[Reciprocal relationships between oscillatory systems of the brain]

Resting EEG data were collected from a sample of 146 children aged from 7 to 17 years and 132 adults aged from 18 to 32 years. Eysenck's, Spilberger's, Gray-Wilson's, and Goodman's questionnaires were used to assess personality and psychopathology. Using factor analysis, the covariance between spectral power measures was decomposed into factors reflecting common positive covariance and reciprocal relationships among different frequency bands. The latter were treated as measures of inhibitory interactions between different oscillatory systems. In children, the common positive covariance was higher, and inhibitory interactions were weaker than in adults. In adults, trait anxiety was positively related to the strength of reciprocal relationship between alpha and delta oscillatory systems. In children, similar relationship was found between anxiety and the strength of reciprocal relationship between theta and delta oscillatory systems. Findings are discussed in terms of evolutionary interpretation of brain oscillations.