ERP effects of movement preparation on visual processing: attention shifts to the hand, not the goal.
Poster Presentation

Elena Gherri
Dipartimento di Scienze Sociali, Cognitive e Quantitative, Universita' di Modena e Reggio Emilia

José Van Velzen
Department of Psychology, Birkbeck College, University of London

Martin Eimer
Department of Psychology, Birkbeck College, University of London

     Abstract ID Number: 106
     Full text: Not available
     Last modified: March 17, 2006
     Presentation date: 06/19/2006 10:00 AM in Hamilton Building, Foyer
     (View Schedule)

Abstract
We investigated whether lateralised ERP components during reaching movement preparation are triggered by effector or target selection, and whether movement preparation induces spatially selective modulations of visual processing. Participants executed one of four possible movements (left/right hand toward left/right target). In experiment 1, a cue indicated the effector to use or the movement direction, and the imperative stimulus contained the lacking information (direction or effector, respectively). In experiment 2, the cue conveyed full information (effector and direction). Task-irrelevant visual probe stimuli were presented randomly near the hand or the target location during response preparation.
In both experiments anterior and posterior lateralised ERP components (ADAN, LDAP) were elicited contralateral to the selected effector and to the selected movement direction. The LDAP was more pronounced during effector selection. During preparation based on partial information, enhanced early visual components were observed in ERPs elicited by probes near the cued hand, but not near the target location. During preparation based on full information, visual processing was enhanced near the target location only when effector and target were located in the same hemifield. These results suggest that during covert reaching movement preparation, visuospatial attention shifts toward the starting location of the cued hand, not to the goal location.