Attention allocation during manual movement preparation and execution

Three experiments investigated the role of visuospatial attention in the relationship between perception and action. Participants performed goal-directed hand movements in response to central or peripheral visual cues. Identification performance was measured for letters that were briefly presented at different locations and time delays relative to the beginning of movement preparation or execution. Letter identification in the plane of movement varied with concurrent motor planning complexity, but similar hemifield differences were obtained irrespective of whether or not directional planning was required (Experiment 1). Independent of movement direction, identification in the hemifield contralateral to the active hand improved relative to ipsilateral performance (Experiment 2). Peripheral movement cues induced holistic motor planning, but hemifield differences for probe identification persisted (Experiment 3). These results violate predictions of a premotor theory of attention (Rizzolatti, Riggio, & Sheliga, 1994).