Emotional facedness in Parkinson's disease

Area of Science:

• Neuroscience
• Psychology
• Movement Disorders

Background:

• Parkinson's disease (PD) is characterized by reduced facial expressivity.
• Hemispheric dominance theories suggest emotional processing and facial expressions may be asymmetric.
• Investigating facial emotion expression asymmetry in PD is crucial for understanding the disorder's impact on non-verbal communication.

Purpose of the Study:

• To evaluate potential asymmetry in facial emotion expressivity in individuals with Parkinson's disease (PD).
• To compare facial emotion expression between PD patients and healthy controls.
• To explore the relationship between facial expressivity laterality and motor laterality in PD.

Main Methods:

• Video-recorded posing of 6 basic emotions by 20 PD patients and 20 healthy controls.
• Creation of chimeric faces from expressive images for subjective rating.
• Analysis of rater responses, reaction times, and confidence levels for facial laterality assessment.

Main Results:

• No significant differences in facial expression asymmetry were found within or between PD patients and healthy controls.
• A significant correlation was observed between global facial laterality and body laterality in PD patients (R = -0.39, P = 0.01).
• The most expressive hemiface in PD patients corresponded to the less affected body side.

Conclusions:

• The study does not support the hypothesis of hemisphere predominance in regulating facial emotion expressions in PD.
• Findings suggest altered facial emotion expression in PD, linked to motor laterality.
• Novel insights into the complex relationship between motor and emotional facial expression in Parkinson's disease are provided.