nascent findings, meditative practices appear to be among the most effective training methodologies in enhancing emotional well-being. Further exploration of the positive and therapeutic qualities of attention warrants the empirical attention of social and personality psychologists. PMID:20435804

  10. Pre-attentive cortical processing of behaviorally perceptible spatial changes in older adults—a mismatch negativity study

    PubMed Central

    Freigang, Claudia; Rübsamen, Rudolf; Richter, Nicole

    2014-01-01

    From behavioral studies it is known that auditory spatial resolution of azimuthal space declines over age. To date, it is not clear how age affects the respective sensory auditory processing at the pre-attentive level. Here we tested the hypothesis that pre-attentive processing of behaviorally perceptible spatial changes is preserved in older adults. An EEG-study was performed in older adults (65–82 years of age) and a mismatch negativity (MMN) paradigm employed. Sequences of frequent standard stimuli of defined azimuthal positions were presented together with rarely occurring deviants shifted by 10° or 20° to the left or to the right of the standard. Standard positions were at +5° (central condition) from the midsagittal plane and at 65° in both lateral hemifields (±65°; lateral condition). The results suggest an effect of laterality on the pre-attentive change processing of spatial deviations in older adults: While for the central conditions deviants close to MAA threshold (i.e., 10°) yielded discernable MMNs, for lateral positions the respective MMN responses were only elicited by spatial deviations of 20° toward the midline (i.e., ±45°). Furthermore, MMN amplitudes were found to be insensitive to the magnitude of deviation (10°, 20°), which is contrary to recent studies with young adults (Bennemann et al., 2013) and hints to a deteriorated pre-attentive encoding of sound sources in older adults. The discrepancy between behavioral MAA data and present results are discussed with respect to the possibility that under the condition of active stimulus processing older adults might benefit from recruiting additional attentional top-down processes to detect small magnitudes of spatial deviations even within the lateral acoustic field. PMID:24982611

  11. Regional and Foreign Accent Processing in English: Can Listeners Adapt?

    ERIC Educational Resources Information Center

    Floccia, Caroline; Butler, Joseph; Goslin, Jeremy; Ellis, Lucy

    2009-01-01

    Recent data suggest that the first presentation of a foreign accent triggers a delay in word identification, followed by a subsequent adaptation. This study examines under what conditions the delay resumes to baseline level. The delay will be experimentally induced by the presentation of sentences spoken to listeners in a foreign or a regional…

  12. Do Problems with Information Processing Affect the Process of Psychotherapy for Adults with Learning Disabilities or Attention Deficit/Hyperactivity Disorder?

    ERIC Educational Resources Information Center

    Cosden, Merith; Patz, Sarah; Smith, Steven

    2009-01-01

    Problems in processing information can affect psychosocial functioning. Psychotherapy can be used to address psychosocial problems; however, the same information-processing problems that contribute to disabilities, such as learning disabilities (LD) or attention deficit/hyperactivity disorder (ADHD), particularly deficits in auditory processing…

  13. Asymmetrical effects of adaptation to left- and right-shifting prisms depends on pre-existing attentional biases.

    PubMed

    Goedert, Kelly M; Leblanc, Andrew; Tsai, Sen-Wei; Barrett, Anna M

    2010-09-01

    Proposals that adaptation with left-shifting prisms induces neglect-like symptoms in normal individuals rely on a dissociation between the postadaptation performance of individuals trained with left- versus right-shifting prisms (e.g., Colent, Pisella, & Rossetti, 2000). A potential problem with this evidence is that normal young adults have an a priori leftward bias (e.g., Jewell & McCourt, 2000). In Experiment 1, we compared the line bisection performance of young adults to that of aged adults, who as a group may lack a leftward bias in line bisection. Participants trained with both left- and right-shifting prisms. Consistent with our hypothesis, while young adults demonstrated aftereffects for left, but not right prisms, aged adults demonstrated reliable aftereffects for both prisms. In Experiment 2, we recruited a larger sample of young adults, some of whom were right-biased at baseline. We observed an interaction between baseline bias and prism-shift, consistent with the results of Experiment 1: Left-biased individuals showed a reduced aftereffect when training with right-shifting prisms and right-biased individuals showed a reduced aftereffect when training with left-shifting prisms. These results suggest that previous failures to find generalizable aftereffects with right-shifting prisms may be driven by participants' baseline biases rather than specific effects of the prism itself.

  14. Perceiving emotions: Cueing social categorization processes and attentional control through facial expressions.

    PubMed

    Cañadas, Elena; Lupiáñez, Juan; Kawakami, Kerry; Niedenthal, Paula M; Rodríguez-Bailón, Rosa

    2016-09-01

    Individuals spontaneously categorise other people on the basis of their gender, ethnicity and age. But what about the emotions they express? In two studies we tested the hypothesis that facial expressions are similar to other social categories in that they can function as contextual cues to control attention. In Experiment 1 we associated expressions of anger and happiness with specific proportions of congruent/incongruent flanker trials. We also created consistent and inconsistent category members within each of these two general contexts. The results demonstrated that participants exhibited a larger congruency effect when presented with faces in the emotional group associated with a high proportion of congruent trials. Notably, this effect transferred to inconsistent members of the group. In Experiment 2 we replicated the effects with faces depicting true and false smiles. Together these findings provide consistent evidence that individuals spontaneously utilise emotions to categorise others and that such categories determine the allocation of attentional control.

  15. Analysis of Interaction and Attention Processes in a Child With Congenital Deafblindness.

    PubMed

    Boas, Denise Cintra; Ferreira, Slie Piccolotto; de Moura, Maria Cec; Maia, Shirley Rodrigues; Amaral, Isabel

    2016-01-01

    Children with deafblindness need support to be able to understand the world and to have access to information. The authors analyzed a dyad consisting of a child with congenital deafblindness and a specialized teacher. The study included participant observations and audiovisual recordings. It was found that the child showed attention to the teacher in activities involving music and rhythm. As potential forms of nonverbal communication, the child presented vocalization, touch, body contact, body movements, facial expressions, and tears. The teacher's forms of communication were verbal, touch, visual, rhythm, and sign language. It was concluded that a significant communication partner is essential to identify, interpret, and respond to attention and communicative behaviors. Use of other forms of communication must comply with individual characteristics so that the child with deafblindness can receive information from the environment through these senses and thus be guaranteed access to the world. PMID:27477040

  16. Children's representation of long duration: when memory and attention meet in processing time.

    PubMed

    Choe, Katherine S

    2013-01-01

    The concepts of the memory and attentional models were examined in children's and adults' time perception in a long duration. One hundred twenty-one children in preschool through Grade 2 and 29 adults for Study 1 and 93 second-, fourth-, and sixth-grade students and 40 adults for Study 2 judged durations of tasks that varied in interest levels and cognitive demands. In Study 1, children overestimated but adults underestimated the movie that they found to be interesting. However, in Study 2, both children and adults consistently overestimated the duration of puzzles they found to be interesting. In a long duration, the findings were more in line with the memory model than with the attention model. A qualitative change also emerged in middle childhood in the way children kept track of time; this difference may influence the developing perception of long duration in children's representation. Implications of the findings are further discussed in examining the perception of long duration. PMID:23534192

  17. Individual differences in attentional bias associated with cocaine dependence are related to varying engagement of neural processing networks.

    PubMed

    Kilts, Clint D; Kennedy, Ashley; Elton, Amanda L; Tripathi, Shanti Prakash; Young, Jonathan; Cisler, Josh M; James, G Andrew

    2014-04-01

    Cocaine and other drug dependencies are associated with significant attentional bias for drug use stimuli that represents a candidate cognitive marker of drug dependence and treatment outcomes. We explored, using fMRI, the role of discrete neural processing networks in the representation of individual differences in the drug attentional bias effect associated with cocaine dependence (AB-coc) using a word counting Stroop task with personalized cocaine use stimuli (cocStroop). The cocStroop behavioral and neural responses were further compared with those associated with a negative emotional word Stroop task (eStroop) and a neutral word counting Stroop task (cStroop). Brain-behavior correlations were explored using both network-level correlation analysis following independent component analysis (ICA) and voxel-level, brain-wide univariate correlation analysis. Variation in the attentional bias effect for cocaine use stimuli among cocaine-dependent men and women was related to the recruitment of two separate neural processing networks related to stimulus attention and salience attribution (inferior frontal-parietal-ventral insula), and the processing of the negative affective properties of cocaine stimuli (frontal-temporal-cingulate). Recruitment of a sensory-motor-dorsal insula network was negatively correlated with AB-coc and suggested a regulatory role related to the sensorimotor processing of cocaine stimuli. The attentional bias effect for cocaine stimuli and for negative affective word stimuli were significantly correlated across individuals, and both were correlated with the activity of the frontal-temporal-cingulate network. Functional connectivity for a single prefrontal-striatal-occipital network correlated with variation in general cognitive control (cStroop) that was unrelated to behavioral or neural network correlates of cocStroop- or eStroop-related attentional bias. A brain-wide mass univariate analysis demonstrated the significant correlation of

  18. Casual Video Games as Training Tools for Attentional Processes in Everyday Life.

    PubMed

    Stroud, Michael J; Whitbourne, Susan Krauss

    2015-11-01

    Three experiments examined the attentional components of the popular match-3 casual video game, Bejeweled Blitz (BJB). Attentionally demanding, BJB is highly popular among adults, particularly those in middle and later adulthood. In experiment 1, 54 older adults (Mage = 70.57) and 33 younger adults (Mage = 19.82) played 20 rounds of BJB, and completed online tasks measuring reaction time, simple visual search, and conjunction visual search. Prior experience significantly predicted BJB scores for younger adults, but for older adults, both prior experience and simple visual search task scores predicted BJB performance. Experiment 2 tested whether BJB practice alone would result in a carryover benefit to a visual search task in a sample of 58 young adults (Mage = 19.57) who completed 0, 10, or 30 rounds of BJB followed by a BJB-like visual search task with targets present or absent. Reaction times were significantly faster for participants who completed 30 but not 10 rounds of BJB compared with the search task only. This benefit was evident when targets were both present and absent, suggesting that playing BJB improves not only target detection, but also the ability to quit search effectively. Experiment 3 tested whether the attentional benefit in experiment 2 would apply to non-BJB stimuli. The results revealed a similar numerical but not significant trend. Taken together, the findings suggest there are benefits of casual video game playing to attention and relevant everyday skills, and that these games may have potential value as training tools. PMID:26448498

  19. Casual Video Games as Training Tools for Attentional Processes in Everyday Life.

    PubMed

    Stroud, Michael J; Whitbourne, Susan Krauss

    2015-11-01

    Three experiments examined the attentional components of the popular match-3 casual video game, Bejeweled Blitz (BJB). Attentionally demanding, BJB is highly popular among adults, particularly those in middle and later adulthood. In experiment 1, 54 older adults (Mage = 70.57) and 33 younger adults (Mage = 19.82) played 20 rounds of BJB, and completed online tasks measuring reaction time, simple visual search, and conjunction visual search. Prior experience significantly predicted BJB scores for younger adults, but for older adults, both prior experience and simple visual search task scores predicted BJB performance. Experiment 2 tested whether BJB practice alone would result in a carryover benefit to a visual search task in a sample of 58 young adults (Mage = 19.57) who completed 0, 10, or 30 rounds of BJB followed by a BJB-like visual search task with targets present or absent. Reaction times were significantly faster for participants who completed 30 but not 10 rounds of BJB compared with the search task only. This benefit was evident when targets were both present and absent, suggesting that playing BJB improves not only target detection, but also the ability to quit search effectively. Experiment 3 tested whether the attentional benefit in experiment 2 would apply to non-BJB stimuli. The results revealed a similar numerical but not significant trend. Taken together, the findings suggest there are benefits of casual video game playing to attention and relevant everyday skills, and that these games may have potential value as training tools.

  20. Evidence for the role of German final devoicing in pre-attentive speech processing: a mismatch negativity study

    PubMed Central

    Truckenbrodt, Hubert; Steinberg, Johanna; Jacobsen, Thomas K.; Jacobsen, Thomas

    2014-01-01

    Results of a mismatch negativity experiment are reported in which the pre-attentive relevance of the German phonological alternation of final devoicing (FD) is shown in two ways. The experiment employs pseudowords. (1) A deviant [vus] paired with standard /vuzə/ did not show a mismatch effect for the voicing change in /z/ versus [s] because the two can be related by FD. When standard and deviant were reversed, the two could not be related by FD and a mismatch effect for the voicing difference occurred. (2) An ill-formed deviant that violates FD, *[vuz], triggered mismatch effects that were plausibly attributed to its ill-formedness. The results show that a syllable-related process like FD is already taken into account by the processing system in early pre-attentive processing. PMID:25505433

  1. Evidence for the role of German final devoicing in pre-attentive speech processing: a mismatch negativity study.

    PubMed

    Truckenbrodt, Hubert; Steinberg, Johanna; Jacobsen, Thomas K; Jacobsen, Thomas

    2014-01-01

    Results of a mismatch negativity experiment are reported in which the pre-attentive relevance of the German phonological alternation of final devoicing (FD) is shown in two ways. The experiment employs pseudowords. (1) A deviant [vus] paired with standard /vuzə/ did not show a mismatch effect for the voicing change in /z/ versus [s] because the two can be related by FD. When standard and deviant were reversed, the two could not be related by FD and a mismatch effect for the voicing difference occurred. (2) An ill-formed deviant that violates FD, *[vuz], triggered mismatch effects that were plausibly attributed to its ill-formedness. The results show that a syllable-related process like FD is already taken into account by the processing system in early pre-attentive processing. PMID:25505433

  2. Processing deficits in monitoring analog and digital displays: Implications for attentional theory and mental-state estimation research

    NASA Technical Reports Server (NTRS)

    Payne, David G.; Gunther, Virginia A. L.

    1988-01-01

    Subjects performed short term memory tasks, involving both spatial and verbal components, and a visual monitoring task involving either analog or digital display formats. These two tasks (memory vs. monitoring) were performed both singly and in conjunction. Contrary to expectations derived from multiple resource theories of attentional processes, there was no evidence that when the two tasks involved the same cognitive codes (i.e., either both spatial or both verbal/linguistics) there was more of a dual task performance decrement than when the two tasks employed different cognitive codes/processes. These results are discussed in terms of their implications for theories of attentional processes and also for research in mental state estimation.

  3. Tracking performance under time sharing conditions with a digit processing task: A feedback control theory analysis. [attention sharing effect on operator performance

    NASA Technical Reports Server (NTRS)

    Gopher, D.; Wickens, C. D.

    1975-01-01

    A one dimensional compensatory tracking task and a digit processing reaction time task were combined in a three phase experiment designed to investigate tracking performance in time sharing. Adaptive techniques, elaborate feedback devices, and on line standardization procedures were used to adjust task difficulty to the ability of each individual subject and manipulate time sharing demands. Feedback control analysis techniques were employed in the description of tracking performance. The experimental results show that when the dynamics of a system are constrained, in such a manner that man machine system stability is no longer a major concern of the operator, he tends to adopt a first order control describing function, even with tracking systems of higher order. Attention diversion to a concurrent task leads to an increase in remnant level, or nonlinear power. This decrease in linearity is reflected both in the output magnitude spectra of the subjects, and in the linear fit of the amplitude ratio functions.

  4. Attachment and Children’s Biased Attentional Processing: Evidence for the Exclusion of Attachment-Related Information

    PubMed Central

    Vandevivere, Eva; Braet, Caroline; Bosmans, Guy; Mueller, Sven C.; De Raedt, Rudi

    2014-01-01

    Research in both infants and adults demonstrated that attachment expectations are associated with the attentional processing of attachment-related information. However, this research suffered from methodological issues and has not been validated across ages. Employing a more ecologically valid paradigm to measure attentional processes by virtue of eye tracking, the current study tested the defensive exclusion hypothesis in late childhood. According to this hypothesis, insecurely attached children are assumed to defensively exclude attachment-related information. We hypothesized that securely attached children process attachment- related neutral and emotional information in a more open manner compared to insecurely attached children. Sixty-two children (59.7% girls, 8–12 years) completed two different tasks, while eye movements were recorded: task one presented an array of neutral faces including mother and unfamiliar women and task two presented the same with happy and angry faces. Results indicated that more securely attached children looked longer at mother’s face regardless of the emotional expression. Also, they tend to have more maintained attention to mother’s neutral face. Furthermore, more attachment avoidance was related to a reduced total viewing time of mother’s neutral, happy, and angry face. Attachment anxiety was not consistently related to the processing of mother’s face. Findings support the theoretical assumption that securely attached children have an open manner of processing all attachment-related information. PMID:25061662

  5. Flight data processing with the F-8 adaptive algorithm

    NASA Technical Reports Server (NTRS)

    Hartmann, G.; Stein, G.; Petersen, K.

    1977-01-01

    An explicit adaptive control algorithm based on maximum likelihood estimation of parameters has been designed for NASA's DFBW F-8 aircraft. To avoid iterative calculations, the algorithm uses parallel channels of Kalman filters operating at fixed locations in parameter space. This algorithm has been implemented in NASA/DFRC's Remotely Augmented Vehicle (RAV) facility. Real-time sensor outputs (rate gyro, accelerometer and surface position) are telemetered to a ground computer which sends new gain values to an on-board system. Ground test data and flight records were used to establish design values of noise statistics and to verify the ground-based adaptive software. The software and its performance evaluation based on flight data are described

  6. Altered intrinsic organisation of brain networks implicated in attentional processes in adult attention-deficit/hyperactivity disorder: a resting-state study of attention, default mode and salience network connectivity.

    PubMed

    Sidlauskaite, Justina; Sonuga-Barke, Edmund; Roeyers, Herbert; Wiersema, Jan R

    2016-06-01

    Deficits in task-related attentional engagement in attention-deficit/hyperactivity disorder (ADHD) have been hypothesised to be due to altered interrelationships between attention, default mode and salience networks. We examined the intrinsic connectivity during rest within and between these networks. Six-minute resting-state scans were obtained. Using a network-based approach, connectivity within and between the dorsal and ventral attention, the default mode and the salience networks was compared between the ADHD and control group. The ADHD group displayed hyperconnectivity between the two attention networks and within the default mode and ventral attention network. The salience network was hypoconnected to the dorsal attention network. There were trends towards hyperconnectivity within the dorsal attention network and between the salience and ventral attention network in ADHD. Connectivity within and between other networks was unrelated to ADHD. Our findings highlight the altered connectivity within and between attention networks, and between them and the salience network in ADHD. One hypothesis to be tested in future studies is that individuals with ADHD are affected by an imbalance between ventral and dorsal attention systems with the former playing a dominant role during task engagement, making individuals with ADHD highly susceptible to distraction by salient task-irrelevant stimuli.

  7. Attention Genes

    ERIC Educational Resources Information Center

    Posner, Michael I.; Rothbart, Mary K.; Sheese, Brad E.

    2007-01-01

    A major problem for developmental science is understanding how the cognitive and emotional networks important in carrying out mental processes can be related to individual differences. The last five years have seen major advances in establishing links between alleles of specific genes and the neural networks underlying aspects of attention. These…

  8. Neural adaptation and behavioral measures of temporal processing and speech perception in cochlear implant recipients.

    PubMed

    Zhang, Fawen; Benson, Chelsea; Murphy, Dora; Boian, Melissa; Scott, Michael; Keith, Robert; Xiang, Jing; Abbas, Paul

    2013-01-01

    The objective was to determine if one of the neural temporal features, neural adaptation, can account for the across-subject variability in behavioral measures of temporal processing and speech perception performance in cochlear implant (CI) recipients. Neural adaptation is the phenomenon in which neural responses are the strongest at the beginning of the stimulus and decline following stimulus repetition (e.g., stimulus trains). It is unclear how this temporal property of neural responses relates to psychophysical measures of temporal processing (e.g., gap detection) or speech perception. The adaptation of the electrical compound action potential (ECAP) was obtained using 1000 pulses per second (pps) biphasic pulse trains presented directly to the electrode. The adaptation of the late auditory evoked potential (LAEP) was obtained using a sequence of 1-kHz tone bursts presented acoustically, through the cochlear implant. Behavioral temporal processing was measured using the Random Gap Detection Test at the most comfortable listening level. Consonant nucleus consonant (CNC) word and AzBio sentences were also tested. The results showed that both ECAP and LAEP display adaptive patterns, with a substantial across-subject variability in the amount of adaptation. No correlations between the amount of neural adaptation and gap detection thresholds (GDTs) or speech perception scores were found. The correlations between the degree of neural adaptation and demographic factors showed that CI users having more LAEP adaptation were likely to be those implanted at a younger age than CI users with less LAEP adaptation. The results suggested that neural adaptation, at least this feature alone, cannot account for the across-subject variability in temporal processing ability in the CI users. However, the finding that the LAEP adaptive pattern was less prominent in the CI group compared to the normal hearing group may suggest the important role of normal adaptation pattern at the

  9. Neural Adaptation and Behavioral Measures of Temporal Processing and Speech Perception in Cochlear Implant Recipients

    PubMed Central

    Zhang, Fawen; Benson, Chelsea; Murphy, Dora; Boian, Melissa; Scott, Michael; Keith, Robert; Xiang, Jing; Abbas, Paul

    2013-01-01

    The objective was to determine if one of the neural temporal features, neural adaptation, can account for the across-subject variability in behavioral measures of temporal processing and speech perception performance in cochlear implant (CI) recipients. Neural adaptation is the phenomenon in which neural responses are the strongest at the beginning of the stimulus and decline following stimulus repetition (e.g., stimulus trains). It is unclear how this temporal property of neural responses relates to psychophysical measures of temporal processing (e.g., gap detection) or speech perception. The adaptation of the electrical compound action potential (ECAP) was obtained using 1000 pulses per second (pps) biphasic pulse trains presented directly to the electrode. The adaptation of the late auditory evoked potential (LAEP) was obtained using a sequence of 1-kHz tone bursts presented acoustically, through the cochlear implant. Behavioral temporal processing was measured using the Random Gap Detection Test at the most comfortable listening level. Consonant nucleus consonant (CNC) word and AzBio sentences were also tested. The results showed that both ECAP and LAEP display adaptive patterns, with a substantial across-subject variability in the amount of adaptation. No correlations between the amount of neural adaptation and gap detection thresholds (GDTs) or speech perception scores were found. The correlations between the degree of neural adaptation and demographic factors showed that CI users having more LAEP adaptation were likely to be those implanted at a younger age than CI users with less LAEP adaptation. The results suggested that neural adaptation, at least this feature alone, cannot account for the across-subject variability in temporal processing ability in the CI users. However, the finding that the LAEP adaptive pattern was less prominent in the CI group compared to the normal hearing group may suggest the important role of normal adaptation pattern at the

  10. Negotiating uncertainty: the transitional process of adapting to life with HIV.

    PubMed

    Perrett, Stephanie E; Biley, Francis C

    2013-01-01

    Glaser's (1978) grounded-theory method was used to investigate the transitional process of adapting to life with HIV. Semistructured interviews took place with 8 male HIV-infected participants recruited from a clinic in South Wales, United Kingdom. Data analysis used open, substantive, and theoretical coding. Adapting to a life with HIV infection emerged as a process of adapting to uncertainty with "negotiating uncertainty" as a core concept. Seven subcategories represented movements between bipolar opposites labeled "anticipating hopelessness" and "regaining optimism." This work progresses the theoretical concepts of transitions, uncertainty, and adaptation in relation to the HIV experience.

