Action-oriented representation of peripersonal and extrapersonal space: Insights from manual and locomotor actions

This paper reviews behavioral evidence demonstrating that space is accurately represented in the brain in relation to action capabilities. We initially review intriguing neuropsychological findings that show that space is differentially represented depending on whether the area is in reach of the hand (peripersonal space) or out of reach of the hand (extrapersonal space). We then review the literature on the characteristics of locomotor actions for avoiding obstacles to show that the relative dimensions of obstacles to relevant body parts are accurately represented at least one step before the obstacles are reached, i.e., while the obstacles are present in the extrapersonal space. The findings obtained from a number of studies on manual and locomotor actions will yield tentative conclusions: (a) the representation of one's body (body schema) is deeply involved in one's representation of space; (b) the representation of space is modified in response to alteration of action capabilities, although this is likely to occur only for well-learned actions, irrespective of the type; and (c) representation of space centered on the hand somewhat differs from that centered on the whole body.