Propagation of repetitive alpha waves over the scalp in relation to subjective preferences for a flickering light

Paired-comparison tests were performed to examine subjective preferences for a flickering light. Electroencephalograms were then recorded from seven electrodes (10-20 system) during presentations of the most and least preferred flickering-light conditions. As a way of investigating the flow of alpha waves on the scalp over both the left and right hemispheres in relation to subjective preference, the alpha waves were analyzed by means of the cross-correlation function (CCF). The maximum value of the CCF, /phi(tau)/(max), between the alpha waves measured at different electrodes and its delay time, tau(m), were analyzed. Results show that the most preferred flickering light has a significant larger /phi(tau)/(max) than the least preferred flickering light, and that /phi(tau)/(max) decreases with increasing distance between comparison (O(1) or O(2)) and test electrodes. On the other hand, the delay time of the maximum value of the CCF, tau(m), increases with the distance between comparison and test electrodes.