Life is full of decisions. From what you eat at night to how you invest your savings, whether you should undergo surgery, whether you should start taking a new drug, and so on.
In fact, the strategies we use to make these decisions are not static, they evolve over time. There has been a lot of research showing that as we get older, we tend to learn more from past experience, take fewer risks, and make decisions faster when we make decisions.
Based on decades of research into the nerve cells and circuits involved in decision-making, neuroscientists have now begun exploring age-related changes in the brain that may be the root cause of changes in decision-making behavior.
At the same time, research is constantly challenging long-standing stereotypes about cognitive decline. Scientists are increasingly finding that many of the differences in age-related behavior and learning abilities may come not from neurodegenerative changes, but from active remodeling of neural circuits. As we get older, it's not so much that everything gets worse than everything that changes.
Neuroscientists believe that a deeper understanding of these changes, and how they perform cognitively and neurologically, can help people, especially older adults, avoid being scammed, better manage their retirement savings, and make better decisions.
Decision-making patterns over a lifetime
Decision-making involves many steps, each of which requires a complex process by the brain. Taking a car change as an example, you first need to realize that your old car has passed its "golden age" and it is time to buy a new car. If you continue to advance this idea, you may start gathering information, assessing which sources are trustworthy, and comparing the advantages and disadvantages of various options. Finally, you have to pay for a new car and evaluate the decision. This process will become your memory and provide a reference for future decisions.
Over the past 20 years, lab studies have documented a variety of ways in which decision-making behavior changes with age, with pros and cons.
For example, older adults are more likely to delay or avoid making decisions than younger adults. Older people may not search for information as exhaustively, preferring to consider information that is important or familiar to them, using simpler strategies, such as considering only one feature or choosing the first option that looks good enough. They tend to use emotions to make decisions, focus on positive information, and become less willing to take risks.
Older people can also be more patient in making decisions. They are less likely to have the so-called time discount, which is a phenomenon that places more emphasis on faster returns. In other words, they are willing to wait longer for a bigger return, for example, choosing the latter in a multiple choice question that gets $10 today or $50 tomorrow.
On the other hand, research shows that as we age, decision-making seems to become less flexible. In laboratory studies, it was found that older adults often need longer to convert their options into new best choices.
The circuit of "aging"
Neuroscientists have begun to map out some of the basic neural circuits that support decision-making. This complex cognitive process involves many functions that are distributed throughout the brain, among which there are two areas that seem particularly important, namely the cortex and the striatum. The importance of the cortex is self-evident, and the striatum is a subcortical region that helps us deal with the consequences of our actions and adapt to changes in our environment. In studies of rodents, disrupting or disrupting neural circuits in these areas alters animal decision-making.
Striatum (red). | Image credit: Life Science Databases (LSDB)/Wiki Commons
Imaging studies of the human brain have shown that these regions change with age. The volume of gray matter in the frontal and apical regions of the cortex is important for making decisions, and over time, these areas tend to shrink due to neuronal degeneration. Both human and animal studies have shown that the link between the cortex and the striatum weakens as we age.
Some studies have begun to link age changes in the cortical parts to differences in decision-making. In a 2021 study, hundreds of participants ranging in age from 17 to 54 completed a gambling task before undergoing structural MRI (magnetic resonance imaging). Participants before the age of 35, who became more willing to take risks as they grew older, began to increase their aversion to loss after the age of 35. The study found that people who were most loss-averse in old age had the thinnest posterior cingulate cortex, an area associated with emotional processing, reward signals, attention, and other decision-making processes.
Approximate location of the back of the human brain (red). | Image credit: Razvan V. Marinescu/Wiki Commons
Researchers are now delving into age-related changes in decision-making circuits, such as exploring how evolving connectivity in the prefrontal cortex affects decision-making throughout life.
Early in life, the number of synapses in the brain grows rapidly, followed by an intensive deletion period. The brain's refined circuits in adulthood enable animals to make more consistent decisions about input information, while modelling studies have shown that adults use past experience more than younger people to make decisions.
Now, some scientists are studying how synapses change later in life. If, with age, another period of massive loss of synapses emerges, it may explain why decision-making flexibility has declined, making it more difficult to change behavior in some cases. Understanding how these structures change may help us understand changes in behavior.
In addition, scientists are looking for clues to neurotransmitters. There is growing evidence that for some people, the decline in dopamine's binding power in multiple regions changes the way we assess value and process rewards, thereby facilitating changes in decision-making. A 2021 study has found that the mode of transmission of dopamine differs in the striatum, depending on the type of decision made by the mice.
Such changes in connectivity and dopamine function may lead older adults to gravitate toward past decisions to make choices and rely more on retrospective strategies than younger people prefer forward-looking strategies. But on a more detailed level, there are still many questions to be solved about exactly how they work.
Break down stereotypes
While stereotypes like to portray brain aging as worse in all areas, including the ability to make good decisions, overall regression doesn't seem inevitable. Studies have shown that often, neurological changes and psychological shifts reflect new strategies for navigating life choices.
In some ways, the brains of older adults may compensate for age-related changes to maintain or even improve decision-making tasks and make better decisions. In the real world, decision-making is often much more complex than laboratory research. Age-related changes can indeed bring some drawbacks, but there are also advantages that are easily overlooked.
For example, working memory and processing speed tend to decrease in aging brains, but older adults use a wider range of brain networks compared to younger people. Older adults may draw nourishment from a larger pool of experience and knowledge to make decisions more efficiently.
Also, even though we end up making more mistakes as we get older, those mistakes can be a useful part of the strategy shift process, and many times, things that look like a mess are actually an exploration. When we see mistakes in older adults, those mistakes may also reflect an aging brain trying to adapt to a new way of making decisions that will accommodate other brain changes associated with aging.
Understanding these behavioral shifts that occur with age, as well as changes in the brain regions and circuits that influence decision-making, can help us better understand the decision-making patterns of older adults. This is also to better understand themselves, after all, no one can avoid aging.
#创作团队:
Written by: Gaviota
Typography: Wenwen
#参考来源:
https://www.simonsfoundation.org/2022/03/02/how-decision-making-changes-with-age/
#图片来源:
Cover image: Marco Verch professional photographer/Flickr
First image: pixabay