Writer Ellen Kornmehl

These days, my husband and I find ourselves relying on each other to finish each other's sentences as we trip over words lodged in the dark recesses of our memory. The power of two is more likely to fill a stalled sentence's void.

Little interruptions can throw me off course. My high schooler asks for the car keys on my way to the fridge. "Now, what was I getting?" A moment like this can drive home that my aging is accompanied by the loss of physical and cognitive flexibility as years go by.

On certain days, my mind can seem like an old short-wave radio.

On certain days, my mind can seem like an old short-wave radio. I feel the static and sputtering as I search to retrieve old colleagues' names or that 90s song title crammed deep inside its neural networks. I imagine the firings in its tangled web of gray matter navigate a corn maze of inefficiencies.

Moving through daily chores can present more of an obstacle, especially when coupled with concentrating on other demands like meeting a work deadline or a flight that needs booking. Overloading circuits by shifting attention from one focus to another makes the effects of getting older more evident.

Changes Occur from Midlife

Unraveling ways the brain compensates to make older adults more resilient as we face memory loss and other facets of age-related decline could help us rise more successfully.

When investigators asked middle-aged adults to perform simple math in response to verbal questions while walking, their findings revealed that the ability to carry out two interfering tasks at once diminishes from age 55.

But why do some individuals experience memory loss early, and others remain cognitively "young" through old age? A better understanding of the early biology of dementia and Alzheimer's Disease could help identify means to reduce risk. It could motivate early diagnosis and strategies to maintain cognitive fitness, similar to how we approach cardiovascular health.

The growing field of Neurocognitive Aging, the study of the brain's complex reasoning and memory functions as we age, can shed light on changes in information processing and reaction time that may precede cognitive decline.

Harvard Medical School's study published in the Lancet this Spring found the capacity to coordinate competing tasks, termed dual-tasking, occurs considerably earlier than previously thought. When investigators asked middle-aged adults to perform simple math in response to verbal questions while walking, their findings revealed that the ability to carry out two interfering tasks at once diminishes from age 55.

Though most of us would sigh in relief, taking comfort that a mid-50s birthday is buffered by at least a decade before age 65, it may, in actuality, be the gateway to the brain's golden age.

How Can the Brain Protect Itself?

One theory Denise C. Park and Gérard N. Bischof from the Center for Vital Longevity at the University of Texas note is that the brain is wired to protect itself through "recruitment of additional circuitry that shores up declining brain function that has become noisy and inefficient."

An individual's education, work and social stimulation also contribute to the "cognitive reserve" that helps maintain later life faculties. Brain training through computerized platforms like Lumosity and NeuroNation promise to improve memory and problem-solving skills.

Unraveling ways the brain compensates to make older adults more resilient as we face memory loss and other facets of age-related decline could help us rise more successfully.

Despite a multi-billion dollar industry that emerged in 2014, whether these apps can deliver on claims remains to be questioned. Cognitive training outcomes in scientific trials are mixed or must be proven durable.

Although practiced skills produce statistically significant improvements, these inconsistently translate into lasting daily life gains. A recent study pointed toward user experience as an essential factor. Older adults fared better with crossword puzzles than computerized platforms, possibly because they were less agile with digital interface gaming.

The University of California, Riverside, with the National Institutes of Health, is recruiting 30,000 volunteers to understand better the effects of gamified memory training to personalize training for various levels of cognitive fitness.

Moving Your Body Impacts the Brain

Somewhat counterintuitive, the answer to up your brain game may not lie simply in mental gymnastics but in the more corporeal realm of moving your body itself. J. Carson Smith, who directs the Exercise for Brain Health Laboratory at the University of Maryland, wondered whether exercise training might further impact the brain's adaptability.

When 33 people, ages 70 to 85, some of whom already had evidence of cognitive impairment, participated in a walking program exercising 30 minutes daily, they fared better on memory and language tests, for example, being asked to recall a story that had been recited to them.

Smith's team then used functional magnetic resonance imaging (fMRI) to determine the activity of neural impulses and the statistical probability their firings are coordinated within brain circuitry. After 12 weeks of walking four days each week, the synaptic connections of these folks showed stronger "connectivity," or signaling within task-specific regions, and more robust cross-talk between large neural networks.

These findings suggest one mechanism behind exercise's benefit, long understood to boost brain health, is bolstering the efficiency and neural flexibility of the brain's circuitry.

"Our findings suggest that moderate-intensity walking, even in older age and with mild cognitive impairment, can produce changes in brain networks [that are related to improved cognitive function,] which could help to preserve or maintain cognitive abilities as we age," said Smith.

Those Most Vulnerable Can Benefit

In Smith's study, exercise promoted increased communication between brain networks that govern attention, memory and executive function.

Two networks are particularly vulnerable to aging; one allows us to sift through complex stimuli to focus attention on the most relevant cues, and the Default Mode Network benefits.

The Default Mode is used at rest when thinking introspectively or daydreaming, and its deterioration is implicated in dementia and Alzheimer's Disease progression.

The science of neurocognitive aging offers a highly optimistic picture that the brain is modifiable late into life.

Cognitively normal adults, two-thirds of whom had a family history of Alzheimer's Disease, who more regularly engaged in physical activity, followed by Johns Hopkins University, also showed greater connectivity on functional MRI.

The stronger signaling in these folks translated into protection from cognitive decline during the study, largely independent of amyloid pathology and genetics predictive of Alzheimer's Disease risk.

While both cognitive and physical engagement correlated with higher connectivity, the effects of physical activity on executive control and default-mode networks were distinct from mental activity, which benefitted attention networks.

Exercise Within Your Limits

How much and how often do you engage in physical activity necessary to be impactful? Interventions have targeted 120-150 minutes of moderate exercise like brisk walking or jogging per week — intensity, as much as duration, counts.

A small recent study at the University of Central Otago found short six-minute bursts of high-intensity activity increased BDNF, a neuroprotective growth factor essential for brain plasticity, the brain's wondrous ability to rebuild itself at a cellular and molecular level.

Boosting metabolism and neural plasticity are likely key to some cognitive benefits exercise provides. Generally, older adults should get out and move within their limits. Mind-body activities that combine movement and attention, like Tai Chi, Pilates, and yoga, have been shown to benefit those over 55.

Exergaming like Wii Sports and Ring Fit is another strategy researchers are exploring as their interactivity offers the advantages of physical and cognitive challenges. These highly entertaining games can enhance flexibility and responsiveness and might be tailored to improve memory and attention in older adults.

The science of neurocognitive aging offers a highly optimistic picture that the brain is modifiable late into life. That should shift our thinking as dementia may not be a foregone aging conclusion.

New developments like blood tests will make diagnosis of Alzheimer's Disease more accessible and hopefully bring more to report dementia symptoms earlier to their physicians, who can now offer risk reduction counseling and, for some, treatment.

In the absence of promising medications that can prevent cognitive loss, interventions such as exercise that can delay progression, including in those who already show mild impairment, should garner our attention.

Too easily, we are lured by the Ozempics and Prevagens, the ease of a pill or the hyperbolic promise of a "magic bullet" to alleviate our ills when the answer already may lie within us.

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