Visual Attention in Peripersonal Space

Bringing the hand near a visual stimulus enhances visual processing. This effect is linked to peripersonal space (PPS), the body-centered region where visual and proprioceptive information interact. Despite extensive behavioral evidence, the neural basis of this interaction in early visual cortex remains unclear. In this study, we investigated how hand proximity modulates orientation selectivity in area V2 by recording single-neuron responses from two rhesus monkeys. The monkeys performed a fixation task while their hand was positioned near a visual stimulus while either being visible or occluded, and compared with when the hand was away from the stimulus. When the near hand was visible, neural firing rates in V2 were significantly higher, accompanied by sharper orientation tuning. In contrast, occluding the hand broadened orientation tuning compared to when the hand was away. These effects emerged rapidly after stimulus onset and were coherent across the population, demonstrating that PPS is actively prioritized during visual processing. Together, the findings reveal two complementary (feedback) signals in V2: a congruence-driven enhancement when visual and proprioceptive inputs align, and a mismatch-driven suppression when they conflict, indicating that V2 integrates multisensory cues to encode PPS and support action-relevant visual processing.