Transfer and maintenance effects of online working-memory training in normal ageing and mild cognitive impairment

Working memory (WM) is one of the cognitive functions that is susceptible to ageing-related decline. Interventions that are able to improve WM functioning at older age are thus highly relevant. In this pilot study, we explored the transfer effects of core WM training on the WM domain and other cognitive domains in 23 healthy older adults and 18 patients with amnestic mild cognitive impairment (MCI). Performance on neuropsychological tests was assessed before and after completion of the online five-week adaptive WM training, and after a three-month follow-up period. After training, both groups improved on the Digit Span and Spatial Span, gains that were maintained at follow-up. At an individual level, a limited number of participants showed reliable training gain. Healthy older adults, and to a lesser extent MCI patients, additionally improved on figural fluency at group level, but not at individual level. Results furthermore showed that global brain atrophy and hippocampal atrophy, as assessed by MRI, may negatively affect training outcome. Our study examined core WM training, showing gains on trained and untrained tasks within the WM domain, but no broad generalisation to other cognitive domains. More research is needed to evaluate the clinical relevance of these findings and to identify participant characteristics that are predictive of training gain.