RT Journal Article SR Electronic T1 Cooperative behavior evokes inter-brain synchrony in the prefrontal and temporoparietal cortex: A systematic review and meta-analysis of fNIRS hyperscanning studies JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.06.03.446922 DO 10.1101/2021.06.03.446922 A1 Artur Czeszumski A1 Sophie Hsin-Yi Liang A1 Suzanne Dikker A1 Peter König A1 Chin-Pang Lee A1 Sander L. Koole A1 Brent Kelsen YR 2021 UL http://biorxiv.org/content/early/2021/12/11/2021.06.03.446922.abstract AB Single-brain neuroimaging studies have shown that human cooperation is associated with neural activity in frontal and temporoparietal regions. However, it remains unclear whether single-brain studies are informative about cooperation in real life, where people interact dynamically. Such dynamic interactions have become the focus of inter-brain studies. An advantageous technique in this regard is functional near-infrared spectroscopy (fNIRS) because it is less susceptible to movement artifacts than more conventional techniques like EEG or fMRI. We conducted a systematic review and the first quantitative meta-analysis of fNIRS hyperscanning of cooperation, based on thirteen studies with 890 participants. Overall, the meta-analysis revealed evidence of statistically significant inter-brain synchrony while people were cooperating, with large overall effect sizes in both frontal and temporoparietal areas. All thirteen studies observed significant inter-brain synchrony in the prefrontal cortex (PFC), suggesting that this region is particularly relevant for cooperative behavior. The consistency in these findings is unlikely to be due to task-related activations, given that the relevant studies used diverse cooperation tasks. Together, the present findings support the importance of inter-brain synchronization of frontal and temporoparietal regions in interpersonal cooperation. Moreover, the present article highlights the usefulness of meta-analyses as a tool for discerning patterns in inter-brain dynamics.Competing Interest StatementThe authors have declared no competing interest.