Long-term effects of training on cognitive speed – An integrative practitioner

Written by Erin Yeh

Cognitive training is known to have both short- and long-term benefits for cognitive performance. In the Advanced Cognitive Training for Independent and Active Older Adults (ACTIVE) study, funded by the National Institutes of Health, it was reported that participants showed improvements after initial cognitive training. Notably, “booster sessions” held 11 and 35 months after the first training resulted in a lower risk of dementia.

Published in Alzheimer’s disease and dementia: translational research and clinical interventions (DOI: 10.1002/trc2.70197), the aim of this study was to determine the effect of ACTIVE cognitive training on the risk of being diagnosed with Alzheimer’s disease and related dementia (ADRD) over a 20-year follow-up period.

Training courses

The study was designed as a four-arm, multisite, single-blind, randomized controlled trial in a large, diverse sample. 2802 participants (26% minorities) were recruited from March 1998 to October 1999 in six metropolitan areas. Participants were aged 65 years and older; 76% of participants were female and 70% were white. Participants were randomly assigned to one of the four intervention arms, and staff were also blind to which group participants were assigned.

Of the original 2,802 participants, 2,763 were matched to Medicare claims based on Acumen’s matching algorithm. The remainder were excluded due to incomplete claims data that could cause inaccurate outcome measurements. Others were excluded due to death, or a diagnosis of ADRD when they entered the study. The final sample size was 2,021 participants.

Participants in three intervention arms received 60- to 75-minute training sessions in small groups over 5-6 weeks. These groups were: processing speed training focusing on visual search and the ability to process increasingly complex information presented in respectively shorter scanning times; Memory training that focuses on improving verbal episodic memory through instruction and practice in using mnemonic strategies; The thinking training focused on improving the ability to solve problems containing a sequential pattern. The fourth group is the control group that did not train.

Participants who completed at least eight out of 10 training sessions were randomized again to booster training sessions 11 and 35 months after the initial training, each of which was up to four 75-minute sessions. These boosters were added because previous studies have shown that they improve training retention.

Cognitive training is key

Nearly half of the control group were diagnosed with ADRD during the 20-year follow-up period. In addition, individuals in the speed group who did not complete the initial speed training sessions or participate in the booster sessions did not show a significant reduction in risk of developing ADRD.

However, members of the speed training group who participated in the booster training after 11 and 35 months showed a 26% reduction in the risk of developing ADRD. Those who did only speed training sessions had a 19% lower risk. Repetitive task training has already been shown to be beneficial and beneficial for other neurological conditions, such as stroke. The researchers hypothesized two possible reasons for the significant improvements in speed training through booster sessions. The first is simply that more training leads to better results. The second reason is that booster sessions may have enhanced training by adapting participants’ improved abilities to increased task difficulty.

Speed ​​training focuses on improving visual processing and attention, especially divided attention. Unlike memory and logical thinking training, speed training was conducted on a computer and automatically adjusted to suit each participant’s performance, and the difficulty of the training increased as skills improved. In other words, this adaptive design may have led to broader brain activation, thus enhancing the effectiveness of speed training.

The research team found it surprising that the memory and thinking training groups did not show significant results. One possible explanation for this is that memory and reasoning training primarily taught participants strategies to improve performance, whereas speed training did not. In other words, memory and reasoning training relied more on declarative memory (conscious learning and application of strategies) while speed training relied more on procedural memory (improving performance through practice without explicit instructions). However, previous results from the ACTIVE study showed that mindfulness training was associated with fewer difficulties with instrumental activities of daily living 10 years after baseline.

Cognitive aging is often associated with declines in controlled processes, such as attention and executive function, while associative memory problems are usually among the early signs of preclinical Alzheimer’s disease. Because nearly all ACTIVE participants were in good cognitive health at baseline, it is possible that training programs targeting controlled processes—such as speed training—may be more effective in delaying the onset of ADRD. Future studies are encouraged to explore why thinking and memory training from this study does not translate into a reduced risk of dementia in the long term.

Limitations to consider

Some participants had other covariates, such as hypertension (66%), ischemia (40%), diabetes (21%), congestive heart failure (20%), atrial fibrillation (8%), and acute myocardial infarction (3%). These covariates, particularly vascular risk, are associated with a higher chance of developing dementia, and therefore the analysis was adjusted for the cardiovascular conditions identified. Furthermore, 38% were former smokers, and this was also included in the analysis.

Selection bias could have occurred due to participants who may have had better access to health care resources, caring family members, or higher education levels, as they were more likely to receive a dementia diagnosis. However, the ability to measure the cumulative incidence of dementia over 20 years using independently collected Medicare data represents a significant strength and likely outweighs these limitations.

Another limitation includes that the booster training sessions were only offered to a randomly selected subset of participants who completed at least eight initial sessions. This issue was addressed by comparing those who were randomly selected to receive boosters with those who were eligible but not selected. Finally, because an active study has generated many publications, there is always a small risk of a false positive result. But this study is the first analysis using Medicare claims data, so the risk may be low.

Cognitive speed training not only reduced the risk of developing ADRD, but also showed beneficial effects on participants’ daily activities. For example, participants who completed speed training were less likely to have car accidents six years after the study, and those who completed booster sessions were more likely to maintain their driving pace. Cognitive training interventions can be included as part of multidomain interventions that can help slow cognitive decline and ADRD. Combining it with lifestyle changes, such as exercise and monitoring heart health, may work better than a single strategy and produce a stronger overall effect.