Scientists are still trying to figure out exactly why exercise promotes cognitive health, especially in older adults.
Some researchers posit that physical activity helps maintain youthful brain structures, but a new study instead suggests exercise changes the way seniors’ brains process information – making the aging brain more adaptable. Understanding how this adaptation occurs can ultimately guide seniors as they work to maintain good mental health.
“Although our cognitive ability will inevitably decline with age, we do have control over the rate of our decline,” says Jennifer Heisz of the Physical Activity Centre of Excellence at McMaster University in Canada. “Specifically, through a program of regular physical exercise, older adults are able to maintain optimal cognitive health for longer.”
As we move from childhood to adulthood, the complexity of our brain activity increases, boosting our capacity to process information. This complexity then starts to reduce in healthy older adults, but it is not a uniform reduction: while long-range brain communication, or “distributed processing,” decreases, local information processing increases.
Heisz and her colleagues wanted to test whether that shift might be an adaption to help older adults’ cognition and whether exercise assists in that adaptation. They used a technique called “multiscale entropy” to analyze the brain activity of seniors while they performed a challenging computer game that tested their ability to focus their attention and ignore distractions.
As published in the Journal of Cognitive Neuroscience, they found that older adults who were physically active had a more unique pattern of brain signal complexity – showing greater local processing of information – than both younger adults and their less-active peers. And, Heisz says, that unique pattern was associated with better performance on the task.
The results suggest that the shift from distributed to local processing that happens when we age is a healthy adaption for cognition, and that exercise helps to enable that “plasticity” in the brain. Heisz discussed with CNS these results and their implications, including sharing some guidelines for exercise as we age.