Changes of EEG and CBF Induced by Visual Tasks under Sunlight and Fluorescent Light

Abstract

Effects of artificial sunlight and fluorescent light were compared for the visual tasks in human, and the power of EEG and near-infrared spectroscopy (NIRS) were examined. The subjects were 12 healthy students, and the Raven′s Coloured Progressive Matrices were used for the visual task. The artificial sunlight lighting increased the beta power of EEG (P = 0.023), Oxy Hb (P = 0.049) and Total Hb (P = 0.034) by NIRS (Wilcoxon signed-rank test) compared with the fluorescent light lighting. These results indicate that artificial sunlight lighting may be useful for the activation of human brain during eye opening and visual tasks comparing with fluorescent light lighting. It has been reported that the circadian rhythm of melatonin production in mammals is regulated by the retinohypothalamic projection system, which includes the medial forebrain bundle and the reticular formation, and this retinohypothalamic projection system may have an important role in the activation of the brain under artificial sunlight lighting.