Brain Training: No Effect on Cognitive Performance

Pauline Anderson

July 13, 2017

Using commercial brain training programs is no better than playing video games for improving cognitive performance, influencing decision making, or altering brain activity, new research shows.

Any changes in these domains is likely due to a practice effect, the study suggests.

"The findings raise a great deal of skepticism about the claims being made about the benefits of cognitive exercise training," author Caryn Lerman, PhD, from the University of Pennsylvania, Philadelphia, told Medscape Medical News.

"Commercial adaptive cognitive training in young adults appears to have no effects beyond those of standard video games on neural activity, choice behavior, or cognition."

The study was published online July 10 in the Journal of Neuroscience.

Previous research by Dr Lerman's group and others has shown that individuals with increased activity in the brain's executive control network, including the prefrontal cortex, have better self-control. Other research suggests that practicing certain cognitive exercises may activate these brain areas.

"Based on those two lines of research, we hypothesized that computer training games would increase activity in the executive control network that would enhance self-control processes, and that would influence decision making and lead people to make less risky choices in these decision-making paradigms," said Dr Lerman.

The new analysis included 128 participants (mean age, 25 years; 44% female) with no history of neurologic, psychiatric, or addictive disorders (excluding nicotine) who completed a 1-week "run-up" period to screen for nonadherence.

They were randomly assigned to a cognitive training group or to an active control group.

The cognitive training condition used Lumosity (Lumos Labs), a commercially available platform that consists of Internet-based games targeting multiple cognitive domains involved in executive function.

All participants in this group were assigned identical games in a standardized order that rotated between the following five cognitive domains:

  • Working memory;

  • Attention;

  • Flexibility;

  • Problem solving; and

  • Short-term memory.

Individual games were about 2 to 3 minutes long, so a 30-minute training session included 10 to 15 games.

A core aspect of cognitive training is that it is adaptive, meaning that difficulty increases progressively across sessions as performance improves, the authors note.

Participants in the "active intervention" control group played video games. They were not prompted to complete particular games within each session and could spend as much time on each game as they wanted, as long as they played for 30 minutes total.

The authors note that these video games were not specifically designed to tax executive function. The control condition, they add, had a similar level of engagement, expectancy, novelty, motivation, and interpersonal interaction as the cognitive training condition.

All participants were instructed to complete the assigned Web-based training from home five times a week for 30 minutes per session, for a total of 50 sessions over 10 weeks. They were monitored for adherence and given small monetary incentives.

Participants in both groups were given the same information on the study purpose: to investigate the effects of certain types of computer games on brain activity and decision-making behavior.

To control for motivation and contact, participants in both groups received the same completion incentives and the same weekly phone calls to review study adherence and were blinded to their specific training condition.

"Both groups were blinded to the hypothesis that one form of training would be more effective than the other," said Dr Lerman. "We wanted to have equal expectations."

Participants underwent functional MRI (fMRI) at baseline and after the 10-week training period. While in the MRI scanner, participants completed the delay discounting test, in which they chose between receiving a smaller amount of money immediately or a larger amount of money later.

"That's like immediate gratification vs being able to exert some control and wait for gratification later," said Dr Lerman.

They also completed the risk sensitivity task, which Dr Lerman described as "like a gambling risk." For this, participants chose between getting a smaller certain reward immediately or a larger but riskier reward later.

The final analysis of the task fMRI data included 114 of the 128 participants.

Validated Tests

Cognitive testing was performed a week before training, at 5 weeks, and at the end of the 10-week training period.

The 1-hour cognitive battery included assessments of attention, working memory, response inhibition, interference control, and cognitive flexibility. The tests were selected on the basis of evidence that performance in these domains may improve after cognitive training.

"These tests are very well validated in the literature," said Dr Lerman. "If in fact the brain training was transferring from the games people play to other tests of performance in those same domains, we would see it."

The investigators found no effects of the training condition on decision making or changes in decision making. There was no main effect of time on delayed discount rates (P = .89) or degree of risk sensitivity (P = .40) and no treatment by time interaction effect on discount rates (P = .74) or degree of risk sensitivity (P = .87).

There were no between-group differences in changes in neural activity during decision making. And both groups showed similar improvement on the cognitive assessments.

The researchers also carried out a follow-up study of 29 young adults not currently using Lumosity's online training. Those participants completed the cognitive test battery three times, a week apart, with no intervention between.

This was a very important part of the study, said Dr Lerman, because it enabled the research team to test for practice effects, wherein the more individuals take tests, the better they get at them.

This analysis showed that levels of improvement on cognitive tests in this third group, which had no training, were similar to those in the two intervention groups.

"All [groups] improved the same amount, which suggests that it's a practice effect," said Dr Lerman.

Cognitive training games "can be fun and engaging," said Dr Lerman. "This is not to say that people shouldn't practice them, but they need to maybe manage their expectations about the potential therapeutic benefit or the idea that it will strengthen their cognitive performance."

She pointed out that the study focused on younger cognitively healthy adults and doesn't rule out the possibility that older adults with some cognitive impairment might see more improvement.

"The jury is still out on that point, and we hope to see some research in that area," she said.

The new findings differ from those of a previous study that reported beneficial effects of cognitive training on delay discounting.

The discrepancy could be due to different training and control conditions. The current study was larger (the previous one had 27 participants) and included healthy young adults, whereas the prior study included stimulant addicts undergoing treatment.

Not Surprising

Commenting on the findings for Medscape Medical News, David S. Knopman, MD, professor of neurology, Mayo Clinic, Rochester, Minnesota, said the findings were not unexpected given that studies of elderly persons participating in cognitively stimulating computer activities "does not generalize in daily life."

"Therefore, that it didn't work in young healthy people is not at all surprising," Dr Knopman said.

Young adults are presumably "already tech savvy" and probably employed, unlike elderly retired patents more at risk for dementia, said Dr Knopman.

"So they're using their brains optimally. It's hard to believe that doing some additional computer exercises would generalize in any way and would be a substantial dose increase of mental activity compared to what they were already exposed to."

The findings are also not all that helpful in that fMRI measures "are not validated for making claims about clinically relevant neural activity," said Dr Knopman.

The study authors and Dr Knopman have disclosed no relevant financial relationships.

J Neurosci. Published July 10, 2017. Abstract

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