Our fellow blogger Jeremy over at PsyBlog has written a thoughtful post comparing the value of a number of cognitive enhancing tools. His overall verdict?

“The evidence for exercise boosting cognitive function is head-and-shoulders above that for brain training, drugs, nutritional supplements and meditation. Scientifically, on the current evidence, exercise is the best way to enhance your cognitive function. And as for its side-effects: yes there is the chance of an injury but exercise can also reduce weight, lower the chance of dementia, improve mood and lead to a longer life-span. Damn those side-effects!”

Article: Which Cognitive Enhancers Really Work: Brain Training, Drugs, Vitamins, Meditation or Exercise?

Jeremy, I started writing this as a comment to your post in your blog, but then it got too long. Let me write my reaction to your post here. 

While I appreciate your analysis and share most of your points, I think the “ranking” effort (this type of intervention is better than that one) is ultimately misleading.  It is based on a faulty search for a general solution/ magic pill for everyone and everything.

If only things were so simple. Perhaps one day there will be research to support that view, but certainly not today. A number of interventions have shown their value. In different populations, and contexts. For “exercise is the best way to enhance your cognitive function” to be true, one needs to have a pretty specific understanding of “best”, “your” and “cognitive function”.

First of all, the main motivator for many people interested in cognitive enhancement interventions is to reduce the probability of developing Alzheimer’s symptoms. For that, leading a mentally stimulating life, or true Lifelong Learning, through Education, Occupation and Leisure activities has been shown (ok, perhaps strongly correlated) to be the strongest variable in a variety of studies, via the so-called Cognitive Reserve. In other words, research-based advice would probably be, for a teenager: Don’t Drop Out of School. For a middle age person: Make Sure you Have a Stimulating Job. For a retired person: Find and Try to Master A New Hobby Every Few Years.

Second, the case for physical exercise is mostly based on moving people from being Sedentary to Doing a Bit (2-3 times/ a week, 20 minutes “sweating”). Now, there are millions of people already doing that. Is there nothing else they can do to improve their cognitive fitness?

You may also have seen this Interview with Prof. Daniel Gopher on cognitive simulations for high-performing individuals. Do military pilots and basketball athletes really need to hear “Please do aerobic activities at least twice a week…”.

What about traders, bankers or consultants who already frequent the gym often, but need help with stress management/ emotional self-regulation in order to remain “cool” when they need to? Would you tell them “Please stop trading/ that Board meeting when things get difficult, leave your desk/ room for 30-40 minutes to take a quick run, and everything will be fine when you come back”. Or would they better learn the cognitive skills needed to manage stress real-time via biofeedback or meditation, for example.

Third, as you point out, there are studies on specific groups of people (add/ adhd, dyslexia, stroke/ TBI) where well-directed cognitive exercise has shown an effect in well-designed trials, whereas physical exercise, to my knowledge, hasn’t to the same degree. We are talking about over 25 million individuals in the US in those 3 categories alone. What do you tell them?

Fourth, the ACTIVE trial. Yes, that study is not perfect. But the results of the 3 different types of cognitive exercise (one computerized, two not) are pretty spectacular, in my view. Can you show me one similarly controlled clinical trial where 10 hours of physical exercise today produces cognitive gains not only now but also 5 years from now?

Fifth, while physical exercise has shown clear value in improving some cognitive abilities, such as some executive functions, it hasn’t show comparable value in others, such as information processing or memory. Which is one crucial reason why, in my view, looking for cure-alls will probably prove elusive.

In summary, you have written a very worthy article, with good analysis but drawing, in my opinion, the wrong conclusion and implications. I have to disagree with the approach, artificial in my view, to “rank” different interventions as if they were mutually exclusive. And as if everyone had the same needs and goals.

There is no research today to back or imply a claim asking people to just do X (physical exercise) and forget for the time being Y (mental exercise). Or the other way. Both play their role.

In our work we try to integrate all these concepts by saying that the 4 main “pillars” for cognitive health are: good nutrition, physical exercise, stress management and mental exercise. In the absence of perfect research, we encourage consumers and the professionals helping them to identify, by themselves, the area to work on next. Based on available research and tools, their specific context, needs and goals.

This conversation exemplifies why we believe that better and more widely available cognitive assessments are needed, and fast, to help set up valid baselines and help users of those “cognitive enhancers” measure their own progress in independent, reliable ways.

Thank you for opening a good conversation…and helping me exercise my brain by composing this answer.

For more information:

- It is Not Only Cars That Deserve Good Maintenance: Brain Care 101

- Neuroscience Interview Series: over 15 conversations with leading neuroscientists and psychologists on cognitive fitness and the brain

Update: the conversation continues at Looking for the Best Brain Fitness Method? Think Balance.