Human cortical responses corresponding to the subjective preference for a flickering light under varying temporal frequency and mean luminance were investigated. Paired-comparison tests were performed to examine the subjective preference for a flickering light, and electroencephalograms (EEGs) were recorded from six electrodes (10-20 International Electrode Placement System) during presentations of the most-preferred and least-preferred flickering lights. The results showed a positive correlation between subjective preference and the effective duration of the autocorrelation function of the alpha waves measured at the visual cortex (O1 and O2 electrodes).