PT - JOURNAL ARTICLE AU - Artur Czeszumski AU - Sophie Hsin-Yi Liang AU - Suzanne Dikker AU - Peter König AU - Chin-Pang Lee AU - Sander L. Koole AU - Brent Kelsen TI - Cooperative behavior evokes inter-brain synchrony in the prefrontal and temporoparietal cortex: A systematic review and meta-analysis of fNIRS hyperscanning studies AID - 10.1101/2021.06.03.446922 DP - 2021 Jan 01 TA - bioRxiv PG - 2021.06.03.446922 4099 - http://biorxiv.org/content/early/2021/12/11/2021.06.03.446922.short 4100 - http://biorxiv.org/content/early/2021/12/11/2021.06.03.446922.full 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.