title: Virtual lesions of the anterior intraparietal area disrupt goal-dependent on-line adjustments of grasp.
abstract: Adaptive motor behavior requires efficient error detection and correction. The posterior parietal cortex is critical for on-line control of reach-to-grasp movements. Here we show a causal relationship between disruption of cortical activity within the anterior intraparietal sulcus (aIPS) by transcranial magnetic stimulation (TMS) and disruption of goal-directed prehensile actions (either grip size or forearm rotation, depending on the task goal, with reaching preserved in either case). Deficits were elicited by applying TMS within 65 ms after object perturbation, which attributes a rapid control process on the basis of visual feedback to aIPS. No aperture deficits were produced when TMS was applied to a more caudal region within the intraparietal sulcus, to the parieto-occipital complex (putative V6, V6A) or to the hand area of primary motor cortex. We contend that aIPS is critical for dynamic error detection during goal-dependent reach-to-grasp action that is visually guided.
authors.affiliation: HB 6162 Moore Hall, Department of Psychological and Brain Sciences, Center for Cognitive Neuroscience, Dartmouth College, Hanover, New Hampshire 03755, USA.
authors.forename: Eugene
authors.initials: E
authors.lastname: Tunik
authors.forename: Scott H
authors.initials: SH
authors.lastname: Frey
authors.forename: Scott T
authors.initials: ST
authors.lastname: Grafton
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D001696:Biomechanical Phenomena / Q000379:methods; D001931:Brain Mapping; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D006040:Goals; D006225:Hand / Q000294:innervation / Q000502:physiology*; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008280:Magnetics; D008297:Male; D009068:Movement / Q000502:physiology* / Q000528:radiation effects; D010296:Parietal Lobe / Q000293:injuries / Q000502:physiology* / Q000528:radiation effects; D011597:Psychomotor Performance / Q000502:physiology* / Q000528:radiation effects; D011930:Reaction Time / Q000528:radiation effects; D013028:Space Perception / Q000528:radiation effects; D013997:Time Factors