  11. Adaptation to recent conflict in the classical color-word Stroop-task mainly involves facilitation of processing of task-relevant information

    PubMed Central

    Purmann, Sascha; Pollmann, Stefan

    2015-01-01

    To process information selectively and to continuously fine-tune selectivity of information processing are important abilities for successful goal-directed behavior. One phenomenon thought to represent this fine-tuning are conflict adaptation effects in interference tasks, i.e., reduction of interference after an incompatible trial and when incompatible trials are frequent. The neurocognitive mechanisms of these effects are currently only partly understood and results from brainimaging studies so far are mixed. In our study we validate and extend recent findings by examining adaption to recent conflict in the classical Stroop task using functional magnetic resonance imaging. Consistent with previous research we found increased activity in a fronto-parietal network comprising the medial prefrontal cortex, ventro-lateral prefrontal cortex, and posterior parietal cortex when contrasting incompatible with compatible trials. These areas have been associated with attentional processes and might reflect increased cognitive conflict and resolution thereof during incompatible trials. While carefully controlling for non-attentional sequential effects we found smaller Stroop interference after an incompatible trial (conflict adaptation effect). These behavioral conflict adaptation effects were accompanied by changes in activity in visual color-selective areas (V4, V4α), while there was no modulation by previous trial compatibility in a visual word-selective area (VWFA). Our results provide further evidence for the notion, that adaptation to recent conflict seems to be based mainly on enhancement of processing of the task-relevant information. PMID:25784868

  12. Pre-Orthographic Character String Processing and Parietal Cortex: A Role for Visual Attention in Reading?

    ERIC Educational Resources Information Center

    Lobier, Muriel; Peyrin, Carole; Le Bas, Jean-Francois; Valdois, Sylviane

    2012-01-01

    The visual front-end of reading is most often associated with orthographic processing. The left ventral occipito-temporal cortex seems to be preferentially tuned for letter string and word processing. In contrast, little is known of the mechanisms responsible for pre-orthographic processing: the processing of character strings regardless of…

  13. Adapt

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  14. The effects of sleep deprivation on divergent thinking and attention processes.

    PubMed

    Wimmer; Hoffmann; Bonato; Moffitt

    1992-12-01

    Twelve male undergraduate students were deprived of sleep for one night and were tested with a series of cognitive tasks. Their performance was compared to the performance of thirteen control subjects. Two hourly tasks and three occasional tasks were administered in order to examine cognitive performance following sleep loss. In an attempt to replicate the findings of Horne (1988a), the figural form of the Torrance Tests of Creative Thinking was administered. To explore the effects of short-term sleep deprivation on attention, the following tasks were also administered: a working memory task, a trail-making task, a vowel/consonant discrimination task, and a letter recognition task. Results of the Torrance test, trail-making task and letter recognition task revealed decreases in cognitive abilities following sleep loss, although all tasks required less than 10 minutes to administer. The results of this study suggest that cognitive measures following sleep deprivation have not been adequately explored. Results support the hypothesis that sleep serves a function of cognitive restitution, particularly in the maintenance of attentional mechanisms. PMID:10607055

  15. Linking attentional processes and conceptual problem solving: visual cues facilitate the automaticity of extracting relevant information from diagrams

    PubMed Central

    Rouinfar, Amy; Agra, Elise; Larson, Adam M.; Rebello, N. Sanjay; Loschky, Lester C.

    2014-01-01

    This study investigated links between visual attention processes and conceptual problem solving. This was done by overlaying visual cues on conceptual physics problem diagrams to direct participants’ attention to relevant areas to facilitate problem solving. Participants (N = 80) individually worked through four problem sets, each containing a diagram, while their eye movements were recorded. Each diagram contained regions that were relevant to solving the problem correctly and separate regions related to common incorrect responses. Problem sets contained an initial problem, six isomorphic training problems, and a transfer problem. The cued condition saw visual cues overlaid on the training problems. Participants’ verbal responses were used to determine their accuracy. This study produced two major findings. First, short duration visual cues which draw attention to solution-relevant information and aid in the organizing and integrating of it, facilitate both immediate problem solving and generalization of that ability to new problems. Thus, visual cues can facilitate re-representing a problem and overcoming impasse, enabling a correct solution. Importantly, these cueing effects on problem solving did not involve the solvers’ attention necessarily embodying the solution to the problem, but were instead caused by solvers attending to and integrating relevant information in the problems into a solution path. Second, this study demonstrates that when such cues are used across multiple problems, solvers can automatize the extraction of problem-relevant information extraction. These results suggest that low-level attentional selection processes provide a necessary gateway for relevant information to be used in problem solving, but are generally not sufficient for correct problem solving. Instead, factors that lead a solver to an impasse and to organize and integrate problem information also greatly facilitate arriving at correct solutions. PMID:25324804

  16. Linking attentional processes and conceptual problem solving: visual cues facilitate the automaticity of extracting relevant information from diagrams.

    PubMed

    Rouinfar, Amy; Agra, Elise; Larson, Adam M; Rebello, N Sanjay; Loschky, Lester C

    2014-01-01

    This study investigated links between visual attention processes and conceptual problem solving. This was done by overlaying visual cues on conceptual physics problem diagrams to direct participants' attention to relevant areas to facilitate problem solving. Participants (N = 80) individually worked through four problem sets, each containing a diagram, while their eye movements were recorded. Each diagram contained regions that were relevant to solving the problem correctly and separate regions related to common incorrect responses. Problem sets contained an initial problem, six isomorphic training problems, and a transfer problem. The cued condition saw visual cues overlaid on the training problems. Participants' verbal responses were used to determine their accuracy. This study produced two major findings. First, short duration visual cues which draw attention to solution-relevant information and aid in the organizing and integrating of it, facilitate both immediate problem solving and generalization of that ability to new problems. Thus, visual cues can facilitate re-representing a problem and overcoming impasse, enabling a correct solution. Importantly, these cueing effects on problem solving did not involve the solvers' attention necessarily embodying the solution to the problem, but were instead caused by solvers attending to and integrating relevant information in the problems into a solution path. Second, this study demonstrates that when such cues are used across multiple problems, solvers can automatize the extraction of problem-relevant information extraction. These results suggest that low-level attentional selection processes provide a necessary gateway for relevant information to be used in problem solving, but are generally not sufficient for correct problem solving. Instead, factors that lead a solver to an impasse and to organize and integrate problem information also greatly facilitate arriving at correct solutions.

  17. Context-Aware Design for Process Flexibility and Adaptation

    ERIC Educational Resources Information Center

    Yao, Wen

    2012-01-01

    Today's organizations face continuous and unprecedented changes in their business environment. Traditional process design tools tend to be inflexible and can only support rigidly defined processes (e.g., order processing in the supply chain). This considerably restricts their real-world applications value, especially in the dynamic and…

  18. Adaptation and habitat selection in the eco-evolutionary process

    PubMed Central

    Morris, Douglas W.

    2011-01-01

    The struggle for existence occurs through the vital rates of population growth. This basic fact demonstrates the tight connection between ecology and evolution that defines the emerging field of eco-evolutionary dynamics. An effective synthesis of the interdependencies between ecology and evolution is grounded in six principles. The mechanics of evolution specifies the origin and rules governing traits and evolutionary strategies. Traits and evolutionary strategies achieve their selective value through their functional relationships with fitness. Function depends on the underlying structure of variation and the temporal, spatial and organizational scales of evolution. An understanding of how changes in traits and strategies occur requires conjoining ecological and evolutionary dynamics. Adaptation merges these five pillars to achieve a comprehensive understanding of ecological and evolutionary change. I demonstrate the value of this world-view with reference to the theory and practice of habitat selection. The theory allows us to assess evolutionarily stable strategies and states of habitat selection, and to draw the adaptive landscapes for habitat-selecting species. The landscapes can then be used to forecast future evolution under a variety of climate change and other scenarios. PMID:21613295

  19. Adaptation as a Political Process: Adjusting to Drought and Conflict in Kenya's Drylands

    NASA Astrophysics Data System (ADS)

    Eriksen, Siri; Lind, Jeremy

    2009-05-01

    In this article, we argue that people’s adjustments to multiple shocks and changes, such as conflict and drought, are intrinsically political processes that have uneven outcomes. Strengthening local adaptive capacity is a critical component of adapting to climate change. Based on fieldwork in two areas in Kenya, we investigate how people seek to access livelihood adjustment options and promote particular adaptation interests through forming social relations and political alliances to influence collective decision-making. First, we find that, in the face of drought and conflict, relations are formed among individuals, politicians, customary institutions, and government administration aimed at retaining or strengthening power bases in addition to securing material means of survival. Second, national economic and political structures and processes affect local adaptive capacity in fundamental ways, such as through the unequal allocation of resources across regions, development policy biased against pastoralism, and competition for elected political positions. Third, conflict is part and parcel of the adaptation process, not just an external factor inhibiting local adaptation strategies. Fourth, there are relative winners and losers of adaptation, but whether or not local adjustments to drought and conflict compound existing inequalities depends on power relations at multiple geographic scales that shape how conflicting interests are negotiated locally. Climate change adaptation policies are unlikely to be successful or minimize inequity unless the political dimensions of local adaptation are considered; however, existing power structures and conflicts of interests represent political obstacles to developing such policies.

  20. Adaptation as a political process: adjusting to drought and conflict in Kenya's drylands.

    PubMed

    Eriksen, Siri; Lind, Jeremy

    2009-05-01

    In this article, we argue that people's adjustments to multiple shocks and changes, such as conflict and drought, are intrinsically political processes that have uneven outcomes. Strengthening local adaptive capacity is a critical component of adapting to climate change. Based on fieldwork in two areas in Kenya, we investigate how people seek to access livelihood adjustment options and promote particular adaptation interests through forming social relations and political alliances to influence collective decision-making. First, we find that, in the face of drought and conflict, relations are formed among individuals, politicians, customary institutions, and government administration aimed at retaining or strengthening power bases in addition to securing material means of survival. Second, national economic and political structures and processes affect local adaptive capacity in fundamental ways, such as through the unequal allocation of resources across regions, development policy biased against pastoralism, and competition for elected political positions. Third, conflict is part and parcel of the adaptation process, not just an external factor inhibiting local adaptation strategies. Fourth, there are relative winners and losers of adaptation, but whether or not local adjustments to drought and conflict compound existing inequalities depends on power relations at multiple geographic scales that shape how conflicting interests are negotiated locally. Climate change adaptation policies are unlikely to be successful or minimize inequity unless the political dimensions of local adaptation are considered; however, existing power structures and conflicts of interests represent political obstacles to developing such policies.

  1. Visuospatial selective attention in chickens.

    PubMed

    Sridharan, Devarajan; Ramamurthy, Deepa L; Schwarz, Jason S; Knudsen, Eric I

    2014-05-13

    Voluntary control of attention promotes intelligent, adaptive behaviors by enabling the selective processing of information that is most relevant for making decisions. Despite extensive research on attention in primates, the capacity for selective attention in nonprimate species has never been quantified. Here we demonstrate selective attention in chickens by applying protocols that have been used to characterize visual spatial attention in primates. Chickens were trained to localize and report the vertical position of a target in the presence of task-relevant distracters. A spatial cue, the location of which varied across individual trials, indicated the horizontal, but not vertical, position of the upcoming target. Spatial cueing improved localization performance: accuracy (d') increased and reaction times decreased in a space-specific manner. Distracters severely impaired perceptual performance, and this impairment was greatly reduced by spatial cueing. Signal detection analysis with an "indecision" model demonstrated that spatial cueing significantly increased choice certainty in localizing targets. By contrast, error-aversion certainty (certainty of not making an error) remained essentially constant across cueing protocols, target contrasts, and individuals. The results show that chickens shift spatial attention rapidly and dynamically, following principles of stimulus selection that closely parallel those documented in primates. The findings suggest that the mechanisms that control attention have been conserved through evolution, and establish chickens--a highly visual species that is easily trained and amenable to cutting-edge experimental technologies--as an attractive model for linking behavior to neural mechanisms of selective attention.

  2. Impaired Early Attentional Processes in Parkinson’s Disease: A High-Resolution Event-Related Potentials Study

    PubMed Central

    Bocquillon, Perrine; Bourriez, Jean-Louis; Palmero-Soler, Ernesto; Defebvre, Luc; Derambure, Philippe; Dujardin, Kathy

    2015-01-01

    Introduction The selection of task-relevant information requires both the focalization of attention on the task and resistance to interference from irrelevant stimuli. A previous study using the P3 component of the event-related potentials suggested that a reduced ability to resist interference could be responsible for attention disorders at early stages of Parkinson’s disease (PD), with a possible role of the dorsolateral prefrontal cortex (DLPFC). Methods Our objective was to better determine the origin of this impairment, by studying an earlier ERP component, the N2, and its subcomponents, as they reflect early inhibition processes and as they are known to have sources in the anterior cingulate cortex (ACC), which is involved together with the DLPFC in inhibition processes. Fifteen early-stage PD patients and 15 healthy controls (HCs) performed a three-stimulus visual oddball paradigm, consisting in detecting target inputs amongst standard stimuli, while resisting interference from distracter ones. A 128-channel electroencephalogram was recorded during this task and the generators of the N2 subcomponents were identified using standardized weighted low-resolution electromagnetic tomography (swLORETA). Results PD patients displayed fewer N2 generators than HCs in both the DLPFC and the ACC, for all types of stimuli. In contrast to controls, PD patients did not show any differences between their generators for different N2 subcomponents. Conclusion Our data suggest that impaired inhibition in PD results from dysfunction of the DLPFC and the ACC during the early stages of attentional processes. PMID:26135906

  3. Visual Attention Allocation Between Robotic Arm and Environmental Process Control: Validating the STOM Task Switching Model

    NASA Technical Reports Server (NTRS)

    Wickens, Christopher; Vieanne, Alex; Clegg, Benjamin; Sebok, Angelia; Janes, Jessica

    2015-01-01

    Fifty six participants time shared a spacecraft environmental control system task with a realistic space robotic arm control task in either a manual or highly automated version. The former could suffer minor failures, whose diagnosis and repair were supported by a decision aid. At the end of the experiment this decision aid unexpectedly failed. We measured visual attention allocation and switching between the two tasks, in each of the eight conditions formed by manual-automated arm X expected-unexpected failure X monitoring- failure management. We also used our multi-attribute task switching model, based on task attributes of priority interest, difficulty and salience that were self-rated by participants, to predict allocation. An un-weighted model based on attributes of difficulty, interest and salience accounted for 96 percent of the task allocation variance across the 8 different conditions. Task difficulty served as an attractor, with more difficult tasks increasing the tendency to stay on task.

  4. Concurrent processing adaptation of aeroplastic analysis of propfans

    NASA Technical Reports Server (NTRS)

    Janetzke, David C.; Murthy, Durbha V.

    1990-01-01

    Discussed here is a study involving the adaptation of an advanced aeroelastic analysis program to run concurrently on a shared memory multiple processor computer. The program uses a three-dimensional compressible unsteady aerodynamic model and blade normal modes to calculate aeroelastic stability and response of propfan blades. The identification of the computational parallelism within the sequential code and the scheduling of the concurrent subtasks to minimize processor idle time are discussed. Processor idle time in the calculation of the unsteady aerodynamic coefficients was reduced by the simple strategy of appropriately ordering the computations. Speedup and efficiency results are presented for the calculation of the matched flutter point of an experimental propfan model. The results show that efficiencies above 70 percent can be obtained using the present implementation with 7 processors. The parallel computational strategy described here is also applicable to other aeroelastic analysis procedures based on panel methods.

  5. The Effects of Changing Attention and Context in an Awake Offline Processing Period on Visual Long-Term Memory

    PubMed Central

    Ellmore, Timothy M.; Feng, Anna; Ng, Kenneth; Dewan, Luthfunnahar; Root, James C.

    2016-01-01

    There is accumulating evidence that sleep as well as awake offline processing is important for the transformation of new experiences into long-term memory (LTM). Yet much remains to be understood about how various cognitive factors influence the efficiency of awake offline processing. In the present study we investigated how changes in attention and context in the immediate period after exposure to new visual information influences LTM consolidation. After presentation of multiple naturalistic scenes within a working memory paradigm, recognition was assessed 30 min and 24 h later in three groups of subjects. One group of subjects engaged in a focused attention task [the Revised Attentional Network Task (R-ANT)] in the 30 min after exposure to the scenes. Another group of subjects remained in the testing room during the 30 min after scene exposure and engaged in no goal- or task-directed activities. A third group of subjects left the testing room and returned 30 min later. A signal detection analysis revealed no significant differences among the three groups in hits, false alarms, or sensitivity on the 30-min recognition task. At the 24-h recognition test, the group that performed the R-ANT made significantly fewer hits compared to the group that left the testing room and did not perform the attention ask. The group that performed the R-ANT and the group that remained in the testing room during the 30-min post-exposure interval made significantly fewer false alarms on the 24-h recognition test compared to the group that left the testing room. The group that stayed in the testing room and engaged in no goal- or task-directed activities exhibited significantly higher sensitivity (d′) compared to the group that left the testing room and the group that performed the R-ANT task. Staying in the same context after exposure to new information and resting quietly with minimal engagement of attention results in the best ability to distinguish old from novel visual stimuli

  6. Low visual information-processing speed and attention are predictors of fatigue in elementary and junior high school students

    PubMed Central

    2011-01-01

    Background Fatigue is a common complaint among elementary and junior high school students, and is known to be associated with reduced academic performance. Recently, we demonstrated that fatigue was correlated with decreased cognitive function in these students. However, no studies have identified cognitive predictors of fatigue. Therefore, we attempted to determine independent cognitive predictors of fatigue in these students. Methods We performed a prospective cohort study. One hundred and forty-two elementary and junior high school students without fatigue participated. They completed a variety of paper-and-pencil tests, including list learning and list recall tests, kana pick-out test, semantic fluency test, figure copying test, digit span forward test, and symbol digit modalities test. The participants also completed computerized cognitive tests (tasks A to E on the modified advanced trail making test). These cognitive tests were used to evaluate motor- and information-processing speed, immediate and delayed memory function, auditory and visual attention, divided and switching attention, retrieval of learned material, and spatial construction. One year after the tests, a questionnaire about fatigue (Japanese version of the Chalder Fatigue Scale) was administered to all the participants. Results After the follow-up period, we confirmed 40 cases of fatigue among 118 students. In multivariate logistic regression analyses adjusted for grades and gender, poorer performance on visual information-processing speed and attention tasks was associated with increased risk of fatigue. Conclusions Reduced visual information-processing speed and poor attention are independent predictors of fatigue in elementary and junior high school students. PMID:21672212

  7. Top-down attentional processes modulate the coding of atypical biological motion kinematics in the absence of motor signals.

    PubMed

    Hayes, Spencer J; Roberts, James W; Elliott, Digby; Bennett, Simon J

    2014-08-01

    The acquisition of sensorimotor parameters that control goal-directed motor behaviors occurs by observing another person in the absence of efferent and afferent motor signals. This is observational practice. During such observation, biological motion properties associated with the observed person are coded into a representation that controls motor learning. Understanding the underlying processes, specifically associated with coding biological motion, has theoretical and practical significance. Here, we examined the following questions. Experiment 1: Are the underlying velocity characteristics associated with observed biological motion kinematics imitated? Experiment 2: Is attention involved in imitating biological motion kinematics? Experiment 3: Can selective attention modulate how biological motion kinematics are imitated/represented? To this end, participants practiced by observing a model performing a movement sequence that contained typical or atypical biological motion kinematics. The differences in kinematics were designed to dissociate the movement constraints of the task and the anatomical constraints of the observer. This way, we examined whether novel motor behaviors are acquired by adopting prototypical movements or coding biological motion. The kinematic analyses indicated the timing and spatial position of peak velocity were represented. Using a dual-task protocol, we attenuated the coding of biological motion kinematics (Experiment 2) and augmented coding using a selective attention protocol (Experiment 3). Findings indicated that velocity characteristics of biological motion kinematics are coded during observational practice, most likely through bottom-up sensorimotor processes. By modulating motion coding using 2 attentional protocols, we showed that bottom-up processes are influenced by input modulation, which is consistent with top-down control during observational practice.

  8. Adaptive information processing in auditory cortex. Annual report, 1 June 1987-31 May 1988

    SciTech Connect

    Weinberger, N.M.

    1988-05-31

    The fact that learning induces frequency-specific modification of receptive fields in auditory cortex implies that the functional organization of auditory (and perhaps other sensory) cortex comprises an adaptively-constituted information base. This project initiates the first systematic investigation of adaptive information processing in cerebral cortex. A major goal is to determine the circumstances under which adaptive information processing is induced by experience. This project also addresses central hypotheses about rules that govern adaptive information processing, at three levels of spatial scale: (a) parallel processing in different auditory fields: (b) modular processing in different cortical lamina within fields; (c) local processing in different neurons within the same locus within lamina. The author emphasized determining the learning circumstances under which adaptive information processing is invoked by the brain. Current studies reveal that the frequency receptive fields of neurons in the auditory cortex, and the physiologically plastic magnocellular medial geniculate nucleus, develop frequency-specific modification such that maximal shifts in tuning are at or adjacent to the signal frequency. Further, this adaptive re-tuning of neurons develops rapidly during habituation, classical conditioning, and instrumental avoidance conditioning. The generality of re-tuning has established that AIP during learning represents a general brain strategy for the acquisition and subsequent processing of information.

  9. A Case for Inhibition: Visual Attention Suppresses the Processing of Irrelevant Objects

    ERIC Educational Resources Information Center

    Wuhr, Peter; Frings, Christian

    2008-01-01

    The present study investigated the ability to inhibit the processing of an irrelevant visual object while processing a relevant one. Participants were presented with 2 overlapping shapes (e.g., circle and square) in different colors. The task was to name the color of the relevant object designated by shape. Congruent or incongruent color words…

  10. Anticipatory Emotions in Decision Tasks: Covert Markers of Value or Attentional Processes?

    ERIC Educational Resources Information Center

    Davis, Tyler; Love, Bradley C.; Maddox, W. Todd

    2009-01-01

    Anticipatory emotions precede behavioral outcomes and provide a means to infer interactions between emotional and cognitive processes. A number of theories hold that anticipatory emotions serve as inputs to the decision process and code the value or risk associated with a stimulus. We argue that current data do not unequivocally support this…

  11. Stimulus-driven and knowledge-driven processes in attention to warbles

    NASA Astrophysics Data System (ADS)

    Dowling, W. Jay; Tillmann, Barbara

    2003-10-01

    Listeners identified warbles differing in amplitude-modulation rate (3-10 Hz). And measured RT while listeners maintained above 90% correct responses. After a practice session listeners identified target warbles following stimulus-driven or knowledge-driven cues. The stimulus-driven cue was a 250-ms ``beep'' at the target pitch (valid) or another pitch (invalid); the knowledge-driven cue was a midrange ``melody'' pointing to the target pitch (always valid). A 500-ms target warble followed the cue after delays of 0-500 ms (250-750 ms SOA). The listener pressed a key to indicate ``slow'' or ``fast.'' RTs were shortest at the briefest delay. In contrast to results from a memory task, RTs here were much shorter, and we found no evidence for IOR or attentional blink. Listeners began generating responses while the target was still sounding. Invalid ``beeps'' slowed responses at the briefest (but not the longer) delays; adding a valid ``beep'' to the valid ``melody'' did not speed responses.

