Daniel D Thayer¹, Thomas C Sprague¹; ¹University of California, Santa Barbara

Attention is directed to locations that are goal-relevant and image-salient (but irrelevant). To identify important locations, priority map theory posits that feature-selective retinotopic maps (e.g., color or motion) index salient (Thayer & Sprague, 2023) and relevant (Thayer & Sprague, 2025) locations based on their preferred feature dimension, which is subsequently integrated into a feature-agnostic priority map, where the most important location guides attention. Even though feature dimension maps are crucial for directing attention, it is unclear how neural responses within these maps reflect the priority signals associated with relevant and salient stimuli during visual search. Here, we used a covert search task to evaluate how concurrently present relevant and salient items are represented in neural feature dimension maps. On each trial, participants were cued to search for a target defined by a specific color or motion direction in a subsequent search array containing 8 colorful moving dot stimuli. All array items had homogenous features, except for the target, which differed solely on the cued feature dimension, and the occasional salient distractor, which was either a unique color or motion direction. We used an encoding-based multiple regression analysis with activation patterns in feature-selective retinotopic regions (motion [TO1/TO2] and color [hV4/VO1/VO2] maps) to assess the response to individual search array items. Targets and distractors were represented in neural feature dimension maps and representations were stronger when defined by the preferred feature dimension of each region. Furthermore, the time course of feature-selective responses was consistent with behavioral response times. However, target responses in parietal cortices (IPS0/IPS1) correlated most strongly with behavior, suggesting that IPS0/IPS1 may be an integrated priority map and ultimately determine what is important in the visual field. These results indicate that neural feature dimension maps are crucial for computing attentional priority and that activation profiles in parietal regions guide behavior.

Acknowledgements: Funding: Alfred P Sloan Research Fellowship, National Eye Institute R01-EY035300