The human visuomotor grasping circuit: distinct contribution of parietal and frontal areas and their interactions with the primary motor cortex. (360G-Wellcome-083450_Z_07_Z)

Object grasping and manipulation involve a complex parieto-frontal cortical network including the anterior intraparietal area (AIP), the ventral premotor cortex (PMv) and the primary motor cortex (M1). However, the precise operations performed by AIP and PMv and both their lateralization and temporal coupling are still unclear. In addition, how grasp-related information, processed in PMv, is conveyed to M1 to generate an appropriate motor command remains unknown. New methods of assessing activi ty and cortico-cortical connectivity in this visuomotor grasping circuit now make it possible to investigate (1) the nature and timing of the interactions between PMv and M1 to visually guided grasping movements (2) the distinct contributions of AIP and PMv to these movements and (3) how contralateral and ipsilateral cortical areas belonging to the visuomotor grasp circuit interact with each other. We propose to use a novel paired-pulse transcranial magnetic stimulation (TMS) to investigate th e functional connectivity between PMv and M1 during different categories of hand movements or action observation and to document the influence of AIP on these PMv-M1 connections. In addition, we will use magnetoencephalography (MEG) to study the lateralization and timing of those interactions to understand the spatio-temporal flow of grasp-related information within the visuomotor circuit.