INHIBITORY CONSEQUENCES OF GRASPING MOVEMENTS: IS GRASPING THE SAME AS REACHING?

Abstract

Studies have shown that past actions can impact present and future actions. More specifically, inhibition of return (IOR) is a phenomenon in which participants respond slower to previously attended areas compared to novel locations (Posner & Cohen, 1984). IOR has been shown for eye movements, key presses and reaching but until now has not been investigated for grasping despite the prevalence of these actions. In this study, participants were asked to reach out and grasp a small or large block following the presentation of a central arrowhead cue indicating which direction to make a movement, while the eyes remained fixated centrally. Results showed slower reaction times for grasping movements made in the same direction as a preceding movement, demonstrating an IOR like effect. The grip scaling function however was not affected which adds to the growing body of evidence that IOR serves a broader function than facilitating visual search behaviour.