Functional dynamic changes of peripersonal space induced by actions
Claudio Brozzoli, Francesco Pavani, Lucilla Cardinali, Christian Urquizar, Olivier Sillan, Alessandro Farnè
Talk
Last modified: 2008-05-13
Abstract
Single cell recording in monkeys’ parietal and frontal cortex showed that visuo-tactile neurons contribute to represent space near to the body. Neuropsychological studies suggested a similar coding of the multisensory peripersonal space (pps) in humans. We have recently shown that action dependent modifications of multisensory coding of pps arise in humans during action execution. Here we asked whether different modulations of multisensory coding of pps may arise on-line during different kinds of action. Healthy subjects were involved in two concurrent tasks: 1) They discriminated the elevation of tactile stimulations delivered on their right hand (up-index finger, down-thumb), while ignoring visual distractors embedded on the upper and lower part of a distant object; 2) They had to grasp or, in a different session, point to the same target object, with the tactually stimulated hand. Visuo-tactile stimulations were delivered before, at the onset or during action execution (250 ms from action onset). Results showed that right-hand actions modulated the visuo-tactile interaction, which increased at the onset of the movement and during its execution. Crucially, grasping induced a stronger effect than pointing to the object. Different actions thus induce different re-mapping of the multisensory pps, as a function of action phases.