Scale-Dependent Development of Neural Signal Complexity and its Association with Working Memory in Childhood.

Neural development during childhood involves progressive reorganization of brain dynamics across multiple temporal scales. The present study examined developmental differences in neural signal complexity, indexed by modified multiscale entropy (mMSE), in 253 typically developing children aged 3-9 years. Resting-state EEG was analyzed across 20 temporal scales spanning approximately 4-80 ms, and age-related differences were assessed using linear mixed-effects models with sex included as a covariate. Results showed systematic age-related increases in neural signal complexity, with developmental effects varying across individual temporal scales and scalp regions. Although positive age-related effects were observed across multiple scales, their magnitude differed across temporal resolutions, indicating a scale-dependent pattern of neural maturation. In addition, regional mMSE values showed positive associations with short-term working memory capacity, with significant effects observed in frontal, occipital, and temporal regions across multiple temporal scales.Together, these findings indicate that childhood brain maturation is characterized by scale-dependent increases in neural temporal complexity that are associated with the development of working memory.