A recent paper published in the journal Nature looked at whether six weeks of online brain training would improve the cognitive performance of 11,430 healthy adults. What’s intriguing about this paper, besides the sheer size of the study, is that it was published in such a prestigious journal despite essentially having a null result.
To examine the effects of brain training on cognitive functioning, Owen Adrian of the Medical Research Council in the United Kingdom and his collaborators conducted a massive clinical trial online. At the start, 52,617 subjects, recruited through the British Broadcasting Corporation science show Bang Goes the Theory, signed up to participate. Ranging in age from 18 to 60, they were instructed to perform certain cognitive tasks for at least 10 minutes a day, three times per week, for six weeks. To do so, they logged on to the show’s website.
The study randomly assigned subjects to either one of two brain-training groups or to a control group. The two training groups differed in the kind of training they received: one practiced tasks designed to improve reasoning, planning, and problem-solving, while the other received training more like that involved in many commercial brain-training programs. For instance, they practiced tests assessing a wide range of cognitive functions, including short-term memory, attention, visuospatial processing, and math. A third group consisted of control subjects whose task involved finding answers to “obscure questions” using any online resources they could find.
To detect cognitive gains, the researchers administered a neuropsychological battery at baseline and six weeks later. It consisted of four tests that assessed verbal short-term memory, spatial working memory, paired-associates learning, and reasoning. The change in scores from pre-test to post-test served as the main outcome measure and an indicator of generalized cognitive improvement. Analyses focused on the 11,430 subjects who had completed at least two training sessions during the six-week period, as well as the neuropsychological test battery before and after that time. Not surprisingly, the training improved performance on the trained tasks. But, the control group also improved, with similar effect sizes. The critical comparison was whether the experimental groups showed greater improvements in performance post-training than the control group did. And the answer, generally speaking, was no. That is, when the researchers directly compared the performance of the three groups across all four tests, they found that all improved, but only slightly, but with no statistically significant differences.
Further studies will be done, including follow up of subjects who continue to participate in the online training for the next year, to see if any significant differences can be teased out.
A.M. Owen, A. Hampshire, J.A. Grahn, R. Stenton, S. Dajani, A.S. Burns, R.J. Howard, & C.G. Gallard (2010). Putting brain training to the test. Nature
Michael Rafii, MD, PhD
Associate Medical Director of the ADCS