Psychophysiological indices of cerebral maturation.

Maturation (1-21 yr) trajectories for quantitative electroencephalographic (QEEG) frequency spectra are presented for four regions of the human brain. The results show that all four regions exhibited discontinuous maturation rates: five stages were identified. The stages were synchronous across regions during the first 10 1/2 years of life. Thereafter, the four maturation trajectories became independent of one another. Interestingly, a major maturational advance was recorded from the frontal regions, during late adolescence. The relationships between these findings to maturation rates in skull volume, cortical thickness, cortical volume and nerve cell density measurements was discussed. These converging results indicate that the observed QEEG stages can reliably be interpreted as landmarks in cerebral maturation.