Australasian Science: Australia's authority on science since 1938

How Strong Is the Evidence for Brain Training Programs?

By Tim Hannan

The quality of research supporting brain training programs has been questioned.

It’s well-established that training on a cognitive task will usually improve performance on that task. However, companies that offer “brain training” software invariably make the bolder claim that the benefits of their products extend beyond the trained tasks to the improvement of a broader range of cognitive skills that enhance the user’s academic studies, professional goals and social pursuits.

Such marketing claims are not always found to be sustainable: the owner of the ubiquitously promoted Lumonosity was found by the US Federal Trade Commission to have engaged in deceptive advertising, as its claims were not supported by “competent and reliable scientific evidence”. (A $50 million judgement was reduced to a $2 million fine because of financial hardship).

Until now one obstacle to evaluating such marketing claims has been the absence of a detailed review of the existing evidence for these brain training programs. Now, a group of researchers have addressed this matter, and their findings do not make happy reading for the brain trainers.

The quantity and quality of the scientific evidence for the utility of brain training has been debated by neuroscientists for several years. In October 2014, the Stanford Center on Longevity and the Max Planck Institute for Human Development published a statement by 70 psychologists and neuroscientists asserting that there is no “compelling scientific evidence” that brain training programs reduce or reverse cognitive decline. Shortly afterwards, 133 other practitioners and researchers replied with the claim that “dozens of randomized controlled trials published in peer-reviewed journals” demonstrate that certain training programs can improve cognitive function, with improvements seen in everyday activities.

With both sides of the debate apparently reading the same research, their markedly contrary conclusions prompted the call for a comprehensive review of the literature supporting the efficacy of brain-training, and a team of psychologists from the USA and UK took up the challenge.

Focusing on peer-reviewed publications cited by proponents of brain training, and other studies listed on the websites of the major brain training software companies, the reviewers examined the quality of the evidence in terms of generally accepted standards for best practice in study design and reporting for intervention trials. The products examined included Fast ForWord, BrainHQ, CogniFit, CogMed and Lumonosity, and the reviewers’ findings were published last month in the journal Psychological Science in the Public Interest.

Precisely none of the studies cited by proponents – and therefore presumably representing the best available evidence for claims of effectiveness of the programs – met all of the reviewers’ criteria for best practice in research design and reporting. The majority were found to have major limitations in design or analysis that precluded any strong conclusions about the efficacy of the programs.

Setting aside the limitations, the cited literature does not support the claim that brain training improves everyday functioning: while there is evidence that these interventions improve performance on the trained tasks, it is not established that performance on distantly related tasks is improved at all.

This last point addresses the most critical question regarding brain training: does training improve performance on tasks other than the trained ones? If there is no reliable evidence of the transfer of training to other tasks, it can hardly be argued that such programs improve cognitive processes in a way that impacts upon everyday “real-world” performance.

The reviewers note that proponents of brain training may object to the adoption of best practice criteria in the evaluation of interventions in a developing field of practice, perhaps arguing that this stifles innovation. However they reject this argument, noting that if the proponents explicitly claim scientific evidence for the efficacy of brain training, those claims should be supported by strong evidence, not merely speculative or exploratory studies.

Despite the negative findings of the review, some proponents remain optimistic that benefits from sustained use will be observed in the long-term, such as healthier cognition in later life, or perhaps a delay in the onset of dementia. This would be a most desirable outcome, of course, but may be one beyond the reach of the currently available brain training programs.

A/Prof Tim Hannan is Head of the School of Psychology at Charles Sturt University, and the Past President of the Australian Psychological Society.