Parkinson disease patients' performance in Theory of Mind (ToM) and decision-making tasks with and without Deep Brain Stimulation (DBS)

Background:Patients with Parkinson’s Disease (PD) show non-motor symptoms, such as cognitive impairment, disrupting executive functions, and mood alterations. Two processes currently researched in these areas are the Theory of Mind (ToM) and the decision-making in PD patients. The ToM is the ability to identify mental states (affective or cognitive) in others, and it is a necessary skill for successful communication in social situations. The decision-making process is researched in PD patients due to alterations in dopaminergic pathways involved in cortico-striatal circuits. These pathways have been linked to cognitive functions. Both processes could be altered in PD patients after the deep brain stimulation (DBS) therapy.Objective:To compare the performance of PD patients (with and without DBS) and healthy controls (HC) in the Theory of Mind and decision-making tasks.Methods:We applied to three groups of patients (PD, n = 4; PD-DBS, n = 5 and HC, n = 5) the Yoni task to identify affective and cognitive features in ToM and the Iowa Gambling Task (IGT) in decision-making.Results:There were no differences across the PD groups in ToM both in the affective and cognitive features. Regarding the decision-making, we obtained results consistent with previous findings, with PD patients showing impairments in this process.Conclusions:Some results suggest that DBS therapy affected PD patients’ performance in decision-making when compared to the healthy control group. Our results describe some non-motor changes due to DBS often seen in PD patients.