Abstract
Parkinson's disease (PD) is primarily a disorder of the motor system. However, recent studies have revealed that PD patients exhibit various kinds of cognitive and emotional impairment. Cognitive impairment seen PD is related to memory, executive function, visual perception. This paper focuses mainly on social cognition in PD. Social cognition plays an important role in the processing of emotional expression and mental state of others, and it is crucial for communications. Previous studies demonstrated that PD patients show impaired patterns in the facial expression recognition and decision making process to select the appropriate behavior. Recently, it has been also discussed whether or not Theory of mind (ToM) ability is affected by PD. ToM, defined as the ability to infer other people's mental states, is a crucial prerequisite of human social interaction. Cognitive and emotional impairment in PD is considered to have multiple causes, and careful attention is necessary in diagnosis and medication and rehabilitation.
