Facial expressions and Parkinson's disease.

Patients with Parkinson's disease (PD) and matched control subjects were photographed posing a range of facial expressions. The same subjects were later asked to identify the posed expressions of the other subjects. They were also asked to rate the quality of expressions posed by the control subjects after being told what each expression was. Expressions posed by healthy control subjects were more readily identifiable than expressions posed by Parkinson's patients, but the two groups did not differ in their ability to recognize facial expressions or in the goodness ratings they gave, and their error patterns were closely similar. There was no significant difference between the groups on other tests of face processing or on ratings of emotionality except for greater reported anxiety in the Parkinson's patients. We conclude that although patients with PD have reduced facial expressiveness, there is no apparent diminution in their comprehension of facial expressions or their day-to-day experience of emotion.