Computerised cognitive training for maintaining cognitive function in cognitively healthy people in midlife

Systematic review and meta-analysis of standalone digital interventions for cognitive symptoms in people without dementia

Cognitive symptoms are prevalent across neuropsychiatric disorders, increase distress and impair quality of life. Self-guided digital interventions offer accessibility, scalability, and may overcome the research-to-practice treatment gap. Seventy-six trials with 5214 participants were identified. A random-effects meta-analysis investigated the effects of all digital self-guided interventions, compared to controls, at post-treatment. We found a small-to-moderate positive pooled effect on cognition (k = 71; g = -0.51, 95%CI -0.64 to -0.37; p < 0.00001) and mental health (k = 30; g = -0.41, 95%CI -0.60 to -0.22; p < 0.0001). Positive treatment effects on fatigue (k = 8; g = -0.27, 95%CI -0.53 to -0.02; p = 0.03) and quality of life (k = 22; g = -0.17, 95%CI -0.34 to -0.00; p = 0.04) were only marginally significant. No significant benefit was found for performance on activities of daily living. Results were independent of control groups, treatment duration, risk of bias and delivery format. Self-guided digital transdiagnostic interventions may benefit at least a subset of patients in the short run, yet their impact on non-cognitive outcomes remains uncertain.

Cognitive Training During Midlife: A Systematic Review and Meta-Analysis

Midlife has been suggested to be a crucial time to introduce interventions for improving cognitive functions. The effects of cognitive training (CT) in healthy middle-aged populations and more specifically during the menopausal transition have not been systematically investigated. To investigate the effects of CT on cognition in healthy middle-aged adults and specifically in females during the menopause transition, literature was searched inception to July 2023 and studies were included that examined the effects of CT on a defined cognitive outcome. The improvement on cognitive performance following CT was the main outcome measured as mean difference (from baseline to immediate post) estimates with corresponding 95% confidence intervals (CI) in meta-analysis and was discussed with the support of subgroup analysis based on outcome type (i.e., far or near-transfer) and cluster tabulations. Nineteen articles were included in the qualitative synthesis with a total of 7765 individuals, and eight articles were included in the meta-analyses. CT was categorized into six type clusters: Game-based CT, General CT, Speed of Processing Training, Working Memory Training, Strategy-based CT, and Cognitive Remediation. Cognitive outcome was divided into six clusters: working memory, verbal memory, language, executive function, attention/processing speed, and visual memory. Meta-analysis reported significant improvement in the domain of executive function (0.48, 95% CI 0.08-0.87), verbal memory (0.22, 95% CI 0.11-0.33), and working memory (0.16, 95% CI 0.05-0.26). CT confers benefits on various cognitive domains, suggesting a potential role of CT to promote optimal cognitive functioning in the midlife and specifically in women during the menopause transition.

The Effects of Cognitive Training in Healthy Community Residing Thai Elderly: A Randomized Controlled Trial

Purpose

Cognitive training intervention (CTI) is defined as any mechanism of action of a non-pharmacological procedure provided to improve cognitive function. CTI in healthy elderly has the potential to improve cognitive function; however, the effects of interactive computerized-CTI in old ages have been inconclusive. The present study aimed to determine the effects of low-technology CTI in community-based populations.

Patients and Methods

The study was a 2-arm parallel single-blinded randomized controlled intervention trial. The main outcome measured global cognitive function utilizing the Thai Mental State Examination (TMSE); the minor outcomes were cognitive subdomains and psychosocial outcomes (ie, quality of life and depression). The primary endpoint assessed the treatment effect at the 12th week (T1), while the secondary endpoint evaluated the carry-over effect at the 24th week (T2).

