Rodent of the week: Stress impairs decision-making skills

People are often advised to avoid making important decisions when they're under a lot of stress. Now a study on rats shows too much stress can lead to cloudy thinking.

University of Washington researchers presenting their work at this week's annual meeting of the Society for Neuroscience found that stressed rats took much longer to respond to a change in rewards given to them in a maze and performed worse than those not exposed to stress. After the changes were made to the rats' maze, those that weren't exposed to stress collected the new reward on 35 out of 40 trials. But rats that were stressed (with a series of unpredictable tail shocks for one hour) were only successful on about 23 of 40 trials. Even after several more days, their performance increased only to 26 out of 40 trials.

Even one episode of stress can cause long-lasting cognitive impairment, concluded the researchers, Lauren Jones, a psychology doctoral student, and Jeansok Kim, an associate professor of psychology.

"Decision-making, both large and small, is part of our lives," Kim said in a news release. "People are prone to make mistakes under stress. Look at what has been going on with the stock market. People are under huge amounts of stress and we have to question some of the decisions that are being made."

-- Shari Roan

Photo: Advanced Cell Technology Inc.