  12. Benefits of an external focus of attention: common coding or conscious processing?

    PubMed

    Poolton, J M; Maxwell, J P; Masters, R S W; Raab, M

    2006-01-01

    We conducted two experiments to assess the effect attentional focus has on learning a complex motor skill and subsequent performance under secondary task loading. Participants in Experiment 1 learnt a golf putting task (300 practice trials) with a single instruction to either focus on their hands (internal focus) or the movement of the putter (external focus). No group differences were evident during learning or retention. Differences between the groups were only apparent under secondary task load; the external group's performance remained robust, while the internal group suffered a drop in performance. Verbal protocols demonstrated that the internal group accumulated significantly more internal knowledge and more task-relevant knowledge in general than the external group. Experiment 2 was designed to establish whether greater internal focus knowledge or greater explicit rule build up in general was responsible for performance breakdown. Two groups were presented with a set of six internal or external rules. Again, no performance differences were found during learning or retention. During the secondary task, both groups experienced performance deterioration. It was concluded that accumulation of explicit rules to guide performance was responsible for the internal group's breakdown in performance under secondary task loading and may be responsible for some of the performance differences reported previously. PMID:16368617

  13. Parallel Block Structured Adaptive Mesh Refinement on Graphics Processing Units

    SciTech Connect

    Beckingsale, D. A.; Gaudin, W. P.; Hornung, R. D.; Gunney, B. T.; Gamblin, T.; Herdman, J. A.; Jarvis, S. A.

    2014-11-17

    Block-structured adaptive mesh refinement is a technique that can be used when solving partial differential equations to reduce the number of zones necessary to achieve the required accuracy in areas of interest. These areas (shock fronts, material interfaces, etc.) are recursively covered with finer mesh patches that are grouped into a hierarchy of refinement levels. Despite the potential for large savings in computational requirements and memory usage without a corresponding reduction in accuracy, AMR adds overhead in managing the mesh hierarchy, adding complex communication and data movement requirements to a simulation. In this paper, we describe the design and implementation of a native GPU-based AMR library, including: the classes used to manage data on a mesh patch, the routines used for transferring data between GPUs on different nodes, and the data-parallel operators developed to coarsen and refine mesh data. We validate the performance and accuracy of our implementation using three test problems and two architectures: an eight-node cluster, and over four thousand nodes of Oak Ridge National Laboratory’s Titan supercomputer. Our GPU-based AMR hydrodynamics code performs up to 4.87× faster than the CPU-based implementation, and has been scaled to over four thousand GPUs using a combination of MPI and CUDA.

  14. Local adaptation in Trinidadian guppies alters ecosystem processes.

    PubMed

    Bassar, Ronald D; Marshall, Michael C; López-Sepulcre, Andrés; Zandonà, Eugenia; Auer, Sonya K; Travis, Joseph; Pringle, Catherine M; Flecker, Alexander S; Thomas, Steven A; Fraser, Douglas F; Reznick, David N

    2010-02-23

    Theory suggests evolutionary change can significantly influence and act in tandem with ecological forces via ecological-evolutionary feedbacks. This theory assumes that significant evolutionary change occurs over ecologically relevant timescales and that phenotypes have differential effects on the environment. Here we test the hypothesis that local adaptation causes ecosystem structure and function to diverge. We demonstrate that populations of Trinidadian guppies (Poecilia reticulata), characterized by differences in phenotypic and population-level traits, differ in their impact on ecosystem properties. We report results from a replicated, common garden mesocosm experiment and show that differences between guppy phenotypes result in the divergence of ecosystem structure (algal, invertebrate, and detrital standing stocks) and function (gross primary productivity, leaf decomposition rates, and nutrient flux). These phenotypic effects are further modified by effects of guppy density. We evaluated the generality of these effects by replicating the experiment using guppies derived from two independent origins of the phenotype. Finally, we tested the ability of multiple guppy traits to explain observed differences in the mesocosms. Our findings demonstrate that evolution can significantly affect both ecosystem structure and function. The ecosystem differences reported here are consistent with patterns observed across natural streams and argue that guppies play a significant role in shaping these ecosystems. PMID:20133670

  15. Delayed Attentional Engagement in the Attentional Blink

    ERIC Educational Resources Information Center

    Nieuwenstein, Mark R.; Chun, Marvin M.; van der Lubbe, Rob H. J.; Hooge, Ignace T. C.

    2005-01-01

    Observers often miss the 2nd of 2 visual targets (first target [T1] and second target [T2]) when these targets are presented closely in time; the attentional blink (AB). The authors hypothesized that the AB occurs because the attentional response to T2 is delayed by T1 processing, causing T2 to lose a competition for attention to the item that…

  16. Double dissociation of working memory and attentional processes in smokers and non-smokers with and without nicotine.

    PubMed

    Grundey, Jessica; Amu, Rosa; Ambrus, Géza Gergely; Batsikadze, Georgi; Paulus, Walter; Nitsche, Michael A

    2015-07-01

    Nicotine has been shown to affect cortical excitability measured using transcranial magnetic stimulation in smoking and non-smoking subjects in different ways. In tobacco-deprived smokers, administration of nicotine restores compromised cortical facilitation while in non-smokers, it enhances cortical inhibition. As cortical excitability and activity are closely linked to cognitive processes, we aimed to explore whether nicotine-induced physiological alterations in non-smokers and smokers are associated with cognitive changes. Specifically, we assessed the impact of nicotine on working memory performance (n-back letter task) and on attentional processes (Stroop interference test) in healthy smokers and non-smokers. Both tasks have been shown to rely on prefrontal areas, and nicotinic receptors are relevantly involved in prefrontal function. Sixteen smoking and 16 non-smoking subjects participated in the 3-back letter task and 21 smoking and 21 non-smoking subjects in the Stroop test after the respective application of placebo or nicotine patches. The results show that working memory and attentional processes are compromised in nicotine-deprived smokers compared to non-smoking individuals. After administration of nicotine, working memory performance in smokers improved, while non-smoking subjects displayed decreased accuracy with increased number of errors. The effects have been shown to be more apparent for working memory performance than attentional processes. In summary, cognitive functions can be restored by nicotine in deprived smokers, whereas non-smokers do not gain additional benefit. The respective changes are in accordance with related effects of nicotine on cortical excitability in both groups. PMID:25721074

  17. Double dissociation of working memory and attentional processes in smokers and non-smokers with and without nicotine.

    PubMed

    Grundey, Jessica; Amu, Rosa; Ambrus, Géza Gergely; Batsikadze, Georgi; Paulus, Walter; Nitsche, Michael A

    2015-07-01

    Nicotine has been shown to affect cortical excitability measured using transcranial magnetic stimulation in smoking and non-smoking subjects in different ways. In tobacco-deprived smokers, administration of nicotine restores compromised cortical facilitation while in non-smokers, it enhances cortical inhibition. As cortical excitability and activity are closely linked to cognitive processes, we aimed to explore whether nicotine-induced physiological alterations in non-smokers and smokers are associated with cognitive changes. Specifically, we assessed the impact of nicotine on working memory performance (n-back letter task) and on attentional processes (Stroop interference test) in healthy smokers and non-smokers. Both tasks have been shown to rely on prefrontal areas, and nicotinic receptors are relevantly involved in prefrontal function. Sixteen smoking and 16 non-smoking subjects participated in the 3-back letter task and 21 smoking and 21 non-smoking subjects in the Stroop test after the respective application of placebo or nicotine patches. The results show that working memory and attentional processes are compromised in nicotine-deprived smokers compared to non-smoking individuals. After administration of nicotine, working memory performance in smokers improved, while non-smoking subjects displayed decreased accuracy with increased number of errors. The effects have been shown to be more apparent for working memory performance than attentional processes. In summary, cognitive functions can be restored by nicotine in deprived smokers, whereas non-smokers do not gain additional benefit. The respective changes are in accordance with related effects of nicotine on cortical excitability in both groups.

  18. Adaptive Memory: The Evolutionary Significance of Survival Processing.

    PubMed

    Nairne, James S; Pandeirada, Josefa N S

    2016-07-01

    A few seconds of survival processing, during which people assess the relevance of information to a survival situation, produces particularly good retention. One interpretation of this benefit is that our memory systems are optimized to process and retain fitness-relevant information. Such a "tuning" may exist, in part, because our memory systems were shaped by natural selection, using a fitness-based criterion. However, recent research suggests that traditional mnemonic processes, such as elaborative processing, may play an important role in producing the empirical benefit. Boundary conditions have been demonstrated as well, leading some to dismiss evolutionary interpretations of the phenomenon. In this article, we discuss the current state of the evolutionary account and provide a general framework for evaluating evolutionary and purportedly nonevolutionary interpretations of mnemonic phenomena. We suggest that survival processing effects are best viewed within the context of a general survival optimization system, designed by nature to help organisms deal with survival challenges. An important component of survival optimization is the ability to simulate activities that help to prevent or escape from future threats which, in turn, depends in an important way on accurate retrospective remembering of survival-relevant information. PMID:27474137

  19. Framework for adaptive multiscale analysis of nonhomogeneous point processes.

    PubMed

    Helgason, Hannes; Bartroff, Jay; Abry, Patrice

    2011-01-01

    We develop the methodology for hypothesis testing and model selection in nonhomogeneous Poisson processes, with an eye toward the application of modeling and variability detection in heart beat data. Modeling the process' non-constant rate function using templates of simple basis functions, we develop the generalized likelihood ratio statistic for a given template and a multiple testing scheme to model-select from a family of templates. A dynamic programming algorithm inspired by network flows is used to compute the maximum likelihood template in a multiscale manner. In a numerical example, the proposed procedure is nearly as powerful as the super-optimal procedures that know the true template size and true partition, respectively. Extensions to general history-dependent point processes is discussed.

  20. How and When Accentuation Influences Temporally Selective Attention and Subsequent Semantic Processing during On-Line Spoken Language Comprehension: An ERP Study

    ERIC Educational Resources Information Center

    Li, Xiao-qing; Ren, Gui-qin

    2012-01-01

    An event-related brain potentials (ERP) experiment was carried out to investigate how and when accentuation influences temporally selective attention and subsequent semantic processing during on-line spoken language comprehension, and how the effect of accentuation on attention allocation and semantic processing changed with the degree of…

  1. Electrophysiological evidence for an attentional bias in processing body stimuli in bulimia nervosa.

    PubMed

    Mai, Sandra; Gramann, Klaus; Herbert, Beate M; Friederich, Hans-Christoph; Warschburger, Petra; Pollatos, Olga

    2015-05-01

    Empirical evidence suggests abnormalities in the processing of body stimuli in bulimia nervosa (BN). This study investigated central markers of processing body stimuli by means of event-related potentials in BN. EEG was recorded from 20 women with BN and 20 matched healthy controls while watching and evaluating underweight, normal and overweight female body pictures. Bulimics evaluated underweight bodies as less unpleasant and overweight bodies as bigger and more arousing. A higher P2 to overweight stimuli occurred in BN only. In contrast to controls, no N2 increase to underweight bodies was observed in BN. P3 was modulated by stimulus category only in healthy controls; late slow waves to underweight bodies were more pronounced in both groups. P2 amplitudes to overweight stimuli were correlated with drive for thinness and body dissatisfaction. We present novel support for altered perceptual and cognitive-affective processing of body images in BN on the subjective and electrophysiological level. PMID:25813122

  2. Judging emotional congruency: Explicit attention to situational context modulates processing of facial expressions of emotion.

    PubMed

    Diéguez-Risco, Teresa; Aguado, Luis; Albert, Jacobo; Hinojosa, José Antonio

    2015-12-01

    The influence of explicit evaluative processes on the contextual integration of facial expressions of emotion was studied in a procedure that required the participants to judge the congruency of happy and angry faces with preceding sentences describing emotion-inducing situations. Judgments were faster on congruent trials in the case of happy faces and on incongruent trials in the case of angry faces. At the electrophysiological level, a congruency effect was observed in the face-sensitive N170 component that showed larger amplitudes on incongruent trials. An interactive effect of congruency and emotion appeared on the LPP (late positive potential), with larger amplitudes in response to happy faces that followed anger-inducing situations. These results show that the deliberate intention to judge the contextual congruency of facial expressions influences not only processes involved in affective evaluation such as those indexed by the LPP but also earlier processing stages that are involved in face perception.

  3. No effect of inversion on attentional and affective processing of facial expressions.

    PubMed

    Lipp, Ottmar V; Price, Sarah M; Tellegen, Cassandra L

    2009-04-01

    The decrease in recognition performance after face inversion has been taken to suggest that faces are processed holistically. Three experiments, 1 with schematic and 2 with photographic faces, were conducted to assess whether face inversion also affected visual search for and implicit evaluation of facial expressions of emotion. The 3 visual search experiments yielded the same differences in detection speed between different facial expressions of emotion for upright and inverted faces. Threat superiority effects, faster detection of angry than of happy faces among neutral background faces, were evident in 2 experiments. Face inversion did not affect explicit or implicit evaluation of face stimuli as assessed with verbal ratings and affective priming. Happy faces were evaluated as more positive than angry, sad, or fearful/scheming ones regardless of orientation. Taken together these results seem to suggest that the processing of facial expressions of emotion is not impaired if holistic processing is disrupted.

  4. The Adapted Dance Process: Planning, Partnering, and Performing

    ERIC Educational Resources Information Center

    Block, Betty A.; Johnson, Peggy V.

    2011-01-01

    This article contains specific planning, partnering, and performing techniques for fully integrating dancers with special needs into a dance pedagogy program. Each aspect is discussed within the context of the domains of learning. Fundamental partnering strategies are related to each domain as part of the integration process. The authors recommend…

  5. Computer simulation program is adaptable to industrial processes

    NASA Technical Reports Server (NTRS)

    Schultz, F. E.

    1966-01-01

    The Reaction kinetics ablation program /REKAP/, developed to simulate ablation of various materials, provides mathematical formulations for computer programs which can simulate certain industrial processes. The programs are based on the use of nonsymmetrical difference equations that are employed to solve complex partial differential equation systems.

  6. Positive Affect Processing and Joint Attention in Infants at High Risk for Autism: An Exploratory Study

    ERIC Educational Resources Information Center

    Key, Alexandra P.; Ibanez, Lisa V.; Henderson, Heather A.; Warren, Zachary; Messinger, Daniel S.; Stone, Wendy L.

    2015-01-01

    Few behavioral indices of risk for autism spectrum disorders (ASD) are present before 12 months, and potential biomarkers remain largely unexamined. This prospective study of infant siblings of children with ASD (n = 16) and low-risk comparison infants (n = 15) examined group differences in event-related potentials (ERPs) indexing processing of…

  7. Foveal vs. Parafoveal Processing in Anxiety: Broadened Spatial Attention for Threat Words

    ERIC Educational Resources Information Center

    Gutierrez, Aida; Calvo, Manuel G.

    2011-01-01

    We investigated the processing of threat-related, positive, and neutral words in parafoveal and in foveal vision as a function of individual differences in trait anxiety. In a lexical-decision task, word primes were presented for 150 ms either parafoveally (2.2[degrees] away from fixation; Experiment 1) or foveally (at fixation; Experiment 3)…

  8. Student Guidance and Attention to Diversity in the Processes of Quality Assurance in Higher Education

    ERIC Educational Resources Information Center

    Ferreira, Camino; Vidal, Javier; Vieira, María José

    2014-01-01

    The main objective of this article is to analyse the importance given to student guidance and diversity in the standards and criteria used in the quality accreditation and evaluation processes in Europe and the US. Agencies selected in this study are the members of ENQA (European Association for Quality Assurance in Higher Education), EQAR…

  9. The Effects of Reinvestment of Conscious Processing on Switching Focus of Attention

    ERIC Educational Resources Information Center

    Weiss, Stephen M.

    2011-01-01

    The effects of switching focusing strategies on complex motor skill learning were investigated using a dart-throwing task. Participants were screened for reinvestment of conscious processing by completing the Reinvestment Scale (RS) of Masters, Polman, and Hammond (1993). After an initial baseline phase, two focusing strategies were described. Low…

  10. Increased Attention to the Search Process Improves the Chances of Foster Kinship Placements

    ERIC Educational Resources Information Center

    Gibson, Priscilla A.; Rinkel, Michaela

    2012-01-01

    Although child protective service (CPS) workers are mandated by social policies to conduct a search for relatives, the search process remains unclear and under scrutiny. Placing children with an appropriate relative is dependent on workers' practices and, to some extent, attitudes. Reviewing social policies that mandate the inclusion of relatives…

  11. Stroop effects in Alzheimer's disease: selective attention speed of processing, or color-naming? A meta-analysis.

    PubMed

    Ben-David, Boaz M; Tewari, Anita; Shakuf, Vered; Van Lieshout, Pascal H H M

    2014-01-01

    Selective attention, an essential part of daily activity, is often impaired in people with Alzheimer's disease (AD). Usually, it is measured by the color-word Stroop test. However, there is no universal agreement whether performance on the Stroop task changes significantly in AD patients; or if so, whether an increase in Stroop effects reflects a decrease in selective attention, a slowing in generalized speed of processing (SOP), or is the result of degraded color-vision. The current study investigated the impact of AD on Stroop performance and its potential sources in a meta-analysis and mathematical modeling of 18 studies, comparing 637 AD patients with 977 healthy age-matched participants. We found a significant increase in Stroop effects for AD patients, across studies. This AD-related change was associated with a slowing in SOP. However, after correcting for a bias in the distribution of latencies, SOP could only explain a moderate portion of the total variance (25%). Moreover, we found strong evidence for an AD-related increase in the latency difference between naming the font-color and reading color-neutral stimuli (r2 = 0.98). This increase in the dimensional imbalance between color-naming and word-reading was found to explain a significant portion of the AD-related increase in Stroop effects (r2 = 0.87), hinting on a possible sensory source. In conclusion, our analysis highlights the importance of controlling for sensory degradation and SOP when testing cognitive performance and, specifically, selective attention in AD patients. We also suggest possible measures and tools to better test for selective attention in AD.

  12. The influence of negative stimulus features on conflict adaption: evidence from fluency of processing

    PubMed Central

    Fritz, Julia; Fischer, Rico; Dreisbach, Gesine

    2015-01-01

    Cognitive control enables adaptive behavior in a dynamically changing environment. In this context, one prominent adaptation effect is the sequential conflict adjustment, i.e., the observation of reduced response interference on trials following conflict trials. Increasing evidence suggests that such response conflicts are registered as aversive signals. So far, however, the functional role of this aversive signal for conflict adaptation to occur has not been put to test directly. In two experiments, the affective valence of conflict stimuli was manipulated by fluency of processing (stimulus contrast). Experiment 1 used a flanker interference task, Experiment 2 a color-word Stroop task. In both experiments, conflict adaptation effects were only present in fluent, but absent in disfluent trials. Results thus speak against the simple idea that any aversive stimulus feature is suited to promote specific conflict adjustments. Two alternative but not mutually exclusive accounts, namely resource competition and adaptation-by-motivation, will be discussed. PMID:25767453

  13. Paying attention to gender and poverty in health research: content and process issues.

    PubMed Central

    Ostlin, Piroska; Sen, Gita; George, Asha

    2004-01-01

    Despite the magnitude of the problem of health inequity within and between countries, little systematic research has been done on the social causes of ill-health. Health researchers have overwhelmingly focused on biomedical research at the level of individuals. Investigations into the health of groups and the determinants of health inequities that lie outside the control of the individual have received a much smaller share of research resources. Ignoring factors such as socioeconomic class, race and gender leads to biases in both the content and process of research. We use two such factors--poverty and gender--to illustrate how this occurs. There is a systematic imbalance in medical journals: research into diseases that predominate in the poorest regions of the world is less likely to be published. In addition, the slow recognition of women's health problems, misdirected and partial approaches to understanding women's and men's health, and the dearth of information on how gender interacts with other social determinants continue to limit the content of health research. In the research community these imbalances in content are linked to biases against researchers from poorer regions and women. Researchers from high-income countries benefit from better funding and infrastructure. Their publications dominate journals and citations, and these researchers also dominate advisory boards. The way to move forward is to correct biases against poverty and gender in research content and processes and provide increased funding and better career incentives to support equity-linked research. Journals need to address equity concerns in their published content and in the publishing process. Efforts to broaden access to research information need to be well resourced, publicized and expanded. PMID:15643794

  14. Implicit and Explicit Attention to Pictures and Words: An fMRI-Study of Concurrent Emotional Stimulus Processing.

    PubMed

    Flaisch, Tobias; Imhof, Martin; Schmälzle, Ralf; Wentz, Klaus-Ulrich; Ibach, Bernd; Schupp, Harald T

    2015-01-01

    The present study utilized functional magnetic resonance imaging (fMRI) to examine the neural processing of concurrently presented emotional stimuli under varying explicit and implicit attention demands. Specifically, in separate trials, participants indicated the category of either pictures or words. The words were placed over the center of the pictures and the picture-word compound-stimuli were presented for 1500 ms in a rapid event-related design. The results reveal pronounced main effects of task and emotion: the picture categorization task prompted strong activations in visual, parietal, temporal, frontal, and subcortical regions; the word categorization task evoked increased activation only in left extrastriate cortex. Furthermore, beyond replicating key findings regarding emotional picture and word processing, the results point to a dissociation of semantic-affective and sensory-perceptual processes for words: while emotional words engaged semantic-affective networks of the left hemisphere regardless of task, the increased activity in left extrastriate cortex associated with explicitly attending to words was diminished when the word was overlaid over an erotic image. Finally, we observed a significant interaction between Picture Category and Task within dorsal visual-associative regions, inferior parietal, and dorsolateral, and medial prefrontal cortices: during the word categorization task, activation was increased in these regions when the words were overlaid over erotic as compared to romantic pictures. During the picture categorization task, activity in these areas was relatively decreased when categorizing erotic as compared to romantic pictures. Thus, the emotional intensity of the pictures strongly affected brain regions devoted to the control of task-related word or picture processing. These findings are discussed with respect to the interplay of obligatory stimulus processing with task-related attentional control mechanisms. PMID:26733895

  15. Implicit and Explicit Attention to Pictures and Words: An fMRI-Study of Concurrent Emotional Stimulus Processing

    PubMed Central

    Flaisch, Tobias; Imhof, Martin; Schmälzle, Ralf; Wentz, Klaus-Ulrich; Ibach, Bernd; Schupp, Harald T.

    2015-01-01

    The present study utilized functional magnetic resonance imaging (fMRI) to examine the neural processing of concurrently presented emotional stimuli under varying explicit and implicit attention demands. Specifically, in separate trials, participants indicated the category of either pictures or words. The words were placed over the center of the pictures and the picture-word compound-stimuli were presented for 1500 ms in a rapid event-related design. The results reveal pronounced main effects of task and emotion: the picture categorization task prompted strong activations in visual, parietal, temporal, frontal, and subcortical regions; the word categorization task evoked increased activation only in left extrastriate cortex. Furthermore, beyond replicating key findings regarding emotional picture and word processing, the results point to a dissociation of semantic-affective and sensory-perceptual processes for words: while emotional words engaged semantic-affective networks of the left hemisphere regardless of task, the increased activity in left extrastriate cortex associated with explicitly attending to words was diminished when the word was overlaid over an erotic image. Finally, we observed a significant interaction between Picture Category and Task within dorsal visual-associative regions, inferior parietal, and dorsolateral, and medial prefrontal cortices: during the word categorization task, activation was increased in these regions when the words were overlaid over erotic as compared to romantic pictures. During the picture categorization task, activity in these areas was relatively decreased when categorizing erotic as compared to romantic pictures. Thus, the emotional intensity of the pictures strongly affected brain regions devoted to the control of task-related word or picture processing. These findings are discussed with respect to the interplay of obligatory stimulus processing with task-related attentional control mechanisms. PMID:26733895

  16. Experimental Training of Children with Attention Deficit/Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Piscalkiene, Viktorija

    2009-01-01

    Attention-deficit/hyperactivity disorder (AD/HD) negatively affects the cognitive and psychomotoric spheres of the pupil's social behavior and social adaptation. The review of many studies states that pupils with AD/HD achieve worse learning results because of insufficiently functioning cognitive processes, such as attention, (work) memory,…

  17. Attentional Set-Shifting in Fragile X Syndrome

    ERIC Educational Resources Information Center

    Van der Molen, M. J. W.; Van der Molen, M. W.; Ridderinkhof, K. R.; Hamel, B. C. J.; Curfs, L. M. G.; Ramakers, G. J. A.

