Developmental changes in spontaneous electrical activity from early to middle childhood and their relation to...

Electrophysiological measures are being increasingly utilized for the study of developmental changes in children. Accordingly, how alpha oscillation may play an important role in child development is of particular interest. This study aimed to better understand the development of alpha rhythm with age in childhood and its relationship with working memory capability. We collected eyes-open resting-state electroencephalogram (EEG) data of 253 children aged 3 to 9 years to explore the development of brain rhythm of the alpha band with age and then explored the relationship between working memory span task and EEG alpha activity. The results demonstrated age-related decline trend in the relative power of delta band and theta band, age-depend increase in the beta 1 band across all regions and beta 2 band in the central and occipital regions, as well as a shifting pattern of the peak alpha frequency towards a higher frequency range with age. Regarding the spatial distribution pattern, the alpha band power showed a similar distribution between adjacent frequencies, and developed towards higher frequencies, especially in the central and occipital regions. Moreover, correlation analysis results demonstrated a positive correlation between the relative power of the alpha 2 band (10-13 Hz) in resting-state EEG and the working memory capacities of children. Higher scores of the longest digital span recalled were correlated with higher resting-state alpha power. This study's findings underscore the significance of the temporal region and the right central region for children's working memory development.