Stress hormone may switch brain between random and strategic thinking
A new study has determined that the human brain may be capable of switching between two different types of thinking--random and strategic.
Random thinking occurs when the brain disconnects past experiences from decision-making brain regions, which causes a person to disregard previously-learned lessons and engage in random behavior. Strategic thinking occurs when the brain draws upon lessons previously learned and makes informed decisions.
In the study, scientists at Howard Hughes Medical Institute's Janelia Research Campus aimed to determine whether the brain has a method of switching strategic thinking on and off.
Using rats, the researchers created an unpredictable environment, in which a computer determined which of two holes would produce a sweet treat. The computer was able to analyze the rats' behavior, predict future behavior and change its actions accordingly. The researchers then used the computer as a sophisticated competitor, which they knew would either cause the rats to figure out how to be a better competitor or give up and switch into random behavior.
The researchers found that when the computer was turned to a low sophistication setting, the rats were able to make strategic choices based on previous trials. They also found that when the computer was turned to a higher sophistication setting, the rats seemed to disregard previous outcomes and followed random behavior.
Following the trials, the researchers investigated the rats' brain mechanisms that were responsible for switching from strategic to random thinking. They found that a stress hormone called norepinephrine was responsible for the change in thinking, and that by manipulating its release, they could switch the rats' behavior between random and strategic modes.
Furthermore, the researchers found that by suppressing the release of the stress hormone into a certain part of the brain--the anterior cingulate cortex--they were able to release the rats from the random mode behavior.
Researchers said that the study's findings, published in the journal Cell, may help them understand how the stress hormone may lead to conditions such as "learned helplessness" and find ways to help alleviate them. The next step will be to examine how random and strategic behaviors are controlled in everyday settings.
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