'Rational' Decisions Clouded by Emotions
Excerpt By John Schieszer, Reuters Health

SEATTLE (Reuters Health) - Decisions that we make every day, such as whether to take a hot bath or use a seat belt, have an emotional component, researchers at the University of Washington say. Their findings may explain why it's difficult for people with certain types of brain injury to make so-called rational personal decisions, they add.

``The circuits are very intertwined. There isn't just one separate part of the brain that drives us in emotional decisions and another part that drives us in rational thinking. In fact, when decisions are personal even if they are not emotional, the emotional part of the brain is actively involved,'' said Dr. Dean Shibata, an assistant professor of radiology at the University of Washington in Seattle.

The old concept of the brain and decision-making divided the concept of thinking into very separate ``rational'' and ''emotional'' components, while the current view is these components are integrated and overlapping, Shibata explained.

Using functional magnetic resonance imaging (fMRI) in volunteers to scan brain activity during the decision-making process, Shibata and his colleagues found the part of the brain typically involved in emotions, the ventromedial frontal lobe, was highly active even when the volunteers were making what typically would be considered rational decisions.

In the study, six men and five women underwent two fMRI scans each. During each scan the participants had to perform two tasks: choosing the better of two desirable events, such as taking a warm bath or eating a good meal, or choosing the worse of two undesirable events, such as being in a car accident or getting robbed. In the first scan, people were asked to make their decision based on how it would affect them personally. In the second, people were asked similar questions, but told to base their choices purely on cost, not on how the decision would affect their lives.

On average, the fMRI scans showed significantly more activity in the ventromedial frontal lobe when the people were making the simple personal decisions than when they were making the choices based on cost.

``It gives some insight I think into our psychological process in everyday life that perhaps we are not aware often of how we make decisions,'' said Shibata in an interview with Reuters Health. ``Our rational decisions are more biased than we may think.''

These findings also are very important, he noted, because they suggest that when someone suffers an injury to the part of the brain that governs emotion, the person may have normal memory and be able to solve abstract problems. But at the same time they may have trouble making routine, rational decisions for themselves.

``If you eliminate the emotional guiding factors, it's impossible to make decisions in daily life,'' Shibata explained. ''Even while making a decision, such as 'should I put on my seatbelt?' you intuitively realize that, without the seatbelt, you might get hurt in a crash. That's an emotional image. If you can't envision that, you can't make the decision to wear the seatbelt.''

The study findings suggest fMRI might be useful in helping to diagnose psychiatric disorders such as schizophrenia or depression, which may involve abnormal metabolism on the ventromedial frontal lobes.

``This area of research is important for two reasons because it helps us understand the human decision-making process,'' Dr. Randy Buckner, an associate professor of psychology, radiology and neurobiology at the Washington University School of Medicine in St. Louis, told Reuters Health. ``We all have intuitions about how it works but for the first time, using these kinds of tools, we can take a direct look. The other reason is, we have in our society individuals who don't make good decisions and we want to understand why.''

Shibata suggests that in the future it may be possible to use fMRI during psychotherapy. This could involve imaging the parts of the brain involved in decision-making and tailoring medicines to the part of the brain that may be impaired or malfunctioning.

Shibata presented his study findings Monday at the 87th Scientific Assembly and Annual Meeting of the Radiological Society of North America in Chicago, Illinois.

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