    2012-01-01

    The ability to flexibly adapt to the changing demands of the environment is often reported as a core deficit in fragile X syndrome (FXS). However, the cognitive processes that determine this attentional set-shifting deficit remain elusive. The present study investigated attentional set-shifting ability in fragile X syndrome males with the…

  18. The functional BDNF Val66Met polymorphism affects functions of pre-attentive visual sensory memory processes.

    PubMed

    Beste, Christian; Schneider, Daniel; Epplen, Jörg T; Arning, Larissa

    2011-01-01

    The brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, is involved in nerve growth and survival. Especially, a single nucleotide polymorphism (SNP) in the BDNF gene, Val66Met, has gained a lot of attention, because of its effect on activity-dependent BDNF secretion and its link to impaired memory processes. We hypothesize that the BDNF Val66Met polymorphism may have modulatory effects on the visual sensory (iconic) memory performance. Two hundred and eleven healthy German students (106 female and 105 male) were included in the data analysis. Since BDNF is also discussed to be involved in the pathogenesis of depression, we additionally tested for possible interactions with depressive mood. The BDNF Val66Met polymorphism significantly influenced iconic-memory performance, with the combined Val/Met-Met/Met genotype group revealing less time stability of information stored in iconic memory than the Val/Val group. Furthermore, this stability was positively correlated with depressive mood exclusively in the Val/Val genotype group. Thus, these results show that the BDNF Val66Met polymorphism has an effect on pre-attentive visual sensory memory processes.

  19. Perceptual decision making for baseball pitch recognition: using P300 latency and amplitude to index attentional processing.

    PubMed

    Radlo, S J; Janelle, C M; Barba, D A; Frehlich, S G

    2001-03-01

    This study was designed to examine the perceptual and attentional processes associated with the effects of administering a cost-benefit precuing paradigm to intermediate and advance-level baseball batters. Psychophysiological and performance data obtained from 10 advanced and 10 intermediate-level players were compared. A total of 400 pitches (200 fastballs, 200 curveballs) was randomly presented via a large projection screen, and participants pressed one of two buttons to indicate the type of pitch thrown. Verbal precues were given for 300 of the pitches. Of those, 75% were valid, and 25% were invalid. Electroencephalographic data collected from the P location was used to assess the latency and amplitude of P300. Analysis of variance (Skill Level x Precue x Pitch) for P300 and reaction time (RT) indicated that intermediate batters produced shorter P300 latencies, larger P300 amplitudes, longer RTs, and less correct responses than the advanced batters; the effects were more pronounced for the curveballs. These results suggest that intermediate batters are less efficient in their perceptual decision-making processes due to greater limitations in attentional capacity when compared with advanced batters.

  20. Processing of affective prosody in boys suffering from attention deficit hyperactivity disorder: A near-infrared spectroscopy study.

    PubMed

    Köchel, Angelika; Schöngaßner, Florian; Feierl-Gsodam, Silke; Schienle, Anne

    2015-01-01

    Neurobiological studies on facial affect recognition have demonstrated reduced response amplitudes to anger cues in patients suffering from attention deficit hyperactivity disorder (ADHD). It is still unclear whether a similar deficit exists in the auditory domain. Therefore, this near-infrared spectroscopy study focused on neuronal correlates of affective prosody processing. Fourteen boys suffering from ADHD and fourteen healthy boys were exposed to emotionally intoned, standardized sentences of the categories anger, sadness, happiness, and to affectively neutral sentences. Relative to controls, the patients displayed a diminished activation of the right superior temporal gyrus (STG) when processing anger prosody, which was correlated with aggressive behavior. There were no group differences for the other emotions. Additionally, the ADHD group showed increased supramarginal gyrus (SMG) activation in the anger condition. This might mirror compensatory attention allocation. In summary, we identified a selectively lowered STG activation to auditory anger cues in ADHD patients. Consequently, STG recruitment during anger exposure might be used for evaluation of psychotherapy effects. PMID:25721229

  1. [Adaptability of sweet corn ears to a frozen process].

    PubMed

    Ramírez Matheus, Alejandra O; Martínez, Norelkys Maribel; de Bertorelli, Ligia O; De Venanzi, Frank

    2004-12-01

    The effects of frozen condition on the quality of three sweet corn ears (2038, 2010, 2004) and the pattern (Bonanza), were evaluated. Biometrics characteristics like ear size, ear diameter, row and kernel deep were measured as well as chemical and physical measurement in fresh and frozen states. The corn ears were frozen at -95 degrees C by 7 minutes. The yield and stability of the frozen ears were evaluated at 45 and 90 days of frozen storage (-18 degrees C). The average commercial yield as frozen corn ear for all the hybrids was 54.2%. The industry has a similar value range of 48% to 54%. The ear size average was 21.57 cm, row number was 15, ear diameter 45.54 mm and the kernel corn deep was 8.57 mm. All these measurements were found not different from commercial values found for the industry. All corn samples evaluated showed good stability despites the frozen processing and storage. Hybrid 2038 ranked higher in quality. PMID:15969270

  2. Incorporating Midbrain Adaptation to Mean Sound Level Improves Models of Auditory Cortical Processing

    PubMed Central

    Schoppe, Oliver; King, Andrew J.; Schnupp, Jan W.H.; Harper, Nicol S.

    2016-01-01

    Adaptation to stimulus statistics, such as the mean level and contrast of recently heard sounds, has been demonstrated at various levels of the auditory pathway. It allows the nervous system to operate over the wide range of intensities and contrasts found in the natural world. Yet current standard models of the response properties of auditory neurons do not incorporate such adaptation. Here we present a model of neural responses in the ferret auditory cortex (the IC Adaptation model), which takes into account adaptation to mean sound level at a lower level of processing: the inferior colliculus (IC). The model performs high-pass filtering with frequency-dependent time constants on the sound spectrogram, followed by half-wave rectification, and passes the output to a standard linear–nonlinear (LN) model. We find that the IC Adaptation model consistently predicts cortical responses better than the standard LN model for a range of synthetic and natural stimuli. The IC Adaptation model introduces no extra free parameters, so it improves predictions without sacrificing parsimony. Furthermore, the time constants of adaptation in the IC appear to be matched to the statistics of natural sounds, suggesting that neurons in the auditory midbrain predict the mean level of future sounds and adapt their responses appropriately. SIGNIFICANCE STATEMENT An ability to accurately predict how sensory neurons respond to novel stimuli is critical if we are to fully characterize their response properties. Attempts to model these responses have had a distinguished history, but it has proven difficult to improve their predictive power significantly beyond that of simple, mostly linear receptive field models. Here we show that auditory cortex receptive field models benefit from a nonlinear preprocessing stage that replicates known adaptation properties of the auditory midbrain. This improves their predictive power across a wide range of stimuli but keeps model complexity low as it

  3. Intentional action processing results from automatic bottom-up attention: An EEG-investigation into the Social Relevance Hypothesis using hypnosis.

    PubMed

    Neufeld, Eleonore; Brown, Elliot C; Lee-Grimm, Sie-In; Newen, Albert; Brüne, Martin

    2016-05-01

    Social stimuli grab our attention. However, it has rarely been investigated how variations in attention affect the processing of social stimuli, although the answer could help us uncover details of social cognition processes such as action understanding. In the present study, we examined how changes to bottom-up attention affects neural EEG-responses associated with intentional action processing. We induced an increase in bottom-up attention by using hypnosis. We recorded the electroencephalographic μ-wave suppression of hypnotized participants when presented with intentional actions in first and third person perspective in a video-clip paradigm. Previous studies have shown that the μ-rhythm is selectively suppressed both when executing and observing goal-directed motor actions; hence it can be used as a neural signal for intentional action processing. Our results show that neutral hypnotic trance increases μ-suppression in highly suggestible participants when they observe intentional actions. This suggests that social action processing is enhanced when bottom-up attentional processes are predominant. Our findings support the Social Relevance Hypothesis, according to which social action processing is a bottom-up driven attentional process, and can thus be altered as a function of bottom-up processing devoted to a social stimulus. PMID:26998562

  4. The process of adapting a universal dating abuse prevention program to adolescents exposed to domestic violence.

    PubMed

    Foshee, Vangie A; Dixon, Kimberly S; Ennett, Susan T; Moracco, Kathryn E; Bowling, J Michael; Chang, Ling-Yin; Moss, Jennifer L

    2015-07-01

    Adolescents exposed to domestic violence are at increased risk of dating abuse, yet no evaluated dating abuse prevention programs have been designed specifically for this high-risk population. This article describes the process of adapting Families for Safe Dates (FSD), an evidenced-based universal dating abuse prevention program, to this high-risk population, including conducting 12 focus groups and 107 interviews with the target audience. FSD includes six booklets of dating abuse prevention information, and activities for parents and adolescents to do together at home. We adapted FSD for mothers who were victims of domestic violence, but who no longer lived with the abuser, to do with their adolescents who had been exposed to the violence. Through the adaptation process, we learned that families liked the program structure and valued being offered the program and that some of our initial assumptions about this population were incorrect. We identified practices and beliefs of mother victims and attributes of these adolescents that might increase their risk of dating abuse that we had not previously considered. In addition, we learned that some of the content of the original program generated negative family interactions for some. The findings demonstrate the utility of using a careful process to adapt evidence-based interventions (EBIs) to cultural sub-groups, particularly the importance of obtaining feedback on the program from the target audience. Others can follow this process to adapt EBIs to groups other than the ones for which the original EBI was designed.

  5. Processes discriminating adaptive and maladaptive Internet use among European adolescents highly engaged online.

    PubMed

    Tzavela, Eleni C; Karakitsou, Chryssoula; Dreier, Michael; Mavromati, Foteini; Wölfling, Klaus; Halapi, Eva; Macarie, George; Wójcik, Szymon; Veldhuis, Lydian; Tsitsika, Artemis K

    2015-04-01

    Today adolescents are highly engaged online. Contrary to common concern, not all highly engaged adolescents develop maladaptive patterns of internet use. The present qualitative study explored the experiences, patterns and impact of use of 124 adolescents (M(age) = 16.0) reporting signs of internet addictive behaviors. The focus was to discern adaptive and maladaptive use patterns, which promote or interfere with adolescents' development, respectively. Semi-structured individual interviews were conducted in seven European countries (Greece, Spain, Poland, Germany, Romania, Netherlands and Iceland) and qualitatively analyzed using grounded theory. Considerable variability emerged in the way adolescents satisfied their personal needs online and offline, in the experienced impact from high online engagement and functional value ascribed to the internet, and in the self-regulatory processes underlying use. Variability in these discriminating processes was linked to adaptive or maladaptive adolescent internet use patterns. The emerged processes can provide direction for designing prevention and intervention programs promoting adaptive use.

  6. Modulating rest-break length induces differential recruitment of automatic and controlled attentional processes upon task reengagement.

    PubMed

    Lim, Julian; Teng, James; Wong, Kian Foong; Chee, Michael W L

    2016-07-01

    Rest breaks are commonly administered as a countermeasure to reduce on-the-job fatigue, both physical and mental. However, this practice makes the assumption that recovery from fatigue, as measured by the reversal of performance declines, is the sole effect of taking a break on behavior. Here, through administering rest breaks of differing lengths in between blocks of a mentally demanding symbol decoding task, we show that this assumption may not be strictly true. First, we replicate previous work by showing that taking a longer break leads to two correlated effects: greater immediate rebound in performance, and greater subsequent time-on-task decline. Using fMRI, we reveal that time-on-task in this paradigm is associated with increasing recruitment of fronto-parietal areas associated with top-down control, and decreasing deactivation in the default-mode network. Finally, by analyzing individual differences, we reveal a potential neural basis for our behavioral observation: greater recovery following long breaks is associated with greater activity in the putamen, an area associated with the automatic generation of motor responses, followed by greater activity in left middle frontal gyrus by the end of those task periods. Taken together, this suggests a shift in the implicit engagement of automatic and controlled attentional processing following longer breaks. This shift may be undesirable or detrimental in real-world situations where maintaining a stable level of attention over time is necessary. PMID:27039697

  7. Robust Brain-Machine Interface Design Using Optimal Feedback Control Modeling and Adaptive Point Process Filtering

    PubMed Central

    Carmena, Jose M.

    2016-01-01

    Much progress has been made in brain-machine interfaces (BMI) using decoders such as Kalman filters and finding their parameters with closed-loop decoder adaptation (CLDA). However, current decoders do not model the spikes directly, and hence may limit the processing time-scale of BMI control and adaptation. Moreover, while specialized CLDA techniques for intention estimation and assisted training exist, a unified and systematic CLDA framework that generalizes across different setups is lacking. Here we develop a novel closed-loop BMI training architecture that allows for processing, control, and adaptation using spike events, enables robust control and extends to various tasks. Moreover, we develop a unified control-theoretic CLDA framework within which intention estimation, assisted training, and adaptation are performed. The architecture incorporates an infinite-horizon optimal feedback-control (OFC) model of the brain’s behavior in closed-loop BMI control, and a point process model of spikes. The OFC model infers the user’s motor intention during CLDA—a process termed intention estimation. OFC is also used to design an autonomous and dynamic assisted training technique. The point process model allows for neural processing, control and decoder adaptation with every spike event and at a faster time-scale than current decoders; it also enables dynamic spike-event-based parameter adaptation unlike current CLDA methods that use batch-based adaptation on much slower adaptation time-scales. We conducted closed-loop experiments in a non-human primate over tens of days to dissociate the effects of these novel CLDA components. The OFC intention estimation improved BMI performance compared with current intention estimation techniques. OFC assisted training allowed the subject to consistently achieve proficient control. Spike-event-based adaptation resulted in faster and more consistent performance convergence compared with batch-based methods, and was robust to

  8. Robust Brain-Machine Interface Design Using Optimal Feedback Control Modeling and Adaptive Point Process Filtering.

    PubMed

    Shanechi, Maryam M; Orsborn, Amy L; Carmena, Jose M

    2016-04-01

    Much progress has been made in brain-machine interfaces (BMI) using decoders such as Kalman filters and finding their parameters with closed-loop decoder adaptation (CLDA). However, current decoders do not model the spikes directly, and hence may limit the processing time-scale of BMI control and adaptation. Moreover, while specialized CLDA techniques for intention estimation and assisted training exist, a unified and systematic CLDA framework that generalizes across different setups is lacking. Here we develop a novel closed-loop BMI training architecture that allows for processing, control, and adaptation using spike events, enables robust control and extends to various tasks. Moreover, we develop a unified control-theoretic CLDA framework within which intention estimation, assisted training, and adaptation are performed. The architecture incorporates an infinite-horizon optimal feedback-control (OFC) model of the brain's behavior in closed-loop BMI control, and a point process model of spikes. The OFC model infers the user's motor intention during CLDA-a process termed intention estimation. OFC is also used to design an autonomous and dynamic assisted training technique. The point process model allows for neural processing, control and decoder adaptation with every spike event and at a faster time-scale than current decoders; it also enables dynamic spike-event-based parameter adaptation unlike current CLDA methods that use batch-based adaptation on much slower adaptation time-scales. We conducted closed-loop experiments in a non-human primate over tens of days to dissociate the effects of these novel CLDA components. The OFC intention estimation improved BMI performance compared with current intention estimation techniques. OFC assisted training allowed the subject to consistently achieve proficient control. Spike-event-based adaptation resulted in faster and more consistent performance convergence compared with batch-based methods, and was robust to parameter

  9. Obsessive-Compulsive Disorder: The Process of Parental Adaptation and Implications for Genetic Counseling.

    PubMed

    Andrighetti, Heather; Semaka, Alicia; Stewart, S Evelyn; Shuman, Cheryl; Hayeems, Robin; Austin, Jehannine

    2016-10-01

    Obsessive-compulsive disorder (OCD) has primarily pediatric onset and well-documented unique impacts on family functioning. Limited research has assessed the understanding that parents of children with OCD have of the etiology of the condition, and there are no data regarding potential applications of genetic counseling for this population. We recruited 13 parents of 13 children diagnosed with OCD from the OCD Registry at British Columbia Children's Hospital, and conducted qualitative semi-structured telephone interviews to explore participants' experiences with their child's OCD, causal attributions of OCD, and perceptions of two genetic counseling vignettes. Interviews were audio-recorded, transcribed, and analyzed using elements of grounded theory qualitative methodology. Analysis revealed key components and contextual elements of the process through which parents adapt to their child's OCD. This adaptation process involved conceptualizing the meaning of OCD, navigating its impact on family dynamics, and developing effective illness management strategies. Adaptation took place against a backdrop of stigmatization and was shaped by participants' family history of mental illness and their child's specific manifestations of OCD. Parents perceived genetic counseling, as described in the vignettes, as being empowering, alleviating guilt and blame, and positively impacting treatment orientation. These data provide insight into the process of parental adaptation to pediatric OCD, and suggest that genetic counseling services for families affected by OCD may help facilitate adaptation to this illness.

  10. The Unique and Combined Effects of Reinforcement and Methylphenidate on Temporal Information Processing in Attention-Deficit/Hyperactivity Disorder.

    PubMed

    Luman, Marjolein; Papanikolau, Alky; Oosterlaan, Jaap

    2015-08-01

    Temporal information processing and reward sensitivity are neurocognitive impairments key to attention-deficit/hyperactivity disorder (ADHD). The aim of this study was to examine the unique and combined impact of reinforcement and methylphenidate (MPH) on temporal information processing in children with ADHD. We predicted that both monetary reinforcement and MPH would ameliorate temporal information processing deficits in ADHD, and we expected that the combined effect of reinforcement and MPH would be most beneficial. Forty children (23 with ADHD and 27 typical controls, aged 8-12 y) performed a time production task under 3 conditions: reward, response cost, and feedback only. Children with ADHD also performed the task (in random order) with placebo, a low, a medium, and a high dose of MPH. Dependent variables were time production accuracy and variability. At baseline, children with ADHD displayed poor internal clock functioning compared with controls, as reflected by greater underestimations of the 1-second interval, and they showed poor motor output as reflected by increased timing variability. Reward and response cost improved motor output (timing variability), with similar effects for both groups. Methylphenidate increased performance (timing variability) compared with placebo, with a higher dose showing greater effects. Effect sizes of reinforcement and medication were medium to large. Contrary to expectations, MPH did not add to the reinforcement effect. The results of this study confirm the value of reward and response cost being similar to that of MPH to optimize (timing) performance of children with ADHD.

  11. Cultural adaptation process for international dissemination of the strengthening families program.

    PubMed

    Kumpfer, Karol L; Pinyuchon, Methinin; Teixeira de Melo, Ana; Whiteside, Henry O

    2008-06-01

    The Strengthening Families Program (SFP) is an evidence-based family skills training intervention developed and found efficacious for substance abuse prevention by U.S researchers in the 1980s. In the 1990s, a cultural adaptation process was developed to transport SFP for effectiveness trials with diverse populations (African, Hispanic, Asian, Pacific Islander, and Native American). Since 2003, SFP has been culturally adapted for use in 17 countries. This article reviews the SFP theory and research and a recommended cultural adaptation process. Challenges in international dissemination of evidence-based programs (EBPs) are discussed based on the results of U.N. and U.S. governmental initiatives to transport EBP family interventions to developing countries. The technology transfer and quality assurance system are described, including the language translation and cultural adaptation process for materials development, staff training, and on-site and online Web-based supervision and technical assistance and evaluation services to assure quality implementation and process evaluation feedback for improvements.

  12. Access to Learning for Handicapped Children: A Handbook on the Instructional Adaptation Process. Field Test Version.

    ERIC Educational Resources Information Center

    Changar, Jerilynn; And Others

    The manual describes the results of a 36 month project to determine ways to modify existing curricula to meet the needs of special needs students in the mainstream. The handbook is designed in the main for administrators and facilitators as well as for teacher-adaptors. Each of eight steps in the adaptation process is broken down according to…

  13. Methods of Adapting Digital Content for the Learning Process via Mobile Devices

    ERIC Educational Resources Information Center

    Lopez, J. L. Gimenez; Royo, T. Magal; Laborda, Jesus Garcia; Calvo, F. Garde

    2009-01-01

    This article analyses different methods of adapting digital content for its delivery via mobile devices taking into account two aspects which are a fundamental part of the learning process; on the one hand, functionality of the contents, and on the other, the actual controlled navigation requirements that the learner needs in order to acquire high…

  14. An Approach to Evaluating Adolescent Adaptive Processes: Validity of an Interview-Based Measure.

    ERIC Educational Resources Information Center

    Beardslee, William R.; And Others

    1986-01-01

    An initial exploration of the validity of 15 scales designed to assess adaptive ego processes in adolescence is presented. Diabetic youngsters, psychiatric patients, and high school students with no illness are compared using the scales. Correlations are found between the scales and a separate, conceptually related measure of ego development.…

  15. The Relevance of the Functional 5-HT1A Receptor Polymorphism for Attention and Working Memory Processes during Mental Rotation of Characters

    ERIC Educational Resources Information Center

    Beste, Christian; Heil, Martin; Domschke, Katharina; Konrad, Carsten

    2010-01-01

    Numerous lines of research indicate that attentional processes, working memory and saccadic processes are highly interrelated. In the current study, we examine the relation between these processes with respect to their cognitive-neurophysiological and neurobiological background by means of event-related potentials (ERPs) in a sample of N = 72…

  16. [Features of brain mechanisms of regulation of the level of wakefulness, organization of cognitive functions and adaptive reactions in children with attention deficit with hyperactivity syndrome and healthy children].

