[P2] Poster: Day 2

[P2-09] Hand proximity enhances visual encoding via anticipatory processing

*Ankit Maurya^1,3, Tsukasa Kimura^2,3, Minto Hashimoto^4,3, Masamichi J. Hayashi^3,4, Tony Thomas¹ (1. Department of Humanities and Social Sciences, Indian Institute of Technology Roorkee, Roorkee (India), 2. Graduate School of Human Sciences, The University of Osaka, Suita (Japan), 3. Center for Information and Neural Networks (CiNeT), Advanced ICT Research Institute, National Institute of Information and Communications Technology, Suita (Japan), 4. Graduate School of Frontier Biosciences, The University of Osaka, Suita (Japan))

Keywords:

Temporal anticipation,Time perception,Near-hand space,Contingent Negative Variation

Precise encoding of physical properties of objects is essential for efficient reaching, grasping, and manipulating. Previous psychophysical studies have reported that perceived duration expands when a visual stimulus is presented near the hand (peri-hand space), suggesting the involvement of anticipatory mechanisms associated with peri-hand space. However, the neural evidence for anticipatory processing associated with peri-hand space remains scarce. In humans, contingent negative variation (CNV), a slow negative deflection in electroencephalography (EEG), has been proposed as a neural signature of anticipatory processing. Therefore, we hypothesized that the appearance of objects in peri-hand space modulates CNV, facilitating accurate encoding of the object’s properties. To test this hypothesis, we recorded EEG while participants performed a visual temporal bisection task (n = 40). Participants judged whether stimulus durations, ranging from 50 to 170 ms, were closer to which of the two reference intervals, Short’ (50 ms) or ‘Long’ (170 ms), that they acquired prior to the EEG recording. The distance between hands and the visual stimulus was manipulated by placing participant’s hands either on the sides of a monitor (Hand condition) or on their lap (No-hand condition), allowing the stimuli to appear inside or outside the graspable space. The results showed that the CNV amplitude building up toward the appearance of the visual stimulus was significantly larger in the Hand condition than in the No-hand condition. Moreover, although there was no significant difference in behavioral performance between the two conditions, participants who exhibited greater CNV amplitude demonstrated higher sensitivity in the bisection task in the Hand condition. These findings suggest that placing the hands near an object enhances anticipatory processing, which may facilitate the precise encoding of stimuli for efficient reaching, grasping, and manipulating.