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Study Finds Light Color Affects Mood

　　From VOA Learning English, this is the Health Report.
　　Some colors that people see late at night could cause signs of the condition mental health experts call (1)__________. That was the finding of a study that builds on earlier study findings. They show that individuals who live or work in low levels of light overnight can develop clinical depression.
　　Doctors use the words clinical depression to describe (2)__________ form of depression. Signs may include loss of interest or (3)__________ in most activities, low energy levels and thoughts of death or suicide.
　　In the new study, American investigators designed an experiment that exposed hamsters to different colors. The researchers chose hamsters because they are nocturnal, which means they sleep during the day and are (4)__________ at night.
　　The animals were (5)__________ into 4 groups. One group of hamsters was kept in the dark during their nighttime period. Another group was placed in (*) blue light, a third group slept in(*)white light. While a fourth was put in (*)red light.
　　After four weeks, the researchers noted how much sugary water the hamsters drank. They found that the more depressed animals drank the least amount of water.
　　Randy Nelson heads the Department of Neuroscience at Ohio State University. He says animals that slept in blue and white light (6)__________ to be the most depressed.
　　"What we saw is these animals didn't show any sleep disruptions at all but they did have mucked up circadian clock genes and they did show depressive phenotypes whereas if they were in the dim red light, they did not."
　　Randy Nelson notes that photosensitive cells in the retina, have little to do with eyesight. He says these cells send signals to (7)__________that controls what has been called the natural sleep-wake cycle.
　　He says there's a lot of blue in white light, this explains why the blue light and white light hamsters appear to be more depressed than the hamsters see red light or (8)__________.

　　Mr Nelson has suggestions for people who work late at night, or those who like to (9)__________.
　　"My recommendation is if you are just living a typical mostly active [life] during the day, mostly inactive at night, you want to limit exposure to TVs which are quite bluish in the light they give off and (10)__________ and things like that. You can get filtered glass, you can get filters on your computer screen and filters on your eReaders to put it more in the reddish light."
　　The report on the effects of light on emotions was published in The Journal of Neuroscience.
　　And that's the Health Report from VOA Learning English, I'm Christopher Cruise.

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