The effects of mindfulness training on working memory performance in high-demand cohorts: a multi-study investigation

Working memory (WM) is critical for successful task performance and higher order cognitive functions, such as planning and decision-making. Yet, WM can become imperiled over periods of stress and high demand. This is particularly true of military service members who depend on peak cognitive functioning to maintain operational readiness and achieve mission goals, but who face intense and protracted demands across their military careers. Mindfulness training (MT) is one potential method to bolster cognitive resilience—the ability to maintain or regain cognitive capacities at risk of decline. We evaluated the efficacy of mindfulness training in six longitudinal studies conducted by our research group investigating the protective benefits of mindfulness practice on working memory. U.S. Military cohorts were recruited from several military installations and participants were assigned to either receive MT or serve as active or no-training comparison participants. Soldiers’ performance was assessed on a delayed-recognition working memory task with embedded military-relevant affective or neutral distracters before (T1) and after (T2) the MT interval. Multivariate and random effects meta-analysis of six studies indicated a consistent moderate difference between MT and comparison groups in standardized mean change (SMC) from T1 to T2. These findings support the supposition that MT protects soldiers’ working memory performance relative to controls. Implications for future research and further MT development, along with suggestions for policy on MT implementation, are discussed.