He said we should think about the ageing brain not as a young person’s brain in decline, but as one specifically adapted to prioritise wisdom.
Ageing as a developmental phase
Fernandez and his colleagues point to a body of research showing that older adults’ brains rely less on the hippocampus, which is responsible for forming and recalling new memories, including details like names and places and spatial navigation.
Instead, during memory tasks, older brains are relying more on the frontal cortex, the area associated with higher-level thinking and synthesising information.
Some scientists have argued that ageing brains rely on the cortex to compensate for decline in the hippocampus, which shrinks over our lives. But Fernandez offers a different theory: In later adulthood, we need wisdom more than we need to retain every new detail we come across.
“It’s this ability to melt away that which does not matter and get to the essence of an issue,” Fernandez said.
Other research has suggested that healthy ageing could be simply another phase of the brain’s development, bringing new strengths and weaknesses. Children, for instance, have an extraordinary ability to learn language but might have more difficulty than adults with emotional regulation and impulse control. For someone in their 70s, 80s or older, it might be helpful to focus less on memorising minutiae and more on understanding a bigger picture.
A takeaway for older adults is that memory changes might be beneficial in later phases of life, according to Daniel Nation, a professor of gerontology and neurology at the University of Southern California who was not involved in the study.
“There may be some cognitive benefits to older adults that come from cognitive changes we normally think of as purely negative,” Nation said of the new paper.
He noted the “grandmother hypothesis,” a theory about the wisdom and perspective of older members of the community when it comes to making decisions and imparting knowledge to younger people.
A call for more research
“I think it’s provocative,” said Patricia Reuter-Lorenz, a professor of psychology and neuroscience at the University of Michigan who conducted some of the studies cited in the new paper.
“It’s taking a new step that’s building on ideas that have been in the literature on ageing for several decades, including the idea that ageing involves adaptive processes,” she said.
Reuter-Lorenz’s work has pointed to older adults using their frontal cortex to compensate for the weakening of the hippocampus. But she said she is interested in the silver linings of old age and is currently studying emotion later in life.
She said her work is “trying to understand the tendency for older adults to have a more positive outlook and better emotion regulation”.
It is advancing existing research showing that older adults tend to focus more on the positive aspects of a situation, and remember them more than negative ones.
Both Reuter-Lorenz and Fernandez say the idea of brain ageing as an adaptive phase more than a declining one needs more study.
How to help your brain age well
Regardless of whether scientists believe that the older brain is adapting to a new phase of life or compensating for decline, they suggest that there are ways we can all age better.
In Fernandez’s paper, he and his colleagues write that older people who “engage in lifelong learning, complex occupations, or high social activity” tend to have more flexible brains. That means they can continue to navigate complicated tasks even as the hippocampus shrinks.
Reuter-Lorenz agreed that lifestyle factors are key.
“Solid fitness, a good diet and sleep are all very important. And maintaining an active social network and cognitive engagement,” she said. “Those are the pillars.”
Reuter-Lorenz also emphasised that the upsides of ageing should continue to be acknowledged by researchers, especially since having a positive view of ageing seems to help people age better.
“There are treasures in ageing that can be cherished,” Reuter-Lorenz said. “And that may only come with age.”
