scholarly journals Using biologically plausible neural models to specify the functional and neural mechanisms of visual search

2009 ◽  
pp. 135-148 ◽  
Author(s):  
Glyn W. Humphreys ◽  
Harriet A. Allen ◽  
Eirini Mavritsaki
Keyword(s):  
Visual Search ◽  
Neural Mechanisms ◽  
Neural Models

scholarly journals Neural Dynamics of Cognitive Control over Working Memory Capture of Attention

2019 ◽  
Vol 31 (7) ◽  
pp. 1079-1090 ◽  
Author(s):  
Peter S. Whitehead ◽  
Mathilde M. Ooi ◽  
Tobias Egner ◽  
Marty G. Woldorff
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Cognitive Control ◽  
Attentional Capture ◽  
Search Display ◽  
Neural Mechanisms ◽  
High Temporal Resolution ◽  
Control Mechanisms ◽  
Attentional Orienting ◽  
Behavioral Studies

The contents of working memory (WM) guide visual attention toward matching features, with visual search being faster when the target and a feature of an item held in WM spatially overlap (validly cued) than when they occur at different locations (invalidly cued). Recent behavioral studies have indicated that attentional capture by WM content can be modulated by cognitive control: When WM cues are reliably helpful to visual search (predictably valid), capture is enhanced, but when reliably detrimental (predictably invalid), capture is attenuated. The neural mechanisms underlying this effect are not well understood, however. Here, we leveraged the high temporal resolution of ERPs time-locked to the onset of the search display to determine how and at what processing stage cognitive control modulates the search process. We manipulated predictability by grouping trials into unpredictable (50% valid/invalid) and predictable (100% valid, 100% invalid) blocks. Behavioral results confirmed that predictability modulated WM-related capture. Comparison of ERPs to the search arrays showed that the N2pc, a posteriorly distributed signature of initial attentional orienting toward a lateralized target, was not impacted by target validity predictability. However, a longer latency, more anterior, lateralized effect—here, termed the “contralateral attention-related negativity”—was reduced under predictable conditions. This reduction interacted with validity, with substantially greater reduction for invalid than valid trials. These data suggest cognitive control over attentional capture by WM content does not affect the initial attentional-orienting process but can reduce the need to marshal later control mechanisms for processing relevant items in the visual world.

scholarly journals Functional brain organization for visual search in ASD

2008 ◽  
Vol 14 (6) ◽  
pp. 990-1003 ◽  
Author(s):  
BRANDON KEEHN ◽  
LAURIE BRENNER ◽  
ERICA PALMER ◽  
ALAN J. LINCOLN ◽  
RALPH-AXEL MÜLLER
Keyword(s):  
Visual Search ◽  
Brain Regions ◽  
Autism Spectrum ◽  
Neural Mechanisms ◽  
Search Efficiency ◽  
Typically Developing ◽  
Brain Organization ◽  
Activation Patterns ◽  
Set Size ◽  
Functional Brain Organization

AbstractAlthough previous studies have shown that individuals with autism spectrum disorder (ASD) excel at visual search, underlying neural mechanisms remain unknown. This study investigated the neurofunctional correlates of visual search in children with ASD and matched typically developing (TD) children, using an event-related functional magnetic resonance imaging design. We used a visual search paradigm, manipulating search difficulty by varying set size (6, 12, or 24 items), distractor composition (heterogeneous or homogeneous) and target presence to identify brain regions associated with efficient and inefficient search. While the ASD group did not evidence accelerated response time (RT) compared with the TD group, they did demonstrate increased search efficiency, as measured by RT by set size slopes. Activation patterns also showed differences between ASD group, which recruited a network including frontal, parietal, and occipital cortices, and the TD group, which showed less extensive activation mostly limited to occipito-temporal regions. Direct comparisons (for both homogeneous and heterogeneous search conditions) revealed greater activation in occipital and frontoparietal regions in ASD than in TD participants. These results suggest that search efficiency in ASD may be related to enhanced discrimination (reflected in occipital activation) and increased top-down modulation of visual attention (associated with frontoparietal activation). (JINS, 2008, 14, 990–1003.)

