It’s long been assumed that the brain gets slower as people age. After all, they drive slower. They forget where they left the car keys. Or the car. They forget dance steps just because it’s been a few weeks since they last used those steps. But a recently published study suggests that this may be a misunderstanding of what is really going on.
The study, published in Perspectives on Pschological Science, looks into how the brain utilizes energy as we age. The researchers arrived at a very interesting theory.
Instead of slowing down, they suggest that the brain is simply using resources in a different way to preserve physical energy.
Based in the University of Arizona, the researchers point out that the brain is merely shifting resources from the hippocampus to the frontal cortex. This process may be the brain optimizing itself rather than retreating. The hippocampus uses a lot of energy. As we age, the body finds ways to become more efficient with available energy. The scientists found that this process is mirrored throughout the animal kingdom, so it makes sense that it would apply to humans as well.
“Prevailing theories of cognitive aging depict late life as a period of compensatory decline – an effort to preserve performance despite progressive neural deterioration,” the researchers state in their paper.
“We propose instead that aging represents a continuation of development: a genetically conserved, adaptive reorganization of memory systems that parallels the brain’s earlier-life transitions.”
As we get older, our episodic memory, which is managed by the hippocampus region, does decrease. This is the type of memory related to details, such as an appointment or location of objects.
Another kind of memory known as the semantic memory, which is controlled by the frontal cortex, becomes more dominant as we age. Unlike episodic memory, this is the big picture memory. It covers principles of behavior, leadership, rules and other more long-term concepts.
The researchers propose that as we grow older, we become more focused on using semantic memory to pass key information along to others in a social context, and that episodic memory becomes less important because we are less likely to need it. Thus, the body is simply behaving in a very natural way to make the best use of the available resources. There’s less need to remember all the details of day-to-day living. In other words, it may be a deliberate choice that better suits older people, who have accumulated much more information in their brains than younger people and can benefit the community by passing that information along.
At this point, it’s just a theory. The researchers are now starting a lengthy study to see if this neural allocation of resources actually turns out to be prevalent in a large group of people, but it’s an interesting idea.
So the next time you forget your dance shoes, it might not be because of declining memory, but just a shifting of mental resources. And if you forget that dance step you haven’t used in a while, I can help with that.
