Duke University Medical Center researchers have discovered that distinct regions of the human brain are activated when people are faced with ambiguous choices versus choices involving only risk. The investigators found the reason behind why people make risky choices, and how such risk-taking can become an addition or lead to compulsive gambling. The study results were published in the journal Neuron.
The research was supported by the National Institute of Mental Health, the National Institute of Neurological Disorders and stroke and Duke.
Scott Huettel, Ph.D., lead author and a neuroscientist with the Brain Imaging and Analysis Center at Duke University said that each individual's brain activity differed depending on the person's preferences or aversions to risk and ambiguity. People who preferred ambiguity had increased activation in the prefrontal cortex, and people who preferred risk had increased activation in the parietal cortex. This shows that each type of decision making is due to the activation of specific neural mechanisms.
the participants included in the study were 13 adult who were asked to choose between pairs of monetary gambles that were predetermined to be certain, risky or ambiguous. In case risky choices the subjects were told the odds that they would win the gambles, but for the ambiguous choices they were not given this information. The participants were rewarded with a cash payout based upon whether or not they won their gambles.
The researchers used functional magnetic resonance imaging (fMRI) to determine which areas of the brain were activated while people were making risky or ambiguous choices. They found that activation of specific brain regions depended on participants' preferences for risk or for ambiguity. By this experiment one can tell whether a person by nature is impulsive by analyzing their brain which would prefer risky gambles to those that were ambiguous.
Michael Platt, Ph.D., a neurobiologist and co-author of the study said that Impulsive behavior can be associated with all sorts of mental disorders like addiction or problem gambling. If it was possible to change the way people perceive risk and ambiguity by introducing a medication that could influence brain chemistry then we might be able to alleviate some types of pathological decision making.
The experiments were an eye opener in the direction of the new and emerging field of neuroeconomics. Neuroeconomics is a relatively new area of research in which neuroscientists, economists, psychologists and psychiatrists together work to better understand how the brain works when people make decisions, evaluate risk, and receive rewards.
Jill Stowe, Ph.D., a decision scientist with Duke's Fuqua School of Business and co-author of the study said that the results help in understanding how people evaluate risky and ambiguous options in different ways.