Abstractness and social interaction through a new lens: the potentialities of hyperscanning in naturalistic settings

Concepts, typically classified into more abstract (e.g., “chair”) and more concrete (e.g., “friendship”), are the mental shortcuts that people commonly use to organize knowledge and navigate their inner and external world. Research on categorization highlights social interaction as crucial for the acquisition and use of abstract concepts. Behavioral evidence shows that people typically learn abstract concepts primarily through language; even after acquisition, they feel less confident about their meaning and tend to rely more on others to refine or negotiate them. Neuroscientific studies support this evidence by showing a greater activation of social and linguistic brain areas for concepts higher in abstractness. However, existing literature relies on constrained experimental methods, testing participants mainly in isolation (“single-brain” approach) or, when using more interactive (conversational) paradigms, they have two main limitations: (I) using non-naturalistic settings; (II) extracting only behavioral indices. Within the emerging “second-person neuroscience” panorama, we contend that hyperscanning—a technique consisting of the simultaneous recording of brain activity from multiple individuals—may be ideally suited to adding evidence on the link between abstract concepts and social interactions by capturing Inter-Brain Synchronization (IBS) of individuals during real-time social exchanges. The availability of portable devices further broadens hyperscanning potential, allowing for the study of brain-to-brain coupling in more ecological environments. Drawing on prior hyperscanning evidence from learning to free conversations, we contend that using hyperscanning in naturalistic settings, with the due care, may offer a novel and interesting lens to investigate the role of social interactions for abstractness, thus enriching categorization research.