The Timecourse of Global Cognitive Gains From Supervised Computer-Assisted Cognitive Training: A Randomised, Active-Controlled Trial in Elderly With Multiple Dementia Risk Factors

Abstract

Background: Home-based computerised cognitive training (CCT) is ineffective at enhancing global cognition, a key marker of cognitive ageing. Objectives: To test the effectiveness of supervised, group-based, multidomain CCT on global cognition in older adults and to characterise the dose-response relationship during and after training. Design: A randomised, double-blind, longitudinal, active-controlled trial. Setting: Community-based training centre in Sydney, Australia Participants: Eighty nondemented community-dwelling older adults (mean age = 72.1, 68.8% females) with multiple dementia risk factors but no major neuropsychiatric or sensory disorder. Of the 80 participants admitted to the study, 65 completed post-training assessment and 55 were followed up one year after training cessation. Interventions: Thirty-six group-based sessions over three months of either CCT targeting memory, speed, attention, language and reasoning tasks, or active control training comprising audiovisual educational exercises. Measurements: Primary outcome was change from baseline in global cognition as defined by a composite score of memory, speed and executive function. Secondary outcome was 15-month change in Bayer Activities of Daily Living from baseline to one year post-training. Results: Intention-to-treat analyses revealed significant effects on global cognition in the cognitive training group compared to active control after three weeks of training (ES = 0.33, P=.039) that increased after 3 months of training (ES = 0.49, P=.003) and persisted three months after training cessation (ES = 0.30, P=0.023). Significant and durable improvements were also noted in memory and processing speed. Dose-response characteristics differed among cognitive domains. Training effects waned gradually but residual gains were noted twelve months post-training. No significant effects on activities of daily living were noted and there were no adverse effects. Conclusions: In older adults with multiple dementia risk factors, group-based CCT is a safe and effective intervention for enhancing overall cognition, memory and processing speed. Dose-response relationships vary for each cognitive domain, vital information for clinical and community implementation and further trial design.

Differential effects of cognitive training modules in healthy aging and mild cognitive impairment: A comprehensive meta-analysis of randomized controlled trials.

“…Furthermore, it yielded a significantly higher far transfer than processing speed training and significantly higher near transfer than episodic memory training. These results are in line with other meta-analyses which have not only found executive functions training to be effective in both younger and older adults (Karbach & Verhaeghen, 2014; Nguyen et al, 2019), but that this training is more effective on overall cognition than other cognitive training modules (Lampit et al, 2014; Mewborn et al, 2017).…”

“…Many researchers have recommended that cognitive training should do away with passive control, in favor of active control, because active control matches most closely the training group on motivation, social contact, and expected cognitive gains from the intervention (Simons et al, 2016). Although at least one meta-analysis on cognitive training supports this recommendation by finding that use of active controls resulted in significantly smaller net-gain effects on cognition than use of passive controls (e.g., N-back training in young and middle-aged adults, Au et al, 2015), other meta-analyses have found no significant difference between studies using active control versus or passive control (e.g., executive functions training across younger and older adults, Karbach & Verhaeghen, 2014; computerized cognitive training in HA, Lampit et al, 2014; video game training in HA, Toril et al, 2014).…”

“…Regarding who would benefit most from cognitive training (cognitively healthy or MCI), no significant difference in the net-gain effect size for overall cognition was observed between the two groups. Our net-gain effect sizes are more conservative estimates than the effect size statistics reported in the previous meta-analyses on HA and MCI, where the reported effect sizes were either gain scores of the training group (calculated from the difference between post- and pretraining cognitive scores) or posttest difference scores between training and control groups that did not account for baseline differences between the groups (gain score d = 0.86 for executive functions training in HA, Karbach & Verhaeghen, 2014; gain score d = 0.41 for cognitive training in MCI, Li et al, 2011; posttraining difference g = 0.28 for computer-based cognitive training in HA, Lampit et al, 2014). Net gain effect size, in contrast, compares the cognitive gains in the training group with the cognitive gains in the control group, and therefore can only be calculated in intervention studies that have a control group and yields a more conservative estimate (Morris, 2008).…”

“…At least three meta-analyses (Lampit et al, 2014; Li et al, 2011; Mewborn et al, 2017) have attempted to synthesize the results, but each had some limitations. These limitations include narrow inclusion criteria of mental status (Lampit et al, 2014; Li et al, 2011) and cognitive outcomes (Karr, Areshenkoff, Rast, & Garcia-Barrera, 2014), an incomplete corpus of existing studies (Mewborn et al, 2017), lack of specificity of near and far transfer (Lampit et al, 2014), or no quantitative contrasts between the best estimates of cognitive gains in the HA to that of the MCI (Mewborn et al, 2017), or of the training group to that of the control group.…”

Information and communication technologies for the improvement of cognitive function in healthy older adults: a systematic review protocol

“…23 A randomised controlled trial (RCT) showed improvements in cognitively unimpaired older adults with multiple dementia risks factors on memory and processing speed, and on global cognition. 30 And a recent RCT demonstrates that CCT provides benefits on executive functions, but when the CCT is combined with exercise it improved multiple cognitive processes of executive functions. 31 The type of interventions has varied as well as the duration of these said interventions, the SR of Lampit et al 23 evidenced that training sessions undertaken more than three times a week or sessions lasting less than 30 min may be ineffective.…”