When emotion and expression diverge: The social costs of Parkinson's disease

Introduction: Patients with Parkinson's disease (PD) are perceived more negatively than their healthy peers, yet it remains unclear what factors contribute to this negative social perception. Method: Based on a cohort of 17 PD patients and 20 healthy controls, we assessed how naive raters judge the emotion and emotional intensity displayed in dynamic facial expressions as adults with and without PD watched emotionally evocative films (Experiment 1), and how age-matched peers naive to patients' disease status judge their social desirability along various dimensions from audiovisual stimuli (interview excerpts) recorded after certain films (Experiment 2). Results: In Experiment 1, participants with PD were rated as significantly more facially expressive than healthy controls; moreover, ratings demonstrated that PD patients were routinely mistaken for experiencing a negative emotion, whereas controls were rated as displaying a more positive emotion than they reported feeling. In Experiment 2, results showed that age-peers rated PD patients as significantly less socially desirable than control participants. Specifically, PD patients were rated as less involved, interested, friendly, intelligent, optimistic, attentive, and physically attractive than healthy controls. Conclusions: Taken together, our results point to a disconnect between how PD patients report feeling and attributions that others make about their emotions and social characteristics, underlining significant social challenges of the disease. In particular, changes in the ability to modulate the expression of negative emotions may contribute to the negative social impressions that many PD patients face.