Brain response during the M170 time interval is sensitive to socially relevant information

Area of Science:

• Neuroscience
• Social Psychology
• Cognitive Science

Background:

• Facial displays convey complex social information.
• The M170 component in MEG/EEG is linked to structural face encoding.
• The extent of information processed during the M170 is under investigation.

Purpose of the Study:

• Investigate the neuronal basis of processing social rank cues (SRCs) and emotional facial expressions (EFEs) during the M170 interval.
• Determine if M170 activity distinguishes between different types of social and emotional facial information.
• Explore the neural circuitry involved in processing integrated facial cues.

Main Methods:

• Magnetoencephalography (MEG) to record brain activity.
• Analysis of the M170 event-related field component.
• Participants viewed faces with integrated emotional expressions and social rank cues (head tilts).

Main Results:

• M170 activity was sensitive to both EFEs and SRCs.
• Dominance-related SRCs elicited stronger M170 activation compared to submissive or egalitarian cues.
• Processing of EFEs and SRCs appeared to involve distinct neural circuits.

Conclusions:

• Vertical head tilts are interpreted as social information, not just structural variations.
• The M170 time window encodes both emotional and social hierarchy information from faces.
• Understanding the neural processing of non-verbal cues is crucial for the social rank biobehavioral system.