title: Time estimation in Parkinson's disease and degenerative cerebellar disease.
abstract: With functional MRI, we recently identified fronto-cerebellar activations in predicting time to reach a target and basal ganglia activation in velocity estimation, that is, small interval assessment. We now tested these functions in patients with Parkinson's disease (PD) and degenerative cerebellar ataxia. They watched a ball that repeatedly appeared, moved, and disappeared. Velocity, stop locations, and predicted target locations as well as time to reach a target were indicated. Compared with controls, PD patients showed impaired velocity estimation (momentary mode) whereas temporal prediction was selectively impaired in cerebellar ataxia patients. The latter highlights feed-forward processing within fronto-cerebellar circuitry. Impaired velocity estimation in PD fits the concept of a basal ganglia clock function.
authors.affiliation: Department of Neurology, University Medical Center Groningen, Groningen University, The Netherlands. M.Beudel@neuro.umcg.nl
authors.forename: Martijn
authors.initials: M
authors.lastname: Beudel
authors.forename: Sjoukje
authors.initials: S
authors.lastname: Galama
authors.forename: Klaus L
authors.initials: KL
authors.lastname: Leenders
authors.forename: Bauke M
authors.initials: BM
authors.lastname: de Jong
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002524:Cerebellar Ataxia / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D020734:Parkinsonian Disorders / Q000503:physiopathology*; D010775:Photic Stimulation / Q000379:methods; D013998:Time Perception / Q000502:physiology*