Does mindfulness meditation training enhance executive control? A systematic review and meta-analysis of randomized controlled trials in adults

Abstract

[This is a pre-print of an article published in Mindfulness. The final authenticated version is available online at: https://link.springer.com/article/10.1007/s12671-019-01279-4] Objectives: Over the last years, mindfulness meditation has been claimed to be effective in enhancing several cognitive domains, including executive control. However, these claims have been mostly based on findings pertaining to case-control and cross-sectional studies, which are by nature unable to reveal causal relationships. Aiming to address this issue, we set out to conduct the first quantitative assessment of the literature concerning mindfulness meditation as an enhancer for executive control considering only randomized controlled studies. Methods: We conducted a systematic review and meta-analysis covering experimental studies testing the effect of mindfulness meditation training on at least one executive control function (working memory, inhibitory control, or cognitive flexibility) in adult samples. Four databases were examined, resulting in the identification of 822 candidate references. After a systematic filtering process, a set of 16 studies was retained for evaluation, of which 13 could be included in a subsequent meta-analysis. Results: We found an average effect size of g = 0.34 [0.16, 0.51], indicating a small-to-medium effect of mindfulness meditation training in enhancing executive control. Effect sizes for individual functions were g = 0.42 [0.10, 0.74] for working memory, g = 0.42 [0.20, 0.63] for inhibitory control, and g = 0.09 [-0.13, 0.31] for cognitive flexibility. Funnel plot asymmetry analysis revealed no evidence of publication bias. Conclusions: Taken together, our findings provide preliminary and moderate yet positive evidence supporting the enhancing effects of mindfulness meditation on executive control. Shortcomings of included studies and considerations for future empirical and meta-analytical research are discussed.