SCIENCE
06/21/2016 11:29 am ET Updated Jun 21, 2016

Positive Results From Brain Games May Be Just A Placebo Effect

A new study deals a blow to the billion-dollar industry.
Diamond Sky Images via Getty Images

The brain-training apps that promise to improve memory and boost your IQ may have nothing more than a placebo effect, according to a new study.

The study, published in the journal Proceedings of the National Academy of Sciences Monday, found that people perform better in intelligence tests if they expect brain-training games to help them. 

There's already growing debate over the efficacy of products that claim to train people's brains. The burgeoning industry -- which was forecast to make $6 billion by 2020 -- is already taking hits. The Federal Trade Commission fined the company behind the brain training program Lumosity $2 million in January for deceptive advertising. Lumosity sold game subscriptions to its 70 million customers ranging from monthly payments of $14.95 to lifetime memberships for $299.95, marketing the games as tools to keep the brain sharp and healthy. But the FTC said the program “preyed on consumers’ fears about age-related cognitive decline,” and it “simply did not have the science to back up its ads.”

Matters are not any less turbulent in the scientific community. In 2014, about 70 neuroscientists signed an open letter pointing out the lack of scientific evidence for claims about positive effects of brain games. Another group of scientists have argued in response that “a substantial and growing body of evidence shows that certain cognitive training regimens can significantly improve cognitive function.”

Studies showing the brain-train games work may be inherently biased from selecting participants who expected to get smarter by playing brain games, according to Cyrus Foroughi, who co-authored the latest research pointing to evidence of a placebo effect.

“Placeboes are very pervasive and they have to be controlled for in a tremendous number of fields. This field is no different,” the George Mason University researcher told The Huffington Post. “So we put together the study to actually test whether expectation for a positive effect can lead to a positive outcome.”

Foroughi and his colleagues put up flyers around the campus inviting students to take part in their research. Half of the flyers were highly suggestive, mentioning brain training and cognitive enhancement. The other half were standard, generic ads that didn’t mention the type of study.

Two different flyers used to recruit study participants.
Placebo effects in cognitive training, Forooghi et al., PNAS, 2016. DOI: 10.1073/pnas.1601243113
Two different flyers used to recruit study participants.

Both groups, each made up of 25 volunteers, did a pre-test to measure their baseline intelligence. They then played a game involving a task called dual n-back for an hour. This task aims to engage and train working memory. The next day, the participants returned to the lab for a second intelligence test.

Previous research, including a meta-analysis of 20 studies published in 2014, had suggested that training working memory could improve intelligence -- particularly the fluid type of intelligence that refers to problem-solving abilities and using logic.

The participants who had responded to the suggestive flyer showed improvement at the second intelligence test amounting to a 5- to 10-point increase on a standard IQ test. The other group, however, showed no improvements, according to the study. 

This placebo effect may have infiltrated a considerable body of research on brain training. Foroughi’s team contacted authors of 19 studies and found 17 of them in some way had introduced bias; they mentioned brain training, for example, or used a set of words that could have influenced the participants, Foroughi said.

Many researchers purposely do this to get motivated participants because people who are interested in playing brain games are more likely to take part than those who have no interest, he added. To  account for the bias, researchers divide their participants into two group. One group plays the real game while the other group plays a fake game or some similar alternative. They then subtract the improvements.

This study design may seem logical at first glance. And it seems to be the type of design that Lumosity has used in its research. “Our scientists had 4,715 participants complete the study," the company states on its website. "Half trained with Lumosity, while the rest did online crossword puzzles to control for placebo effects. After 10 weeks, the Lumosity group improved more than the crosswords group on an aggregate assessment of cognition.”

But the new finding that just expecting to get smarter might make people test better questions the real reason behind people’s improvements in those studies.

Lumosity said in a statement to HuffPost:

The recent study on placebo effects in cognitive training is interesting and underscores the importance of proper study design, suggesting that appropriately accounting for confounds such as self-selection bias and expectancy effects should be an important aspect of study design.

Lumosity is built on the philosophy that intrinsic motivation is essential to users’ training experience, and in the 2015 study “Enhancing Cognitive Abilities with Comprehensive Training: A Large, Online, Randomized, Active-Controlled Trial,” researchers were interested in studying cognitive training’s effects in users who’d demonstrated motivation and recruited participants accordingly. To mitigate placebo effects, the study used crossword puzzles as an active control. While there are always limitations to any given study, we welcome all research that serves to improve the quality of cognitive training research and, subsequently, the products available.

Other popular brain-training products include Happy Neuron, which has about 11 million users; Rosetta Stone's Fit Brains and The British Cogmed, which has games for children and students to improve learning. Neuronation, which has 7 million members, even claims that “working memory is directly related to intelligence -- the more you train, the smarter you can be.”

While the new finding doesn't prove that none of these brain training programs work, it does provide an alternative explanation for effects observed in the cognitive-training research and the brain-training industry, "revealing the need to account for confounds in future research,” Foroughi and his colleagues wrote in their study.

Jacky Au of University of California, Irvine, who authored the 2014 meta-analysis, agrees that a placebo effect "almost certainly" exists, but points out that we don't know if it explains all of the improvement people see from brain games. "The critical question is to parcel out the relative contributions of placebo and training," Au told HuffPost.  

Foroughi said the George Mason University study doesn't mean the debate is over. "I think we are moving in the right direction, getting better data and eliminating possible confounders like placebo effects," he said. "The brain training industry is growing. It may or may not work but we need a lot more evidence before we come to something conclusive.”

HuffPost

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