Social synchronization of brain activity increases during eye-contact.

Area of Science:

• Neuroscience
• Social Psychology
• Cognitive Science

Background:

• Eye-contact is crucial for understanding others' mental states.
• Existing research shows eye-contact synchronizes brain activity between individuals.
• The impact of eye-contact on intra-brain activity and network dynamics remains less understood.

Purpose of the Study:

• To investigate how eye-contact influences synchronization frequency and direction within and between two brains.
• To analyze the network characteristics of these synchronized brain activities.
• To assess the functional relevance of eye-contact networks by comparing friends vs. strangers and leader-follower dynamics.

Main Methods:

• Electroencephalography (EEG) to measure brain activity.
• Network analysis to characterize synchronization patterns.
• Comparison of synchronization in friends vs. strangers and leader-follower dyads.

Main Results:

• Eye-contact significantly increases inter- and intra-brain synchronization, particularly in the gamma frequency band.
• Specific brain regions act as hubs connecting within- and between-brain networks.
• Friends exhibit stronger inter-brain synchronization than strangers during eye-contact.
• A directional synchronization from leader to follower is observed in the alpha frequency band in leader-follower dyads.

Conclusions:

• Eye-contact enhances both within- and between-brain synchronization, with a greater effect on inter-brain synchrony, underscoring its role as a social signal.
• The findings reveal distinct network properties and functional relevance of brain synchronization during eye-contact.
• Differences in synchronization between friends and strangers, and in leader-follower contexts, provide insights into the social modulation of brain activity.