Segregation of individual networks is associated with distinct behavior of older and young adults as a function of system type. a) Individual networks’ segregation values by age. All networks showed stronger segregation in young adults. b) Generalized linear mixed-effects models for accuracy revealed significant interactions with age and network segregation for 2 systems, whereas c) linear mixed-effects models for response time showed significant interactions for 3 networks. For most networks, increasing segregation was associated with better and faster performance in young adults and worse and slower reactions in older adults. d) Significant correlations between network segregation and neuropsychological measures. For young adults, we detected a positive correlation of increasing segregation of VAN-B with executive functions, whereas for older adults, a negative correlation of increasing segregation of DMN-B with semantic memory was found. Note that segregation and global efficiency values were mean-centered for analyses with behavior. VAN, ventral attention network; DAN, dorsal attention network.