RMS measurements of amplitude symmetry were calculated for samples of typical active and quiet sleep periods in 12 normal full term, 5 premature and 7 Trisomy-21 infants from recordings obtained at 1, 4, 12, 26 and 52 weeks post term. The frequency distributions of the symmetry data for each group did not deviate significantly from the expected normal distributions. The mean symmetry ratios were not significantly different among the 3 groups. It was concluded that the EEGs of the 3 groups are characterized by amplitude symmetry in the first year of life. The possibility that symmetry data may be used for classification of abnormal EEGs was discussed. © 1981.
Peters, J. F., Varner, J. L., & Ellingson, R. J. (1981). Interhemispheric amplitude symmetry in the EEGs of normal full term, low risk premature, and trisomy-21 infants. Electroencephalography and Clinical Neurophysiology, 51(2), 165–169. https://doi.org/10.1016/0013-4694(81)90005-5