Shared roles and team membership are reflected in functional connectome similarity: Neural evidence from real-world volleyball teams

In task-oriented teams, long-term coordination among specialized roles may contribute to shared patterns of cognition and behavior, yet little is known about how such experience is reflected in brain functional organization. Here, we examined whether cross-individual differences in whole-brain functional connectivity were associated with court position and team membership in professional volleyball players. In the resting-state and naturalistic volleyball game-viewing conditions, we analyzed dyadic functional connectivity differences to test whether effects of shared position and team were evident across intrinsic and contextually engaged brain states, controlling for differences in playing time and performance-related statistics. We found that same-position players showed smaller functional connectivity differences. These effects were most prominent and widespread across brain networks during game viewing, whereas at rest they were specific to the somatomotor network. Team membership was also associated with smaller functional connectivity differences during game viewing, although position x team interactions varied across networks after covariate adjustment. A complementary machine learning classifier further showed that shared position could be predicted from intersubject differences in functional connectivity with accuracy exceeding a frequency-based baseline. Together, these findings suggest that shared role-specific and team-based experience may contribute to structured similarity in functional brain organization within a real-world team setting.