title: Delayed visual feedback and movement control in Parkinson's disease.
abstract: The dependence of movement on visual information was compared for healthy individuals and Stage II-III patients with Parkinson's disease (PD). A time delay (0-1400 ms) was introduced into a visually guided motor tracking task which required the subject to maintain constant index finger position relative to a stationary baseline on an oscilloscope. For healthy individuals, delayed visual feedback induced complex oscillations in finger displacement. Similar results were obtained for four of eight patients with PD. However, oscillations were not induced in four of eight patients with PD because of reduced gain and/or a higher tremor amplitude at zero delay which obscured the tracking error. These results suggest that some patients with PD are able to utilize visual information for controlling tracking in this motor task in the same manner as healthy individuals.
authors.affiliation: Départment de Kinanthropologie, Université du Québec à Montreal.
authors.forename: A
authors.initials: A
authors.lastname: Beuter
authors.forename: J G
authors.initials: JG
authors.lastname: Milton
authors.forename: C
authors.initials: C
authors.lastname: Labrie
authors.forename: L
authors.initials: L
authors.lastname: Glass
authors.forename: S
authors.initials: S
authors.lastname: Gauthier
mesh_terms: D000328:Adult; D000368:Aged; D005246:Feedback; D005260:Female; D005385:Fingers / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D009068:Movement; D010300:Parkinson Disease / Q000503:physiopathology*; D011597:Psychomotor Performance; D014785:Vision, Ocular / Q000502:physiology*