title: Role of posterior parietal cortex in reaching movements in humans: clinical implication for 'optic ataxia'.
abstract: OBJECTIVE
  To clarify the spatio-temporal profile of cortical activity related to reaching movement in the posterior parietal cortex (PPC) in humans.
  
  
  METHODS
  Four patients with intractable partial epilepsy who underwent subdural electrode implantation were studied as a part of pre-surgical evaluation. We investigated the Bereitschaftspotential (BP) associated with reaching and correlated the findings with the effect of electrical stimulation of the same cortical area.
  
  
  RESULTS
  BPs specific for reaching, as compared with BPs for simple movements by the hand or arm contralateral to the implanted hemisphere, were recognized in all patients, mainly around the intraparietal sulcus (IPS), the superior parietal lobule (SPL) and the precuneus. BPs near the IPS had the earlier onset than BPs in the SPL. Electrical stimulation of a part of the PPC, where the reach-specific BPs were recorded, selectively impaired reaching.
  
  
  CONCLUSIONS
  Intracranial BP recording and cortical electrical stimulation delineated human reach-related areas in the PPC.
  
  
  CONCLUSIONS
  The present study for the first time by direct cortical recording in humans demonstrates that parts of the cortices around the IPS and SPL play a crucial role in visually-guided reaching.
authors.affiliation: Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Morito
authors.initials: M
authors.lastname: Inouchi
authors.forename: Riki
authors.initials: R
authors.lastname: Matsumoto
authors.forename: Junya
authors.initials: J
authors.lastname: Taki
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kikuchi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Mitsueda-Ono
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Mikuni
authors.forename: Lewis
authors.initials: L
authors.lastname: Wheaton
authors.forename: Mark
authors.initials: M
authors.lastname: Hallett
authors.forename: Hidenao
authors.initials: H
authors.lastname: Fukuyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shibasaki
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Takahashi
authors.forename: Akio
authors.initials: A
authors.lastname: Ikeda
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000503:physiopathology / Q000601:surgery; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D010296:Parietal Lobe / Q000033:anatomy & histology / Q000502:physiology* / Q000601:surgery; D011597:Psychomotor Performance / Q000502:physiology*; D013647:Task Performance and Analysis; D009626:Terminology as Topic; D055815:Young Adult
keywords: Bereitschaftspotential; Cortical electrical stimulation; Optic ataxia; Posterior parietal cortex; Reaching