Audiovisual stimulation to influence alpha brain oscillations: An EEG study of gender differences

We focused on gender differences regarding audiovisual stimulation on the alpha activity, as measured by the EEG. The bipolar “double banana” montage was used, placing nineteen scalp electrodes according to the 10–20 system. Subjects were 30 healthy, right handed, individuals, 15 males (mean age: 23.47 ± 3.39) and 15 females (mean age: 22.8 ± 3.74). The protocol consisted of 12 audiovisual stimuli: an 8 Hz binaural beat (right 450 Hz–left 442 Hz) combined with an 8 Hz flickering light at 4 different colours (RGBY), a 10 Hz binaural beat (right 450 Hz–left 440 Hz) combined with a 10 Hz flickering light at 4 different colours (RGBY), and 4 placebo stimuli (100 Hz flickering RGBY light combined with 100 Hz at both ears). The duration of the experiment for each subject was 653 s. Results were analyzed using the ERD/ERS method for lower (8–10 Hz) and upper (10–12 Hz) alpha band. Statistical analysis highlight significant gender differences concerning the stimuli’ effect at P4-O2 channel at specific time intervals: 1. Lower alpha: Green 8 Hz (0–300 ms) and Placebo red (500–900 ms) resulted in synchronization for females and desynchronization for males. Green 10 Hz synchronized (0–200 ms) for males and desynchronized for females. 2. Upper alpha: Placebo blue resulted in synchronization (200–600 ms) for females and desynchronization for males. Green 10 Hz synchronized (600–800 ms) for males while it desynchronized for females