Keywords: Hyperscanning; Social Interaction; Two-Brain Approach; Multi-Brain Frame of Reference.
Although human social nature has been an extremely interesting subject for researchers, cerebral activity during social interaction has only been investigated over the last two decades. In the past, some researchers studied individuals' behavioural and neural effects in isolation, in other words in the absence of real social interaction. Recent studies, acknowledging this aspect as a limit, have explored inter-brain processes by the use of the approach called hyperscanning. It is based on the simultaneous recording of cerebral activity from two or more subjects and can explore "inter-brain" correlations, thus allowing investigations under more ecologically valid conditions. This review aims to provide a briefly summary to this approach, in the context of several techniques for the recording of brain activity and to illustrate studies and their main findings to clarify its potentiality and limits.