[52,58,185–188], our finding corroborated the phenomenon of a gradual shift towards anteriorized topography and greater frontal activation in theta activity (i.e., “frontalization”) [189,190], whereby the prefrontal cortex progressively matures and assumes greater control over neural processing from childhood through adolescence to adulthood by virtue of a posterior to anterior progression during brain development [191,192]. According to Gogtay et al. [191], higher-order association cortices (e.g., the prefrontal cortex), mature only after lower-order structures (e.g., somatosensory and visual cortices) in a parietal-to-frontal direction, and phylogenetically older brain areas (e.g., basal ganglia and the limbic system) mature earlier than newer ones (e.g., the prefrontal cortex). Frontalization has also been observed in resting EEG, which corresponds to grey matter development, showing relative power distributed as a function of age with posterior regions maturing earlier than anterior regions (cf. Segalowitz et al. [193]). Specifically, theta-alpha maturation of resting EEG occurs first in occipital regions and then progresses gradually to frontal regions [170,172,194]. These electrophysiological and neuroimaging studies support our finding of more anteriorized theta activation in older subjects compared to the younger group.
