Ebook: What binds us? Inter-brain neural synchronization and its implications for theories of human consciousness

The association between neural oscillations and functional integration is widely recognized in the study of human cognition.
Large-scale synchronization of neural activity has also been proposed as the neural basis of consciousness.
Intriguingly, a growing number of studies in social cognitive neuroscience reveal that phase synchronization similarly
appears across brains during meaningful social interaction. Moreover, this inter-brain synchronization has been associated
with subjective reports of social connectedness, engagement, and cooperativeness, as well as experiences of social cohesion
and ‘self-other merging’. These findings challenge the standard view of human consciousness as essentially first-person
singular and private. We therefore revisit the recent controversy over the possibility of extended consciousness and argue
that evidence of inter-brain synchronization in the fastest frequency bands overcomes the hitherto most convincing sceptical
position. If this proposal is on the right track, our understanding of human consciousness would be profoundly transformed,
and we propose a method to test this proposal experimentally.