Investigating decision-making in Parkinson's disease in tasks characterized by probabilistic cue-outcome associations: the role of optimality

Is probabilistic information one of the critical factors contributing to decision-making impairments in Parkinson’s disease (PD)? The results of many studies may suggest that in fact it is, and that PD patients struggle to process probabilities accurately. However, a growing body of evidence suggests otherwise. To explore this issue further, a novel gambling scenario was developed in order to compare decision-making behaviour in the form of betting in three different set ups: deterministic, probabilistic, and unpredictable. Participants’ behaviour was analysed using newly developed metrics, designed to examine optimal betting strategies. In our novel task PD patients performed as well as age-matched healthy controls (OHCs) across different set ups. Thus, in answer to the question posed, probabilistic information persedoes not seem to be the critical factor in causing impaired decision-making in PD.