The effects of a single session of audio-visual stimulation (AVS) at the dominant alpha rhythm and twice-dominant alpha frequency on EEG coherence were studied in 23 subjects. An eyes-closed baseline EEG determined each subject’s dominant alpha frequency. Subjects were stimulated at their dominant alpha frequency or at their twice dominant alpha frequency for 20 minutes, while EEG was recorded in five-minute intervals. A post-session baseline was recorded 30 minutes after each session.
AVS decreased coherence in the intrahemispheric projections from the occipital region and the parietal midline, and generally increased coherence, with few exceptions, among all other longitudinal pairs. Interhemispheric coherence increased posteriorly and at high frequencies, and tended to decrease frontally and at low frequencies. Alpha AVS was more effective than twice-alpha AVS at increasing interhemispheric coherence, and tended to produce more effects overall…