    PubMed

    Iliukhina, V A; Krivoshchapova, M N; Manzhosova, G V

    2011-01-01

    In work results of research of features of infringement superslow cortical-truncal, limbic-reticular and upsegmentary mechanisms of regulation of a level of wakefulness at children of 6-7 years with a syndrome of deficiency of attention and hyperactivity and healthy children, pupils of 1 class of a comprehensive school with different type of psychological adaptation are generalized. At use system-integrativity psychophysiology the approach features are established: a) organization emotional-motivational and cognitive spheres; b) psychophysiology mechanisms of formation of adaptive reactions at tactile interaction about earlier unknown alive object--a dolphin at the surveyed contingent of healthy and ill children. PMID:21542315

  17. Moving to Capture Children's Attention: Developing a Methodology for Measuring Visuomotor Attention.

    PubMed

    Hill, Liam J B; Coats, Rachel O; Mushtaq, Faisal; Williams, Justin H G; Aucott, Lorna S; Mon-Williams, Mark

    2016-01-01

    Attention underpins many activities integral to a child's development. However, methodological limitations currently make large-scale assessment of children's attentional skill impractical, costly and lacking in ecological validity. Consequently we developed a measure of 'Visual Motor Attention' (VMA)-a construct defined as the ability to sustain and adapt visuomotor behaviour in response to task-relevant visual information. In a series of experiments, we evaluated the capability of our method to measure attentional processes and their contributions in guiding visuomotor behaviour. Experiment 1 established the method's core features (ability to track stimuli moving on a tablet-computer screen with a hand-held stylus) and demonstrated its sensitivity to principled manipulations in adults' attentional load. Experiment 2 standardised a format suitable for use with children and showed construct validity by capturing developmental changes in executive attention processes. Experiment 3 tested the hypothesis that children with and without coordination difficulties would show qualitatively different response patterns, finding an interaction between the cognitive and motor factors underpinning responses. Experiment 4 identified associations between VMA performance and existing standardised attention assessments and thereby confirmed convergent validity. These results establish a novel approach to measuring childhood attention that can produce meaningful functional assessments that capture how attention operates in an ecologically valid context (i.e. attention's specific contribution to visuomanual action). PMID:27434198

  18. An adaptive altitude information fusion method for autonomous landing processes of small unmanned aerial rotorcraft.

    PubMed

    Lei, Xusheng; Li, Jingjing

    2012-01-01

    This paper presents an adaptive information fusion method to improve the accuracy and reliability of the altitude measurement information for small unmanned aerial rotorcraft during the landing process. Focusing on the low measurement performance of sensors mounted on small unmanned aerial rotorcraft, a wavelet filter is applied as a pre-filter to attenuate the high frequency noises in the sensor output. Furthermore, to improve altitude information, an adaptive extended Kalman filter based on a maximum a posteriori criterion is proposed to estimate measurement noise covariance matrix in real time. Finally, the effectiveness of the proposed method is proved by static tests, hovering flight and autonomous landing flight tests. PMID:23201993

  19. An Adaptive Altitude Information Fusion Method for Autonomous Landing Processes of Small Unmanned Aerial Rotorcraft

    PubMed Central

    Lei, Xusheng; Li, Jingjing

    2012-01-01

    This paper presents an adaptive information fusion method to improve the accuracy and reliability of the altitude measurement information for small unmanned aerial rotorcraft during the landing process. Focusing on the low measurement performance of sensors mounted on small unmanned aerial rotorcraft, a wavelet filter is applied as a pre-filter to attenuate the high frequency noises in the sensor output. Furthermore, to improve altitude information, an adaptive extended Kalman filter based on a maximum a posteriori criterion is proposed to estimate measurement noise covariance matrix in real time. Finally, the effectiveness of the proposed method is proved by static tests, hovering flight and autonomous landing flight tests. PMID:23201993

  20. Adaptive automation of human-machine system information-processing functions.

    PubMed

    Kaber, David B; Wright, Melanie C; Prinzel, Lawrence J; Clamann, Michael P

    2005-01-01

    The goal of this research was to describe the ability of human operators to interact with adaptive automation (AA) applied to various stages of complex systems information processing, defined in a model of human-automation interaction. Forty participants operated a simulation of an air traffic control task. Automated assistance was adaptively applied to information acquisition, information analysis, decision making, and action implementation aspects of the task based on operator workload states, which were measured using a secondary task. The differential effects of the forms of automation were determined and compared with a manual control condition. Results of two 20-min trials of AA or manual control revealed a significant effect of the type of automation on performance, particularly during manual control periods as part of the adaptive conditions. Humans appear to better adapt to AA applied to sensory and psychomotor information-processing functions (action implementation) than to AA applied to cognitive functions (information analysis and decision making), and AA is superior to completely manual control. Potential applications of this research include the design of automation to support air traffic controller information processing.

  1. Approaches to evaluating climate change impacts on species: a guide to initiating the adaptation planning process.

    PubMed

    Rowland, Erika L; Davison, Jennifer E; Graumlich, Lisa J

    2011-03-01

    Assessing the impact of climate change on species and associated management objectives is a critical initial step for engaging in the adaptation planning process. Multiple approaches are available. While all possess limitations to their application associated with the uncertainties inherent in the data and models that inform their results, conducting and incorporating impact assessments into the adaptation planning process at least provides some basis for making resource management decisions that are becoming inevitable in the face of rapidly changing climate. Here we provide a non-exhaustive review of long-standing (e.g., species distribution models) and newly developed (e.g., vulnerability indices) methods used to anticipate the response to climate change of individual species as a guide for managers grappling with how to begin the climate change adaptation process. We address the limitations (e.g., uncertainties in climate change projections) associated with these methods, and other considerations for matching appropriate assessment approaches with the management questions and goals. Thorough consideration of the objectives, scope, scale, time frame and available resources for a climate impact assessment allows for informed method selection. With many data sets and tools available on-line, the capacity to undertake and/or benefit from existing species impact assessments is accessible to those engaged in resource management. With some understanding of potential impacts, even if limited, adaptation planning begins to move toward the development of management strategies and targeted actions that may help to sustain functioning ecosystems and their associated services into the future.

  2. The Neural Substrates Associated with Attentional Resources and Difficulty of Concurrent Processing of the Two Verbal Tasks

    ERIC Educational Resources Information Center

    Mizuno, Kei; Tanaka, Masaaki; Tanabe, Hiroki C.; Sadato, Norihiro; Watanabe, Yasuyoshi

    2012-01-01

    The kana pick-out test has been widely used in Japan to evaluate the ability to divide attention in both adult and pediatric patients. However, the neural substrates underlying the ability to divide attention using the kana pick-out test, which requires participants to pick out individual letters (vowels) in a story while also reading for…

  3. A neurodevelopmental approach to understanding memory processes among intellectually gifted youth with attention-deficit hyperactivity disorder.

    PubMed

    Whitaker, Ashley M; Bell, Terece S; Houskamp, Beth M; O'Callaghan, Erin T

    2015-01-01

    Intellectual giftedness is associated with strong strategic verbal memory while attention-deficit hyperactivity disorder (ADHD) is associated with strategic verbal memory deficits; however, no previous research has explored how this contradiction manifests in gifted populations with diagnoses of ADHD. The purpose of this study was to explore strategic verbal memory processes among intellectually gifted youth with and without ADHD to provide clarification regarding this specific aspect of neuropsychological functioning within this population. One hundred twenty-five youth completed neuropsychological evaluations including the Wechsler Intelligence Scale for Children-Fourth Edition and California Verbal Learning Test-Children's Version (CVLT-C). Results revealed significant differences between groups, with intellectually gifted youth with ADHD achieving lower T scores on CVLT-C Trials 1 through 5 compared with intellectually gifted youth without ADHD, and intellectually gifted youth with ADHD achieving higher T scores than youth of average intellectual abilities with ADHD. Additionally, repeated-measures analysis of variance revealed a main effect improvement among gifted youth with ADHD in short-delay recall when provided with organizational cues. Findings revealed new evidence about the role of twice exceptionality (specifically intellectual giftedness and ADHD) in strategic verbal memory and have important implications for parents, educators, psychologists and neuropsychologists, and other mental health professionals working with this population.

  4. Adaptation of swallowing hyo-laryngeal kinematics is distinct in oral vs. pharyngeal sensory processing

    PubMed Central

    Lokhande, Akshay; Christopherson, Heather; German, Rebecca; Stone, Alice

    2012-01-01

    Before a bolus is pushed into the pharynx, oral sensory processing is critical for planning movements of the subsequent pharyngeal swallow, including hyoid bone and laryngeal (hyo-laryngeal) kinematics. However, oral and pharyngeal sensory processing for hyo-laryngeal kinematics is not fully understood. In 11 healthy adults, we examined changes in kinematics with sensory adaptation, sensitivity shifting, with oropharyngeal swallows vs. pharyngeal swallows (no oral processing), and with various bolus volumes and tastes. Only pharyngeal swallows showed sensory adaptation (gradual changes in kinematics with repeated exposure to the same bolus). Conversely, only oropharyngeal swallows distinguished volume differences, whereas pharyngeal swallows did not. No taste effects were observed for either swallow type. The hyo-laryngeal kinematics were very similar between oropharyngeal swallows and pharyngeal swallows with a comparable bolus. Sensitivity shifting (changing sensory threshold for a small bolus when it immediately follows several very large boluses) was not observed in pharyngeal or oropharyngeal swallowing. These findings indicate that once oral sensory processing has set a motor program for a specific kind of bolus (i.e., 5 ml water), hyo-laryngeal movements are already highly standardized and optimized, showing no shifting or adaptation regardless of repeated exposure (sensory adaptation) or previous sensory experiences (sensitivity shifting). Also, the oral cavity is highly specialized for differentiating certain properties of a bolus (volume) that might require a specific motor plan to ensure swallowing safety, whereas the pharyngeal cavity does not make the same distinctions. Pharyngeal sensory processing might not be able to adjust motor plans created by the oral cavity once the swallow has already been triggered. PMID:22403349

  5. Adaptive methods of two-scale edge detection in post-enhancement visual pattern processing

    NASA Astrophysics Data System (ADS)

    Rahman, Zia-ur; Jobson, Daniel J.; Woodell, Glenn A.

    2008-04-01

    Adaptive methods are defined and experimentally studied for a two-scale edge detection process that mimics human visual perception of edges and is inspired by the parvo-cellular (P) and magno-cellular (M) physiological subsystems of natural vision. This two-channel processing consists of a high spatial acuity/coarse contrast channel (P) and a coarse acuity/fine contrast (M) channel. We perform edge detection after a very strong non-linear image enhancement that uses smart Retinex image processing. Two conditions that arise from this enhancement demand adaptiveness in edge detection. These conditions are the presence of random noise further exacerbated by the enhancement process, and the equally random occurrence of dense textural visual information. We examine how to best deal with both phenomena with an automatic adaptive computation that treats both high noise and dense textures as too much information, and gracefully shifts from a smallscale to medium-scale edge pattern priorities. This shift is accomplished by using different edge-enhancement schemes that correspond with the (P) and (M) channels of the human visual system. We also examine the case of adapting to a third image condition, namely too little visual information, and automatically adjust edge detection sensitivities when sparse feature information is encountered. When this methodology is applied to a sequence of images of the same scene but with varying exposures and lighting conditions, this edge-detection process produces pattern constancy that is very useful for several imaging applications that rely on image classification in variable imaging conditions.

  6. Repair or Violation Detection? Pre-Attentive Processing Strategies of Phonotactic Illegality Demonstrated on the Constraint of g-Deletion in German

    ERIC Educational Resources Information Center

    Steinberg, Johanna; Jacobsen, Thomas Konstantin; Jacobsen, Thomas

    2016-01-01

    Purpose: Effects of categorical phonotactic knowledge on pre-attentive speech processing were investigated by presenting illegal speech input that violated a phonotactic constraint in German called "g-deletion." The present study aimed to extend previous findings of automatic processing of phonotactic violations and to investigate the…

  7. Role of Attention in the Regulation of Fear and Anxiety

    PubMed Central

    White, Lauren K.; Helfinstein, Sarah M.; Reeb-Sutherland, Bethany C.; Degnan, Kathryn A.; Fox, Nathan A.

    2009-01-01

    Emotion regulation makes use of specific aspects of attention and executive functions that are critical for the development of adaptive social functioning, and perturbations in these processes can result in maladaptive behavior and psychopathology. Both involuntary and voluntary attention processes have been examined at both the behavioral and the neural levels and are implicated in the maintenance of fearful or anxious behaviors. However, relatively little is known about how these attention processes come to influence emotional behavior across development. The current review summarizes the extant literature on the links between voluntary and involuntary attention processes and the role that these attention processes have in the etiology, maintenance, and regulation of anxious behavior. PMID:19546568

  8. Visual Attentional Engagement Deficits in Children with Specific Language Impairment and Their Role in Real-Time Language Processing

    PubMed Central

    Dispaldro, Marco; Leonard, Laurence B.; Corradi, Nicola; Ruffino, Milena; Bronte, Tiziana; Facoetti, Andrea

    2015-01-01

    In order to become a proficient user of language, infants must detect temporal cues embedded within the noisy acoustic spectra of ongoing speech by efficient attentional engagement. According to the neuro-constructivist approach, a multi-sensory dysfunction of attentional engagement – hampering the temporal sampling of stimuli – might be responsible for language deficits typically shown in children with Specific Language Impairment (SLI). In the present study, the efficiency of visual attentional engagement was investigated in 22 children with SLI and 22 typically developing (TD) children by measuring attentional masking (AM). AM refers to impaired identification of the first of two sequentially presented masked objects (O1 and O2) in which the O1-O2 interval was manipulated. Lexical and grammatical comprehension abilities were also tested in both groups. Children with SLI showed a sluggish engagement of temporal attention, and individual differences in AM accounted for a significant percentage of unique variance in grammatical performance. Our results suggest that an attentional engagement deficit – probably linked to a dysfunction of the right fronto-parietal attentional network – might be a contributing factor in these children’s language impairments. PMID:23154040

  9. Adapting School-Based Substance Use Prevention Curriculum Through Cultural Grounding: A Review and Exemplar of Adaptation Processes for Rural Schools

    PubMed Central

    Colby, Margaret; Hecht, Michael L.; Miller-Day, Michelle; Krieger, Janice L.; Syvertsen, Amy K.; Graham, John W.; Pettigrew, Jonathan

    2014-01-01

    A central challenge facing twenty-first century community-based researchers and prevention scientists is curriculum adaptation processes. While early prevention efforts sought to develop effective programs, taking programs to scale implies that they will be adapted, especially as programs are implemented with populations other than those with whom they were developed or tested. The principle of cultural grounding, which argues that health message adaptation should be informed by knowledge of the target population and by cultural insiders, provides a theoretical rational for cultural regrounding and presents an illustrative case of methods used to reground the keepin’ it REAL substance use prevention curriculum for a rural adolescent population. We argue that adaptation processes like those presented should be incorporated into the design and dissemination of prevention interventions. PMID:22961604

  10. Moving to Capture Children’s Attention: Developing a Methodology for Measuring Visuomotor Attention

    PubMed Central

    Coats, Rachel O.; Mushtaq, Faisal; Williams, Justin H. G.; Aucott, Lorna S.; Mon-Williams, Mark

    2016-01-01

    Attention underpins many activities integral to a child’s development. However, methodological limitations currently make large-scale assessment of children’s attentional skill impractical, costly and lacking in ecological validity. Consequently we developed a measure of ‘Visual Motor Attention’ (VMA)—a construct defined as the ability to sustain and adapt visuomotor behaviour in response to task-relevant visual information. In a series of experiments, we evaluated the capability of our method to measure attentional processes and their contributions in guiding visuomotor behaviour. Experiment 1 established the method’s core features (ability to track stimuli moving on a tablet-computer screen with a hand-held stylus) and demonstrated its sensitivity to principled manipulations in adults’ attentional load. Experiment 2 standardised a format suitable for use with children and showed construct validity by capturing developmental changes in executive attention processes. Experiment 3 tested the hypothesis that children with and without coordination difficulties would show qualitatively different response patterns, finding an interaction between the cognitive and motor factors underpinning responses. Experiment 4 identified associations between VMA performance and existing standardised attention assessments and thereby confirmed convergent validity. These results establish a novel approach to measuring childhood attention that can produce meaningful functional assessments that capture how attention operates in an ecologically valid context (i.e. attention's specific contribution to visuomanual action). PMID:27434198

  11. Adapting existing natural language processing resources for cardiovascular risk factors identification in clinical notes.

    PubMed

    Khalifa, Abdulrahman; Meystre, Stéphane

    2015-12-01

    The 2014 i2b2 natural language processing shared task focused on identifying cardiovascular risk factors such as high blood pressure, high cholesterol levels, obesity and smoking status among other factors found in health records of diabetic patients. In addition, the task involved detecting medications, and time information associated with the extracted data. This paper presents the development and evaluation of a natural language processing (NLP) application conceived for this i2b2 shared task. For increased efficiency, the application main components were adapted from two existing NLP tools implemented in the Apache UIMA framework: Textractor (for dictionary-based lookup) and cTAKES (for preprocessing and smoking status detection). The application achieved a final (micro-averaged) F1-measure of 87.5% on the final evaluation test set. Our attempt was mostly based on existing tools adapted with minimal changes and allowed for satisfying performance with limited development efforts.

  12. The association of physical activity to neural adaptability during visuo-spatial processing in healthy elderly adults: A multiscale entropy analysis.

    PubMed

    Wang, Chun-Hao; Tsai, Chia-Liang; Tseng, Philip; Yang, Albert C; Lo, Men-Tzung; Peng, Chung-Kang; Wang, Hsin-Yi; Muggleton, Neil G; Juan, Chi-Hung; Liang, Wei-Kuang

    2014-10-29

    Physical activity has been shown to benefit brain and cognition in late adulthood. However, this effect is still unexplored in terms of brain signal complexity, which reflects the level of neural adaptability and efficiency during cognitive processing that cannot be acquired via averaged neuroelectric signals. Here we employed multiscale entropy analysis (MSE) of electroencephalography (EEG), a new approach that conveys important information related to the temporal dynamics of brain signal complexity across multiple time scales, to reveal the association of physical activity with neural adaptability and efficiency in elderly adults. A between-subjects design that included 24 participants (aged 66.63±1.31years; female=12) with high physical activity and 24 age- and gender-matched low physical activity participants (aged 67.29±1.20years) was conducted to examine differences related to physical activity in performance and MSE of EEG signals during a visuo-spatial cognition task. We observed that physically active elderly adults had better accuracy on both visuo-spatial attention and working memory conditions relative to their sedentary counterparts. Additionally, these physically active elderly adults displayed greater MSE values at larger time scales at the Fz electrode in both attention and memory conditions. The results suggest that physical activity may be beneficial for adaptability of brain systems in tasks involving visuo-spatial information. MSE thus might be a promising approach to test the effects of the benefits of exercise on cognition.

  13. A process for developing community consensus regarding the diagnosis and management of attention-deficit/hyperactivity disorder.

    PubMed

    Foy, Jane Meschan; Earls, Marian F

    2005-01-01

    There remain large discrepancies between pediatricians' practice patterns and the American Academy of Pediatrics (AAP) guidelines for the assessment and treatment of children with attention-deficit/hyperactivity disorder (ADHD). Several studies raise additional concerns about access to ADHD treatment for girls, blacks, and poorer individuals. Barriers may occur at multiple levels, including identification and referral by school personnel, parents' help-seeking behavior, diagnosis by the medical provider, treatment decisions, and acceptance of treatment. Such findings confirm the importance of establishing appropriate mechanisms to ensure that children of both genders and all socioeconomic, racial, and ethnic groups receive appropriate assessment and treatment. Publication of the AAP ADHD toolkit provides resources to assist with implementing the ADHD guidelines in clinical practice. These resources address a number of the barriers to office implementation, including unfamiliarity with Diagnostic and Statistical Manual of Mental Disorders criteria, difficulty identifying comorbidities, and inadequate knowledge of effective coding practices. Also crucial to the success of improved processes within clinical practice is community collaboration in care, particularly collaboration with the educational system. Such collaboration addresses other barriers to good care, such as pressures from parents and schools to prescribe stimulants, cultural biases that may prevent schools from assessing children for ADHD or may prevent families from seeking health care, and inconsistencies in recognition and referral among schools in the same system. Collaboration may also create efficiencies in collection of data and school-physician communications, thereby decreasing physicians' non-face-to-face (and thus nonreimbursable) elements of care. This article describes a process used in Guilford County, North Carolina, to develop a consensus among health care providers, educators, and child

  14. Adaptive finite element program for automatic modeling of thermal processes during laser-tissue interaction

    NASA Astrophysics Data System (ADS)

    Yakunin, Alexander N.; Scherbakov, Yury N.

    1994-02-01

    The absence of satisfactory criteria for discrete model parameters choice during computer modeling of thermal processes of laser-biotissue interaction may be the premier sign for the accuracy of the numerical results obtained. The approach realizing the new concept of direct automatical adaptive grid construction is suggested. The intellectual program provides high calculation accuracy and is simple in practical usage so that a physician receives the ability to prescribe treatment without any assistance of a specialist in mathematical modeling.

  15. Low Temperature Adaptation Is Not the Opposite Process of High Temperature Adaptation in Terms of Changes in Amino Acid Composition

    PubMed Central

    Yang, Ling-Ling; Tang, Shu-Kun; Huang, Ying; Zhi, Xiao-Yang

    2015-01-01

    Previous studies focused on psychrophilic adaptation generally have demonstrated that multiple mechanisms work together to increase protein flexibility and activity, as well as to decrease the thermostability of proteins. However, the relationship between high and low temperature adaptations remains unclear. To investigate this issue, we collected the available predicted whole proteome sequences of species with different optimal growth temperatures, and analyzed amino acid variations and substitutional asymmetry in pairs of homologous proteins from related species. We found that changes in amino acid composition associated with low temperature adaptation did not exhibit a coherent opposite trend when compared with changes in amino acid composition associated with high temperature adaptation. This result indicates that during their evolutionary histories the proteome-scale evolutionary patterns associated with prokaryotes exposed to low temperature environments were distinct from the proteome-scale evolutionary patterns associated with prokaryotes exposed to high temperature environments in terms of changes in amino acid composition of the proteins. PMID:26614525

  16. Spectroscopic analyses of chemical adaptation processes within microalgal biomass in response to changing environments.

    PubMed

    Vogt, Frank; White, Lauren

    2015-03-31

    Via photosynthesis, marine phytoplankton transforms large quantities of inorganic compounds into biomass. This has considerable environmental impacts as microalgae contribute for instance to counter-balancing anthropogenic releases of the greenhouse gas CO2. On the other hand, high concentrations of nitrogen compounds in an ecosystem can lead to harmful algae blooms. In previous investigations it was found that the chemical composition of microalgal biomass is strongly dependent on the nutrient availability. Therefore, it is expected that algae's sequestration capabilities and productivity are also determined by the cells' chemical environments. For investigating this hypothesis, novel analytical methodologies are required which are capable of monitoring live cells exposed to chemically shifting environments followed by chemometric modeling of their chemical adaptation dynamics. FTIR-ATR experiments have been developed for acquiring spectroscopic time series of live Dunaliella parva cultures adapting to different nutrient situations. Comparing experimental data from acclimated cultures to those exposed to a chemically shifted nutrient situation reveals insights in which analyte groups participate in modifications of microalgal biomass and on what time scales. For a chemometric description of these processes, a data model has been deduced which explains the chemical adaptation dynamics explicitly rather than empirically. First results show that this approach is feasible and derives information about the chemical biomass adaptations. Future investigations will utilize these instrumental and chemometric methodologies for quantitative investigations of the relation between chemical environments and microalgal sequestration capabilities. PMID:25813024

  17. Spectroscopic analyses of chemical adaptation processes within microalgal biomass in response to changing environments.

    PubMed

    Vogt, Frank; White, Lauren

    2015-03-31

    Via photosynthesis, marine phytoplankton transforms large quantities of inorganic compounds into biomass. This has considerable environmental impacts as microalgae contribute for instance to counter-balancing anthropogenic releases of the greenhouse gas CO2. On the other hand, high concentrations of nitrogen compounds in an ecosystem can lead to harmful algae blooms. In previous investigations it was found that the chemical composition of microalgal biomass is strongly dependent on the nutrient availability. Therefore, it is expected that algae's sequestration capabilities and productivity are also determined by the cells' chemical environments. For investigating this hypothesis, novel analytical methodologies are required which are capable of monitoring live cells exposed to chemically shifting environments followed by chemometric modeling of their chemical adaptation dynamics. FTIR-ATR experiments have been developed for acquiring spectroscopic time series of live Dunaliella parva cultures adapting to different nutrient situations. Comparing experimental data from acclimated cultures to those exposed to a chemically shifted nutrient situation reveals insights in which analyte groups participate in modifications of microalgal biomass and on what time scales. For a chemometric description of these processes, a data model has been deduced which explains the chemical adaptation dynamics explicitly rather than empirically. First results show that this approach is feasible and derives information about the chemical biomass adaptations. Future investigations will utilize these instrumental and chemometric methodologies for quantitative investigations of the relation between chemical environments and microalgal sequestration capabilities.

