Do Parkinson's Disease Patients Have Deficits in Sequential Sampling Tasks?

The aim of this study was to assess the neuropsychological behavior of Parkinson's disease (PD) patients with addictive behaviors. Characteristically, these patients have younger onset of PD, higher novelty-seeking personality traits, jump to conclusions, and often make irrational choices. We assessed whether PD patients with and without addictive behaviors have deficits in a sequential sampling task, often called the secretary problem. In this task, participants needed to pick the best out of multiple offers. Critically, once participants rejected a deal, this option became unavailable. Thus, decisions needed to be balanced not to stop too soon or sample for too long and miss the best deal. We tested 13 PD patients with and 13 patients without addictive behaviors. Results were compared to healthy volunteers. We found that all patients declined fewer options before committing to a deal. There was, however, no difference between the two patient groups. Furthermore, there was no difference in overall choice rank between patients and controls. These results suggest that, compared to controls, PD patients gather less evidence before committing to an offer, but have no deficits in recognizing the best deal out of many options, regardless of whether or not they have addictive behaviors.