The Influence of Individual Differences in Cognitive Ability on Working Memory Training Gains.

Working memory training research has produced mixed results in terms of finding benefits beyond the trained tasks (i.e., transfer). One potential limitation is that the research thus far has failed to isolate the specific combination of factors that makes working memory training work best. Individual differences in cognitive ability at pretest may be an important factor, suggesting possible aptitude-by-treatment interactions. Baseline cognitive ability could be (a) positively related, (b) negatively related, or (c) unrelated to training task improvements. The relationship between ability and training gains is important given the idea that larger training improvements should lead to greater transfer. However, the majority of training studies tend to be under-powered to examine individual differences. We pooled studies conducted in related labs to increase power while minimizing differences between studies. In the studies that were identified for this project, young adults completed complex span training and working memory and/or fluid intelligence as pretest measures. The combined samples from seven studies resulted in a sample of 192 participants. Analyses focused on the relationship between pretest cognitive ability and training performance across training days. There was no evidence that individuals lower in cognitive ability improved more than high-ability subjects on the training tasks. Instead, we found a positive relationship for both working memory and fluid intelligence measured at pretest with the amount of training improvement. In addition, the association between pretest working memory and working memory training performance appears to be domain-general - verbal and visuospatial content do not produce differential relationships.