Implicit and explicit emotional processing in Parkinson's disease

Abstract

Introduction: Our study investigated the ability of nondemented Parkinson's disease (PD) patients to explicitly identify emotional words and to show implicit sensitivity to these emotions in a task that did not require emotional processing. Methods: Twelve PD patients and 12 healthy controls, matched for age and education, performed lexical decision (LD) and emotional categorisation tasks (fear, disgust, and happiness) on the same words. Results: PD patients were specifically impaired in the explicit identification of disgust with a decreased accuracy in LD. However, a slowdown in LD latency in both PD patients and the control group suggested the persistence of emotional sensitivity to disgust. Conclusion: Despite the persistence of an automatic capture by the emotional content of disgust, PD patients may suffer from emotional deficits in recognising both the emotional and semantic components of words, resulting in blunted emotional responses.

Keywords:

• Parkinson's disease
• Emotion
• Disgust
• Implicit processing
• Explicit processing