As I get older I find my memory isn’t quite what it used to be. I have the most trouble with names and articles I have recently written. It has occurred to me on more than one occasion that I’m on the cusp of dementia or something worse down the road. Quite a few of my older clients tell me that “It’s a normal part of aging to become forgetful”, or “Welcome to the golden years.” It doesn’t seem “normal” to me-in fact; it’s frustrating; even more so after reading the results of a study by researchers at Johns Hopkins University and the Center for the Neurobiology of Learning and Memory at the University of California, Irvine, during which young and older volunteers watched pictures flash on a screen, while scientists watched their brains. ( The complete story is in the New York Times, 5/25/11, written by a woman who is fast becoming my favorite fitness writer, Gretchen Reynolds).
Neuroscientists already know that a lot of the memory processing occurs in the dentate gyrus, a part of the brain within the hippocampus, a larger portion of the brain known to be involved with learning and thinking.
In the study, subjects, wearing head sensors, were shown a series of pictures of everyday objects, like computers, cell phones, pineapples, pizza, pianos, and tractors, and asked to press a button indicating whether each object was found indoors or outside. They were not asked to remember the images. But later they were shown another set of images and asked whether they remembered seeing that particular photo before or a similar photo. The researchers tracked brain activity throughout both tasks.
It turns out that the brains of the young adults were quite adept at differentiating the images, while the older volunteers, ages 60-80, did not fare so well (surprise).
The results weren’t severe, but they showed that the older adults were less successful at the ability to differentiate things that are quite similar. End result; less memory processing.
The researchers found that the dentate gyrus in older persons was not as well-connected as those in younger adults, and there was less blood flow. Messages did not flow as easily from other areas in the brain to the dentate gyrus memory center, and vice versa.
But, there is hope, said Dr. Michael A. Yassa, an assistant professor of psychological and brain sciences at Johns Hopkins and lead author of this study. “Exercise is one of the things that might directly change this process,” he said. “In other experiments, exercise has been found to jump-start neurogenesis (creation of new brain cells), especially in the dentate gyrus, potentially improving that area’s health and functioning.”
I’m not sure if exercise is working for me regarding my short-term memory, but I figure I can’t go wrong by exercising-there are too many other benefits.
Stay well, John R Blilie, M.S.