Eeg Oscillations During Menstrual Cycle

Abstract

12 sessions of EEG activity, one every second day, were recorded at F3, F4, C3, C4, P3, P4, O1 and O2 in 9 women with regular menstrual cycles. The following significant oscillations were observed: 1) absolute power was lower during periovulatory period; 2) absolute power of delta theta and alpha1 was higher during premenstrual period whereas absolute power of alpha2, betal and beta2 was higher during menstruation; 3) relative power of low alpha frequencies was lower and that of high frequencies was higher during premenstrual period; 4) interhemispheric correlation between frontals was higher during ovulation and between occipitals was higher during premenstrual phase; 5) no significant power asymmetries were observed. The present findings suggest higher activation of centro-parietal regions during menstruation and lower activation of frontal regions during premenstrual phase.

Key Words:

• Absolute power
• relative power
• interhemispheric correlation
• intrahemispheric correlation
• EEG
• menstrual cycle