Figure 3From: Preliminary evidence that both blue and red light can induce alertness at nightAverage relative (percent) power for alpha frequencies and beta frequencies for each lighting condition. Higher levels of EEG alertness were associated with light than with dark; see text for details. Each pair of panels (A through I) represents the average relative (percent) power for alpha frequencies (α) and beta frequencies (β) obtained for a set of lighting conditions relative to those recorded during the corresponding set of preceding dark conditions. Error bars represent ± standard error of the mean (s.e.m.) for each condition. Asterisks represent significant differences (p < 0.00625). Panel A compares α and β obtained from all lighting conditions compared to α and β from the preceding dark conditions. Panels B and C compare α and β for the two light colors relative to α and β for the preceding dark conditions. Panels D and E compare α and β for the two light levels relative to α and β for the preceding dark conditions. Panels F through I compare α and β for the four combinations of light color and light level relative to α and β for the preceding dark conditions.Back to article page