Five Weeks of Computer Training Slashes Dementia Risk for Two Decades

A Simple Game Changes Everything

A computer-based brain training program that takes just five to six weeks to complete may hold the key to preventing dementia for decades. In a remarkable 20-year study, participants who completed speed-of-processing training sessions had a 25% lower risk of developing dementia compared to those who received no training , marking the first time researchers have documented such long-lasting protection from a cognitive intervention.

The speed training was designed to teach the brain to process visual information more quickly and accurately, with individuals asked to identify objects on a screen quickly and make decisions about them . Think of it as similar to the split-second decisions drivers make when navigating traffic. "The thing that's so astonishing, it's really a very modest amount of training," says study author Marilyn Albert, director of the Johns Hopkins Alzheimer's Disease Research Center.

The Science Behind the Success

Investigators enrolled 2,802 adults into the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study in 1998–1999, randomly assigning participants to three different types of cognitive training—memory, reasoning, and speed of processing—or to a control group who received no training . Participants received up to 10 sessions of 60 to 75 minutes of cognitive training over five to six weeks, with half also receiving booster sessions at 11 and 35 months after initial training .

What made speed training uniquely effective? The program was adaptive, meaning that as people improved, the game got harder, and speed training drives implicit learning (an unconscious habit or skill), while memory and reasoning training drive explicit learning (more like learning facts and strategies) . Scientists know that implicit and explicit learning engage different brain systems, and this distinction may help explain why only speed training was associated with lower dementia risk .

Real-World Impact

Researchers say it is one of the first results from a large randomized, controlled trial to demonstrate that any intervention, whether it is cognitive training, brain games, physical exercise, diet or drugs, can lower the incidence of Alzheimer's disease and related dementias . The training involved a maximum of 18 sessions spread over three years, yet "It seemed implausible that we might still see benefits two decades later," noted researcher Michael Marsiske.

"Seeing that boosted speed training was linked to lower dementia risk two decades later is remarkable because it suggests that a fairly modest nonpharmacological intervention can have long-term effects. Even small delays in the onset of dementia may have a large impact on public health and help reduce rising health care costs," Albert explained.

Looking Ahead

The split-attention speed brain game was developed by professors in Alabama and Kentucky and sold in 2008 to the owners of BrainHQ, a for-profit brain-training company. The updated game now goes by the name Double Decision , though similar programs have been developed by other companies.

While researchers emphasize that more studies are needed to understand the biological mechanisms behind these results, the findings offer hope for aging populations worldwide. Scientists suggest that adding this cognitive training to lifestyle change interventions may delay dementia onset, and that speed training may synergistically support other lifestyle interventions that strengthen neural connections . The research demonstrates that protecting brain health may be more achievable than previously thought, requiring neither expensive treatments nor dramatic lifestyle overhauls—just a few weeks of focused mental exercise.