Theory of Mind in Parkinson's disease.

Theory of Mind is an important concept within social cognition and refers to the ability to attribute mental states to oneself and others. Other terms for this concept include mentalizing and mind reading. Deficits in Theory of Mind may contribute to behavioral abnormalities, such as paranoia and delusions that are common in dementia. There are several experimental tasks for measuring Theory of Mind. A classical example is the false belief test. Examples of other measures include tests of understanding metaphor, sarcasm, irony, deception, and faux pas, determining what a person is thinking or feeling from photographs of the eye region, and visual perspective taking. There are several anatomical areas related to Theory of Mind. These include regions within the frontal and temporal lobes, and temporoparietal junction. There is a small but emerging literature on Theory of Mind in Parkinson's disease (PD). The data suggest that Theory of Mind is impaired in PD and that the deficits precede the development of dementia. Future studies are needed to better define the nature of the Theory of Mind deficits in PD, as well as the impact of these deficits on clinical disability in this disorder.