What if 23 hours of playing a computer game could cut your risk of Alzheimer’s by a quarter — for two decades? That’s exactly what the ACTIVE trial, a massive NIH-funded study out of Johns Hopkins, found when they published their results in Alzheimer’s and Dementia this month.
The study enrolled nearly 3,000 adults aged 65 and older from six U.S. cities starting in 1998, with 20 years of follow-up data. Participants were randomly assigned to one of four groups: memory training, reasoning training, speed training, or a control group that received no intervention.
The results were striking. Memory training — learning strategies for remembering lists and schedules — showed zero protective effect against dementia. Reasoning training — solving pattern puzzles and sequences — also showed zero effect. But speed training, where participants identified objects flashing briefly on screen while tracking peripheral information, was a completely different story.
The key distinction was that speed training engaged automatic, unconscious processing rather than deliberate thinking strategies. The computer automatically ramped up difficulty as participants improved, constantly pushing them at the edge of their ability. Researchers call this “adaptive challenge” — you weren’t memorizing tricks, you were rebuilding fundamental processing capacity.
But there was a critical caveat: the initial training alone (about 10-12 hours) wasn’t enough. Only participants who returned for booster sessions at the one-year and three-year marks saw the benefit. This booster group, with roughly 23 total hours of training, had a 40% dementia diagnosis rate compared to 49% in the control group — a 25% reduction in relative risk.
The takeaway? Like physical exercise, brain training needs maintenance. A single burst of training won’t change your trajectory, but consistent tune-ups might build something lasting. The study also found the effect was strongest in Black participants, who face disproportionate dementia risk, suggesting speed training could help address health disparities.
Several commercial programs now use this same speed training approach, with Double Decision (available through BrainHQ) being the closest to the protocol used in the trial. At roughly $14/month, it may be one of the most cost-effective health interventions available.