Neurocognition and Self-Regulation of the Agentic Self in Patients with Parkinson's Disease

It was hypothesized that high-level action control systems (agentic portions of the self) were impaired in patients with Parkinson's disease (PD). Four pilot studies and an experiment were conducted. In pilot study 1, patients with right-onset disease enumerated fewer agentic roles and endorsed fewer agentic traits to describe themselves in these roles. In pilot study 2, right-onset patients with PD evidenced lower levels of self-directedness and higher levels of novelty seeking (i.e., impulsivity/lack of self-control) than either left-onset patients with PD or control subjects (CS). In pilot study 3, right-onset patients with PD evidenced greater levels of apathy than left-onset patients with PD or CS. In pilot study 4, right-onset patients with PD self-reported being farther from a 'hoped-for self' and closer to a 'feared self' and tended to use more prevention strategies than left-onset patients with PD or CS.

In experiment 1, reaction times of right-onset patients with PD were slowest to high agentic words that described 'Me' and fastest to low agentic words that described 'Me'. Taken together, the findings from these pilot studies and the experiment suggest that there is a clinically significant impairment of the sense of agency in patients with PD and in their action control systems, especially in patients with right-onset disease. The impairment may be related to failure to quickly activate cognitive schemas or representations that describe the Self system as agentic and that are used by the Self system for action control. These cognitive schemas can therefore not be used to efficiently initiate or to control ongoing actions. Patients with right-onset disease are predicted to be at greater risk for agentic impairments including apathy, apraxia and the pursuit of goal-directed behaviors more generally.