LAUSR

BACKGROUND Parkinson's disease (PD) has been associated with a tendency towards more risky decisions. However, the commonly used paradigms typically neglect the social context. OBJECTIVE Here, we investigated social decision-making and self-estimation in a competitive experimental task. METHODS A computerized experimental setting was used in which 86 PD patients (age = 66.5 [50-79], 62.8% male, H&Y = 2 [1.5-3]) and 44 healthy controls (HC; age = 67 [54-79], 54.4% male) in groups of four performed mathematical addition tasks in which they were asked to calculate as many sums as possible in five minutes. Participants had to choose their preferred compensation scheme ("piece rate" versus "tournament") and retrospectively rank their performance in comparison to the suspected performance of the others. A comprehensive neuropsychological test battery was also conducted. RESULTS No significant difference was found in overall social decision-making and self-estimation between PD patients and HC. However, for those individuals who made inadequate decisions, PD patients engaged in significantly more risk-averse and HC in more risky decisions. Concerning those inadequate decisions, the PD patients made more extreme decisions (severity of social decision-making) in both directions (risk-averse, risk-seeking). CONCLUSION Our data indicate that social decision-making behavior and self-estimation are largely intact in PD patients with mild to moderate disease stages and intact global cognition, executive functions, and social cognition. Future studies with more heterogeneous PD samples regarding their neuropsychological profile will have to examine at which state social decision-making may be affected and by which factors this behavior might be influenced.