The two-brain approach: how can mutually interacting brains teach us something about social interaction?

Area of Science:

• Neuroscience
• Social Neuroscience
• Cognitive Neuroscience

Background:

• Studying social interaction necessitates measuring brain activity in multiple interacting individuals simultaneously.
• Despite its appeal, two-person brain imaging is methodologically challenging, limiting its application.

Purpose of the Study:

• To review existing two-brain recording methodologies and their conceptual strategies.
• To discuss the application of these methods in understanding social cognition and inter-brain neural effects.

Main Methods:

• Review of two primary two-brain recording approaches: dual fMRI and dual EEG/NIRS.
• Categorization of studies based on interaction type (turn-based vs. continuous) and experimental design (interactive vs. pseudo-interactive).

Main Results:

• Dual fMRI studies examine turn-based interactions and information flow in pseudo-interactive scenarios.
• Dual EEG/NIRS studies investigate functional connectivity in face-to-face interactions and neural coupling in continuous mutual interactions.

Conclusions:

• Simultaneous two-brain recordings are crucial for specific research questions in social neuroscience.
• Novel analytical tools, including emergence measures and multivariate decoding, can enhance the study of brains in interaction and social cognition.