Is blue a cure for the blues? Researchers have learned how the color of light can affect the internal clocks in humans' and animals' bodies. They also learned that the brain's internal clock determines this change in color.
The University of Manchester scientists identified the neurological devices for how the human's internal clock measures changes in hues that occur from dusk to dawn. They discovered that light's intensity changes during sunrise, sunset, and twilight.
The scientists used mice as the study's subjects, since the nocturnal animals are active at night. Another benefit is that mice's brains are quite similar to humans' brains, sharing many neurons and chemicals, according to The Market Business.
The researchers used various visual stimuli, and then recorded the brain clock's electrical activity. They learned that the brain's neurons were more sensitive to changes in color between yellow and blue, instead of changes in brightness.
From the top of one of the university's buildings, the scientists created an artificial sky stimulus by using changes in color and brightness. Mice participating in the study were put below the artificial sky for several days.
The researchers recorded the highest body temperatures soon after sunset. That is the time when the sky turned blue, indicating that the body's clock was optimized then.
However, when the researchers only changed the sky's brightness, the mice's body clock functioned poorly, according to American Live Wire. Also, the creatures were more active before sunset.
A researcher explained that this was the "first time" scientists were able to test the theory that color affects the internal clocks of mammals. By using new "experimental tools" they could separate the change in color and brightness.
The researchers' findings in the experiments with mice can also be applied to humans. Colors could be changed to "manipulate" the internal clocks of worldwide travelers or shift workers, for example.
Another application of the study is for people with Seasonal Affective Disorder (SAD). Better treatments could be developed for people who experience depression due to less sunlight in wintertime.
The researchers' findings were recently published in the journal PLOS Biology.