Key Finding: A 20-year follow-up of a landmark trial suggests that a specific computer-based speed-of-processing training, combined with booster sessions, was associated with a 25% lower risk of Alzheimer's and related dementias compared to a control group.
Study Design and Methodology
The Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial was a large, multisite randomized controlled trial launched in 1998-1999. It enrolled 2,802 community-dwelling adults aged 65 and older.
Participants were randomly assigned to one of four groups:
- Memory training
- Reasoning training
- Speed-of-processing training
- No-contact control group
Each training group completed up to 10 sessions (60-75 minutes each) over five to six weeks. Half of these participants were also randomized to receive up to four additional "booster" sessions at 11 and 35 months.
For the 20-year follow-up, researchers analyzed Medicare claims data for 2,021 participants (72% of the original cohort) from 1999 to 2019. At the start, the average age was 74, and the cohort was approximately 75% women and 70% white.
Key Findings on Dementia Incidence
Over the 20-year period, 48.7% of the control group received a dementia diagnosis. The analysis produced these results:
- Speed training with booster sessions: Showed a statistically significant 25% lower risk of diagnosed dementia compared to the control group. In this group, 40% (105 of 264) received a diagnosis, versus 49% (239 of 491) in the control group.
- Speed training without booster sessions: Did not show a statistically significant reduction in dementia risk.
- Memory and reasoning training: Neither group showed a statistically significant reduction in dementia incidence, regardless of booster sessions.
- Initial training alone (without boosters): No training arm showed a statistically significant decrease in dementia risk.
"The link between boosted speed training and lower dementia risk two decades later suggests a modest, nonpharmacological intervention can have long-term effects." — Marilyn Albert, Ph.D., Johns Hopkins Medicine
Potential Mechanisms and Expert Commentary
Researchers propose several reasons why speed training may have been effective while memory and reasoning training were not.
Implicit vs. Explicit Learning: Speed training targets "implicit learning"—the unconscious acquisition of automatic skills. This contrasts with "explicit learning" fostered by memory and reasoning training (facts and conscious strategies). Implicit learning is believed to engage distinct brain processes and may be more resistant to age-related decline.
Adaptive Nature: The speed training program was adaptive, adjusting difficulty based on each participant's performance. This personalized progression allowed for individualized challenge, whereas memory and reasoning programs used standardized strategies.
Cognitive Reserve: The hypothesis suggests that mental stimulation may help build a "buffer" in the brain, potentially delaying the onset of dementia symptoms.
George Rebok, Ph.D., a site principal investigator, noted that speed training's effectiveness may stem from its focus on visual processing and divided attention abilities, and could complement other lifestyle interventions.
Context and Caveats
- Methodology: The study relied on Medicare claims data to identify dementia diagnoses, not clinical evaluations or standardized cognitive assessments, which may impact classification accuracy.
- Generalizability: The study excluded Medicare Advantage enrollees, which may limit the applicability of findings.
- Mechanism: The exact mechanism by which training may reduce risk is not yet fully understood, and further studies are needed.
- Regulatory Context: In 2016, Lumos Labs (behind Lumosity) settled with the U.S. Federal Trade Commission for $2 million over claims that its games could prevent memory loss.
Future Research
The ongoing Preventing Alzheimer's with Cognitive Training (PACT) study, funded by the National Institutes of Health, is enrolling approximately 7,500 individuals aged 65 and older. It aims to investigate the effects of a more intensive training regimen, with initial results anticipated around 2028.
Researchers suggest that combining cognitive training with other lifestyle interventions—such as maintaining cardiovascular health and engaging in regular physical activity—may further delay dementia onset. Further research is necessary to explore these interactions.
Funding
This study received funding from NIH grants, including R01AG056486 from the National Institute on Aging. The original ACTIVE trial was supported by NIH grants to its field sites and coordinating center.