Alterations in event-related potential responses to empathy for pain in Parkinson's disease on and off medication

Abstract

Objective: How Parkinson's disease (PD) affects an individual's empathic capacity remains poorly understood. By using the event-related potential (ERP) technique, we sought to: (1) study the temporal dynamics of empathic responses in patients with PD; (2) explore whether dopaminergic medication modulates empathic processing.

Methods: Twenty-six patients with early-to-moderate PD (13 on- and 13 off-medication) and 14 healthy controls performed an empathy-for-pain paradigm test while we recorded their electroencephalography. The participants responded to neutral or painful pictures during an active empathic condition (pain judgment task) and a control condition that was manipulated by task demands (laterality judgment task).

Results: The ERP results demonstrated an early automatic frontal response and a late controlled parietal response to pain in healthy elderly controls. The observed early and late ERP responses were detected in the on-medication patients but not in the off-medication patients.

Conclusions: PD is associated with deficits in both affective and cognitive empathic responses, dopaminergic medication may have the potential to alleviate these deficits.

Significance: This study helps to understand empathic deficits in patients with PD. Within-subject studies are required to reliably assess the effect of dopaminergic medication on empathic processing.

Keywords: Event-related potentials; Medication effect; Pain empathy; Parkinson’s disease.