A relatively brief course of cognitive training may offer surprisingly long-lasting protection against dementia, including Alzheimer’s disease, according to a new study spanning two decades. Researchers found that adults age 65 and older who completed five to six weeks of “speed of processing” training, coupled with follow-up booster sessions, exhibited a significantly reduced risk of developing dementia up to 20 years later.
The study, published February 9 in Alzheimer’s & Dementia: Translational Research and Clinical Interventions, involved 2,802 participants initially enrolled in 1998-1999. Participants underwent one of three types of cognitive training – memory, reasoning, or speed of processing – or a control group with no training. The speed of processing training focuses on helping individuals quickly identify visual information on a computer screen and manage increasingly complex tasks within a limited timeframe.
Investigators followed participants for 20 years, analyzing Medicare data from 2,021 individuals (72% of the original cohort) between 1999 and 2019. The results revealed that 40% (105 out of 264) of those in the speed-training group with booster sessions were diagnosed with dementia, compared to 49% (239 out of 491) in the control group. This translates to a 25% reduction in dementia risk for those who received the speed training and boosters – a statistically significant finding.
“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,” says Marilyn Albert, MD, corresponding study author and director of the Alzheimer’s Disease Research Center at Johns Hopkins Medicine.
How Does Speed Training Work?
The speed of processing training is designed to be adaptive, adjusting the difficulty level based on each participant’s performance. Individuals who demonstrated faster processing speeds were quickly presented with more challenging tasks, while those needing more time started with simpler exercises. This contrasts with the memory and reasoning training programs, which utilized a standardized approach for all participants.
Researchers believe this adaptive nature may be a key factor in the training’s effectiveness. The training also emphasizes implicit learning – the acquisition of skills and habits without conscious awareness – as opposed to the explicit learning involved in memory and reasoning exercises, which rely on conscious recall of facts and strategies. Scientists suggest that implicit learning engages different brain mechanisms and may contribute to the observed long-term benefits.
Beyond the 20-Year Mark: Previous Findings
This 20-year follow-up builds upon earlier findings from the original ACTIVE (Advanced Cognitive Training for Independent and Vital Elderly) trial. Previous research demonstrated that cognitive training improved participants’ ability to perform everyday tasks involving thinking, remembering, reasoning, and decision-making for up to five years. A 10-year follow-up showed a 29% lower incidence of dementia in the speed training group compared to the control group, with each booster session linked to further risk reduction.
Understanding Dementia and its Impact
Dementia is not a single disease but rather a collection of symptoms characterized by a decline in cognitive function severe enough to interfere with daily life. It’s estimated to affect 42% of adults over age 55 at some point in their lives and carries a substantial economic burden, costing the US more than $600 billion annually.
Alzheimer’s disease is the most prevalent form of dementia, accounting for 60% to 80% of cases. Vascular dementia represents another 5% to 10%, while other types include Lewy body dementia and frontotemporal dementia.
Implications for Public Health and Future Research
The study’s findings suggest that even small delays in the onset of dementia can have a significant impact on public health and healthcare costs. George Rebok, PhD, a lifespan developmental psychologist and site principal investigator, emphasizes the potential for incorporating this type of cognitive training into broader lifestyle interventions aimed at promoting healthy aging.
“Our findings provide support for the development and refinement of cognitive training interventions for older adults, particularly those that target visual processing and divided attention abilities,” says Dr. Rebok.
Researchers acknowledge the need for further investigation to elucidate the underlying mechanisms responsible for these long-term effects and to determine why the reasoning and memory interventions did not demonstrate similar 20-year benefits. They also suggest exploring potential synergies between cognitive training and other lifestyle factors known to support brain health, such as cardiovascular health management and regular physical activity.
“adding this cognitive training to lifestyle change interventions may delay dementia onset, but that remains to be studied,” Dr. Rebok added.
The study was funded by grants from the National Institute on Aging (NIH). The original ACTIVE trial received support from NIH grants to multiple field sites, including Hebrew SeniorLife, Indiana University School of Medicine, Johns Hopkins University, New England Research Institutes, Pennsylvania State University, University of Alabama at Birmingham, and Wayne State University/University of Florida.