  18. Attention Alters Perceived Attractiveness.

    PubMed

    Störmer, Viola S; Alvarez, George A

    2016-04-01

    Can attention alter the impression of a face? Previous studies showed that attention modulates the appearance of lower-level visual features. For instance, attention can make a simple stimulus appear to have higher contrast than it actually does. We tested whether attention can also alter the perception of a higher-order property-namely, facial attractiveness. We asked participants to judge the relative attractiveness of two faces after summoning their attention to one of the faces using a briefly presented visual cue. Across trials, participants judged the attended face to be more attractive than the same face when it was unattended. This effect was not due to decision or response biases, but rather was due to changes in perceptual processing of the faces. These results show that attention alters perceived facial attractiveness, and broadly demonstrate that attention can influence higher-level perception and may affect people's initial impressions of one another. PMID:26966228

  19. Visual attention to dynamic faces and objects is linked to face processing skills: a combined study of children with autism and controls.

    PubMed

    Parish-Morris, Julia; Chevallier, Coralie; Tonge, Natasha; Letzen, Janelle; Pandey, Juhi; Schultz, Robert T

    2013-01-01

    Although the extant literature on face recognition skills in Autism Spectrum Disorder (ASD) shows clear impairments compared to typically developing controls (TDC) at the group level, the distribution of scores within ASD is broad. In the present research, we take a dimensional approach and explore how differences in social attention during an eye tracking experiment correlate with face recognition skills across ASD and TDC. Emotional discrimination and person identity perception face processing skills were assessed using the Let's Face It! Skills Battery in 110 children with and without ASD. Social attention was assessed using infrared eye gaze tracking during passive viewing of movies of facial expressions and objects displayed together on a computer screen. Face processing skills were significantly correlated with measures of attention to faces and with social skills as measured by the Social Communication Questionnaire (SCQ). Consistent with prior research, children with ASD scored significantly lower on face processing skills tests but, unexpectedly, group differences in amount of attention to faces (vs. objects) were not found. We discuss possible methodological contributions to this null finding. We also highlight the importance of a dimensional approach for understanding the developmental origins of reduced face perception skills, and emphasize the need for longitudinal research to truly understand how social motivation and social attention influence the development of social perceptual skills.

  20. ERP Characterization of Sustained Attention Effects in Visual Lexical Categorization

    PubMed Central

    Martin, Clara D.; Thierry, Guillaume; Démonet, Jean-François

    2010-01-01

    As our understanding of the basic processes underlying reading is growing, the key role played by attention in this process becomes evident. Two research topics are of particular interest in this domain: (1) it is still undetermined whether sustained attention affects lexical decision tasks; (2) the influence of attention on early visual processing (i.e., before orthographic or lexico-semantic processing stages) remains largely under-specified. Here we investigated early perceptual modulations by sustained attention using an ERP paradigm adapted from Thierry et al. [1]. Participants had to decide whether visual stimuli presented in pairs pertained to a pre-specified category (lexical categorization focus on word or pseudoword pairs). Depending on the lexical category of the first item of a pair, participants either needed to fully process the second item (hold condition) or could release their attention and make a decision without full processing of the second item (release condition). The P1 peak was unaffected by sustained attention. The N1 was delayed and reduced after the second item of a pair when participants released their attention. Release of sustained attention also reduced a P3 wave elicited by the first item of a pair and abolished the P3 wave elicited by the second. Our results are consistent with differential effects of sustained attention on early processing stages and working memory. Sustained attention modulated early processing stages during a lexical decision task without inhibiting the process of stimulus integration. On the contrary, working memory involvement/updating was highly dependent upon the allocation of sustained attention. Moreover, the influence of sustained attention on both early and late cognitive processes was independent of lexical categorization focus. PMID:20361039

  1. Adaptive constructive processes and memory accuracy: Consequences of counterfactual simulations in young and older adults

    PubMed Central

    Gerlach, Kathy D.; Dornblaser, David W.; Schacter, Daniel L.

    2013-01-01

    People frequently engage in counterfactual thinking: mental simulations of alternative outcomes to past events. Like simulations of future events, counterfactual simulations serve adaptive functions. However, future simulation can also result in various kinds of distortions and has thus been characterized as an adaptive constructive process. Here we approach counterfactual thinking as such and examine whether it can distort memory for actual events. In Experiments 1a/b, young and older adults imagined themselves experiencing different scenarios. Participants then imagined the same scenario again, engaged in no further simulation of a scenario, or imagined a counterfactual outcome. On a subsequent recognition test, participants were more likely to make false alarms to counterfactual lures than novel scenarios. Older adults were more prone to these memory errors than younger adults. In Experiment 2, younger and older participants selected and performed different actions, then recalled performing some of those actions, imagined performing alternative actions to some of the selected actions, and did not imagine others. Participants, especially older adults, were more likely to falsely remember counterfactual actions than novel actions as previously performed. The findings suggest that counterfactual thinking can cause source confusion based on internally generated misinformation, consistent with its characterization as an adaptive constructive process. PMID:23560477

  2. Adaptive optimal control of highly dissipative nonlinear spatially distributed processes with neuro-dynamic programming.

    PubMed

    Luo, Biao; Wu, Huai-Ning; Li, Han-Xiong

    2015-04-01

    Highly dissipative nonlinear partial differential equations (PDEs) are widely employed to describe the system dynamics of industrial spatially distributed processes (SDPs). In this paper, we consider the optimal control problem of the general highly dissipative SDPs, and propose an adaptive optimal control approach based on neuro-dynamic programming (NDP). Initially, Karhunen-Loève decomposition is employed to compute empirical eigenfunctions (EEFs) of the SDP based on the method of snapshots. These EEFs together with singular perturbation technique are then used to obtain a finite-dimensional slow subsystem of ordinary differential equations that accurately describes the dominant dynamics of the PDE system. Subsequently, the optimal control problem is reformulated on the basis of the slow subsystem, which is further converted to solve a Hamilton-Jacobi-Bellman (HJB) equation. HJB equation is a nonlinear PDE that has proven to be impossible to solve analytically. Thus, an adaptive optimal control method is developed via NDP that solves the HJB equation online using neural network (NN) for approximating the value function; and an online NN weight tuning law is proposed without requiring an initial stabilizing control policy. Moreover, by involving the NN estimation error, we prove that the original closed-loop PDE system with the adaptive optimal control policy is semiglobally uniformly ultimately bounded. Finally, the developed method is tested on a nonlinear diffusion-convection-reaction process and applied to a temperature cooling fin of high-speed aerospace vehicle, and the achieved results show its effectiveness.

  3. Adaptive optimal control of highly dissipative nonlinear spatially distributed processes with neuro-dynamic programming.

    PubMed

    Luo, Biao; Wu, Huai-Ning; Li, Han-Xiong

    2015-04-01

    Highly dissipative nonlinear partial differential equations (PDEs) are widely employed to describe the system dynamics of industrial spatially distributed processes (SDPs). In this paper, we consider the optimal control problem of the general highly dissipative SDPs, and propose an adaptive optimal control approach based on neuro-dynamic programming (NDP). Initially, Karhunen-Loève decomposition is employed to compute empirical eigenfunctions (EEFs) of the SDP based on the method of snapshots. These EEFs together with singular perturbation technique are then used to obtain a finite-dimensional slow subsystem of ordinary differential equations that accurately describes the dominant dynamics of the PDE system. Subsequently, the optimal control problem is reformulated on the basis of the slow subsystem, which is further converted to solve a Hamilton-Jacobi-Bellman (HJB) equation. HJB equation is a nonlinear PDE that has proven to be impossible to solve analytically. Thus, an adaptive optimal control method is developed via NDP that solves the HJB equation online using neural network (NN) for approximating the value function; and an online NN weight tuning law is proposed without requiring an initial stabilizing control policy. Moreover, by involving the NN estimation error, we prove that the original closed-loop PDE system with the adaptive optimal control policy is semiglobally uniformly ultimately bounded. Finally, the developed method is tested on a nonlinear diffusion-convection-reaction process and applied to a temperature cooling fin of high-speed aerospace vehicle, and the achieved results show its effectiveness. PMID:25794375

  4. Coevolution of information processing and topology in hierarchical adaptive random Boolean networks

    NASA Astrophysics Data System (ADS)

    Górski, Piotr J.; Czaplicka, Agnieszka; Hołyst, Janusz A.

    2016-02-01

    Random Boolean Networks (RBNs) are frequently used for modeling complex systems driven by information processing, e.g. for gene regulatory networks (GRNs). Here we propose a hierarchical adaptive random Boolean Network (HARBN) as a system consisting of distinct adaptive RBNs (ARBNs) - subnetworks - connected by a set of permanent interlinks. We investigate mean node information, mean edge information as well as mean node degree. Information measures and internal subnetworks topology of HARBN coevolve and reach steady-states that are specific for a given network structure. The main natural feature of ARBNs, i.e. their adaptability, is preserved in HARBNs and they evolve towards critical configurations which is documented by power law distributions of network attractor lengths. The mean information processed by a single node or a single link increases with the number of interlinks added to the system. The mean length of network attractors and the mean steady-state connectivity possess minima for certain specific values of the quotient between the density of interlinks and the density of all links in networks. It means that the modular network displays extremal values of its observables when subnetworks are connected with a density a few times lower than a mean density of all links.

  5. Capturing Attention When Attention "Blinks"

    ERIC Educational Resources Information Center

    Wee, Serena; Chua, Fook K.

    2004-01-01

    Four experiments addressed the question of whether attention may be captured when the visual system is in the midst of an attentional blink (AB). Participants identified 2 target letters embedded among distractor letters in a rapid serial visual presentation sequence. In some trials, a square frame was inserted between the targets; as the only…

  6. ADAPT: building conceptual models of the physical and biological processes across permafrost landscapes

    NASA Astrophysics Data System (ADS)

    Allard, M.; Vincent, W. F.; Lemay, M.

    2012-12-01

    Fundamental and applied permafrost research is called upon in Canada in support of environmental protection, economic development and for contributing to the international efforts in understanding climatic and ecological feedbacks of permafrost thawing under a warming climate. The five year "Arctic Development and Adaptation to Permafrost in Transition" program (ADAPT) funded by NSERC brings together 14 scientists from 10 Canadian universities and involves numerous collaborators from academia, territorial and provincial governments, Inuit communities and industry. The geographical coverage of the program encompasses all of the permafrost regions of Canada. Field research at a series of sites across the country is being coordinated. A common protocol for measuring ground thermal and moisture regime, characterizing terrain conditions (vegetation, topography, surface water regime and soil organic matter contents) is being applied in order to provide inputs for designing a general model to provide an understanding of transfers of energy and matter in permafrost terrain, and the implications for biological and human systems. The ADAPT mission is to produce an 'Integrated Permafrost Systems Science' framework that will be used to help generate sustainable development and adaptation strategies for the North in the context of rapid socio-economic and climate change. ADAPT has three major objectives: to examine how changing precipitation and warming temperatures affect permafrost geosystems and ecosystems, specifically by testing hypotheses concerning the influence of the snowpack, the effects of water as a conveyor of heat, sediments, and carbon in warming permafrost terrain and the processes of permafrost decay; to interact directly with Inuit communities, the public sector and the private sector for development and adaptation to changes in permafrost environments; and to train the new generation of experts and scientists in this critical domain of research in Canada

  7. Improved electromagnetic induction processing with novel adaptive matched filter and matched subspace detection

    NASA Astrophysics Data System (ADS)

    Hayes, Charles E.; McClellan, James H.; Scott, Waymond R.; Kerr, Andrew J.

    2016-05-01

    This work introduces two advances in wide-band electromagnetic induction (EMI) processing: a novel adaptive matched filter (AMF) and matched subspace detection methods. Both advances make use of recent work with a subspace SVD approach to separating the signal, soil, and noise subspaces of the frequency measurements The proposed AMF provides a direct approach to removing the EMI self-response while improving the signal to noise ratio of the data. Unlike previous EMI adaptive downtrack filters, this new filter will not erroneously optimize the EMI soil response instead of the EMI target response because these two responses are projected into separate frequency subspaces. The EMI detection methods in this work elaborate on how the signal and noise subspaces in the frequency measurements are ideal for creating the matched subspace detection (MSD) and constant false alarm rate matched subspace detection (CFAR) metrics developed by Scharf The CFAR detection metric has been shown to be the uniformly most powerful invariant detector.

  8. Two Adaptation Processes in Auditory Hair Cells Together Can Provide an Active Amplifier

    PubMed Central

    Vilfan, Andrej; Duke, Thomas

    2003-01-01

    The hair cells of the vertebrate inner ear convert mechanical stimuli to electrical signals. Two adaptation mechanisms are known to modify the ionic current flowing through the transduction channels of the hair bundles: a rapid process involves Ca2+ ions binding to the channels; and a slower adaptation is associated with the movement of myosin motors. We present a mathematical model of the hair cell which demonstrates that the combination of these two mechanisms can produce “self-tuned critical oscillations”, i.e., maintain the hair bundle at the threshold of an oscillatory instability. The characteristic frequency depends on the geometry of the bundle and on the Ca2+ dynamics, but is independent of channel kinetics. Poised on the verge of vibrating, the hair bundle acts as an active amplifier. However, if the hair cell is sufficiently perturbed, other dynamical regimes can occur. These include slow relaxation oscillations which resemble the hair bundle motion observed in some experimental preparations. PMID:12829475

  9. Performance-Based Adaptive Fuzzy Tracking Control for Networked Industrial Processes.

    PubMed

    Wang, Tong; Qiu, Jianbin; Yin, Shen; Gao, Huijun; Fan, Jialu; Chai, Tianyou

    2016-08-01

    In this paper, the performance-based control design problem for double-layer networked industrial processes is investigated. At the device layer, the prescribed performance functions are first given to describe the output tracking performance, and then by using backstepping technique, new adaptive fuzzy controllers are designed to guarantee the tracking performance under the effects of input dead-zone and the constraint of prescribed tracking performance functions. At operation layer, by considering the stochastic disturbance, actual index value, target index value, and index prediction simultaneously, an adaptive inverse optimal controller in discrete-time form is designed to optimize the overall performance and stabilize the overall nonlinear system. Finally, a simulation example of continuous stirred tank reactor system is presented to show the effectiveness of the proposed control method.

  10. ERP and Adaptive Autoregressive identification with spectral power decomposition to study rapid auditory processing in infants.

    PubMed

    Piazza, C; Cantiani, C; Tacchino, G; Molteni, M; Reni, G; Bianchi, A M

    2014-01-01

    The ability to process rapidly-occurring auditory stimuli plays an important role in the mechanisms of language acquisition. For this reason, the research community has begun to investigate infant auditory processing, particularly using the Event Related Potentials (ERP) technique. In this paper we approach this issue by means of time domain and time-frequency domain analysis. For the latter, we propose the use of Adaptive Autoregressive (AAR) identification with spectral power decomposition. Results show EEG delta-theta oscillation enhancement related to the processing of acoustic frequency and duration changes, suggesting that, as expected, power modulation encodes rapid auditory processing (RAP) in infants and that the time-frequency analysis method proposed is able to identify this modulation.

  11. Effects of Age and Attention on Auditory Global-Local Processing in Children with Autism Spectrum Disorder.

    PubMed

    Foster, Nicholas E V; Ouimet, Tia; Tryfon, Ana; Doyle-Thomas, Krissy; Anagnostou, Evdokia; Hyde, Krista L

    2016-04-01

    In vision, typically-developing (TD) individuals perceive "global" (whole) before "local" (detailed) features, whereas individuals with autism spectrum disorder (ASD) exhibit a local bias. However, auditory global-local distinctions are less clear in ASD, particularly in terms of age and attention effects. To these aims, here ASD and TD children judged local and global pitch structure in nine-tone melodies. Both groups showed a similar global precedence effect, but ASD children were less sensitive to global interference than TD children at younger ages. There was no effect of attention task. These findings provide novel evidence of developmental differences in auditory perception and may help to refine sensory phenotypes in ASD.

  12. Evolutionary adaptations for the temporal processing of natural sounds by the anuran peripheral auditory system.

    PubMed

    Schrode, Katrina M; Bee, Mark A

    2015-03-01

    Sensory systems function most efficiently when processing natural stimuli, such as vocalizations, and it is thought that this reflects evolutionary adaptation. Among the best-described examples of evolutionary adaptation in the auditory system are the frequent matches between spectral tuning in both the peripheral and central auditory systems of anurans (frogs and toads) and the frequency spectra of conspecific calls. Tuning to the temporal properties of conspecific calls is less well established, and in anurans has so far been documented only in the central auditory system. Using auditory-evoked potentials, we asked whether there are species-specific or sex-specific adaptations of the auditory systems of gray treefrogs (Hyla chrysoscelis) and green treefrogs (H. cinerea) to the temporal modulations present in conspecific calls. Modulation rate transfer functions (MRTFs) constructed from auditory steady-state responses revealed that each species was more sensitive than the other to the modulation rates typical of conspecific advertisement calls. In addition, auditory brainstem responses (ABRs) to paired clicks indicated relatively better temporal resolution in green treefrogs, which could represent an adaptation to the faster modulation rates present in the calls of this species. MRTFs and recovery of ABRs to paired clicks were generally similar between the sexes, and we found no evidence that males were more sensitive than females to the temporal modulation patterns characteristic of the aggressive calls used in male-male competition. Together, our results suggest that efficient processing of the temporal properties of behaviorally relevant sounds begins at potentially very early stages of the anuran auditory system that include the periphery.

  13. General and craniofacial development are complex adaptive processes influenced by diversity.

    PubMed

    Brook, A H; O'Donnell, M Brook; Hone, A; Hart, E; Hughes, T E; Smith, R N; Townsend, G C

    2014-06-01

    Complex systems are present in such diverse areas as social systems, economies, ecosystems and biology and, therefore, are highly relevant to dental research, education and practice. A Complex Adaptive System in biological development is a dynamic process in which, from interacting components at a lower level, higher level phenomena and structures emerge. Diversity makes substantial contributions to the performance of complex adaptive systems. It enhances the robustness of the process, allowing multiple responses to external stimuli as well as internal changes. From diversity comes variation in outcome and the possibility of major change; outliers in the distribution enhance the tipping points. The development of the dentition is a valuable, accessible model with extensive and reliable databases for investigating the role of complex adaptive systems in craniofacial and general development. The general characteristics of such systems are seen during tooth development: self-organization; bottom-up emergence; multitasking; self-adaptation; variation; tipping points; critical phases; and robustness. Dental findings are compatible with the Random Network Model, the Threshold Model and also with the Scale Free Network Model which has a Power Law distribution. In addition, dental development shows the characteristics of Modularity and Clustering to form Hierarchical Networks. The interactions between the genes (nodes) demonstrate Small World phenomena, Subgraph Motifs and Gene Regulatory Networks. Genetic mechanisms are involved in the creation and evolution of variation during development. The genetic factors interact with epigenetic and environmental factors at the molecular level and form complex networks within the cells. From these interactions emerge the higher level tissues, tooth germs and mineralized teeth. Approaching development in this way allows investigation of why there can be variations in phenotypes from identical genotypes; the phenotype is the outcome

  14. Evolutionary adaptations for the temporal processing of natural sounds by the anuran peripheral auditory system

    PubMed Central

    Schrode, Katrina M.; Bee, Mark A.

    2015-01-01

    ABSTRACT Sensory systems function most efficiently when processing natural stimuli, such as vocalizations, and it is thought that this reflects evolutionary adaptation. Among the best-described examples of evolutionary adaptation in the auditory system are the frequent matches between spectral tuning in both the peripheral and central auditory systems of anurans (frogs and toads) and the frequency spectra of conspecific calls. Tuning to the temporal properties of conspecific calls is less well established, and in anurans has so far been documented only in the central auditory system. Using auditory-evoked potentials, we asked whether there are species-specific or sex-specific adaptations of the auditory systems of gray treefrogs (Hyla chrysoscelis) and green treefrogs (H. cinerea) to the temporal modulations present in conspecific calls. Modulation rate transfer functions (MRTFs) constructed from auditory steady-state responses revealed that each species was more sensitive than the other to the modulation rates typical of conspecific advertisement calls. In addition, auditory brainstem responses (ABRs) to paired clicks indicated relatively better temporal resolution in green treefrogs, which could represent an adaptation to the faster modulation rates present in the calls of this species. MRTFs and recovery of ABRs to paired clicks were generally similar between the sexes, and we found no evidence that males were more sensitive than females to the temporal modulation patterns characteristic of the aggressive calls used in male–male competition. Together, our results suggest that efficient processing of the temporal properties of behaviorally relevant sounds begins at potentially very early stages of the anuran auditory system that include the periphery. PMID:25617467

  15. Maternal migration and child health: An analysis of disruption and adaptation processes in Benin

    PubMed Central

    Smith-Greenaway, Emily; Madhavan, Sangeetha

    2016-01-01

    Children of migrant mothers have lower vaccination rates compared to their peers with non-migrant mothers in low-income countries. Explanations for this finding are typically grounded in the disruption and adaptation perspectives of migration. Researchers argue that migration is a disruptive process that interferes with women’s economic well-being and social networks, and ultimately their health-seeking behaviors. With time, however, migrant women adapt to their new settings, and their health behaviors improve. Despite prominence in the literature, no research tests the salience of these perspectives to the relationship between maternal migration and child vaccination. We innovatively leverage Demographic and Health Survey data to test the extent to which disruption and adaptation processes underlie the relationship between maternal migration and child vaccination in the context of Benin—a West African country where migration is common and child vaccination rates have declined in recent years. By disaggregating children of migrants according to whether they were born before or after their mother’s migration, we confirm that migration does not lower children’s vaccination rates in Benin. In fact, children born after migration enjoy a higher likelihood of vaccination, whereas their peers born in the community from which their mother eventually migrates are less likely to be vaccinated. Although we find no support for the disruption perspective of migration, we do find evidence of adaptation: children born after migration have an increased likelihood of vaccination the longer their mother resides in the destination community prior to their birth. PMID:26463540

  16. General and craniofacial development are complex adaptive processes influenced by diversity.

    PubMed

    Brook, A H; O'Donnell, M Brook; Hone, A; Hart, E; Hughes, T E; Smith, R N; Townsend, G C

    2014-06-01

    Complex systems are present in such diverse areas as social systems, economies, ecosystems and biology and, therefore, are highly relevant to dental research, education and practice. A Complex Adaptive System in biological development is a dynamic process in which, from interacting components at a lower level, higher level phenomena and structures emerge. Diversity makes substantial contributions to the performance of complex adaptive systems. It enhances the robustness of the process, allowing multiple responses to external stimuli as well as internal changes. From diversity comes variation in outcome and the possibility of major change; outliers in the distribution enhance the tipping points. The development of the dentition is a valuable, accessible model with extensive and reliable databases for investigating the role of complex adaptive systems in craniofacial and general development. The general characteristics of such systems are seen during tooth development: self-organization; bottom-up emergence; multitasking; self-adaptation; variation; tipping points; critical phases; and robustness. Dental findings are compatible with the Random Network Model, the Threshold Model and also with the Scale Free Network Model which has a Power Law distribution. In addition, dental development shows the characteristics of Modularity and Clustering to form Hierarchical Networks. The interactions between the genes (nodes) demonstrate Small World phenomena, Subgraph Motifs and Gene Regulatory Networks. Genetic mechanisms are involved in the creation and evolution of variation during development. The genetic factors interact with epigenetic and environmental factors at the molecular level and form complex networks within the cells. From these interactions emerge the higher level tissues, tooth germs and mineralized teeth. Approaching development in this way allows investigation of why there can be variations in phenotypes from identical genotypes; the phenotype is the outcome

  17. Flexible Description and Adaptive Processing of Earth Observation Data through the BigEarth Platform

    NASA Astrophysics Data System (ADS)

