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

Published: Oct. 2, 2020, 2:02 a.m.

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.09.30.321729v1?rss=1 Authors: Adam, K. C. S., Serences, J. T. Abstract: To 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. Copy rights belong to original authors. Visit the link for more info