Jun 11 2010

More Trouble for Brain Training

Brain training is the idea that training in a specific task will improve brain function for a type of skill that will then transfer more broadly to other tasks. For example, a memory task with improve your overall memory and therefore improve your performance on a different memory task. There is now a multi-million dollar industry based upon this concept.

But as is typical, for-profit commercial claims tend to race ahead of the science. The evidence for this generalizability effect is weak at best. Those who play video games have some performance advantages over those who do not. There may be benefits to engaging in novel cognitive activities. But brain training products either do not work or have a minimal effect below the resolution of research to detect.

Now a recent study published in Nature add further evidence for lack of efficacy to brain-training  products. They report:

Here we report the results of a six-week online study in which 11,430 participants trained several times each week on cognitive tasks designed to improve reasoning, memory, planning, visuospatial skills and attention. Although improvements were observed in every one of the cognitive tasks that were trained, no evidence was found for transfer effects to untrained tasks, even when those tasks were cognitively closely related.

This was an online study, so there may be some self-selection bias. But it is a fairly large study. If there were a significant effect it probably could have detected it.

One thing to note is that the subjects became better at the task at which they were training. This is universally true in such studies, even in other research areas, like stroke recovery, for example. There is a generic training effect – people become better at specific tasks at which they train. This has to be taken into consideration for any study that uses performance at baseline and after an intervention – subjects will get better at the task from training alone, even if the intervention had no effect at all. Keep an eye out for that training effect, because it can make any intervention seem to work.

But again – the question here is does training in one task create generic skills that transfer to other tasks that use those same skills? The answer appears to be no, at least not significantly. This is in line with other research.

I admit, however, that this does not entirely make sense to me – which means that the research is somehow misleading, or my concept of how the brain works is not accurate. It seems that skills should transfer. My concept, which is probably common, is that working out the brain is similar to working out a muscle. If you build muscle strength by lifting weights, that strength will transfer to other tasks, like doing pull ups. Of course, the brain is not a muscle, and cognitive ability is more complex than something as straightforward as how much force your muscles can generate. But still, this conceptual framework is compelling.

What does this research on the lack of efficacy of brain training mean, then? Assuming it is accurately reflecting underlying reality, it could mean that learning is very specific. The mechanism of memory and plasticity are such that they apply to a very narrow range of activity, not generic skills. Perhaps generic skills, like how good your memory is, are more inherent and not subject to training. But applying those base skills to a specific task is all about training. Perhaps this is the relationship between talent and skill. You are born with whatever talent you are ever going to have, but you have to learn how to apply it to fairly specific skills.

To add another dimension to this, some skills are more generally useful than others. Reading seems like a more useful skill than playing the kazoo. But this is different than the underlying cognitive substrate of learning one versus the other.

At this point the bottom line of this research is that expensive brain training products and programs are probably not worth the time and money. School systems should not invest their resources and their classroom time in such systems. Learn and teach those skills that serve some function for you themselves – they are practical or fun.

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