In an excellent monograph the author presents a study of the influence of heredity within normal patterns of the electroencephalogram. His series included 208 pairs of normal twins, of whom 110 were monozygotic and 98 dizygotic. Their ages ranged from 6 to 30 years. The electroencephalograms were made on a 16-channel machine permitting the simultaneous recordings from the twin pair with eight leads for each individual. The EEG's were recorded during rest, hyperventilation, oxygen deprivation, and natural sleep.
The parameters measured were the basic rhythm, the alpha index, the subalpha percentage (introduced by the author), the average wave amplitude, the wave continuity, and the phase coordination. An identification test after Travis and Gottlober was performed.
The results indicate that in the resting EEG as well as those taken during hyperventilation and oxygen deprivation there is, with rare exceptions, no constant difference of the cerebral electrical activity in monozygotic twins, whereas