Brain Advance Access originally published online on March 31, 2009
Brain 2009 132(5):1386-1395; doi:10.1093/brain/awp052
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Do parkinsonian patients have trouble telling lies? The neurobiological basis of deceptive behaviour
1 Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Japan 2 Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan 3 Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Japan 4 Department of Nuclear Medicine and Radiology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
Correspondence to: Nobuhito Abe, Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan E-mail: abe-n{at}mail.tains.tohoku.ac.jp
Parkinson's disease is a common neurodegenerative disorder with both motor symptoms and cognitive deficits such as executive dysfunction. Over the past 100 years, a growing body of literature has suggested that patients with Parkinson's disease have characteristic personality traits such as industriousness, seriousness and inflexibility. They have also been described as honest, indicating that they have a tendency not to deceive others. However, these personality traits may actually be associated with dysfunction of specific brain regions affected by the disease. In the present study, we show that patients with Parkinson's disease are indeed honest, and that this personality trait might be derived from dysfunction of the prefrontal cortex. Using a novel cognitive task, we confirmed that patients with Parkinson's disease (n = 32) had difficulty making deceptive responses relative to healthy controls (n = 20). Also, using resting-state 18F-fluorodeoxyglucose PET, we showed that this difficulty was significantly correlated with prefrontal hypometabolism. Our results are the first to demonstrate that the ostensible honesty found in patients with Parkinson's disease has a neurobiological basis, and they provide direct neuropsychological evidence of the brain mechanisms crucial for human deceptive behaviour.
Key Words: Parkinson's disease; prefrontal cortex; neuropsychology; PET; executive function
Abbreviations: ADAS = Alzheimer's Disease Assessment Scale, ; FDG = 18F-fluorodeoxyglucose, ; MMSE = Mini-Mental State Examination, ; OSEM = ordered subset expectation maximization, ; WMS-R = Wechsler Memory Scale-Revised,
Received November 12, 2008. Revised January 20, 2009. Accepted February 4, 2009.