A specific type of cognitive training, focused on processing speed, may delay the onset of dementia – including Alzheimer’s disease – by as much as two decades, according to a landmark 20-year study released Tuesday. The research, funded by the National Institutes of Health, found that older adults who participated in the training and crucially, completed follow-up “booster” sessions, experienced a 25% reduction in dementia diagnoses compared to a control group.
The study, initially launched in 1998-1999 as the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial, involved 2,802 adults aged 65 and older. Participants were randomly assigned to one of three cognitive training groups – memory, reasoning, or speed of processing – or a control group that received no training. Each training regimen consisted of up to 10 sessions, lasting 60 to 75 minutes, over five to six weeks. Half of the participants then received booster sessions at 11 and 35 months after the initial training.
Researchers analyzed Medicare claims data from 2,021 participants (72% of the original cohort) spanning 1999 to 2019. The analysis revealed that 105 out of 264 participants (40%) in the speed-training group with boosters were diagnosed with dementia, a significantly lower rate than the 239 out of 491 (49%) in the control group. The memory and reasoning training groups did not demonstrate the same long-term protective effect.
“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,” said Marilyn Albert, director of the Alzheimer’s Disease Research Center at Johns Hopkins Medicine and the study’s corresponding author. “Even small delays in the onset of dementia may have a large impact on public health and facilitate reduce rising health care costs.”
The speed of processing training involved computer-based tasks designed to sharpen visual attention and reaction time, challenging participants to quickly identify and locate visual information across a widening field of view. Unlike the memory and reasoning programs, the speed training was adaptive, adjusting the difficulty level based on each participant’s individual performance. This adaptive quality, researchers believe, may be a key factor in its effectiveness.
According to the study, speed training targets “implicit” learning – automatic skills – even as memory and reasoning training focus on “explicit” strategies, such as facts and logic. Researchers hypothesize that implicit learning may be more resistant to age-related cognitive decline.
The findings build upon previous research from the ACTIVE trial, which demonstrated that cognitive training could improve everyday tasks related to thinking, remembering, reasoning, and decision-making for up to five years. A ten-year follow-up showed a 29% lower incidence of dementia in the speed training group compared to the control group, with booster sessions further reducing risk.
The study’s authors emphasize the need for further research to understand the underlying mechanisms driving these associations and to determine why the reasoning and memory interventions did not yield similar long-term benefits. They similarly suggest that combining cognitive training with other lifestyle interventions, such as cardiovascular health management and regular physical activity, may offer synergistic benefits.
The research appeared in Alzheimer’s & Dementia: Translational Research and Clinical Interventions. The National Institute on Aging funded the study, with support provided to multiple field sites including Hebrew SeniorLife in Boston, Indiana University School of Medicine, and Johns Hopkins University.
