Sex-specific amplitude and coherence changes in the EEC of rest

Sex-specific EEG differences with open versus closed eyes were studied by m eans of spectral analysis in two groups each of 15 females and mates. Betwe en 0.5 and 25.0 Hz the EEG was divided into ten frequency bands. For each o f them, the following parameters: amplitude at the 19 recording positions, and coherence between all possible electrode combinations, were computed fo r periods of 2 min. Here are the main results: 1. With opened eyes coherence in theta, alpha and beta decreases frontally in both genders; in the posterior regions it increases in males in particul ar in alpha1 (8.0-10.0 Nz) and beta3 (18.0-20.0 Hz), which is interpreted a s a sex-specific difference in visual information processing. The observed frequencies in changes of amplitude;and coherence in women and men are tabu lated. 2. Delta1 (0.5-2.5 Hz) shows differences in coherence and indicates increas ed interhemispheric co-operation with open eyes, more distinctly in males t han in females. A possible metabolic reason for this is discussed.