Article

Previous studies have shown a motor recruitment during the observation of
graspable objects. This recruitment has been considered crucial in encoding the
observed objects in terms of one or more potential motor acts. However, an agent
can actually act upon an object only when the latter is close enough to be
reached. Thus, the question we deal with in this paper is whether the motor
system is always activated whenever a graspable object comes into view or whether
it requires the object to be located within the reachable space of the perceiver.
The left primary motor cortex was magnetically stimulated and motor evoked
potentials (MEPs) were recorded while participants observed graspable and non
graspable objects located within or outside their own reachable space. We found
higher MEPs during the observation of graspable objects falling within the
reachable space compared to the observation of either a non graspable object or a
graspable object falling outside the reachable space.
Our results shed new light
on the functional role of the motor system in encoding visually presented
objects. Indeed, they clearly indicate that its recruitment is spatially
constrained, as it depends on whether the object falls within the actual reaching
space of the onlooker.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS