Improving fluid intelligence with training on working memory: a meta-analysis

Abstract

Working memory (WM), the ability to store and manipulate information for short periods of time, is an important predictor of scholastic aptitude and a critical bottleneck underlying higher-order cognitive processes, including controlled attention and reasoning. Recent interventions targeting WM have suggested plasticity of the WM system by demonstrating improvements in both trained and untrained WM tasks. However, evidence on transfer of improved WM into more general cognitive domains such as fluid intelligence (Gf) has been more equivocal. Therefore, we conducted a meta-analysis focusing on one specific training program, n-back. We searched PubMed and Google Scholar for all n-back training studies with Gf outcome measures, a control group, and healthy participants between 18 and 50 years of age. In total, we included 20 studies in our analyses that met our criteria and found a small but significant positive effect of n-back training on improving Gf. Several factors that moderate this transfer are identified and discussed. We conclude that short-term cognitive training on the order of weeks can result in beneficial effects in important cognitive functions as measured by laboratory tests.

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Notes

  1. 1.

    Classic fail-safe N calculation: The 24 observed studies, with weighted g = 0.24, led to a combined weighted ES of g = 5.78. Adding the 59 null effect studies would increase the sample size to n = 83. Average ES in the new sample would be: \( \frac{5.78}{83}=.069 \). The new SE would be calculated assuming the same SD: \( \frac{0.338}{\left(\sqrt{83}\right)}=.037 \). Therefore, with 59 null effect studies, the ES would drop down to g = .07, with SE = .04.

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Author’s Notes

S. M. Jaeggi and M. Buschkuehl came up with the study concept and coded data. E. Sheehan and J. Au also coded data. J. Au performed the data analyses and drafted the manuscript. G. J. Duncan consulted regarding meta-analytical techniques. All authors contributed to the data interpretation and writing, and all authors read and approved the final manuscript.

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Correspondence to Jacky Au.

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Au, J., Sheehan, E., Tsai, N. et al. Improving fluid intelligence with training on working memory: a meta-analysis. Psychon Bull Rev 22, 366–377 (2015). https://doi.org/10.3758/s13423-014-0699-x

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Keywords

  • Cognitive training
  • Transfer
  • Plasticity