Sunday, May 11, 2025
5/11/2025
Adaptive visual representation in human posterior parietal cortex - PROJECT SUMMARY A key component of human cognition is goal-directed visual information processing. We have shown extensively in prior research that not only do visual representations exist in posterior parietal cortex (PPC), but also these representations exhibit greater attention and task effects and greater distractor resistance in visual working memory (VWM) than those in occipitotemporal cortex (OTC). Incorporating PPC’s other well-known role in space, attention and action-related processing, we argue that PPC is an adaptive visual processing center, such that the interactions among the different PPC functions allow incoming visual information to be selected, represented and sustained to guide thoughts, solve problems, and, if needed, support the execution of timely and appropriate actions. Despite these advances, presently, there is a lack of a detailed mechanistic understanding of how goal-directed visual information is represented in PPC to support its function, especially in the face of distraction. In the current funding period, we have made a number of significant discoveries regarding the adaptive nature of PPC visual representation. In particular, we found that, rather than blocking distractor representation in VWM, PPC forms independent target and distractor representations, effectively combating distraction and reducing interference. Just like ventral regions’ ability to form visual object identity representation tolerant to changes across viewing conditions, dorsal regions thus appear to achieve a different kind of representational tolerance: the ability to maintain stable object representations in VWM in the face of ever-changing visual input. In the current funding period, we also made the important discovery that feedback from PPC can actively shape the VWM content of OTC. In this renewal proposal, we seek continuous funding to significantly expand the important discoveries made in the current funding period and, through a number of critical experimental manipulations, further test the utility and significance of distractor-tolerant object representations in VWM. We will additionally examine how feedback and distraction may interact to jointly determine the content of VWM. Together, results of this proposal shall provide an in-depth and mechanistic understanding of the adaptive nature of VWM representation in the human brain.
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