Brain Quickly Detects Happiness in Others

MONDAY, July 6 (HealthDay News) -- When it comes to picking up emotional signals from others, the brain responds to happiness faster than sadness, a new study has found.

Researchers at the University of Barcelona in Spain zeroed in on the right cerebral hemisphere as the brain's center for processing emotional signals from other people. Not only does the right hemisphere process emotions faster than the left hemisphere, it's particularly eager when it comes to happy vibes, they found.

"Positive expressions, or expressions of approach, are perceived more quickly and more precisely than negative or withdrawal ones," study author J. Antonio Aznar-Casanova told a Spanish science news service. "So, happiness and surprise are processed faster than sadness and fear."

The researchers tested 80 psychology students -- 65 women and 15 men -- using the "divided visual field" technique to determine which hemisphere processes the information faster. The study is part of a growing body of research into the brain's asymmetry and how the two hemispheres are able to get a reasonably accurate first impression of people's social signals after seeing their faces for only a tenth of a second.

Scientists are settling on two theories. One theory puts much of the emotional processing workload, both positive and negative, on the right hemisphere. The other theory -- known as the approach-withdrawal hypothesis -- suggests that both hemispheres play a part, with the left one better at crunching negative data.

Determining how people make value judgments based on first impressions is important in many areas of society, said Aznar-Casanova, adding that "these inferences can strongly influence election results or the sentences given in trials."

The findings are reported in the third issue this year of the journal Laterality: Asymmetries of Body, Brain and Cognition.

More information

The U.S. National Institute of Neurological Disorders and Stroke has more on the brain.