Luke Mason and Jose van Velzen
The Premotor Theory of Attention (Rizzolatti et al., 1987, 1994) predicts that the intention to carry out an action will cause enhanced perceptual processing at the location of the action goal. This enhancement is often interpreted as a shift of spatial attention and is presumed to serve the purpose of selecting one goal amongst many distracters towards which to plan an action (selection-for-action, Allport, 1987 and Neumann, 1987). Early research on the premotor effect focused on the planning of saccades, whilst more recent work has extended the principle of enhanced processing at the goal to uni-manual movements such as reaching, pointing and grasping. Unlike saccades, however, successful planning of such uni-manual movements implies selection of an effector as well as a goal. We investigated this effect by recording participants’ EEG whilst cueing them to point to one of six targets arranged in an annular array. Visual processing was measured by reference to the size of the posterior N1 event related potential, elicited in response to task-irrelevant visual ‘probe’ stimuli presented at one of the six locations in the interval between the presentation of an auditory cue and the execution of the movement. Results showed enhanced perceptual processing simultaneously at the location of the effector and at the location of the action goal. We conclude that action planning leads to a pattern of facilitation and inhibition in perception, which achieves the selection of all action relevant locations, not just that of the goal.