History-driven modulations of population codes in early visual cortex during visual search

AbstractTo find important objects, we must focus on our goals, ignore distractions, and take our changing environment into account. This is formalized in models of visual search whereby goal-driven, stimulus-driven and history-driven factors are integrated into a priority map that guides attention. History is invoked to explain behavioral effects that are neither wholly goal-driven nor stimulus-driven, but whether history likewise alters goal-driven and/or stimulus-driven signatures of neural priority is unknown. We measured fMRI responses in human visual cortex during a visual search task where trial history was manipulated (colors switched unpredictably or repeated). History had a near-constant impact on responses to singleton distractors, but not targets, from V1 through parietal cortex. In contrast, history-independent target enhancement was absent in V1 but increased across regions. Our data suggest that history does not alter goal-driven search templates, but rather modulates canonically stimulus-driven sensory responses to create a temporally-integrated representation of priority.

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Visual search for object categories is predicted by the representational architecture of high-level visual cortex

Journal of Neurophysiology ◽

10.1152/jn.00569.2016 ◽

2017 ◽

Vol 117 (1) ◽

pp. 388-402 ◽

Cited By ~ 14

Author(s):

Michael A. Cohen ◽

George A. Alvarez ◽

Ken Nakayama ◽

Talia Konkle

Keyword(s):

Visual Cortex ◽

Visual Search ◽

Visual System ◽

Visual Processing ◽

Search Task ◽

Visual Search Task ◽

Visual Object ◽

Neural Responses ◽

Object Categories ◽

High Level

Visual search is a ubiquitous visual behavior, and efficient search is essential for survival. Different cognitive models have explained the speed and accuracy of search based either on the dynamics of attention or on similarity of item representations. Here, we examined the extent to which performance on a visual search task can be predicted from the stable representational architecture of the visual system, independent of attentional dynamics. Participants performed a visual search task with 28 conditions reflecting different pairs of categories (e.g., searching for a face among cars, body among hammers, etc.). The time it took participants to find the target item varied as a function of category combination. In a separate group of participants, we measured the neural responses to these object categories when items were presented in isolation. Using representational similarity analysis, we then examined whether the similarity of neural responses across different subdivisions of the visual system had the requisite structure needed to predict visual search performance. Overall, we found strong brain/behavior correlations across most of the higher-level visual system, including both the ventral and dorsal pathways when considering both macroscale sectors as well as smaller mesoscale regions. These results suggest that visual search for real-world object categories is well predicted by the stable, task-independent architecture of the visual system. NEW & NOTEWORTHY Here, we ask which neural regions have neural response patterns that correlate with behavioral performance in a visual processing task. We found that the representational structure across all of high-level visual cortex has the requisite structure to predict behavior. Furthermore, when directly comparing different neural regions, we found that they all had highly similar category-level representational structures. These results point to a ubiquitous and uniform representational structure in high-level visual cortex underlying visual object processing.

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Visual Attention in The Fovea and The Periphery during Visual Search

10.1101/2021.11.22.469359 ◽

2021 ◽

Author(s):

Jie Zhang ◽

Xiaocang Zhu ◽

Shanshan Wang ◽

Hossein Esteky ◽

Yonghong Tian ◽

...

Keyword(s):

Visual Cortex ◽

Visual Search ◽

Visual Field ◽

Visual Attention ◽

Search Task ◽

Visual Search Task ◽

Common View ◽

Serial Process ◽

Feature Attention ◽

Task Feature

Visual search depends on both the foveal and peripheral visual system, yet the foveal attention mechanisms is still lack of insights. We simultaneously recorded the foveal and peripheral activities in V4, IT and LPFC, while monkeys performed a category-based visual search task. Feature attention enhanced responses of Face-selective, House-selective, and Non-selective foveal cells in visual cortex. While foveal attention effects appeared no matter the peripheral attention effects, paying attention to the foveal stimulus dissipated the peripheral feature attentional effects, and delayed the peripheral spatial attentional effects. When target features appeared both in the foveal and the peripheral, feature attention effects seemed to occur predominately in the foveal, which might not distribute across the visual field according to common view of distributed feature attention effects. As a result, the parallel attentive process seemed to occur during distractor fixations, while the serial process predominated during target fixations in visual search.

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