Increased sensorimotor activity during categorisation of emotionally ambiguous faces.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Social Neuroscience

Background:

• Actions are often linked to emotions, yet neural mechanisms of action observation typically exclude emotional context.
• Understanding the brain's response to observed actions requires integrating emotional information.

Purpose of the Study:

• To investigate neural mechanisms of mental simulation during facial emotion categorization.
• To explore the role of alpha-mu rhythm modulation in processing emotional facial expressions.

Main Methods:

• High-density electroencephalography (EEG) was used to measure alpha-mu rhythm (8–13 Hz) during a facial emotion categorization task.
• A control task assessed responses to head orientation categorization (14–20 Hz beta band activity).

Main Results:

• Sensorimotor activity, indicated by mu suppression, was sensitive to emotional information in faces.
• Neutral faces elicited stronger mu suppression than happy or sad faces, suggesting simulation beyond motor mimicry.
• Beta band activity differentiated processing of emotional facial expressions from head orientation.

Conclusions:

• Facial emotion categorization involves sensorimotor simulation, with unique responses to neutral expressions.
• Mu rhythm responses to facial emotions may serve as a biomarker for empathy circuit activation.
• Further research is needed to explore atypical mu rhythm responses in relation to emotional understanding and sharing difficulties.