title: Dysfunctional counting of mental time in Parkinson's disease.
abstract: Patients with Parkinson's disease (PD) often underestimate time intervals, however it remains unclear why they underestimate rather than overestimate them. The current study examined time underestimation and counting in patients with PD, in relation to dopamine transporter (DaT) located on presynaptic nerve endings in the striatum. Nineteen non-dementia patients with PD and 20 age- and sex-matched healthy controls performed two time estimation tasks to produce or reproduce time intervals with counting in the head, to examine dysfunctional time counting processing. They also performed tapping tasks to measure cycles of counting with 1 s interval with time estimation. Compared to controls, patients underestimated time intervals above 10 s on time production not reproduction tasks, and the underestimation correlated with fast counting on the tapping task. Furthermore, striatal DaT protein levels strongly correlated with underestimation of time intervals. These findings suggest that distortion of time intervals is guided by cumulative output of fast cycle counting and that this is linked with striatal DaT protein deficit.
authors.affiliation: Department of Neurology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8666, Japan.
authors.forename: Motoyasu
authors.initials: M
authors.lastname: Honma
authors.affiliation: Department of Neurology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8666, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kuroda
authors.affiliation: Department of Neurology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8666, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Futamura
authors.affiliation: Department of Neurology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8666, Japan.
authors.forename: Azusa
authors.initials: A
authors.lastname: Shiromaru
authors.affiliation: Department of Neurology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8666, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Kawamura
mesh_terms: D016022:Case-Control Studies; D003342:Corpus Striatum / Q000378:metabolism; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D000073216:Mental Status and Dementia Tests; D010300:Parkinson Disease / Q000523:psychology*; D017729:Presynaptic Terminals / Q000378:metabolism; D013998:Time Perception
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins