Article

Spatial attention and eye-movements are tightly coupled, but the precise nature
of this coupling is controversial. The influential but controversial Premotor
theory of attention makes four specific predictions about the relationship
between motor preparation and spatial attention.
Firstly, spatial attention and
motor preparation use the same neural substrates. Secondly, spatial attention is
functionally equivalent to planning goal directed actions such as eye-movements
(i.e. planning an action is both necessary and sufficient for a shift of spatial
attention). Thirdly, planning a goal directed action with any effector system is
sufficient to trigger a shift of spatial attention. Fourthly, the eye-movement
system has a privileged role in orienting visual spatial attention. This article
reviews empirical studies that have tested these predictions. Contrary to
predictions one and two there is evidence of anatomical and functional
dissociations between endogenous spatial attention and motor preparation.
However, there is compelling evidence that exogenous attention is reliant on
activation of the oculomotor system. With respect to the third prediction, there
is correlational evidence that spatial attention is directed to the endpoint of
goal-directed actions but no direct evidence that this attention shift is
dependent on motor preparation. The few studies to have directly tested the
fourth prediction have produced conflicting results, so the extent to which the
oculomotor system has a privileged role in spatial attention remains unclear.
Overall, the evidence is not consistent with the view that spatial attention is
functionally equivalent to motor preparation so the Premotor theory should be
rejected, although a limited version of the Premotor theory in which only
exogenous attention is dependent on motor preparation may still be tenable. A
plausible alternative account is that activity in the motor system contributes to
biased competition between different sensory representations with the winner of
the competition becoming the attended item.
CI - Copyright (c) 2012 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS