Abstract
Previous research has shown that the preparation of both eye and hand movements orients visuo-spatial attention towards the position aimed for by that movement.
The definition of the “aimed-for” position is currently under debate. Indeed, movement preparation could orient attention toward the goal of the movement (i.e. the sensory coordinates as defined by movement intention) or towards the position defined by the motor coordinates of the movement itself. These two positions (movement goal versus motor endpoint) are habitually closely aligned but must be dissociated to investigate which one guides attention. We examined hand movement preparation and dissociated the goal of the movement from the movement endpoint by tool use.
Participants had to point towards a visual target with the tip of a hand-held tool. The movement goal corresponded to the position aimed for with the tip of the tool, and the motor coordinates corresponded to the position towards which the hand moved to place the tool correctly on the visual target.
Visual discrimination performance was tested at both positions with a feature discrimination task. The results shed new light on the debate regarding the role of movement intention and motor computation in the orientation of visuo-spatial attention during movement preparation.