A landmark, two-decade-long study reveals that only brain-training exercises focused on speed and divided attention significantly reduce the risk of dementia. Traditional memory or reasoning exercises, despite decades of popularity, showed no discernible protective effect. The findings, published in Alzheimer’s & Dementia, suggest a new avenue for cognitive preservation as populations age.
The Long-Term Trial
The study, initiated in the late 1990s, tracked 2,021 participants aged 65 and older. Participants were divided into four groups: speed training, memorization, reasoning, and a control group receiving no cognitive training. The training groups underwent 5–6 weeks of sessions (60–75 minutes each) with some receiving follow-up “booster” sessions years later.
Twenty years later, the results were stark. Only the speed-training group showed a measurable reduction in dementia diagnoses. Those who also participated in booster sessions experienced a 25% lower risk of dementia compared to other groups. The memorization and reasoning groups showed no benefit over the control group.
Why Speed Matters
Researchers believe the key lies in the adaptive nature of speed training. The exercises involved identifying matching objects presented simultaneously in central and peripheral vision, with difficulty increasing as performance improved. This constant challenge may build cognitive resilience unlike static memory or reasoning tasks.
As Marilyn Albert, a neuroscientist at Johns Hopkins University, explains, “Speed-of-processing training isn’t a whole lot of fun. It’s hard.” This suggests that effective cognitive training isn’t about ease, but about pushing mental limits in a structured way.
Implications for Brain-Training Games
The study raises questions about the potential of commercial brain-training apps and video games. While many claim to boost cognitive health, evidence supporting their effectiveness remains limited. Experts caution against exaggerated claims, but suggest that if designed correctly, similar speed-focused exercises could yield comparable benefits.
The Next Steps
Future research will focus on identifying the specific brain changes triggered by speed training. MRI scans and animal studies may reveal the underlying mechanisms driving neuroprotection. Meanwhile, established lifestyle factors—regular physical activity and healthy blood pressure—remain critical in dementia prevention.
The trial demonstrates that a relatively short period of intensive speed training (weeks, not years) can provide long-term cognitive protection. This suggests that targeted mental exercise could become a viable strategy for delaying dementia in an aging population.
