The Effects of Dual n-back Training on the Components of Working Memory and Fluid Intelligence: An Individual Differences Approach by

Measures of working memory capacity are associated with performance on a variety of cognitive tasks, and reliably predict academic achievement, fluid intelligence, controlled attention, problem solving, the ability to follow directions, and a number of other cognitive abilities. A number of recent studies have provided evidence that training working memory can lead to improvements in fluid intelligence, working memory span, and performance on other untrained tasks. However, in addition to a number of mixed results, many of these studies suffer from design limitations. The aim of the present study was to experimentally investigate the effects of a dual n-back working memory training task on a variety of measures of fluid intelligence, reasoning, working memory span, and attentional control. The present study compared a training group with an active control group (a placebo group), using appropriate methods that overcame the limitations of previous studies. The dual n-back training group improved more than the active control group on some, but not all outcome measures. Differential improvement for the training group was observed on fluid intelligence, working memory capacity, and response times on conflict trials in the Stroop task. In addition, individual differences in pre-training fluid intelligence scores and initial performance on the training task explain some of the variance in outcome measure improvements. We discuss these results in the context of previous studies, and suggest that additional work is needed in order to further understand the variables responsible for transfer from training.