Research: risk avoidance in old age is related to brain structure - not age

Can brain structure explain people's tendency to take risks? A new study shows that the amount of gray matter, in a certain area of ​​the brain, predicts in a good and significant way the level of personal risk-taking.

A new study by Dr. Sharon Gilai-Dotan from the Department of Optometry and Vision Sciences at the Faculty of Life Sciences at Bar-Ilan University found that avoiding risks in old age is related to brain structure and not age. The study was conducted by Dr. Gilai-Dotan and her partners, Prof. Yifat Levy from Yale University and Dr. Michael Grove from Trinity College, Agnieszka Timola from the University of Sydney, and Prof. Paul Glimzer from New York University.

The study was published in the journal Nature Communication.

For many years, researchers have been searching, without success, for a biological characterization (marker) of the levels of risk-taking in humans, the research group wanted to test whether brain structure can explain people's tendency to take risks. This study, and a previous study, show for the first time that the amount of gray matter in a certain area of ​​the brain predicts in a good and significant way the level of personal risk-taking. The researchers examined the phenomenon in adults up to old age who experience a natural decrease in gray matter with age. The research group examined whether changes in gray matter in the same area identified in the previous study, or aging itself, could explain the tendency of adults to avoid taking risks.

Dr. Gilai-Dotan: "As we get older, we are less inclined to take risks, but it is possible that this behavioral preference is related to changes in the structure of the brain and not to age." According to her, "the research result adds to the understanding of the mechanisms that support decision-making and may lead to treatment strategies related to the changes that occur in risk-taking as people age. Studies have shown that older people are less likely to take certain types of risks, such as participating in lotteries. In a previous study, we showed that there is a relationship between willingness to take financial risks and the volume of gray matter in a posterior region of the brain, also called the posterior parietal cortex. That is, the more gray matter there was for young adults, the more likely they would take risks."

In the study, the researchers presented a series of choices to 52 male and female participants between the ages of 18 and 88. Participants could choose in each trial between receiving $5 and taking the risk of drawing varying amounts with varying odds of winning. For example, a participant could choose between $5 and a 25% chance of getting $20. For each participant, the level of personal risk-taking was calculated according to the choices made in the experiment. In addition, the researchers measured for each of the participants the gray matter in the posterior parietal cortex by brain MRI scans.

"After analyzing the results, the researchers confirmed that a decrease in risk-taking with age is more in line with brain structure than with age," says Dr. Gilai-Dotan. "We found that if we use gray matter volume and age as predictors of risk-taking propensities, gray matter volume predicts the propensity to take financial risk so well that age no longer has anything left to explain." This means that the volume of the gray matter explains changes in risk taking better than the age factor." Dr. Gilai-Dotan concludes, "The finding provides new insights regarding neurological factors related to risk-taking and decision-making in the older population. This data can lead to strategies to change decision making. That is, we can use these insights to try to intervene, change and improve decision-making processes, whether by way of behavior or through drugs."

The research was supported by grants from the National Institutes of Health (NIH) in the USA.

The full article can be found On the website of Dr. Gilai-Dotan's laboratory.