Age and sex effects in the EEG: development of the normal child

Clin Neurophysiol. 2001 May;112(5):806-14. doi: 10.1016/s1388-2457(01)00488-6.


Objectives: This study investigated age-related changes and sex differences in the EEGs of normal children.

Methods: Forty boys and 40 girls, between the ages of 8 and 12 years, participated in this study. The EEG was recorded during an eyes-closed resting condition and Fourier transformed to provide estimates for total power, absolute and relative power in the delta, theta, alpha and beta bands, and for theta/alpha and theta/beta ratios.

Results: Absolute delta activity decreased with age. Relative delta and theta decreased and alpha and beta increased with increasing age. The theta/alpha and theta/beta ratios decreased with increasing age. All of these indicated a developmental reduction in slow wave activity. Maturational differences were found in the rates of change between the midline and the two hemispheres. In the absolute delta and the theta/beta ratio, the midline and the two hemispheres became more equipotential with age. In the beta band, power increased at a greater rate than in the two hemispheres. Sex differences were found, with males having less theta and more alpha than females.

Conclusions: These results indicated that maturation occurs earlier at the midline than in the two hemispheres. Females were also found to have a developmental lag in the EEG compared with males.

MeSH terms

  • Age Factors
  • Aging / physiology*
  • Alpha Rhythm
  • Beta Rhythm
  • Brain / physiology*
  • Child
  • Child Development / physiology*
  • Delta Rhythm
  • Electroencephalography*
  • Female
  • Functional Laterality
  • Humans
  • Longitudinal Studies
  • Male
  • Reference Values
  • Sex Characteristics
  • Theta Rhythm