Fig. 2
From: Suppression of salivary melatonin secretion under 100-Hz flickering and non-flickering blue light
Temporal changes in the mean melatonin concentrations under dim (dark circle), non-flickering (gray diamond), and 100-Hz flickering blue light (white square). Data are shown as mean + S.D. A number of the subject was eleven. Single asterisk (*) means statistical significance (p < 0.05) between light conditions by a repeated measures t test with the Bonferroni correction