Results

Eighty-six eligible participants were recruited from a senior society on the edge of Bangkok. At baseline (T0), the mean age and TMSE score among CTI (n = 44) and wait-list (n = 42) groups were similar (age; 66.66 ± 5.52 and 67.52 ± 6.46; TMSE; 28.84 ± 1.38 and 28.83 ± 1.12, respectively). For the CTI group, the mean number of cognitive training sessions was 14.82 ± 7.62. By using intention-to-treat analysis at the primary endpoint, the mean difference score of TMSE in the CTI group was significantly higher than the wait-list group (∆TMSE_{between group} at T1-T0 = 0.57; 95% CI = 0.07 to 1.08), while the effect size was 0.48. At the secondary endpoint, there was no significant difference observed between the CTI and wait-list groups (∆TMSE_{between group} at T2-T0 = 0.33; 95% CI = -0.23 to 0.88), while the effect size was 0.25. The cognitive subdomains and psychosocial outcomes were discovered with no significant difference.

Conclusion

CTI showed significant treatment effect for improvement in global cognitive function in healthy Thai elderly but did not demonstrate carry-over effect. This study provided preliminary evidence of the feasibility of implementing low-technology CTI in middle-income countries.

Cognitive impairment, anxiety and depression: a map of Cochrane evidence relevant to rehabilitation for people with post COVID-19 condition

INTRODUCTION

Currently, no evidence exists on specific treatments for post COVID-19 condition (PCC). However, rehabilitation interventions that are effective for similar symptoms in other health conditions could be applied to people with PCC. With this overview of systematic reviews with mapping, we aimed to describe the Cochrane evidence on rehabilitation interventions proposed for cognitive impairment, anxiety and depression in different health conditions that can be relevant for PCC.

EVIDENCE ACQUISITION

We searched the last five years' Cochrane Systematic Review (CSRs) using the terms "cognitive impairment," "depressive disorder," "anxiety disorder," their synonyms and variants, and "rehabilitation" in the Cochrane Library. We extracted and summarized the available evidence using a map. We grouped the included CSRs for health conditions and interventions, indicating the effect and the quality of evidence.

EVIDENCE SYNTHESIS

We found 3596 CSRs published between 2016 and 2021, and we included 17 on cognitive impairment and 37 on anxiety and depression. For cognitive impairment, we found 7 CSRs on participants with stroke, 3 with cancer, 2 with Parkinson's disease, and one each for five other health conditions. Each intervention improved a different domain, and included exercises, cognitive and attention-specific training, and computerized cognition-based training (from very low to high-quality evidence). For anxiety and depression, we found 10 CSRs including participants with cancer, 8 with stroke, 3 with chronic obstructive pulmonary disease, and 2 or 1 each in 11 other health conditions. Exercise training, physical activity and yoga resulted effective in several pathologies (very low- to moderate-quality evidence). In specific diseases, we found effective acupuncture, animal-assisted therapy, aromatherapy, educational programs, home-based multidimensional survivorship programs, manual acupressure massage, memory rehabilitation, non-invasive brain stimulation, pulmonary rehabilitation, and telerehabilitation (very low- to moderate-quality evidence).

CONCLUSIONS

These results are the first step of indirect evidence able to generate helpful hypotheses for clinical practice and future research. They served as the basis for the three recommendations on treatments for these PCC symptoms published in the current WHO Guidelines for clinical practice.

Genes Versus Lifestyles: Exploring Beliefs About the Determinants of Cognitive Ageing

Genetic and lifestyle factors contribute to cognitive ageing. However, the extent to which the public attribute changes in thinking skills to either genetic or lifestyle factors is largely unknown. This may be important if it impacts engagement in activities deemed beneficial to thinking skills. This study, therefore, explored people's beliefs about determinants of cognitive ageing and whether those beliefs were associated with engagement in potentially beneficial behaviours. Data were collected through a United Kingdom-wide survey of people aged 40 and over. Participants completed questions about their beliefs regarding cognitive ageing, and specifically the extent to which they believed lifestyle or genetic factors influence those changes, and their engagement in specific behaviours that may be cognitively beneficial. Responses from 3,130 individuals (94.0% of the survey sample) were analysed using chi-square tests of independence, principal component analysis and ANCOVAs to investigate whether their attribution of genetic or lifestyle determinants were associated with their beliefs about cognitive ageing and their participation in brain health-related behaviours. Most respondents (62.2%) believed genes and lifestyle contribute equally to age-related changes in cognitive skills. Respondents who believed genetic factors were more influential were less likely to expect cognitive skills might be improved or maintained with age, less sure what behaviours might be associated with brain health, and less likely to engage in behaviours comprising mental challenge/novelty supported as beneficial for brain health. From this United Kingdom-wide survey about beliefs regarding potential determinants of cognitive ageing, some of our respondents' views were not aligned with the findings from ageing research. It is important for the public to know how to keep their brains healthy. Our results indicate a need for clearer messaging highlighting the role of lifestyle factors for brain health.

