Reductions in phase locking and/or measures of coherence between brain areas in children as compared to adults have been reported previously in human subjects [40]. It has been suggested that phase locking of EROs within a brain area (PLI) may differ from phase locking of EROs between brain areas (PDLI) in terms of both the cognitive and neuroanatomical substrates of the effects. Local phase synchronization most likely reflects maturation in inhibitory-excitatory dynamics within local circuits that may be influenced by such processes as synaptic pruning and local structural reorganization [5, 11]. Synchronization between brain areas may rely on communication between brain areas that are influenced by such factors as maturation of white matter during development [15]. Vakorin et al. [119] and others (see [120-121]) have suggested that increased integration between distributed neuronal populations is the key factor contributing to the “increased complexity” of brain signals that occurs during development. They have further suggested that over development less information is processed locally and more information is processed over distributed circuits in the brain [119]. Our study suggests that the increase in synchrony between brain areas increases over development not only in human subjects but also in rodents.
