The Long-term Efficacy of Working Memory Training for Healthy Older Adults: A Systematic Review and Meta-Analysis of 22 Randomized Controlled Trials.

OBJECTIVES The long-lasting efficacy of WM training has been a controversial and still ardently debated issue. In this meta-analysis, the authors, concerning the long-term effects of WM training in healthy older adults on WM subdomains and abilities outside the WM domain assessed in randomized controlled studies. METHODS A systematic literature search of PubMed, Web of Science, PsycINFO, Cochrane Library, ProQuest, clinicaltrials.gov and Google Scholar was conducted. Random-effects models were used to quantitatively synthesize the existing data. RESULTS Twenty-two eligible studies were included in the meta-analysis. The mean participant age ranged from 63.77 to 80.1 years. The meta-synthesized long-term effects on updating were 0.45 (95% confidence interval [CI] 0.253-0.648, < 6 months: 0.395, 0.171-0.619, ≥ 6 months: 0.641, 0.223-1.058), on shifting, 0.447 (0.246-0.648, < 6 months: 0.448, 0.146-0.75, ≥ 6 months: 0.446, 0.176-0.716); on inhibition, 0.387 (0.228-0.547, < 6 months: 0.248, 0.013-0.484, ≥ 6 months: 0.504, 0.288-0.712); on maintenance, 0.486 (0.352-0.62, < 6 months: 0.52, 0.279-0.761, ≥ 6 months: 0.471, 0.31-0.63).