scholarly journals The Neural Mechanisms of Prediction in Visual Search

2015 ◽  
Vol 26 (11) ◽  
pp. 4327-4336 ◽  
Author(s):  
Eelke Spaak ◽  
Yvonne Fonken ◽  
Ole Jensen ◽  
Floris P. de Lange
Keyword(s):  
Visual Search ◽  
Neural Mechanisms

scholarly journals Neural Mechanisms for Executive Control of Speed-Accuracy Tradeoff

2019 ◽  
Author(s):  
Thomas R. Reppert ◽  
Richard P. Heitz ◽  
Jeffrey D. Schall
Keyword(s):  
Visual Search ◽  
Frontal Cortex ◽  
Error Detection ◽  
Neural Mechanisms ◽  
Medial Frontal Cortex ◽  
List Type ◽  
Timing Errors ◽  
Supplementary Eye Field ◽  
Speed Accuracy ◽  
Accuracy Tradeoff

SUMMARYThe balance of speed with accuracy requires error detection and performance adaptation. To date, neural concomitants of these processes have been investigated only with noninvasive measures. To provide the first neurophysiological description, macaque monkeys performed visual search under cued speed accuracy tradeoff (SAT). Monkeys changed SAT emphasis immediately after a cued switch while neuron discharges were sampled in medial frontal cortex area supplementary eye field (SEF). A multiplicity of SEF neurons signaled production of choice errors and timing errors. Modulation of SEF activity after choice errors predicted production of un-rewarded corrective saccades. Modulation of activity after timing errors signaled reward prediction error. Adaptation of performance during SAT of visual search was accomplished through pronounced changes in neural state from before search array presentation until after reward delivery. These results contextualize previous findings using noninvasive measures, complement neurophysiological findings in visuomotor structures, endorse the role of medial frontal cortex as a critic relative to the actor instantiated in visuomotor structures, and extend our understanding of the distributed neural mechanisms of SAT.HIGHLIGHTSMedial frontal cortex enables post-error adjustment during SATChoice and timing errors were signaled by partially overlapping neural poolsMedial frontal cortex can proactively modulate visuomotor processesMedial frontal cortex is to visuomotor circuits as critic to actor

scholarly journals Working memory availability affects neural indices of distractor processing during visual search

2018 ◽  
Author(s):  
Dion T. Henare ◽  
Jude Buckley ◽  
Paul M. Corballis
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Memory Load ◽  
Individual Performance ◽  
Event Related Potential ◽  
Neural Mechanisms ◽  
Human Cognition ◽  
Working Memory Load ◽  
Distractor Processing ◽  
Selective Processing

AbstractWorking memory and selective attention are traditionally viewed as distinct processes in human cognition. However, increasing research demonstrates significant overlap between these constructs such that as working memory availability decreases, individuals perform worse on attention-based tasks. To date, the neural mechanisms involved in this interaction are unknown. We measured three candidate lateralized event-related potential components (N2pc, Ptc, and SPCN) to observe the effects of increased working memory load on selective processing of targets and distractors. We found that increased working memory load impaired the processing of distractors, but not targets, and this was reflected in attentuation of the Ptc to distractors. We also found that individual performance on the task is related to the neural response to both targets and distractors. This study suggests that working memory availability impacts individuals’ ability to disengage from irrelevant stimuli, and that individual differences in visual search ability under load are related to both target and distractor processing.

The Explanatory Autonomy of Cognitive Models

2018 ◽  
Author(s):  
Daniel A. Weiskopf
Keyword(s):  
Cognitive Models ◽  
Neural Mechanisms ◽  
Complete Picture ◽  
Neural Models ◽  
Brain System ◽  
Mechanistic Explanations ◽  
Behavioral Phenomena ◽  
The Mind

Psychology and neuroscience offer distinctive ways of modeling the mind/brain. However, cognitive and neural models often have significantly different structures, raising challenging questions about how they should be integrated to provide a complete picture of how the mind/brain system is organized. According to a certain mechanistic perspective, cognitive models should be viewed as being sketchy, incomplete versions of the fuller and more adequate models produced by neuroscience. Psychology is essentially an approximation to the mechanistic explanations given in neuroscience. Cognitive models are inherently inadequate, pending their gaps being filled in by a completed neuroscientific model. I argue that cognitive models are autonomous: they are sufficient in themselves to give adequate explanations of psychological and behavioral phenomena. In particular, they are not mere sketches, or approximations to underlying neuroscientific explanations. I offer a criterion for how psychological entities and processes may be real despite not mapping onto entities in neural mechanisms.

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