Visual attention in peripersonal space is dependent on differential modulation of V2 feature selectivity by hand...

The well-documented near-hand effect enhances visual processing when a hand is placed close to a stimulus, improving performance in tasks such as target detection, figure-ground discrimination, orientation processing, and working memory.^1,2,3 These behavioral advantages are thought to facilitate efficient reaching and grasping^4,5,6 in peripersonal space (PPS), the multisensory region surrounding the body. This effect has been attributed to enhanced attentional selection, potentially mediated by fronto-parietal bimodal neurons and feedback from grasping-related parietal areas (e.g., anterior intraparietal area [AIP] and V6A) to the early visual cortex.^7,8,9,10,11 Notably, prior neurophysiological evidence in monkeys demonstrated that a visible hand near a stimulus increases firing rates and sharpens orientation tuning in V2 neurons,¹² a modulation distinct from classic covert spatial attention, which typically affects response gain without altering tuning width.^13,14 This study extends these findings by recording single-neuron activity in V2 of two rhesus monkeys during a fixation task, comparing three conditions: hand near and visible, hand near but occluded, and hand far away. Replicating earlier results, a visible hand near the stimulus enhanced firing rates and sharpened orientation selectivity.¹² Critically, occluding the hand reversed this pattern, producing broader orientation tuning relative to the hand-away baseline, a novel indicator of visuo-proprioceptive mismatch. These rapid, population-coherent effects reveal two complementary feedback signals in V2: congruence-driven enhancement when visual and proprioceptive inputs align and mismatch-driven suppression when they conflict. Together, the findings show that V2 actively integrates multisensory cues to encode PPS and prioritize action-relevant visual processing.