LIMITATIONS
SEPARATION
Further investigation of the dynamics of behavioral synchrony, between‐brains and within brain coupling, is required. In particular, although the results of the current work showed that instructed synchrony is predicted by between‐brain coupling while within‐brain coupling negatively predicts behavior, these results cannot be interpreted as showing causal relationship between brain and behavior. The findings are suggestive and may pave the way for future examinations with larger samples, balanced samples of men and women, and additional fNIRS channels that will allow examination of larger scale network reconfiguration.In conclusion, this study demonstrates that the brain has the ability to change its functional network organization of between‐ and within‐brain networks engaged by different task conditions.The findings that between‐brain coupling positively predicts intentional synchrony while within‐brain coupling negatively predicts intentional synchrony and that within‐brain coupling predicts synchronization during free movement, may indicate that within‐brain coupling is important for the early phases of attempting to synchronize (free movement) but when synchronization is obtained there is a growing need for reliance on between‐brain networks. This emphasizes the utility of interpreting task related differences in brain organization in terms of within‐ and between‐brains organization. We hold that probing the balance between networks may elucidate the optimal network structures underlying various aspects of effective social interactions. One limitation of the current study is the absence of short separation channels (SSCs) in the systems we used. This caused the measured fNIRS signals representing cerebral blood flow to be intermixed with blood flow to the scalp and other intermittent tissue. However, we counteracted this to the best of our ability by removing this interference in signal post‐processing by the method suggested by Zhang et al., 