Autocorrelation and cross-correlation analyses of alpha waves in relation to subjective preference of a flickering light

Abstract

To clarify the relationship between the human brain activity and subjective preference of a flickering light under changing temporal frequency and mean luminance, alpha waves were analyzed by autocorrelation function (ACF) and cross-correlation function (CCF). Paired-comparison tests were performed to examine the subjective preference of a flickering light. Electroencephalograms (EEGs) were recorded from 7 electrodes (10-20 system) during presentations of the most preferred and the least preferred flickering-light conditions. From the initial delay range of the ACF, the effective duration (/spl tau//sub e/) was determined to describe the temporal characteristics of the alpha waves. Results show that the preferred flickering light has a significant larger /spl tau//sub e/ than that of the least preferred flickering light especially at the occipital area. In addition, the maximum value of the CCF (|/spl phi/(/spl tau/)|/sub max/) between the alpha waves and its delay time were analyzed. Results show that the preferred flickering light has a significant larger |/spl phi/(/spl tau/)|/sub max/ than that of the least preferred flickering light.