Tool-use extends visual-tactile peripersonal space
Single Paper Presentation

Nicholas Holmes
Experimental Psychology, University of Oxford

Charles Spence
Experimental Psychology, University of Oxford

Gemma Calvert
Physiological Laboratories, University of Oxford

     Abstract ID Number: 70
     Full text: Not available
     Last modified: May 20, 2003

Abstract
Recent research suggests that the visual-tactile representation of peripersonal space can be modified by active tool-use. Specifically, in single-cell neurophysiology, in crossmodal extinction, and in the crossmodal congruency task (Maravita et al., 2002), tool-use resulted in remapping of extrapersonal space as an extension of peripersonal space. We studied this modulation at different distances from human participants using the crossmodal congruency task. Participants discriminated the elevation of vibrotactile targets embedded in a 'tool' handle, responding either 'upper' or 'lower' while trying to ignore a simultaneously presented visual distractor. Previous studies demonstrated robust crossmodal congruency effects (CCE), such that vibrotactile targets were discriminated more rapidly and accurately when visual distractors came from the same vs. from different elevations. Crucially, the CCE was larger for same-side (left or right) than opposite-side visual distractors. We hypothesised that tool-use would modulate the CCE for visual distractors presented at the tool tip. We found a large CCE for distractors near the hands, which decreased in the middle of the tool shaft, and increased at the tool tip. The CCE for same-side distractors was larger than that for opposite-side distractors at all distances. These data demonstrate that tool-use extends the visual-tactile representation of peripersonal space.

Reference:
Maravita A, Spence C, Kennett S, Driver J (2002) Tool-use changes multimodal spatial interactions between vision and touch in normal humans. Cognition, 83:B25-B34