Michael Valenzuela and colleagues systematically review and meta-analyze the evidence that computerized cognitive training improves cognitive skills in older adults with normal cognition. Please see later in the article for the Editors' Summary

Computerized cognitive training (CCT) is a safe and inexpensive intervention to enhance cognitive performance in the elderly. However, the neural underpinning of CCT-induced effects and the timecourse by which such neural changes occur are unknown. Here, we report on results from a pilot study of healthy older adults who underwent three 1-h weekly sessions of either multidomain CCT program (n = 7) or an active control intervention (n = 5) over 12 weeks. Multimodal magnetic resonance imaging (MRI) scans and cognitive assessments were performed at baseline and after 9 and 36 h of training. Voxel-based structural analysis revealed a significant Group × Time interaction in the right post-central gyrus indicating increased gray matter density in the CCT group compared to active control at both follow-ups. Across the entire sample, there were significant positive correlations between changes in the post-central gyrus and change in global cognition after 36 h of training. A post-hoc vertex-based analysis found a significant between-group difference in rate of thickness change between baseline and post-training in the left fusiform gyrus, as well as a large cluster in the right parietal lobe covering the supramarginal and post-central gyri. Resting-state functional connectivity between the posterior cingulate and the superior frontal gyrus, and between the right hippocampus and the superior temporal gyrus significantly differed between the two groups after 9 h of training and correlated with cognitive change post-training. No significant interactions were found for any of the spectroscopy and diffusion tensor imaging data. Though preliminary, our results suggest that functional change may precede structural and cognitive change, and that about one-half of the structural change occurs within the first 9 h of training. Future studies are required to determine the role of these brain changes in the mechanisms underlying CCT-induced cognitive effects.

Objective:To quantify the effects of cognitive training (CT) on cognitive and behavioral outcome measures in patients with Parkinson disease (PD).Methods:We systematically searched 5 databases for randomized controlled trials (RCTs) of CT in patients with PD reporting cognitive or behavioral outcomes. Efficacy was measured as standardized mean difference (Hedges g) of post-training change.Results:Seven studies encompassing 272 patients with Hoehn & Yahr Stages 1–3 were included. The overall effect of CT over and above control conditions was small but statistically significant (7 studies: g = 0.23, 95% confidence interval [CI] 0.014–0.44, p = 0.037). True heterogeneity across studies was low (I2 = 0%) and there was no evidence of publication bias. Larger effect sizes were noted on working memory (4 studies: g = 0.74, CI 0.32–1.17, p = 0.001), processing speed (4 studies: g = 0.31, CI 0.01–0.61, p = 0.04), and executive function (5 studies: g = 0.30, CI 0.01–0.58, p = 0.042), while effects on measures of global cognition (4 studies), memory (5 studies), visuospatial skills (4 studies), and depression (5 studies), as well as attention, quality of life, and instrumental activities of daily living (3 studies each), were not statistically significant. No adverse events were reported.Conclusions:Though still small, the current body of RCT evidence indicates that CT is safe and modestly effective on cognition in patients with mild to moderate PD. Larger RCTs are necessary to examine the utility of CT for secondary prevention of cognitive decline in this population.

Cognition-oriented treatmentscommonly categorized as cognitive training, cognitive rehabilitation and cognitive stimulationare promising approaches for the prevention of cognitive and functional decline in older adults. We conducted a systematic overview of meta-analyses investigating the efficacy of cognition-oriented treatments on cognitive and non-cognitive outcomes in older adults with or without cognitive impairment. Review quality was assessed by A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR). We identified 51 eligible reviews, 46 of which were included in the quantitative synthesis. The confidence ratings were "moderate" for 9 (20%), "low" for 13 (28%) and "critically low" for 24 (52%) of the 46 reviews. While most reviews provided pooled effect estimates for objective cognition, non-cognitive outcomes of potential relevance were more sparsely reported. The mean effect estimate on cognition was small for cognitive training in healthy older adults (mean Hedges' g = 0.32, range 0.13-0.64, 19 reviews), mild cognitive impairment (mean Hedges' g = 0.40, range 0.32-0.60, five reviews), and dementia (mean Hedges' g = 0.38, range 0.09-1.16, seven reviews), and small for cognitive stimulation in dementia (mean Hedges' g = 0.36, range 0.26-0.44, five reviews). Meta-regression revealed that higher AMSTAR score was associated with larger effect estimates for cognitive outcomes. The available evidence supports the efficacy of cognition-oriented treatments improving cognitive performance in older adults. The extent to which such effects are of clinical value remains unclear, due to the scarcity of high-quality evidence and heterogeneity in reported findings. An important avenue for future trials is to include relevant non-cognitive outcomes in a more consistent way and, for meta-analyses in the field, there is a need for better adherence to methodological standards. PROSPERO registration number: CRD42018084490.

