title: Involvement of ipsilateral parieto-occipital cortex in the planning of reaching movements: evidence by TMS.
abstract: Involvement of the ipsilateral hemisphere during planning of reaching movements is still matter of debate. While it has been demonstrated that the contralateral hemisphere is dominant in visuo-motor integration, involvement of the ipsilateral hemisphere has also been proposed. Furthermore, a dominant role for left posterior parietal cortex has been shown in this process, independently of the hand and visual field involved. In this study, the possible involvement of ipsilateral parieto-occipital cortex in planning of reaching movements was investigated by transcranial magnetic stimulation (TMS). TMS was applied on four points of the parietal and occipital cortex at 50% (Time 1), 75% (Time 2) and 90% (Time 3) of reaction time from a go-signal to hand movement. The only effect observed was an increase in reaction time when a region around the parieto-occipital junction was stimulated at Time 2. These results provide further support to the hypothesis that, in the posterior parietal cortex, planning of reaching movements also relies on the ipsilateral hemisphere, in addition to the contralateral or dominant one.
authors.affiliation: BRAIN Center, Department of Life Sciences, University of Trieste, Via Fleming, 22, 34127 Trieste, Italy. busan@dfp.units.it
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Busan
authors.forename: Joanna
authors.initials: J
authors.lastname: Jarmolowska
authors.forename: Mauro
authors.initials: M
authors.lastname: Semenic
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Monti
authors.forename: Giovanna
authors.initials: G
authors.lastname: Pelamatti
authors.forename: Gilberto
authors.initials: G
authors.lastname: Pizzolato
authors.forename: Piero Paolo
authors.initials: PP
authors.lastname: Battaglini
mesh_terms: D000328:Adult; D001931:Brain Mapping; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D009778:Occipital Lobe / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult