title: Co-registering kinematics and evoked related potentials during visually guided reach-to-grasp movements.
abstract: BACKGROUND
  In non-human primates grasp-related sensorimotor transformations are accomplished in a circuit involving the anterior intraparietal sulcus (area AIP) and both the ventral and the dorsal sectors of the premotor cortex (vPMC and dPMC, respectively). Although a human homologue of such a circuit has been identified, the time course of activation of these cortical areas and how such activity relates to specific kinematic events has yet to be investigated.
  
  
  RESULTS
  We combined kinematic and event-related potential techniques to explicitly test how activity within human grasping-related brain areas is modulated in time. Subjects were requested to reach towards and grasp either a small stimulus using a precision grip (i.e., the opposition of index finger and thumb) or a large stimulus using a whole hand grasp (i.e., the flexion of all digits around the stimulus). Results revealed a time course of activation starting at the level of parietal regions and continuing at the level of premotor regions. More specifically, we show that activity within these regions was tuned for specific grasps well before movement onset and this early tuning was carried over--as evidenced by kinematic analysis--during the preshaping period of the task.
  
  
  CONCLUSIONS
  Data are discussed in terms of recent findings showing a marked differentiation across different grasps during premovement phases which was carried over into subsequent movement phases. These findings offer a substantial contribution to the current debate about the nature of the sensorimotor transformations underlying grasping. And provide new insights into the detailed movement information contained in the human preparatory activity for specific hand movements.
authors.affiliation: Department of General Psychology, University of Padua, Padua, Italy.
authors.forename: Teresa
authors.initials: T
authors.lastname: De Sanctis
authors.forename: Vincenza
authors.initials: V
authors.lastname: Tarantino
authors.forename: Elisa
authors.initials: E
authors.lastname: Straulino
authors.forename: Chiara
authors.initials: C
authors.lastname: Begliomini
authors.forename: Umberto
authors.initials: U
authors.lastname: Castiello
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D001931:Brain Mapping; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006225:Hand / Q000502:physiology; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*