What Your Life Experiences Can Do for Your Brain

The idea of getting older often leaves people uncertain about what to expect, especially when it comes to holding onto their mental acuity. These worries are only made worse by the racket in the media about the aging of the minds of political leaders. Despite the evidence to the contrary, it’s common to fear the prospect of getting old and losing one’s wits.

This evidence to the contrary often appears in scientific articles, but may not make it to the popular press. For example, since the early 2000s (at least), researchers in the field have pointed to the possibility of plasticity, both in the brain and in cognitive functioning. This evidence also includes the idea of “cognitive reserve,” the existence of a repository of both neurons and information that people acquire over their lifetimes. Like a bank, people can dip into this reserve to balance out losses that might occur due to normal aging or changes in the brain associated with chronic diseases.

Why, then, is this good news about aging so often dismissed? It’s extremely hard to overcome not just decades but centuries of looking at later life as a miserable period of existence (Shakespeare’s line- “sans teeth, sans eyes, sans everything”). However, with the aging of the population, this perspective is more important to keep in mind than ever. It can also provide individuals with hope about their own personal futures.

Modeling the Aging Mind

One of the most compelling arguments in favor of plasticity comes from a 2014 article by University of Tübingen Michael Ramscar and colleagues. Using computer modeling to simulate the amount of information the aging brain has acquired, the authors showed that if you stuff a computer with as much knowledge as people accumulate through life, such as names and facts, a computer will take as long and make as many retrieval errors as research on live subjects tends to produce. Think of how much new information you pick up every day, whether through a chat with a friend or by watching an episode of "Jeopardy!" on TV. Sorting through all of this could definitely take time and potentially be error-prone.

In a more recent article also using computer simulation, Ramscar and his associates (2017) conducted a similar investigation. This time, they were interested in finding out whether the adage “Old dogs can’t learn new tricks” could also be turned on its head.

The target in the 2017 article was the learning of “paired associates” (PAL). In a typical PAL experiment, participants must form associations between pairs of unrelated words across multiple trials. As Ramscar et al. report from prior research, the largest age differences in this ability occur not in later adulthood, but between the ages of 20 and 40 years. This seemingly preposterous result, the authors note, “cannot be construed as evidence of significant cognitive decline between the ages of 20 and 40 years.” Something else must be going on.

The authors suspected that PAL may be affected by the need, early in adulthood, to focus on learning experiences that make sense, not those that are randomly presented in a lab. To test this possibility, the authors compared the performance of native versus nonnative speakers ranging between the ages of 18-28 and 39-53 years. The monolinguals completed the PAL in their native language (German) and the bilinguals in two (Mandarin Chinese and German).

The findings supported the predictions that having a proper assessment of cognitive performance in healthy aging cannot be made unless the knowledge and skills that are inevitably accumulated as experience grows are controlled for. Older adults performed better in their second than in their first language except in the very hardest word pairs. The people who performed worse, furthermore, were those with advanced educational degrees, reflecting their greater exposure to language compared to individuals whose livings weren’t made through extensive reading. It’s worth pointing out that by “older,” the authors are including people in their 40s—again, those over the age shown in previous research to suffer PAL deficits.

As the authors concluded, their findings support the interpretation that, much as in the cramming of information in life that affects memory, a “well-discriminated lexical knowledge base” can create a “PAL cost.”

Putting these findings into perspective, Ramscar et al. further go on to note that “a proper assessment of cognitive performance in healthy aging cannot be made unless the knowledge and skills that are inevitably accumulated as experience grows are controlled for,” and, what’s more, scientific prudence further indicates that current beliefs about the supposed deterioration of cognitive faculties across the life span ought to be seriously questioned.”

The Brain’s Role in Continued Learning Potential With Age

This one study, though compelling, might not satisfy your need to be shown the counter-evidence about aging and decline. However, two 2024 studies of brain aging provide a complementary set of findings that augment the Ramscar et al. studies.

Underlying the cognitive abilities needed to learn and remember is the brain’s facility to coordinate incoming information and integrate it with the knowledge people already have. These processes require brain regions to communicate with each other, functions performed by the tracts of white matter, which, like insulated electric lines, shoot signals back and forth. The more extensive the white matter, the more efficiently these signals are both sent and received.

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Research from two recent studies investigating the integrity of the brain’s white matter among older adults shows positive roles for both education and lifestyle. More years of education could trip an older individual up when having to learn nonsense lists of word pairs, as Ramscar et al. showed. However, according to University of Granada’s Tibor Stöffel and colleagues (2024), individuals with more education can avoid what would otherwise be a loss of this all-important functional connectivity.

In the second study by UNSW Sydney’s Jing Du and colleagues (2024), data were provided from more than 37,000 individuals in the U.K. Biobank Study. The “brain age” of white matter in these participants could be predicted by the presence of hypertension and diabetes. Their brain age, further, significantly predicted their performance on both speed of cognitive processing and ability to use the higher-order so-called “executive functions" of planning and decision-making.

To sum up, the growing body of data shows that later adulthood need not be a time of cognitive decline. Identifying modifiable risk factors and sources of plasticity will remain a goal of cognitive science and aging. As this knowledge trickles out to the public at large, there may be a time when the focus becomes not on what people lose but on what they can gain as the years go by.