    Gorgan, Dorian; Bacu, Victor; Stefanut, Teodor; Nandra, Cosmin; Mihon, Danut

    2016-04-01

    The Earth Observation data repositories extending periodically by several terabytes become a critical issue for organizations. The management of the storage capacity of such big datasets, accessing policy, data protection, searching, and complex processing require high costs that impose efficient solutions to balance the cost and value of data. Data can create value only when it is used, and the data protection has to be oriented toward allowing innovation that sometimes depends on creative people, which achieve unexpected valuable results through a flexible and adaptive manner. The users need to describe and experiment themselves different complex algorithms through analytics in order to valorize data. The analytics uses descriptive and predictive models to gain valuable knowledge and information from data analysis. Possible solutions for advanced processing of big Earth Observation data are given by the HPC platforms such as cloud. With platforms becoming more complex and heterogeneous, the developing of applications is even harder and the efficient mapping of these applications to a suitable and optimum platform, working on huge distributed data repositories, is challenging and complex as well, even by using specialized software services. From the user point of view, an optimum environment gives acceptable execution times, offers a high level of usability by hiding the complexity of computing infrastructure, and supports an open accessibility and control to application entities and functionality. The BigEarth platform [1] supports the entire flow of flexible description of processing by basic operators and adaptive execution over cloud infrastructure [2]. The basic modules of the pipeline such as the KEOPS [3] set of basic operators, the WorDeL language [4], the Planner for sequential and parallel processing, and the Executor through virtual machines, are detailed as the main components of the BigEarth platform [5]. The presentation exemplifies the development

  18. Can survival processing enhance story memory? Testing the generalizability of the adaptive memory framework.

    PubMed

    Seamon, John G; Bohn, Justin M; Coddington, Inslee E; Ebling, Maritza C; Grund, Ethan M; Haring, Catherine T; Jang, Sue-Jung; Kim, Daniel; Liong, Christopher; Paley, Frances M; Pang, Luke K; Siddique, Ashik H

    2012-07-01

    Research from the adaptive memory framework shows that thinking about words in terms of their survival value in an incidental learning task enhances their free recall relative to other semantic encoding strategies and intentional learning (Nairne, Pandeirada, & Thompson, 2008). We found similar results. When participants used incidental survival encoding for a list of words (e.g., "Will this object enhance my survival if I were stranded in the grasslands of a foreign land?"), they produced better free recall on a surprise test than did participants who intentionally tried to remember those words (Experiment 1). We also found this survival processing advantage when the words were presented within the context of a survival or neutral story (Experiment 2). However, this advantage did not extent to memory for a story's factual content, regardless of whether the participants were tested by cued recall (Experiment 3) or free recall (Experiments 4-5). Listening to a story for understanding under intentional or incidental learning conditions was just as good as survival processing for remembering story content. The functionalist approach to thinking about memory as an evolutionary adaptation designed to solve reproductive fitness problems provides a different theoretical framework for research, but it is not yet clear if survival processing has general applicability or is effective only for processing discrete stimuli in terms of fitness-relevant scenarios from our past. PMID:22288816

  19. Shared Attention.

    PubMed

    Shteynberg, Garriy

    2015-09-01

    Shared attention is extremely common. In stadiums, public squares, and private living rooms, people attend to the world with others. Humans do so across all sensory modalities-sharing the sights, sounds, tastes, smells, and textures of everyday life with one another. The potential for attending with others has grown considerably with the emergence of mass media technologies, which allow for the sharing of attention in the absence of physical co-presence. In the last several years, studies have begun to outline the conditions under which attending together is consequential for human memory, motivation, judgment, emotion, and behavior. Here, I advance a psychological theory of shared attention, defining its properties as a mental state and outlining its cognitive, affective, and behavioral consequences. I review empirical findings that are uniquely predicted by shared-attention theory and discuss the possibility of integrating shared-attention, social-facilitation, and social-loafing perspectives. Finally, I reflect on what shared-attention theory implies for living in the digital world. PMID:26385997

  20. Auditory Temporal Processing in Children with Specific Reading Disability with and without Attention Deficit/Hyperactivity Disorder.

    ERIC Educational Resources Information Center

    Breier, Joshua I.; Fletcher, Jack M.; Foorman, Barbara R.; Klaas, Patricia; Gray, Lincoln C.

    2003-01-01

    Tasks assessing perception of auditory temporal and nontemporal cues were administered to children with reading disorders (RD) with or without attention deficit hyperactivity disorder or with ADHD alone. The presence of RD was associated only with a deficit in detection of a tone onset time synchrony. The presence of ADHD was associated with a…

  1. Effects of Age and Attention on Auditory Global-Local Processing in Children with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Foster, Nicholas E. V.; Ouimet, Tia; Tryfon, Ana; Doyle-Thomas, Krissy; Anagnostou, Evdokia; Hyde, Krista L.

    2016-01-01

    In vision, typically-developing (TD) individuals perceive "global" (whole) before "local" (detailed) features, whereas individuals with autism spectrum disorder (ASD) exhibit a local bias. However, auditory global-local distinctions are less clear in ASD, particularly in terms of age and attention effects. To these aims, here…

  2. A Follow-Up Study of Relational Processes and Consultation Outcomes for Students with Attention Deficit Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Erchul, William P.; DuPaul, George J.; Bennett, Megan S.; Grissom, Priscilla F.; Jitendra, Asha K.; Tresco, Katy E.; Volpe, Robert J.; Vile Junod, Rosemary E.; Flammer-Rivera, Lizette M.; Mannella, Mark C.

    2009-01-01

    The purpose of this study was to link consultant and teacher verbal interaction patterns to consultation outcomes. Participants were 4 consultants, 20 teachers, and 20 elementary school students with attention deficit hyperactivity disorder. Audiotaped Problem Analysis Interviews (PAIs) from Project PASS (Promoting Academic Success in Students)…

  3. Response Switching Process in Children with Attention-Deficit-Hyperactivity Disorder on the Novel Continuous Performance Test

    ERIC Educational Resources Information Center

    Inoue, Yuki; Inagaki, Masumi; Gunji, Atsuko; Furushima, Wakana; Kaga, Makiko

    2008-01-01

    We examined the effects of previous trials on subsequent trials on performance in the continuous performance test (CPT) in children with attention-deficit-hyperactivity disorder (ADHD). Thirty-five non-medicated children with ADHD (31 males, four females; mean age 9y 10mo [SD 2y 4mo]) and 33 comparison children (20 males, 13 females; mean age 10y…

  4. Slow Perceptual Processing at the Core of Developmental Dyslexia: A Parameter-Based Assessment of Visual Attention

    ERIC Educational Resources Information Center

    Stenneken, Prisca; Egetemeir, Johanna; Schulte-Korne, Gerd; Muller, Hermann J.; Schneider, Werner X.; Finke, Kathrin

    2011-01-01

    The cognitive causes as well as the neurological and genetic basis of developmental dyslexia, a complex disorder of written language acquisition, are intensely discussed with regard to multiple-deficit models. Accumulating evidence has revealed dyslexics' impairments in a variety of tasks requiring visual attention. The heterogeneity of these…

  5. Allocation of Attention to Second Language Form and Meaning: Issues of Think-Alouds and Depth of Processing

    ERIC Educational Resources Information Center

    Morgan-Short, Kara; Heil, Jeanne; Botero-Moriarty, Andrea; Ebert, Shane

    2012-01-01

    The aims of the present study were twofold. The study addressed the issues of simultaneous attention to form and meaning in second language (L2) written input and reactivity of think-alouds. Specifically, the study examined the comprehension of L2 learners of Spanish who either attended to lexical or grammatical forms while reading for meaning or…

  6. Working Memory, Processing Speed, and Set-Shifting in Children with Developmental Coordination Disorder and Attention-Deficit-Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Piek, Jan P.; Dyck, Murray J.; Francis, Mona; Conwell, Alistair

    2007-01-01

    It has been suggested that the high levels of comorbidity between attention-deficit-hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) may be attributed to a common underlying neurocognitive mechanism. This study assessed whether children with DCD and ADHD share deficits on tasks measuring working memory, set-shifting, and…

  7. Forest, Trees, Dynamics: Results from a Novel Wisconsin Card Sorting Test Variant Protocol for Studying Global-Local Attention and Complex Cognitive Processes

    PubMed Central

    Cowley, Benjamin; Lukander, Kristian

    2016-01-01

    Background: Recognition of objects and their context relies heavily on the integrated functioning of global and local visual processing. In a realistic setting such as work, this processing becomes a sustained activity, implying a consequent interaction with executive functions. Motivation: There have been many studies of either global-local attention or executive functions; however it is relatively novel to combine these processes to study a more ecological form of attention. We aim to explore the phenomenon of global-local processing during a task requiring sustained attention and working memory. Methods: We develop and test a novel protocol for global-local dissociation, with task structure including phases of divided (“rule search”) and selective (“rule found”) attention, based on the Wisconsin Card Sorting Task (WCST). We test it in a laboratory study with 25 participants, and report on behavior measures (physiological data was also gathered, but not reported here). We develop novel stimuli with more naturalistic levels of information and noise, based primarily on face photographs, with consequently more ecological validity. Results: We report behavioral results indicating that sustained difficulty when participants test their hypotheses impacts matching-task performance, and diminishes the global precedence effect. Results also show a dissociation between subjectively experienced difficulty and objective dimension of performance, and establish the internal validity of the protocol. Contribution: We contribute an advance in the state of the art for testing global-local attention processes in concert with complex cognition. With three results we establish a connection between global-local dissociation and aspects of complex cognition. Our protocol also improves ecological validity and opens options for testing additional interactions in future work. PMID:26941689

  8. Adapting Semantic Natural Language Processing Technology to Address Information Overload in Influenza Epidemic Management

    PubMed Central

    Keselman, Alla; Rosemblat, Graciela; Kilicoglu, Halil; Fiszman, Marcelo; Jin, Honglan; Shin, Dongwook; Rindflesch, Thomas C.

    2013-01-01

    Explosion of disaster health information results in information overload among response professionals. The objective of this project was to determine the feasibility of applying semantic natural language processing (NLP) technology to addressing this overload. The project characterizes concepts and relationships commonly used in disaster health-related documents on influenza pandemics, as the basis for adapting an existing semantic summarizer to the domain. Methods include human review and semantic NLP analysis of a set of relevant documents. This is followed by a pilot-test in which two information specialists use the adapted application for a realistic information seeking task. According to the results, the ontology of influenza epidemics management can be described via a manageable number of semantic relationships that involve concepts from a limited number of semantic types. Test users demonstrate several ways to engage with the application to obtain useful information. This suggests that existing semantic NLP algorithms can be adapted to support information summarization and visualization in influenza epidemics and other disaster health areas. However, additional research is needed in the areas of terminology development (as many relevant relationships and terms are not part of existing standardized vocabularies), NLP, and user interface design. PMID:24311971

  9. OFDM Radar Space-Time Adaptive Processing by Exploiting Spatio-Temporal Sparsity

    SciTech Connect

    Sen, Satyabrata

    2013-01-01

    We propose a sparsity-based space-time adaptive processing (STAP) algorithm to detect a slowly-moving target using an orthogonal frequency division multiplexing (OFDM) radar. We observe that the target and interference spectra are inherently sparse in the spatio-temporal domain. Hence, we exploit that sparsity to develop an efficient STAP technique that utilizes considerably lesser number of secondary data and produces an equivalent performance as the other existing STAP techniques. In addition, the use of an OFDM signal increases the frequency diversity of our system, as different scattering centers of a target resonate at different frequencies, and thus improves the target detectability. First, we formulate a realistic sparse-measurement model for an OFDM radar considering both the clutter and jammer as the interfering sources. Then, we apply a residual sparse-recovery technique based on the LASSO estimator to estimate the target and interference covariance matrices, and subsequently compute the optimal STAP-filter weights. Our numerical results demonstrate a comparative performance analysis of the proposed sparse-STAP algorithm with four other existing STAP methods. Furthermore, we discover that the OFDM-STAP filter-weights are adaptable to the frequency-variabilities of the target and interference responses, in addition to the spatio-temporal variabilities. Hence, by better utilizing the frequency variabilities, we propose an adaptive OFDM-waveform design technique, and consequently gain a significant amount of STAP-performance improvement.

  10. Functional identification of biological neural networks using reservoir adaptation for point processes.

    PubMed

    Gürel, Tayfun; Rotter, Stefan; Egert, Ulrich

    2010-08-01

    The complexity of biological neural networks does not allow to directly relate their biophysical properties to the dynamics of their electrical activity. We present a reservoir computing approach for functionally identifying a biological neural network, i.e. for building an artificial system that is functionally equivalent to the reference biological network. Employing feed-forward and recurrent networks with fading memory, i.e. reservoirs, we propose a point process based learning algorithm to train the internal parameters of the reservoir and the connectivity between the reservoir and the memoryless readout neurons. Specifically, the model is an Echo State Network (ESN) with leaky integrator neurons, whose individual leakage time constants are also adapted. The proposed ESN algorithm learns a predictive model of stimulus-response relations in in vitro and simulated networks, i.e. it models their response dynamics. Receiver Operating Characteristic (ROC) curve analysis indicates that these ESNs can imitate the response signal of a reference biological network. Reservoir adaptation improved the performance of an ESN over readout-only training methods in many cases. This also held for adaptive feed-forward reservoirs, which had no recurrent dynamics. We demonstrate the predictive power of these ESNs on various tasks with cultured and simulated biological neural networks.

  11. Serum testosterone levels and excessive erythrocytosis during the process of adaptation to high altitudes

    PubMed Central

    Gonzales, Gustavo F

    2013-01-01

    Populations living at high altitudes (HAs), particularly in the Peruvian Andes, are characterized by a mixture of subjects with erythrocytosis (16 g dl−121 g dl−1). Elevated haemoglobin values (EE) are associated with chronic mountain sickness, a condition reflecting the lack of adaptation to HA. According to current data, native men from regions of HA are not adequately adapted to live at such altitudes if they have elevated serum testosterone levels. This seems to be due to an increased conversion of dehydroepiandrosterone sulphate (DHEAS) to testosterone. Men with erythrocytosis at HAs show higher serum androstenedione levels and a lower testosterone/androstenedione ratio than men with EE, suggesting reduced 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity. Lower 17beta-HSD activity via Δ4-steroid production in men with erythrocytosis at HA may protect against elevated serum testosterone levels, thus preventing EE. The higher conversion of DHEAS to testosterone in subjects with EE indicates increased 17beta-HSD activity via the Δ5-pathway. Currently, there are various situations in which people live (human biodiversity) with low or high haemoglobin levels at HA. Antiquity could be an important adaptation component for life at HA, and testosterone seems to participate in this process. PMID:23524530

  12. Simple process for building large homogeneous adaptable retarders made from polymeric materials.

    PubMed

    Delplancke, F; Sendrowicz, H; Bernaerd, R; Ebbeni, J

    1995-06-01

    A process for building large, homogeneous, adaptable retarders easily and at low cost is proposed and analyzed. This method is based on the properties of high polymers to present variable birefringence as a function of applied stresses and on the possibility of freezing these stresses inside the material by a thermal process. Various geometries for the applied forces make obtaining a large range of birefringence profiles possible. In the process that we describe composed bending leads to a linear birefringence profile. The superimposition of two pieces with identical profiles with opposite directions gives homogeneous constant retardation. This retardation can be adjusted by a relative displacement between the pieces. A precision of better than 1% over large areas (more than 3 cm in diameter) for a quarter-wave value has been obtained. The correct choice of material makes many applications possible with a large range of wavelengths.

  13. Adaptive Classification of Landscape Process and Function: An Integration of Geoinformatics and Self-Organizing Maps

    SciTech Connect

    Coleman, Andre M.

    2009-07-17

    The advanced geospatial information extraction and analysis capabilities of a Geographic Information System (GISs) and Artificial Neural Networks (ANNs), particularly Self-Organizing Maps (SOMs), provide a topology-preserving means for reducing and understanding complex data relationships in the landscape. The Adaptive Landscape Classification Procedure (ALCP) is presented as an adaptive and evolutionary capability where varying types of data can be assimilated to address different management needs such as hydrologic response, erosion potential, habitat structure, instrumentation placement, and various forecast or what-if scenarios. This paper defines how the evaluation and analysis of spatial and/or temporal patterns in the landscape can provide insight into complex ecological, hydrological, climatic, and other natural and anthropogenic-influenced processes. Establishing relationships among high-dimensional datasets through neurocomputing based pattern recognition methods can help 1) resolve large volumes of data into a structured and meaningful form; 2) provide an approach for inferring landscape processes in areas that have limited data available but exhibit similar landscape characteristics; and 3) discover the value of individual variables or groups of variables that contribute to specific processes in the landscape. Classification of hydrologic patterns in the landscape is demonstrated.

  14. A New Feedback-Based Method for Parameter Adaptation in Image Processing Routines

    PubMed Central

    Mikut, Ralf; Reischl, Markus

    2016-01-01

    The parametrization of automatic image processing routines is time-consuming if a lot of image processing parameters are involved. An expert can tune parameters sequentially to get desired results. This may not be productive for applications with difficult image analysis tasks, e.g. when high noise and shading levels in an image are present or images vary in their characteristics due to different acquisition conditions. Parameters are required to be tuned simultaneously. We propose a framework to improve standard image segmentation methods by using feedback-based automatic parameter adaptation. Moreover, we compare algorithms by implementing them in a feedforward fashion and then adapting their parameters. This comparison is proposed to be evaluated by a benchmark data set that contains challenging image distortions in an increasing fashion. This promptly enables us to compare different standard image segmentation algorithms in a feedback vs. feedforward implementation by evaluating their segmentation quality and robustness. We also propose an efficient way of performing automatic image analysis when only abstract ground truth is present. Such a framework evaluates robustness of different image processing pipelines using a graded data set. This is useful for both end-users and experts. PMID:27764213

  15. Investigating bottom-up auditory attention

    PubMed Central

    Kaya, Emine Merve; Elhilali, Mounya

    2014-01-01

    Bottom-up attention is a sensory-driven selection mechanism that directs perception toward a subset of the stimulus that is considered salient, or attention-grabbing. Most studies of bottom-up auditory attention have adapted frameworks similar to visual attention models whereby local or global “contrast” is a central concept in defining salient elements in a scene. In the current study, we take a more fundamental approach to modeling auditory attention; providing the first examination of the space of auditory saliency spanning pitch, intensity and timbre; and shedding light on complex interactions among these features. Informed by psychoacoustic results, we develop a computational model of auditory saliency implementing a novel attentional framework, guided by processes hypothesized to take place in the auditory pathway. In particular, the model tests the hypothesis that perception tracks the evolution of sound events in a multidimensional feature space, and flags any deviation from background statistics as salient. Predictions from the model corroborate the relationship between bottom-up auditory attention and statistical inference, and argues for a potential role of predictive coding as mechanism for saliency detection in acoustic scenes. PMID:24904367

  16. Adapting high-level language programs for parallel processing using data flow

    NASA Technical Reports Server (NTRS)

    Standley, Hilda M.

    1988-01-01

    EASY-FLOW, a very high-level data flow language, is introduced for the purpose of adapting programs written in a conventional high-level language to a parallel environment. The level of parallelism provided is of the large-grained variety in which parallel activities take place between subprograms or processes. A program written in EASY-FLOW is a set of subprogram calls as units, structured by iteration, branching, and distribution constructs. A data flow graph may be deduced from an EASY-FLOW program.

  17. Adapted waveform analysis, wavelet packets, and local cosine libraries as a tool for image processing

    NASA Astrophysics Data System (ADS)

    Coifman, Ronald R.; Woog, Lionel J.

    1995-09-01

    Adapted wave form analysis, refers to a collection of FFT like adapted transform algorithms. Given an image these methods provide special matched collections of templates (orthonormal bases) enabling an efficient coding of the image. Perhaps the closest well known example of such coding method is provided by musical notation, where each segment of music is represented by a musical score made up of notes (templates) characterised by their duration, pitch, location and amplitude, our method corresponds to transcribing the music in as few notes as possible. The extension to images and video is straightforward we describe the image by collections of oscillatory patterns (paint brush strokes)of various sizes locations and amplitudes using a variety of orthogonal bases. These selected basis functions are chosen inside predefined libraries of oscillatory localized functions (trigonometric and wavelet-packets waveforms) so as to optimize the number of parameters needed to describe our object. These algorithms are of complexity N log N opening the door for a large range of applications in signal and image processing, such as compression, feature extraction denoising and enhancement. In particular we describe a class of special purpose compressions for fingerprint irnages, as well as denoising tools for texture and noise extraction. We start by relating traditional Fourier methods to wavelet, wavelet-packet based algorithms using a recent refinement of the windowed sine and cosine transforms. We will then derive an adapted local sine transform show it's relation to wavelet and wavelet-packet analysis and describe an analysis toolkit illustrating the merits of different adaptive and nonadaptive schemes.

  18. Effects of Age and Attention on Auditory Global-Local Processing in Children with Autism Spectrum Disorder.

    PubMed

    Foster, Nicholas E V; Ouimet, Tia; Tryfon, Ana; Doyle-Thomas, Krissy; Anagnostou, Evdokia; Hyde, Krista L

    2016-04-01

    In vision, typically-developing (TD) individuals perceive "global" (whole) before "local" (detailed) features, whereas individuals with autism spectrum disorder (ASD) exhibit a local bias. However, auditory global-local distinctions are less clear in ASD, particularly in terms of age and attention effects. To these aims, here ASD and TD children judged local and global pitch structure in nine-tone melodies. Both groups showed a similar global precedence effect, but ASD children were less sensitive to global interference than TD children at younger ages. There was no effect of attention task. These findings provide novel evidence of developmental differences in auditory perception and may help to refine sensory phenotypes in ASD. PMID:26724923

  19. How the deployment of attention determines what we see

    PubMed Central

    Treisman, Anne

    2007-01-01

    Attention is a tool to adapt what we see to our current needs. It can be focused narrowly on a single object or spread over several or distributed over the scene as a whole. In addition to increasing or decreasing the number of attended objects, these different deployments may have different effects on what we see. This chapter describes some research both on focused attention and its use in binding features, and on distributed attention and the kinds of information we gain and lose with the attention window opened wide. One kind of processing that we suggest occurs automatically with distributed attention results in a statistical description of sets of similar objects. Another gives the gist of the scene, which may be inferred from sets of features registered in parallel. Flexible use of these different modes of attention allows us to reconcile sharp capacity limits with a richer understanding of the visual scene. PMID:17387378

  20. Established and Adapted Diagnostic Tools for Investigation of a Special Twin-Wire Arc Spraying Process

    NASA Astrophysics Data System (ADS)

    König, Johannes; Lahres, Michael; Zimmermann, Stephan; Schein, Jochen

    2016-10-01

    In the LDS® ( Lichtbogendrahtspritzen) process, a twin-wire arc spraying (TWAS) process developed by Daimler AG, the gas injection and feed to the arc play a crucial role in separating the molten particles from the wire ends. This paper describes an investigation of the gas and particle behavior according to individual LDS® process parameters. Coating problems are not considered. The measurements are separated into two different parts: "cold" (without arc and particles) and "hot" (with arc and particles). The results provide the first detailed understanding of the effect of different LDS® process parameters. A correlation between the gas parameter settings and the particle beam properties was found. Using established and adapted diagnostic tools, as also applied for conventional TWAS processes, this special LDS® process was investigated and the results (gas and particle behavior) validated, thereby allowing explanation and comparison of the diagnostic methods, which is the main focus of this paper. Based on error analysis, individual instabilities, limits, and deviations during the gas determinations and particle measurements are explained in more detail. The paper concludes with presentation of the first particle-shadow diagnostic results and main statements regarding these investigations.

