A Few Hours of Brain Training in Your Sixties Could Ward Off Dementia Two Decades Later

Picture yourself at 74, seated in front of a computer screen. Shapes flash up, briefly, then vanish. Your job is to spot a target object while simultaneously tracking something in your peripheral vision. The images get faster. The task gets harder. You do this for about an hour, once or twice a week, over five or six weeks. Then you come back for a few top-up sessions a year or so later. That’s it.

It doesn’t sound like much. But this modest bit of computer-based brain training, it turns out, might be one of the most effective non-drug interventions we’ve ever seen against dementia.

A 20-year follow-up of nearly 3000 older adults has found that those who completed a specific type of cognitive speed training, followed by booster sessions, were 25 per cent less likely to receive a dementia diagnosis over the next two decades. The study, published in Alzheimer’s & Dementia: Translational Research and Clinical Interventions, is the longest randomised trial to track such links, and the only one of its kind. The participants who got the speed training with boosters had a hazard ratio of 0.75 compared to controls, meaning their risk of an eventual dementia diagnosis dropped by roughly a quarter. In the control group, about 49% were diagnosed with dementia during the follow-up. Among the speed-trained group who got boosters, that figure fell to 40 per cent.

The results come from the ACTIVE study (Advanced Cognitive Training for Independent and Vital Elderly), which enrolled 2802 adults aged 65 and over across six US cities between 1998 and 1999. Participants were randomly assigned to one of four groups: speed of processing training, memory training, reasoning training or a no-contact control group. Each training arm involved up to ten sessions of 60 to 75 minutes in small groups. Half of the participants were then randomised again to receive booster sessions at 11 and 35 months after the initial training.

Here’s the thing, though. Only the speed training worked. Not memory training. Not reasoning training. And even within the speed group, the benefit was confined to those who got the booster sessions as well. Participants who did speed training but skipped the top-ups showed no statistically significant reduction in dementia risk at all (their hazard ratio was essentially 1.01, which is to say, no different from the controls).

“Seeing that boosted speed training was linked to lower dementia risk two decades later … suggests that a fairly modest nonpharmacological intervention can have long-term effects,” says Marilyn Albert at Johns Hopkins Medicine, the study’s corresponding author and director of the university’s Alzheimer’s Disease Research Center. “Even small delays in the onset of dementia may have a large impact on public health and help reduce rising health care costs.”

So why speed training and not the others? The researchers reckon it comes down to how the brain learns. The speed programme was adaptive, meaning it ratcheted up the difficulty as each person improved. If you were quicker, the challenges got harder, faster. If you needed more time, you started at a gentler pace. The memory and reasoning programmes, by contrast, taught everyone the same strategies at the same pace, regardless of individual ability.

There is something else going on, too. Speed training taps into what neuroscientists call implicit or procedural learning, the sort of unconscious skill acquisition that happens when you learn to ride a bike or touch-type. You get better without really knowing how. Memory and reasoning training, on the other hand, rely on explicit, declarative learning, where you’re consciously absorbing strategies and facts. These two systems work very differently in the brain, and the distinction could be crucial. Since cognitive ageing tends to affect controlled processes first (and the ACTIVE participants were cognitively healthy at baseline), programmes targeting those faster, more automatic processes may have had more protective power.

The booster sessions seem to matter enormously, perhaps because they allowed the training to adapt again to each person’s improving abilities, or perhaps simply because more practice yielded a stronger dose. Repetitive task training has a well-established track record in neurorehabilitation for conditions like stroke, and the principle here could be similar. The investigators also point out that speed training was previously linked to fewer at-fault car collisions six years after baseline. Divided attention, it seems, pays off in quite practical ways.

“Our findings provide support for the development and refinement of cognitive training interventions for older adults, particularly those that target visual processing and divided attention abilities,” says George Rebok, a lifespan developmental psychologist and professor emeritus at the Johns Hopkins Bloomberg School of Public Health. “It is possible that adding this cognitive training to lifestyle change interventions may delay dementia onset, but that remains to be studied.”

That last point is worth sitting with. Dementia is estimated to affect 42% of adults over 55 at some point in their lives, costing the US alone more than $600 billion a year. We still don’t have a drug that reliably prevents it. And yet here we are, looking at roughly ten hours of structured computer training, spread across a handful of weeks, with a couple of refresher sessions down the line, apparently shifting the odds for 20 years. Nobody is claiming this is a cure, or even a definitive prevention. The study tracked Medicare claims rather than conducting clinical assessments, three quarters of participants died during the follow-up period (average age at death: about 84), and the researchers are careful to note that the underlying mechanisms still aren’t clear. But for a field that has seen so many pharmaceutical disappointments, even a modest, low-cost intervention that nudges the trajectory in the right direction feels like something worth paying attention to. What we don’t yet know is whether combining speed training with other lifestyle changes, exercise, cardiovascular monitoring, social engagement, could amplify the effect. That, Albert and her colleagues say, remains to be studied.

Study link: https://alz-journals.onlinelibrary.wiley.com/doi/10.1002/trc2.70197