Sung-Mu Lee¹, Ishita Agarwal¹, Jinho Lee¹, Anne B Sereno¹; ¹Purdue University

Attention is a fundamental cognitive function that allows humans to filter irrelevant information and focus on task-relevant stimuli. It plays a crucial role in how we process complex visual environments, influencing the neural representations of the visual input. Visual information is processed via two segregated pathways in the brain: the ventral stream, which is primarily responsible for processing object features (the “what” pathway), and the dorsal stream, which focuses on spatial location (the “where” pathway). However, recent explanations posit that both pathways process shape and space, with attention or task context influencing the differential representations observed1,2 and more so in the ventral pathway3. This study aims to investigate whether and how attention, directed either toward the shape or location of an image, modulates neural representations of spatial locations in these two pathways. Participants underwent MRI scanning while performing a 1-back task under two attention conditions using identical visual stimuli. In the “attend to shape” condition, participants were instructed to attend to the shape of the images and press a button when the same shape was repeated. In the “attend to location” condition, participants focused on the location of the images and pressed a button when the same location was repeated. Multivariate Pattern Analysis (MVPA) with Multidimensional Scaling (MDS) was applied to assess spatial encoding in both ventral and dorsal regions under both attention conditions. The MDS results revealed increased distance of spatial locations in “attend to shape” and “attend to location” conditions compared to a “passive viewing” condition in ventral but not dorsal regions. This suggests that while both the ventral and dorsal pathways are involved in spatial processing, attention (to either shape or location) selectively increases discrimination of the neural representations of spatial locations in the ventral pathway.

Acknowledgements: NIH CTSI and Purdue University