Genetic and environmental influences on frontal EEG asymmetry and alpha power in 9-10-year-old twins.

Modest genetic influences on frontal EEG asymmetry have been found in adults, but little is known about its genetic origins in children. Resting frontal asymmetry and alpha power were examined in 951 9-10-year-old twins. Results showed that in both males and females: (1) a modest but significant amount of variance in frontal asymmetry was accounted for by genetic factors (11-28%) with the remainder accounted for by non-shared environmental influences, and (2) alpha power were highly heritable, with 71-85% of the variance accounted for by genetic factors. Results suggest that the genetic architecture of frontal asymmetry and alpha power in late childhood are similar to that in adulthood and that the high non-shared environmental influences on frontal asymmetry may reflect environmentally influenced individual differences in the maturation of frontal cortex as well as state-dependent influences on specific measurements.