title: Callosotomy patients exhibit temporal uncoupling during continuous bimanual movements.
abstract: Rhythmic bimanual movements are highly constrained in the temporal domain, with the gestures of the two hands tightly synchronized. Previous studies have implicated a subcortical locus for temporal coupling based on the observation that these constraints persist in callosotomy patients. We now report that such coupling is restricted to movements entailing a discrete event (such as a movement onset). Three callosotomy patients exhibited a striking lack of temporal coupling during continuous movements, with the two hands oscillating at non-identical frequencies. We propose a subcortical locus of temporal coupling for movements involving discrete events. In contrast, synchronization between the hands during continuous movements depends on interhemispheric transmission across the corpus callosum.
authors.affiliation: University of California, Berkeley, 3210 Tolman Hall #1650, Berkeley, California 94720, USA.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Kennerley
authors.forename: Jörn
authors.initials: J
authors.lastname: Diedrichsen
authors.forename: Eliot
authors.initials: E
authors.lastname: Hazeltine
authors.forename: Andras
authors.initials: A
authors.lastname: Semjen
authors.forename: Richard B
authors.initials: RB
authors.lastname: Ivry
mesh_terms: D000328:Adult; D003337:Corpus Callosum / Q000502:physiology* / Q000601:surgery*; D006225:Hand; D006801:Humans; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D013997:Time Factors