April 2, 2015
U-T San Diego
Staff Reporter

Competing statements add to debate over whether brain-training software can reduce or reverse cognitive decline

Of the many debates in science, few are as fiery as the one over whether computer “brain games” help make people smarter and broadly preserve or improve a person’s memory.

The debate flared in a particularly public way last October, when the Stanford Center on Longevity and the Max Planck Institute for Human Development issued a joint statement insisting there is no evidence that such games reduce or reverse cognitive decline.

The statement was signed by dozens of scientists from across the nation.

Those remarks drew a sharp rebuttal in December from Michael Merzenich, a distinguished emeritus neuroscientist at UC San Francisco who is also chief science officer for Posit Science, a company that provides brain-training software. Merzenich’s piece was signed by dozens of scientists as well.

The essence of the competing statements is presented below.

Key points from the Stanford and Max Planck statement:

Computer-based “brain games” claim a growing share of the marketplace in aging societies. Consumers are told that playing the games will make them smarter, more alert and able to learn faster and better. The implied and often explicit promise is that adherence to prescribed regimens of cognitive exercise will reduce and potentially reverse creeping cognitive slowing and forgetfulness, improve everyday functioning and help to prevent Alzheimer’s disease.

It is customary for advertising to highlight the benefits and overstate potential advantages of their products. In the brain-game market, however, advertisements also assure consumers that claims and promises are based on solid scientific evidence, as the games are “designed by neuroscientists” at top universities and research centers. These claims are reinforced through paid advertising and distributed by trusted news sources.

Thus, a group of cognitive scientists and neuroscientists felt obliged to issue a direct statement to the public: The strong consensus of this group is that the scientific literature does not support claims that the use of software-based “brain games” alters neural functioning in ways that improve general cognitive performance in everyday life, or prevent cognitive slowing and brain disease. Much more research is needed before firm conclusions on these issues can be drawn.

To quote the summary statement:

“We object to the claim that brain games offer consumers a scientifically grounded avenue to reduce or reverse cognitive decline when there is no compelling scientific evidence to date that they do. The promise of a magic bullet detracts from the best evidence to date, which is that cognitive health in old age reflects the long-term effects of healthy, engaged lifestyles. In the judgment of the signatories below, exaggerated and misleading claims exploit the anxieties of older adults about impending cognitive decline. We encourage continued careful research and validation in this field.”

Key points of rebuttal by Michael Merzenich:

We cannot agree with the part of your statement that says “there is no compelling scientific evidence” that brain exercises “offer consumers a scientifically grounded avenue to reduce or reverse cognitive decline.”

We fear that most readers would take this to mean there is little or no peer-reviewed evidence that certain brain exercises have been shown to drive cognitive improvements. There is, in fact, a large and growing body of such evidence. That evidence now includes dozens of randomized, controlled trials published in peer-reviewed journals that document specific benefits of defined types of cognitive training.

Many of these studies show improvements that encompass a broad array of cognitive and everyday activities, show gains that persist for a reasonable amount of time, document positive changes in real-life indices of cognitive health and employ control strategies designed to account for “placebo” effects.

While we can debate strengths and limitations of each study, it is a serious error of omission to ignore such studies in a consensus reviewing the state of this science. Over three decades, researchers have built a huge body of evidence that brain plasticity is a lifelong phenomenon — as you acknowledge.

However, the statement fails to acknowledge that this evidence was derived from training experiments directly documenting the improvement of sensory, cognitive, motor and functional performance.

We believe that by not acknowledging (1) the training basis of the literature that shows that brain plasticity exists throughout the brain and throughout life, (2) the many demonstrations of the effectiveness of well-designed plasticity-based training regimens, and (3) the specific findings of efficacy in the area of aging, your statement derogates the time, effort and expertise of the thousands of scientists and clinicians engaged in designing, conducting, analyzing, publishing and reviewing the research.

It also diminishes the contribution of thousands of volunteer research participants who gave their time and effort to these studies, and the time, effort and expertise of the grant-makers who awarded the funding for most of these studies through the National Institutes of Health, other government agencies and foundations.