  1. Established and Adapted Diagnostic Tools for Investigation of a Special Twin-Wire Arc Spraying Process

    NASA Astrophysics Data System (ADS)

    König, Johannes; Lahres, Michael; Zimmermann, Stephan; Schein, Jochen

    2016-09-01

    In the LDS® (Lichtbogendrahtspritzen) process, a twin-wire arc spraying (TWAS) process developed by Daimler AG, the gas injection and feed to the arc play a crucial role in separating the molten particles from the wire ends. This paper describes an investigation of the gas and particle behavior according to individual LDS® process parameters. Coating problems are not considered. The measurements are separated into two different parts: "cold" (without arc and particles) and "hot" (with arc and particles). The results provide the first detailed understanding of the effect of different LDS® process parameters. A correlation between the gas parameter settings and the particle beam properties was found. Using established and adapted diagnostic tools, as also applied for conventional TWAS processes, this special LDS® process was investigated and the results (gas and particle behavior) validated, thereby allowing explanation and comparison of the diagnostic methods, which is the main focus of this paper. Based on error analysis, individual instabilities, limits, and deviations during the gas determinations and particle measurements are explained in more detail. The paper concludes with presentation of the first particle-shadow diagnostic results and main statements regarding these investigations.

  2. [Dynamics of adaptation processes and morbidity risk for the popupation of the territory of industrial cities].

    PubMed

    Prusakov, V M; Prusakova, A V

    2014-01-01

    There was investigated the character of the adaptation processes in the population residing in conditions ofprolonged exposure to environmental pollution in the territory of the industrial cities of the Irkutsk region in order to identify the possible periodicity of their manifestations in the formation of the morbidity risk for the population of different age groups. Under conditions of prolonged exposure to air pollution and other adverse unfavorable factors of industrial cities in the population of all age groups long cyclic changes of adaptation processes in the body in the form of repeated 11-15-years cycles in which a period of relative destabilization of physiological functions with lowered resistance is replaced by the period with the state of elevated nonspecific resistance were established to be observed. Undulating changes of the dynamics of the relative risks of general morbidity should be considered in the assessment of the medical and environmental situation in the territory and making the managing decisions at the base on the data of public health monitoring.

  3. [Super sweet corn hybrid sh2 adaptability for industrial canning process].

    PubMed

    Ortiz de Bertorelli, Ligia; De Venanzi, Frank; Alfonzo, Braunnier; Camacho, Candelario

    2002-12-01

    The super sweet corns Krispy king, Victor and 324 (sh2 hybrids) were evaluated to determine their adaptabilities to the industrial canning process as whole kernels. All these hybrids and Bonanza (control) were sown in San Joaquín (Carabobo, Venezuela), harvested and canned. After 110 days storage at room temperature they were analyzed to be compared physically, chemically and sensorially with Bonanza hybrid. Results did not show significant differences among most of the physical characteristics, except for percentage of broken kernels which was higher in 324 hybrid. Chemical parameters showed significant differences (P < 0.05) comparing each super sweet hybrid with Bonanza. The super sweet hybrids presented a higher sugar content and soluble solid of the brine than Bonanza, also a lower pH. The super sweet whole kernel presented a lower soluble solids content than Bonanza but they were not significant (Krispy king and 324). Appearance, odor and overall quality were the same for super sweet hybrids and Bonanza (su). Color, flavor and sweetness were better for 324 than all the other hybrids. Super sweet hybrids presented a very good adaptation to the canning process, having as an advantage that doesn't require sugar addition in the brine and a very good texture (firm and crispy). PMID:12868279

  4. Workload-Matched Adaptive Automation Support of Air Traffic Controller Information Processing Stages

    NASA Technical Reports Server (NTRS)

    Kaber, David B.; Prinzel, Lawrence J., III; Wright, Melanie C.; Clamann, Michael P.

    2002-01-01

    Adaptive automation (AA) has been explored as a solution to the problems associated with human-automation interaction in supervisory control environments. However, research has focused on the performance effects of dynamic control allocations of early stage sensory and information acquisition functions. The present research compares the effects of AA to the entire range of information processing stages of human operators, such as air traffic controllers. The results provide evidence that the effectiveness of AA is dependent on the stage of task performance (human-machine system information processing) that is flexibly automated. The results suggest that humans are better able to adapt to AA when applied to lower-level sensory and psychomotor functions, such as information acquisition and action implementation, as compared to AA applied to cognitive (analysis and decision-making) tasks. The results also provide support for the use of AA, as compared to completely manual control. These results are discussed in terms of implications for AA design for aviation.

  5. Processing of pulse oximeter signals using adaptive filtering and autocorrelation to isolate perfusion and oxygenation components

    NASA Astrophysics Data System (ADS)

    Ibey, Bennett; Subramanian, Hariharan; Ericson, Nance; Xu, Weijian; Wilson, Mark; Cote, Gerard L.

    2005-03-01

    A blood perfusion and oxygenation sensor has been developed for in situ monitoring of transplanted organs. In processing in situ data, motion artifacts due to increased perfusion can create invalid oxygenation saturation values. In order to remove the unwanted artifacts from the pulsatile signal, adaptive filtering was employed using a third wavelength source centered at 810nm as a reference signal. The 810 nm source resides approximately at the isosbestic point in the hemoglobin absorption curve where the absorbance of light is nearly equal for oxygenated and deoxygenated hemoglobin. Using an autocorrelation based algorithm oxygenation saturation values can be obtained without the need for large sampling data sets allowing for near real-time processing. This technique has been shown to be more reliable than traditional techniques and proven to adequately improve the measurement of oxygenation values in varying perfusion states.

  6. Adaptive sparse signal processing for discrimination of satellite-based radiofrequency (RF) recordings of lightning events

    NASA Astrophysics Data System (ADS)

    Moody, Daniela I.; Smith, David A.

    2015-05-01

    For over two decades, Los Alamos National Laboratory programs have included an active research effort utilizing satellite observations of terrestrial lightning to learn more about the Earth's RF background. The FORTE satellite provided a rich satellite lightning database, which has been previously used for some event classification, and remains relevant for advancing lightning research. Lightning impulses are dispersed as they travel through the ionosphere, appearing as nonlinear chirps at the receiver on orbit. The data processing challenge arises from the combined complexity of the lightning source model, the propagation medium nonlinearities, and the sensor artifacts. We continue to develop modern event classification capability on the FORTE database using adaptive signal processing combined with compressive sensing techniques. The focus of our work is improved feature extraction using sparse representations in overcomplete analytical dictionaries. We explore two possible techniques for detecting lightning events, and showcase the algorithms on few representative data examples. We present preliminary results of our work and discuss future development.

  7. Rethinking infant knowledge: toward an adaptive process account of successes and failures in object permanence tasks.

    PubMed

    Munakata, Y; McClelland, J L; Johnson, M H; Siegler, R S

    1997-10-01

    Infants seem sensitive to hidden objects in habituation tasks at 3.5 months but fail to retrieve hidden objects until 8 months. The authors first consider principle-based accounts of these successes and failures, in which early successes imply knowledge of principles and failures are attributed to ancillary deficits. One account is that infants younger than 8 months have the object permanence principle but lack means-ends abilities. To test this, 7-month-olds were trained on means-ends behaviors and were tested on retrieval of visible and occluded toys. Means-ends demands were the same, yet infants made more toy-guided retrievals in the visible case. The authors offer an adaptive process account in which knowledge is graded and embedded in specific behavioral processes. Simulation models that learn gradually to represent occluded objects show how this approach can account for success and failure in object permanence tasks without assuming principles and ancillary deficits.

  8. Automatic ultrasonic imaging system with adaptive-learning-network signal-processing techniques

    SciTech Connect

    O'Brien, L.J.; Aravanis, N.A.; Gouge, J.R. Jr.; Mucciardi, A.N.; Lemon, D.K.; Skorpik, J.R.

    1982-04-01

    A conventional pulse-echo imaging system has been modified to operate with a linear ultrasonic array and associated digital electronics to collect data from a series of defects fabricated in aircraft quality steel blocks. A thorough analysis of the defect responses recorded with this modified system has shown that considerable improvements over conventional imaging approaches can be obtained in the crucial areas of defect detection and characterization. A combination of advanced signal processing concepts with the Adaptive Learning Network (ALN) methodology forms the basis for these improvements. Use of established signal processing algorithms such as temporal and spatial beam-forming in concert with a sophisticated detector has provided a reliable defect detection scheme which can be implemented in a microprocessor-based system to operate in an automatic mode.

  9. Current Tracking Control of Voltage Source PWM Inverters Using Adaptive Digital Signal Processing

    NASA Astrophysics Data System (ADS)

    Fukuda, Shoji; Furukawa, Yuya

    An active filter (AF) is required to have a high control capability of tracking a time-varying current reference. However, a steady-state current error always exists if a conventional proportional and integral (PI) regulator is used because the current reference varies in time. This paper proposes the application of adaptive digital signal processing (ADSP) to the current control of voltage source PWM inverters. ADSP does not require any additional hardware. It can automatically minimize the mean square-error. Since the processing time available by a computer is limited, ADSP cannot eliminate higher order harmonics but can eliminate lower order harmonics such as 5th to 17th. Experimental results demonstrate that ADSP is useful for improving the reference tracking performance of voltage source inverters.

  10. Combining molecular evolution and environmental genomics to unravel adaptive processes of MHC class IIB diversity in European minnows (Phoxinus phoxinus)

    PubMed Central

    Collin, Helene; Burri, Reto; Comtesse, Fabien; Fumagalli, Luca

    2013-01-01

    Abstract Host–pathogen interactions are a major evolutionary force promoting local adaptation. Genes of the major histocompatibility complex (MHC) represent unique candidates to investigate evolutionary processes driving local adaptation to parasite communities. The present study aimed at identifying the relative roles of neutral and adaptive processes driving the evolution of MHC class IIB (MHCIIB) genes in natural populations of European minnows (Phoxinus phoxinus). To this end, we isolated and genotyped exon 2 of two MHCIIB gene duplicates (DAB1 and DAB3) and 1′665 amplified fragment length polymorphism (AFLP) markers in nine populations, and characterized local bacterial communities by 16S rDNA barcoding using 454 amplicon sequencing. Both MHCIIB loci exhibited signs of historical balancing selection. Whereas genetic differentiation exceeded that of neutral markers at both loci, the populations' genetic diversities were positively correlated with local pathogen diversities only at DAB3. Overall, our results suggest pathogen-mediated local adaptation in European minnows at both MHCIIB loci. While at DAB1 selection appears to favor different alleles among populations, this is only partially the case in DAB3, which appears to be locally adapted to pathogen communities in terms of genetic diversity. These results provide new insights into the importance of host–pathogen interactions in driving local adaptation in the European minnow, and highlight that the importance of adaptive processes driving MHCIIB gene evolution may differ among duplicates within species, presumably as a consequence of alternative selective regimes or different genomic context. Using next-generation sequencing, the present manuscript identifies the relative roles of neutral and adaptive processes driving the evolution of MHC class IIB (MHCIIB) genes in natural populations of a cyprinid fish: the European minnow (Phoxinus phoxinus). We highlight that the relative importance of neutral

  11. Human Topological Task Adapted for Rats: Spatial Information Processes of the Parietal Cortex

    PubMed Central

    Goodrich-Hunsaker, Naomi J.; Howard, Brian P.; Hunsaker, Michael R.; Kesner, Raymond P.

    2008-01-01

    Human research has shown that lesions of the parietal cortex disrupt spatial information processing, specifically topological information. Similar findings have been found in nonhumans. It has been difficult to determine homologies between human and non-human mnemonic mechanisms for spatial information processing because methodologies and neuropathology differ. The first objective of the present study was to adapt a previously established human task for rats. The second objective was to better characterize the role of parietal cortex (PC) and dorsal hippocampus (dHPC) for topological spatial information processing. Rats had to distinguish whether a ball inside a ring or a ball outside a ring was the correct, rewarded object. After rats reached criterion on the task (>95%) they were randomly assigned to a lesion group (control, PC, dHPC). Animals were then re-tested. Post-surgery data show that controls were 94% correct on average, dHPC rats were 89% correct on average, and PC rats were 56% correct on average. The results from the present study suggest that the parietal cortex, but not the dHPC processes topological spatial information. The present data are the first to support comparable topological spatial information processes of the parietal cortex in humans and rats. PMID:18571941

  12. The Process of Adaptation of a Community-Level, Evidence-Based Intervention for HIV-Positive African American Men Who Have Sex with Men in Two Cities

    ERIC Educational Resources Information Center

    Robinson, Beatrice E.; Galbraith, Jennifer S.; Lund, Sharon M.; Hamilton, Autumn R.; Shankle, Michael D.

    2012-01-01

    We describe the process of adapting a community-level, evidence-based behavioral intervention (EBI), Community PROMISE, for HIV-positive African American men who have sex with men (AAMSM). The Centers for Disease Control and Prevention (CDC) Map of the Adaptation Process (MAP) guided the adaptation process for this new target population by two…

  13. Creating and maintaining dialogue on climate information - Reflections on the adaptation process in Sweden

    NASA Astrophysics Data System (ADS)

    Nilsson, C.

    2010-09-01

    Climate information can be communicated in many ways to various actors within society. Dialogue as a means to communicate is often emphasised as an important tool to deliver and receive information. However, a dialogue can be initiated and maintained in many different ways. In Sweden the Swedish Meteorological and Hydrological Institute, SMHI, can be seen as one of the actors in between the climate science experts and the society, and together with the Swedish Geotechnical Institute, SGI, they had recognised that the County Administrative Boards required climate information and knowledge in how to use and how not to use climate scenarios in order to start coordinating regional adaptation activities. At the same time the National Authorities called for a more detailed compilation on the needs in the counties, regarding climate information for decision making. Together the SMHI and SGI visited the 21 counties in Sweden with a start in the autumn of 2008, initiating a dialogue with the County Administrative Boards. The process continued with a first seminar in springtime 2009, on adaptation. In spring 2009 the County Administrative Boards were appointed as the formal foci of adaptation coordination in Sweden, and a new phase in the dialogue started, when the counties had specific goals with the interaction. Personal visits and seminars have continued to be the arena for the dialogue, and new climate information products have been initiated as a response to the interaction. Here, reflections are presented on the role of the dialogue in Sweden as a tool towards a sustainable way to communicate climate information.

  14. Behavioural and ecological consequences of limited attention.

    PubMed Central

    Dukas, Reuven

    2002-01-01

    Ecological research in the past few decades has shown that most animals acquire and respond adaptively to information that affects survival and reproduction. At the same time, neurobiological studies have established that the rate of information processing by the brain is much lower than the rate at which information is encountered in the environment, and that attentional mechanisms enable the brain to focus only on the most essential information at any given time. Recent integration of the ecological and neurobiological approaches helps us to understand key behaviours with broad ecological and evolutionary implications. Specifically, current data indicate that limited attention affects diet choice and constrains animals' ability simultaneously to feed and attend to predators. Recent experiments also suggest that limited attention influences social interactions, courtship and mating behaviour. PMID:12495511

  15. Neuroelectric adaptations to cognitive processing in virtual environments: an exercise-related approach.

    PubMed

    Vogt, Tobias; Herpers, Rainer; Scherfgen, David; Strüder, Heiko K; Schneider, Stefan

    2015-04-01

    Recently, virtual environments (VEs) are suggested to encourage users to exercise regularly. The benefits of chronic exercise on cognitive performance are well documented in non-VE neurophysiological and behavioural studies. Based on event-related potentials (ERP) such as the N200 and P300, cognitive processing may be interpreted on a neuronal level. However, exercise-related neuroelectric adaptation in VE remains widely unclear and thus characterizes the primary aim of the present study. Twenty-two healthy participants performed active (moderate cycling exercise) and passive (no exercise) sessions in three VEs (control, front, surround), each generating a different sense of presence. Within sessions, conditions were randomly assigned, each lasting 5 min and including a choice reaction-time task to assess cognitive performance. According to the international 10:20 system, EEG with real-time triggered stimulus onset was recorded, and peaks of N200 and P300 components (amplitude, latency) were exported for analysis. Heart rate was recorded, and sense of presence assessed prior to and following each session and condition. Results revealed an increase in ERP amplitudes (N200: p < 0.001; P300: p < 0.001) and latencies (N200: p < 0.001) that were most pronounced over fronto-central and occipital electrode sites relative to an increased sense of presence (p < 0.001); however, ERP were not modulated by exercise (each p > 0.05). Hypothesized to mirror cognitive processing, decreases of cognitive performance's accuracy and reaction time failed significance. With respect to previous research, the present neuroelectric adaptation gives reason to believe in compensative neuronal resources that balance demanding cognitive processing in VE to avoid behavioural inefficiency. PMID:25630906

  16. Neuroelectric adaptations to cognitive processing in virtual environments: an exercise-related approach.

    PubMed

    Vogt, Tobias; Herpers, Rainer; Scherfgen, David; Strüder, Heiko K; Schneider, Stefan

    2015-04-01

    Recently, virtual environments (VEs) are suggested to encourage users to exercise regularly. The benefits of chronic exercise on cognitive performance are well documented in non-VE neurophysiological and behavioural studies. Based on event-related potentials (ERP) such as the N200 and P300, cognitive processing may be interpreted on a neuronal level. However, exercise-related neuroelectric adaptation in VE remains widely unclear and thus characterizes the primary aim of the present study. Twenty-two healthy participants performed active (moderate cycling exercise) and passive (no exercise) sessions in three VEs (control, front, surround), each generating a different sense of presence. Within sessions, conditions were randomly assigned, each lasting 5 min and including a choice reaction-time task to assess cognitive performance. According to the international 10:20 system, EEG with real-time triggered stimulus onset was recorded, and peaks of N200 and P300 components (amplitude, latency) were exported for analysis. Heart rate was recorded, and sense of presence assessed prior to and following each session and condition. Results revealed an increase in ERP amplitudes (N200: p < 0.001; P300: p < 0.001) and latencies (N200: p < 0.001) that were most pronounced over fronto-central and occipital electrode sites relative to an increased sense of presence (p < 0.001); however, ERP were not modulated by exercise (each p > 0.05). Hypothesized to mirror cognitive processing, decreases of cognitive performance's accuracy and reaction time failed significance. With respect to previous research, the present neuroelectric adaptation gives reason to believe in compensative neuronal resources that balance demanding cognitive processing in VE to avoid behavioural inefficiency.

  17. An adaptive threshold based image processing technique for improved glaucoma detection and classification.

    PubMed

    Issac, Ashish; Partha Sarathi, M; Dutta, Malay Kishore

    2015-11-01

    Glaucoma is an optic neuropathy which is one of the main causes of permanent blindness worldwide. This paper presents an automatic image processing based method for detection of glaucoma from the digital fundus images. In this proposed work, the discriminatory parameters of glaucoma infection, such as cup to disc ratio (CDR), neuro retinal rim (NRR) area and blood vessels in different regions of the optic disc has been used as features and fed as inputs to learning algorithms for glaucoma diagnosis. These features which have discriminatory changes with the occurrence of glaucoma are strategically used for training the classifiers to improve the accuracy of identification. The segmentation of optic disc and cup based on adaptive threshold of the pixel intensities lying in the optic nerve head region. Unlike existing methods the proposed algorithm is based on an adaptive threshold that uses local features from the fundus image for segmentation of optic cup and optic disc making it invariant to the quality of the image and noise content which may find wider acceptability. The experimental results indicate that such features are more significant in comparison to the statistical or textural features as considered in existing works. The proposed work achieves an accuracy of 94.11% with a sensitivity of 100%. A comparison of the proposed work with the existing methods indicates that the proposed approach has improved accuracy of classification glaucoma from a digital fundus which may be considered clinically significant.

  18. GAMER: A GRAPHIC PROCESSING UNIT ACCELERATED ADAPTIVE-MESH-REFINEMENT CODE FOR ASTROPHYSICS

    SciTech Connect

    Schive, H.-Y.; Tsai, Y.-C.; Chiueh Tzihong

    2010-02-01

    We present the newly developed code, GPU-accelerated Adaptive-MEsh-Refinement code (GAMER), which adopts a novel approach in improving the performance of adaptive-mesh-refinement (AMR) astrophysical simulations by a large factor with the use of the graphic processing unit (GPU). The AMR implementation is based on a hierarchy of grid patches with an oct-tree data structure. We adopt a three-dimensional relaxing total variation diminishing scheme for the hydrodynamic solver and a multi-level relaxation scheme for the Poisson solver. Both solvers have been implemented in GPU, by which hundreds of patches can be advanced in parallel. The computational overhead associated with the data transfer between the CPU and GPU is carefully reduced by utilizing the capability of asynchronous memory copies in GPU, and the computing time of the ghost-zone values for each patch is diminished by overlapping it with the GPU computations. We demonstrate the accuracy of the code by performing several standard test problems in astrophysics. GAMER is a parallel code that can be run in a multi-GPU cluster system. We measure the performance of the code by performing purely baryonic cosmological simulations in different hardware implementations, in which detailed timing analyses provide comparison between the computations with and without GPU(s) acceleration. Maximum speed-up factors of 12.19 and 10.47 are demonstrated using one GPU with 4096{sup 3} effective resolution and 16 GPUs with 8192{sup 3} effective resolution, respectively.

  19. Therapeutic adherence and competence scales for Developmentally Adapted Cognitive Processing Therapy for adolescents with PTSD

    PubMed Central

    Gutermann, Jana; Schreiber, Franziska; Matulis, Simone; Stangier, Ulrich; Rosner, Rita; Steil, Regina

    2015-01-01

    Background The assessment of therapeutic adherence and competence is often neglected in psychotherapy research, particularly in children and adolescents; however, both variables are crucial for the interpretation of treatment effects. Objective Our aim was to develop, adapt, and pilot two scales to assess therapeutic adherence and competence in a recent innovative program, Developmentally Adapted Cognitive Processing Therapy (D-CPT), for adolescents suffering from posttraumatic stress disorder (PTSD) after childhood abuse. Method Two independent raters assessed 30 randomly selected sessions involving 12 D-CPT patients (age 13–20 years, M age=16.75, 91.67% female) treated by 11 therapists within the pilot phase of a multicenter study. Results Three experts confirmed the relevance and appropriateness of each item. All items and total scores for adherence (intraclass correlation coefficients [ICC]=0.76–1.00) and competence (ICC=0.78–0.98) yielded good to excellent inter-rater reliability. Cronbach's alpha was 0.59 for the adherence scale and 0.96 for the competence scale. Conclusions The scales reliably assess adherence and competence in D-CPT for adolescent PTSD patients. The ratings can be helpful in the interpretation of treatment effects, the assessment of mediator variables, and the identification and training of therapeutic skills that are central to achieving good treatment outcomes. Both adherence and competence will be assessed as possible predictor variables for treatment success in future D-CPT trials. PMID:25791915

  20. Planning an adaptive management process for biodiversity conservation and resource development in the Camisea River Basin.

    PubMed

    Dallmeier, Francisco; Alonso, Alfonso; Jones, Murray

    2002-05-01

    The Smithsonian Institution's Monitoring and Assessment of Biodiversity Program joined Shell Prospecting and Development Peru (SPDP) to protect biodiversity during a natural gas exploration project. Emphasis was on long-term societal and environmental benefits in addition to financial gain for the company. The systematic, cyclical adaptive management process was used to generate feedback for SPDP managers. Adaptive management enables ongoing improvement of management policies and practices based on lessons learned from operational activities. Previous to this study, very little information about the local biodiversity was available. Over a 2-year period, the team conducted biological assessments of six taxonomic groups at five sites located within 600 km2. A broad range of management options such as location, timing and technology were developed from the beginning of the project. They were considered in conjunction with emerging lessons from the biodiversity assessments. Critical decisions included location of a gas plant and the cost of helicopter access versus roads to service the full field development. Both of these decisions were evaluated to ensure that they were economically and environmentally feasible. Project design changes, addressed in the planning stage, were accepted once consensus was achieved. Stakeholders were apprised of the implications of the baseline biodiversity assessments.