Risk Tolerance Linked to Two Brain Regions

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A new study published in the journal Neuron links willingness to take risks to brain structure and function, specifically the amygdala and the prefrontal cortex, and connections between the two.

According to Jung et al, risk tolerance was positively associated with functional connectivity between amygdala and medial prefrontal cortex and negatively associated with structural connectivity between these regions. Image credit: University of Pennsylvania.

According to Jung et al, risk tolerance was positively associated with functional connectivity between amygdala and medial prefrontal cortex and negatively associated with structural connectivity between these regions. Image credit: University of Pennsylvania.

“The more the amygdala and medial prefrontal cortex are functionally connected, the greater tolerance for risk individuals have. In addition, more risk is associated with a larger amygdala. But a structural connection goes in the opposite direction; the fewer connections you have there, the more tolerant of risk you are,” said study senior author Dr. Joseph Kable, a researcher in the Department of Psychology at the Perelman School of Medicine at the University of Pennsylvania.

Dr. Kable and co-authors recruited 108 healthy 18- to 35-year-olds to participate in a study focused on understanding why people act in ways detrimental to their health and whether it is feasible to positively shape such actions.

Part of the trial comprised a single MRI imaging session that evaluated many different brain regions, called a multi-modal imaging assessment.

The researchers also put participants through a rapid-fire decision-making exercise, asking them to choose between receiving a small-but-certain reward, $20, or a larger-but-tentative one, ranging from $21 to $85. The degree of chance for the latter scenario changed, hitting anywhere from 9% to 98%.

Participants made more than 100 of these decisions to expose a clear picture of their overall risk-tolerance level.

To ensure that the scientists were getting at true openness to risk, the contributors’ final decision had real financial consequences:

(i) Option 1: definitively leave with $20;

(ii) Option 2: roll the metaphorical dice for the chance to receive a larger dollar value — or perhaps walk away with nothing at all.

“Decision-making tendencies are a good indicator of someone’s tolerance for risk, whether he’s someone who is risk-averse and takes the safe option or risk-seeking and willing to take as much risk as we’ll give to get a higher payoff,” Dr. Kable said.

“These findings could have implications for many of the health-specific choices people make on a day-to-day basis, such as how much junk food they eat or whether to stop smoking,” said co-author Professor Caryn Lerman, from the Department of Psychiatry at the University of Pennsylvania.

“On a continuum from conservative to daredevil, those who fall closer to the latter, for example, are more likely to take up smoking and less likely to quit once they begin.”

“There are also implications for mood disorders like attention deficit hyperactivity disorder and anxiety, as well as disorders of impulse control like gambling and addiction.”

“If you can characterize patterns of risk tolerance and the associated structural and functional neural markers, we could identify individuals who are most susceptible to these conditions and target preventive efforts accordingly.”

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Wi Hoon Jung et al. Amygdala Functional and Structural Connectivity Predicts Individual Risk Tolerance. Neuron, published online April 5, 2018; doi: 10.1016/j.neuron.2018.03.019