Introduction: For those who like more detail, this entry delves deeper into the meta-analysis of Melby-Lervag and Hulme (2012) and examines their finding that there is no solid evidence that working memory training is of benefit for those with ADHD. Please see the entry of 1/13/2013 for an overview of their meta-analysis which clearly shows that there is no evidence that Working Memory Training programs, such as Cogmed, are effective in treating ADHD.
Methodological Issues, or why the quality of the research matters: One of the problems in trying to ascertain whether a given approach is helpful, is the quality of the research. Poorly designed studies can show support for a treatment approach. However, the problem is that these the flaws in design, or the lack of robust research design, may account for the positive findings. A simple example: if researchers are testing the benefits of working memory training by comparing it to a no treatment group, the fact that participants are receiving some intervention (an expectancy or placebo affect) may account for positive results rather than the intervention itself. This is but one example of how flawed research can claim to support an intervention when in reality the findings more likely reflect design flaws.
Generalizability or Transfer of Gains: A key issue in demonstrating the clinical value of an intervention, whether it really makes a difference, is whether the purported benefits of an intervention carry over to how study participants function in the real world. For example, we would expect that those receiving training on working memory tasks would do better when tested on similar types of tasks, a practice effect. The relevant question is: can working memory training show positive changes in areas that participants have not been trained in. For example, working memory training showed show benefits in theoretically related areas such as attention (sustained focus) and verbal ability.
Results of the Meta-Analysis on Working Memory Training: The findings are quite consistent, working memory training does not show any significant benefit for participants other than improved ability to perform working memory tasks after receiving training. Working memory training does not appear to generalize, lead to benefits in other related areas of functioning. Moreover, at follow up (re-evaluation several months or more after receiving training) working memory training showed no benefit for ADHD related symptoms.
In conclusion: One cannot say that working memory training absolutely does not work. Perhaps the dose (the amount of training received) or the type of training could be modified/improved and benefit might be found. However, the current review strongly suggests that there is a need for solid evidence that working memory training works before it is utilized as a treatment approach for ADHD, or other disorders for that matter.
* Melby-Lervag M, & Hulme, C. “Is working memory training effective? A meta-analytic review.” Developmental Psychology. Advance online publication. (May 21, 2012.)