Author(s): Martha F Hanby, Michelle Barraclough, Shane McKie, Neal Hinvest, Kathryn McDonald, Rebecca Elliott and Iracema Leroi
Background: Apathy is a common non-motor syndrome of Parkinson’s disease (PD), understood as a quantitative reduction in goal-directed behaviour consisting of cognitive and emotional dimensions. Methods: Participants with PD (n=61) were assessed in different medication states on tasks of executive function and emotional processing. Performance was compared to that of a healthy control group (HC, n=19). The PD group was further divided into those with and without clinically significant apathy and compared using the same measures in an exploratory manner. Results: Compared to the HC group, the PD participants performed significantly worse on tests of executive function, the Iowa Gambling Task, and recognition of happiness on the Facial Emotional Recognition Task. Compared to PD participants without apathy, those with PD and apathy were found to have selective impairments on tasks of attention and the recognition of disgust, fear and happiness. No ef fects of dopamine were seen. Conclusion: The presence of apathy in PD is associated with selective cognitive and emotional processing deficits, which do not appear to be dopamine dependent.
