Newfound Brain Switch Labels Experiences as Good or Bad

Ingrid Wickelgren in Scientific American:

For as long as she can remember, Kay Tye has wondered why she feels the way she does. Rather than just dabble in theories of the mind, however, Tye has long wanted to know what was happening in the brain. In college in the early 2000s, she could not find a class that spelled out how electrical impulses coursing through the brain’s trillions of connections could give rise to feelings. “There wasn’t the neuroscience course I wanted to take,” says Tye, who now heads a lab at the Salk Institute for Biological Studies in La Jolla, Calif. “It didn’t exist.” When she dedicated a chapter of her Ph.D. thesis to emotion, she was criticized for it, she recalls. The study of feelings had no place in behavioral neuroscience, she was told. Tye disagreed at the time, and she still does. “Where do we think emotions are being implemented—somewhere other than the brain?”

Since then, Tye’s research team has taken a step toward deciphering the biological underpinnings of such ineffable experiences as loneliness and competitiveness. In a recent Nature study, she and her colleagues uncovered something fundamental: a molecular “switch” in the brain that flags an experience as positive or negative. Tye is no longer an outlier in pursuing these questions. Other researchers are thinking along the same lines. “If you have a brain response to anything that is important, how does it differentiate whether it is good or bad?” says Daniela Schiller, a neuroscientist at the Icahn School of Medicine at Mount Sinai in New York City, who wasn’t involved in the Nature paper. “It’s a central problem in the field.”

More here.