Maybe you keep a crossword by your coffee every morning, or your doctor once told you to keep your mind busy. We often hear that memory is like a muscle: work it and it grows stronger, ignore it and it weakens. But is that actually true, or just a nice saying?
The answer is partly yes. Your brain isn't a muscle, but it is plastic, meaning it can physically change in response to what you do, throughout your whole life. The catch is that practicing one mental skill mostly makes you better at that skill, and scientists still debate how much brain games help with everyday memory.
The Brain Keeps Changing at Any Age
One of the best-known examples comes from London's taxi drivers. To earn their license, they must learn the city's tangle of streets by heart. Neuroscientist Eleanor Maguire found changes in a memory-related part of their brains, called the hippocampus, linked to learning that map.
It isn't just younger brains, either. A 2008 study that taught older adults to juggle found an increase in gray matter after the training. Studies of musicians show something similar, with expertise linked to bigger volumes in certain brain areas.
Where the Muscle Idea Gets Tricky
Here's where the comparison breaks down a bit. When you lift weights, stronger arms help with all kinds of tasks. With the brain, getting better at one game doesn't always spill over into other skills. Scientists call this spillover transfer.
In one study, both younger and older adults got better at the specific memory task they trained on. But a broader improvement on new tasks showed up only in the younger group. Researchers are still arguing over how well brain training works in general.
That debate became a legal matter. Starting in 2015, the Federal Trade Commission sued companies selling brain training products, including the maker of Lumosity. The FTC said the company's ads played on people's fears of memory loss and dementia without scientific evidence. The company agreed to a $50 million settlement, later reduced to $2 million.
What Seems to Help
Physical exercise has some of the strongest evidence. Regular aerobic exercise over several months has been linked to more gray matter in key brain areas, including the hippocampus, along with improvements in spatial memory. In other words, a brisk walk may do more for your memory than you'd expect.
Staying social counts, too. A simple conversation asks a lot of your brain: paying attention, remembering what was said, seeing another person's point of view, and keeping your own behavior in check.
Puzzles still have their place. Jigsaw puzzles exercise visual and spatial thinking, and staying involved in mentally challenging activities is linked to a lower risk of thinking problems later in life. Just remember that a link isn't the same as proof of cause.
A Reserve in the Bank
Scientists also talk about cognitive reserve, the brain's ability to keep working well despite age or disease. A 1988 study of about 137 older people found 10 nursing home residents whose brains showed signs of Alzheimer's disease after death, yet who had shown little or no memory trouble while alive.
So keep the crossword, but don't stop there. Take the walk, call the friend, and try something new now and then. If you notice memory changes that worry you, talk to your doctor. Your brain is still learning, and it's never too late to give it something good to work on.
