Quality of light modulates emotional brain responses in humans

Light therapy can be an effective treatment for seasonal mood disorders, suggesting that light and mood may be connected. Researchers using functional magnetic resonance imaging of the brain in human subjects have observed that blue light (compared to green) increased responses to emotional stimuli in selected areas such as the hippocampus and temporal cortex. Considering that blue-enriched white light in the workplace has been reported to improve self-reported alertness, performance and sleep quality, these results may have therapeutic potential for mood disorders in humans.
Vandewalle G et al., Spectral quality of light modulates emotional brain responses in humans. Proc. Natl. Acad. Sci. USA 107: 19549-19554 (2010).
http://www.ncbi.nlm.nih.gov/pubmed/20974959