Older adults are less inclined to take certain types of risks, such as participating in a lottery, due to changes in brain anatomy rather than age, according to a new study.
The finding adds to scientific understanding of decision making and may lead to strategies for modifying changes in risk behaviour as people age.
Researchers from the Yale University and the New York University in the US examined the phenomenon in older adults, who experience a natural decline in grey matter volume with age.
They studied whether changes in grey matter volume in the posterior parietal cortex or ageing itself, accounted for older adult’s tendency to avoid risk.
They presented a series of choices to 52 participants, aged 18 to 88 years. Participants could either receive some money or take their chances with a lottery of varying amounts and probabilities. For example, a participant could choose the certain gain of $5 or opt for a 25 per cent chance of getting $20. Participants were each assigned a number denoting their level of risk tolerance based on their choices.
Researchers also measured the gray matter volume in the posterior parietal cortex of each subject, drawn from MRI scans. After analysing the risk choices and MRI measurements, the researchers confirmed that age-related decline in risk tolerance correlates more with changes in brain anatomy than with age.
“We found that if we use both the gray matter volume and age together as predictors of risk attitudes, the gray matter volume is significant, while age is not,” said Ifat Levy, associate professor at Yale University.
“This means that grey matter volume accounts for age-related changes in risk attitude more than age itself,” said Levy.
The finding provides new insight into neurological factors that affect risk preferences and decision making among older adults. It may also lead to strategies for modifying decision making.
“We could use this understanding in order to try to, behaviourally or pharmacologically, change flawed decision making,” said Levy.
“By understanding the basic processes at the core of complex behavioural changes, we facilitate ways to intervene and improve decision making,” she said.