Could a few hours spent playing a brain-training game today really shield your mind from dementia decades down the road? According to a landmark study published February 9, 2026, in Alzheimer’s & Dementia: Translational Research & Clinical Interventions, the answer might just be yes. Researchers have found that older adults who engaged in a specific type of cognitive training—focused on processing speed—enjoyed a striking 25% reduction in their risk of developing dementia up to 20 years later, compared to peers who didn’t receive the training.
This finding, reported by several outlets including AARP and NBC News, comes from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial, a massive, long-term study funded by the National Institutes of Health (NIH). The trial enrolled nearly 3,000 healthy adults aged 65 and older from six different regions across the United States, all without significant prior cognitive impairment. Notably, about a quarter of the participants were minorities and the majority were women—a group especially vulnerable to Alzheimer’s, as women develop dementia at nearly twice the rate of men.
The ACTIVE study tracked participants for an astonishing 20 years, making it one of the longest and most comprehensive investigations into brain training and dementia risk ever conducted. Participants were randomly assigned to one of three cognitive training programs: memory training, reasoning training, or speed training. There was also a control group that received no cognitive training. The initial training consisted of 10 hour-long sessions over five to six weeks, with about half of each group receiving additional booster sessions—up to a total of 23 hours of training—over the next three years.
So what set the speed training apart? According to Dr. Marilyn Albert, professor of neurology and director of the Johns Hopkins Alzheimer’s Disease Research Center, speed training was designed to teach the brain to process visual information more quickly and accurately. In practical terms, participants were asked to identify objects on a screen as fast as possible and make split-second decisions about them. "If we’re driving in a car and we have all these things going on in the periphery that we’re paying attention to, we have to decide what’s important and what’s not," Albert explained to NBC News. This kind of rapid, divided-attention task is a real-world skill that relies on the brain’s ability to adapt—what scientists call neuroplasticity.
While memory and reasoning training might seem intuitively important for staving off dementia, the ACTIVE trial found no protective effect from those approaches. Only the speed training group, and specifically those who received the booster sessions, showed the dramatic 25% drop in dementia risk over two decades. As Dr. Sanjula Singh, a physician-scientist at Harvard Medical School, put it, “Once the brain rewires for these skills, the change is durable even without continued practice. A child can learn how to ride a bike in about 10 hours, and afterwards that learning lasts a lifetime.”
Why does speed training seem to work so well, when other forms of cognitive training fall short? One theory, Albert told AARP, is that speed training taps into implicit learning—the kind of unconscious skill-building that becomes automatic, like riding a bike—rather than explicit learning, which is more about memorizing facts. Implicit learning draws on different parts of the brain and may build more durable cognitive reserve, a concept that describes the brain’s resilience to damage and disease. Dr. Kellyann Niotis, a preventive neurologist at Weill Cornell Medicine, suggested that speed training might engage broader neuronal networks, effectively making the brain more robust against the ravages of dementia.
Another factor may be the adaptive nature of the speed training program. Its difficulty adjusted based on how well participants performed, so those who excelled were pushed to even greater speeds. This wasn’t the case for the memory or reasoning training, which remained at a fixed level.
The speed training exercise used in the ACTIVE trial was originally created by psychologists Karlene Ball and Daniel Roenker, with support from the NIH. It’s now available to the public as “Double Decision” through BrainHQ, an online subscription service. Dr. Albert recommends the program for adults aged 65 and older, though she notes that the benefits for younger adults remain uncertain.
Despite the excitement, experts urge some caution. Dr. Andrew Budson, associate director of the Alzheimer’s Disease Research Center at Boston University, told AARP, “I'm both skeptical but also somewhat impressed. It's really quite rare for any computerized-game brain training study to show positive results—and to show effects on a diagnosis of Alzheimer’s disease 20 years later.” Budson and others point out that the study relied on Medicare records to diagnose dementia, rather than biological markers like amyloid plaques or tau proteins, and that dropout rates over two decades could have influenced the results. Still, Dr. Thomas Wisniewski, director of cognitive neurology at NYU Langone Health, called the findings “astonishing,” adding, “It’s really the first clear documentation in a randomized controlled trial that at least some form of cognitive training can lower the risk of dementia.”
With more than 7 million Americans currently living with Alzheimer’s disease—a number expected to nearly double by 2060, according to the Alzheimer’s Association—the search for effective prevention strategies has never felt more urgent. While there’s no magic bullet to ward off dementia, experts say that maintaining brain health is a lifelong endeavor. Beyond cognitive training, Dr. Niotis advises her patients to get regular hearing and vision screenings, manage metabolic risk factors like cholesterol and blood pressure, and stay physically active. There’s even emerging evidence that the shingles vaccine may lower dementia risk: a 2025 study published in Nature found that people vaccinated against shingles were 20% less likely to develop dementia over seven years.
Ultimately, the ACTIVE trial’s results offer hope—and a practical tool—for those looking to protect their cognitive health. As Dr. Richard Isaacson, a preventive neurologist at the Institute for Neurodegenerative Diseases in Boca Raton, Florida, put it, “It builds on the concept that relatively small amounts of effort can really pay dividends for decades to come.” For anyone concerned about their brain’s future, that’s a message worth remembering.