Hyperscanning of brain-to-brain interactions in the prefrontal cortex during a joint sentence reading task: an optical brain imaging study

İşbilir, Erdinç
A functioning and developing human society is possible due to successful communication and joint actions between the members of the group that constitute the society at large. Synchrony among members of a society is widespread and is seen in many distinct areas such as military parades and political activities as well as in the daily lives of people such as singing together, dancing and simply taking turns during a conversation. Although such synchronous behavior between people are central to their daily lives, the behavioral and neural correlates of such behavior have only recently been studied in the context of cognitive neuroscience. With the recent advent of the new neuroimaging methods such as functional near infrared spectroscopy (fNIRS) that are both portable and cheaper compared to more traditional methods such as fMRI, many researchers have started to investigate the neural correlates of social interactions in terms of synchronization of neural activations across the interlocutors‟ brains. In this regard, hyperscanning, which is defined as the simultaneous measurement of multiple people‟s brain activity, has emerged as a central method in social neuroscience studies. Motivated by these developments, in this study two speakers‟ brain activity at their prefrontal cortices were measured during a joint sentence reading task in Turkish in order to investigate brain-to-brain interactions in different behavioral coupling conditions. The results of this dissertation indicated that pairs showed different levels of behavioral synchrony in relation to different levels of auditory (self, both, other) and block conditions (match, mismatch). Moreover, in terms of brain-to-brain interactions the results indicated a significant coherence increase bilaterally in prefrontal cortex, especially in dorsolateral prefrontal cortex, dorsomedial prefrontal cortex and right-superior frontal cortex, which are regions implicated in related social neuroscience literature.