Sports performance at the highest level requires a wealth of cognitive functions such as attention, decision making, and working memory to be functioning at optimal levels in stressful and demanding environments. Whilst a substantial research base exists focusing on psychological skills for performance (e.g., imagery) or therapeutic techniques for emotion regulation (e.g., cognitive behavioral therapy), there is a scarcity of research examining whether the enhancement of core cognitive abilities leads to improved performance in sport. Cognitive training is a highly researched method of enhancing cognitive skills through repetitive and targeted exercises. In this article, we outline the potential use of cognitive training (CT) in athlete populations with a view to supporting athletic performance. We propose how such an intervention could be used in the future, drawing on evidence from other fields where this technique is more fruitfully researched, and provide recommendations for both researchers and practitioners working in the field.

Objective: To quantitatively aggregate effects of cognitive training (CT) on cognitive and functional outcome measures in patients with traumatic brain injury (TBI) more than 12-months post-injury.Design: We systematically searched six databases for non-randomized and randomized controlled trials of CT in TBI patients at least 12-months post-injury reporting cognitive and/or functional outcomes.Main Measures: Efficacy was measured as standardized mean difference (Hedges’ g) of post-training change. We investigated heterogeneity across studies using subgroup analyses and meta-regressions.Results: Fourteen studies encompassing 575 patients were included. The effect of CT on overall cognition was small and statistically significant (g = 0.22, 95%CI 0.05 to 0.38; p = 0.01), with low heterogeneity (I2 = 11.71%) and no evidence of publication bias. A moderate effect size was found for overall functional outcomes (g = 0.32, 95%CI 0.08 to 0.57, p = 0.01) with low heterogeneity (I2 = 14.27%) and possible publication bias. Statistically significant effects were also found only for executive function (g = 0.20, 95%CI 0.02 to 0.39, p = 0.03) and verbal memory (g = 0.32, 95%CI 0.14 to 0.50, p < 0.01).Conclusion: Despite limited studies in this field, this meta-analysis indicates that CT is modestly effective in improving cognitive and functional outcomes in patients with post-acute TBI and should therefore play a more significant role in TBI rehabilitation.

Background Computerized cognitive training (CCT) is a broad category of drill-and-practice interventions aims to maintain cognitive performance in older adults. Despite a supportive evidence base for general efficacy, it is unclear what types of CCT are most likely to be beneficial and what intervention design factors are essential for clinical implementation. Methods We searched MEDLINE, Embase, and PsycINFO to August 2019 for randomized controlled trials (RCTs) of any type of CCT in cognitively healthy older adults. Risk of bias within studies was assessed using the Cochrane Risk of Bias 2 tool. The primary outcome was change in overall cognitive performance between CCT and control groups. Secondary outcomes were individual cognitive domains. A series of meta-regressions were performed to estimates associations between key design factors and overall efficacy using robust variance estimation models. Network meta-analysis was used to compare the main approaches to CCT against passive or common active control conditions. Results Ninety RCTs encompassing 7219 participants across 117 comparisons were included. The overall cognitive effect size across all trials was small (g=0.18, 95% CI 0.14 to 0.23) with considerable heterogeneity (τ2=0.074, 95% prediction interval -0.36 to 0.73), robust to small-study effect or risk of bias. Effect sizes for individual cognitive domains were small, heterogeneous and statistically significant apart from fluid intelligence and visual processing. Meta-regressions revealed significantly larger effect sizes in trials using supervised training or up to three times per week. Multidomain training was the most efficacious CCT approach against any type of control, with greater benefits in a subset of supervised training studies. Conclusions The efficacy of CCT varies substantially across designs, independent of the type of control. Multidomain supervised CCT appears to be the most efficacious approach, and should be developed to accommodate for individual needs and remote delivery settings. Future research should focus on identifying the intervention components and regimens that could attenuate aging-related cognitive decline.

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.