title: Parkinson's disease patients showed delayed awareness of motor intention.
abstract: Although dopamine plays an important role for motor control and modulates the frontal function via basal ganglia-thalamo-cortical loop, it is not known whether dopamine can affect the awareness of motor intention or not. To test this hypothesis, we applied Libet's clock paradigm to Parkinson's disease (PD) patients. Thirteen PD patients and 13 age-matched, healthy controls took part in the experiment which consisted of three judgment paradigms: W, M and S judgment. In W and M judgments, subjects were asked to press the key at self-willed timing. In W judgment, subjects reported the location of the clock's hand when they became aware of the intention (W-time). In M judgment, subjects reported the time when they became aware of the actual movement (M-time). In S judgment, subjects reported the time of the electrical stimulation given to their hand (S-time). W-time was significantly shorter in PD patients than in healthy control subjects while M-time and S-time were not different between the two groups. Delayed awareness of motor intention but not of action in PD patients might be related to dopamine depletion in those patients.
authors: Kitano Research Center of Mental Neurological, Sensory and Motor Organ Disorders, Osaka 530-8480, Japan; Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan.
authors: Hayato
authors: H
authors: Tabu
authors: Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan.
authors: Toshihiko
authors: T
authors: Aso
authors: Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan.
authors: Masao
authors: M
authors: Matsuhashi
authors: Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; Department of Neurology and Neuroscience, Graduate School of Medical Sciences, Nagoya City University, Nagoya 467-8602, Japan.
authors: Yoshino
authors: Y
authors: Ueki
authors: Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan.
authors: Ryosuke
authors: R
authors: Takahashi
authors: Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan.
authors: Hidenao
authors: H
authors: Fukuyama
authors: Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan; Emeritus Professor of Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan.
authors: Hiroshi
authors: H
authors: Shibasaki
authors: Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan. Electronic address: mima@kuhp.kyoto-u.ac.jp.
authors: Tatsuya
authors: T
authors: Mima
mesh_terms: D000368:Aged; D001364:Awareness; D005260:Female; D006801:Humans; D033182:Intention; D007600:Judgment; D008297:Male; D008875:Middle Aged; D009068:Movement; D010300:Parkinson Disease / Q000523:psychology*; D011597:Psychomotor Performance
keywords: Libet clock task; Motor intention; Parkinson disease