The blues make the world more gray.
Artists often depict sadness with sweeping gray tones. A new study in Biological Psychiatry finds that depressed individuals actually do perceive the world as more gray.
Lauren F. Friedman edits science stories at Business Insider and oversees the site's health coverage, from breaking news to reported features. She was previously an editor at Psychology Today, a fellow at The Forward, and a contributing writer for Philadelphia City Paper. She has also written for Scientific American, Scientific American Mind, The Philadelphia Inquirer, OnEarth, and other publications, and she's appeared on TV shows like Good Morning America and The Debrief to talk about health news.
Editor: Saad Shaheed
Ludger Tebartz van Elst, a researcher at the University of Freiburg in Germany, noticed that depressed patients had trouble rating the contrast levels of black and white images. To rule out the possibility that decreased attention (rather than vision) was to blame, van Elst had subjects watch a flashing image of a black and white checkerboard, while a scan recorded electrical impulses onthe retina.
Of the 32 subjects with below-average contrast responses, only one was not depressed, confirming van Elst's hypothesis. And the more severe the depression, the more impaired the perception. "You still see the windows, the tree, the book—but they look somehow different," he explains.
Certain contrast-perceiving retinal cells interact with dopamine, a neurotransmitter that plays a key role in the brain's system of emotion and reward. Researchers have long suspected a link between dopamine and depression, and, according to van Elst, this link might explain the hampered retinal performance.
A clear, measurable marker for depression could open up new possibilities for diagnosis. Research still needs to determine whether other psychiatric disorders have the same effect, but van Elst believes his findings hold promise. "I've never seen such a strong objective signal that tells apart depressed and non-depressed patients with such high predictive power," he says. —Lauren F. Friedman
Sound a Warning
Attention, those of you who can't write a memo or prep for a presentation without an iTunes playlist blaring: Listening to even your favorite tune impairs cognitive performance as much as listening to music you hate (death metal) or listening to a voice bleating random numbers, according to new research published in Applied Cognitive Psychology. Study with the sounds of silence.