Why Stress Hurts Your Concentration

Stress affects neurons in prefrontal cortex that manage working memory

(RxWiki News) It is well known that stress can make it harder to concentrate. Math problems, for example, are more difficult when a person is stressed out. Until recently, researchers were not sure why.

A new animal study suggests that stress affects neurons involved with the working memory in the brain. These neurons are in an area of the brain called the prefrontal cortex (PFC).

When stressed, the activity of these neurons actually changes making it more difficult to solve problems.

"Ask your psychologist about healthy ways to manage stress."

The study was led by David Devilbiss, PhD, of the University of Wisconsin - Madison Department of Psychology.

"Based on drug studies, it had been believed stress simply suppressed prefrontal cortex activity," said study co-author Craig Berridge, PhD. "These studies demonstrate that rather than suppressing activity, stress modifies the nature of that activity."

The researchers put rats in the maze with chocolate marking the path to the exit. Without stress, the rats completed the maze about 90 percent of the time.

However, when a very loud and stress-inducing ‘white noise’ sound was played, the rats only completed the maze 65 percent of the time.

By measuring the electrical signals in the brains of the rats, researchers were able to pinpoint a specific group of neurons in the PFC part of the brain that regulates how long information is stored in the neurons. What they found is that as these neurons changed their activity under stress, the PFC was not able to hold information for as long.

These changes in neuron activity resulted in the rats becoming easily distractible.

More research is necessary in order to understand the neuronal activity in humans, but researchers believe that there are great safety implications involved with understanding how stress affects the brain’s ability to concentrate.

"Stress plays a role in more than half of all workplace accidents, and a lot of people have to work under what we would consider a great deal of stress," adds Devilbiss. "And now we know that this distraction is happening at the level of individual cells in the brain."

The study was published September 13, 2012 in the journal PLOS Computational Biology and was funded by the University of Wisconsin - Madison.

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Review Date: 
September 14, 2012