They claim that a short course of “speed of processing” training – designed to boost how quickly participants recognize objects – can produce cognitive benefits in older people even ten years later.
Jerri Edwards, a psychiatrist from the University of South Florida, said that “speed of processing training resulted in a decreased risk of dementia across the 10-year period of 29% on average when compared to the control group. When we examined the dose-response, we found that those who trained more received more protective benefit.”
Edward’s team analyzed data from the ACTIVE (Advanced Cognitive Training in Vital Elderly) study, which closely monitored 2,802 healthy older adults for a period of 10 years as they aged from 74 to 84 on average.
As part of this study, participants were randomly assigned to groups performing one of three different kinds of cognitive training, namely memory, reasoning or speed-of-process training. There was a fourth group who didn’t engage in any brain training activities, which was the control group.
The participants received 10 one-hour training sessions over a period of weeks, with a smaller group receiving a limited amount of follow-up sessions about a year after the initial training.
Due to inevitable deaths and other factors, only 1,220 of the original 2,802 were able to complete the whole ten-year study, which tested the participants’ cognitive and functional ability after the first six weeks, and at one, two, three, five and 10 years.
Of these remaining 1,220 participants, 260 had developed dementia by the conclusion of study but the researchers say the risk of developing the condition was 29% lower for those who had done speed-of process training when compared to the control group.
However, as promising as the results seem to be, other scientists are urging considerable caution when it comes to interpreting the team’s findings.
First of all, speed-of-processing training was found to only marginally reduce the risk of developing dementia. Scientific convention holds that a percentage-value of 0.05 represents the minimum threshold for statistical relevance – any lower and it’s possible that the result occurred by chance. In this study, the reduced risk percentage-value was 0.049, which meant that it was on the borderline for being considered irrelevant.
Secondly, participants in this study self-reported their dementia, meaning they weren’t clinically diagnosed as having the condition. This represents a significant limitation for a study that is claiming to lower the risk of developing the disease.
Doug Brown, the director of research at the Alzheimer’s Society in the UK, said: "it’s positive that this study compared several types of brain training and was both long-term and large scale in nature. However, as it relied on self-reporting of dementia in many cases rather than a robust clinical diagnosis, the results should be interpreted with caution.
"Concerns are also being raised about how such a small amount of cognitive training could produce lasting effects even a decade later.
"Rob Howard, a psychiatrist from University College London, said: “the results reported here, of apparent reduction in risk of dementia after 10 years following on a few hours of cognitive training, are therefore rather surprising and should be treated with caution. I find it implausible that such a brief intervention could have this effect, and it is worth bearing in mind that the results could have occurred by chance or as a consequence of uncontrolled confounding factors.
"This is not the first time that we have seen the promises of brain training apps criticized, but while there are definite limitations with the study that we need to be aware of, it’s also important that other researchers continue to examine the area.
"If these results can be replicated in a separate study without the same caveats described above, we could be onto something amazing here.
"For their part, the researchers are convinced that their speed training hypothesis correlates with the broader conversation about how mental activity is good for the brain as we get older. Frederick W. Unverzagt, a psychiatrist who was a member of the team, has stated that the study is “completely consistent with a large literature that talks about the beneficial effects of mental engagement. All of that epidemiological research has found support for the idea that those things are helpful to brain health, and in terms of risk for later development of dementia, Alzheimer's disease, engagement with those things is associated with a lower risk. It's quite consistent with that literature."