Inter-brain neurofeedback

Inter-brain neurofeedback closes a loop around hyperscanning: the real-time inter-brain synchrony of a dyad is computed and fed back to the pair (as a visual or auditory signal), with the goal of training them to raise their coupling and, through it, cooperation, rapport, or joint performance. It is an emerging attempt to turn a correlational social-neuroscience measure into an interventional tool.

The evidence is early and thin. Demonstrations exist, but sample sizes are small, effect sizes uncertain, and it is often unclear whether any behavioral benefit comes from raising a genuine neural coupling or simply from giving two people a shared task and a reward for coordinating. It sits between hyperscanning and BBIs — a real closed loop, but one that modulates behavior indirectly through feedback rather than by writing into either brain.