Evaluation of Computerized Cognitive Training and Cognitive and Daily Function in Patients Living With HIV: A Meta-analysis

IMPORTANCE

In the era of antiretroviral therapy (ART), the incidence of HIV-associated neurocognitive disorder (HAND) has not yet been controlled. With the exception of ART, there is no beneficial pharmacologic treatment. However, some studies have reported that computerized cognitive training (CCT) programs may improve cognitive function among people living with HIV.

OBJECTIVE

To examine the association between CCT programs and 8 domains measuring cognitive function (7 domains) and daily function (1 domain) among people living with HIV.

DATA SOURCES

Records from the Cochrane Library, PsycINFO, PubMed, and Web of Science were searched from database inception to December 15, 2020. Supplementary searches to identify missing studies were conducted in Google Scholar using updated search terms from database inception to November 18, 2021.

STUDY SELECTION

Studies that compared changes before and after a CCT intervention among people living with HIV were included. Search terms were a combination of words associated with HIV (eg, people living with HIV, HIV, and/or AIDS) and cognitive training (eg, cognitive intervention, nonpharmacology intervention, computer game, video game, computerized training, cognitive exercise, cognitive stimulation, and/or cognitive enhancement). Studies were included if they (1) used CCT as the primary intervention or combined CCT with other types of interventions; (2) used placebo, passive control conditions, traditional cognitive training, or single training tasks as control conditions; (3) reported changes between baseline and posttraining; (4) included participants 18 years or older; and (5) were randomized clinical trials (RCTs). Studies were excluded if they (1) were not associated with HIV, (2) were research protocols or feedback reports, (3) were case reports, or (4) did not report findings for domains of interest.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted data. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Random-effects models were used to quantitatively synthesize the existing data.

MAIN OUTCOMES AND MEASURES

Primary outcomes were the meta-synthesized changes in each domain after CCT.

RESULTS

Among 1245 records identified, 1043 were screened after removal of duplicates. Of those, 1019 records were excluded based on titles and abstracts, and 24 full-text articles were assessed for eligibility. After exclusions, 12 eligible RCTs were selected for inclusion in the meta-analysis. These RCTs involved 596 total participants, with 320 individuals in the CCT group (mean age, 47.5-59.7 years; 0%-94% female; 8.3-14.2 years of education) and 276 individuals in the control group (mean age, 44.2-60.0 years; 19%-90% female; 9.0-14.9 years of education). The average HIV inhibition ratio (the proportion of participants who achieved virological suppression) ranged from 30% to 100%, and the CD4+ T-cell count ranged from 471 to 833 cells/μL. The time since training ranged from 3 to 24 weeks. After receipt of CCT, function significantly improved in 6 of the 8 domains: abstraction and executive function (standardized mean difference [SMD], 0.58; 95% CI, 0.26-0.91; P < .001), attention and working memory (SMD, 0.62; 95% CI, 0.33-0.91; P < .001), memory (SMD, 0.59; 95% CI, 0.20-0.97; P = .003), motor skills (SMD, 0.50; 95% CI, 0.24-0.77; P < .001), speed of information processing (SMD, 0.65; 95% CI, 0.37-0.94; P < .001), and daily function (SMD, 0.44; 95% CI, 0.02-0.86; P = .04). Sensory and perceptual skills (SMD, 0.06; 95% CI, -0.36 to 0.48; P = .78) and verbal and language skills (SMD, 0.46; 95% CI, -0.07 to 0.99; P = .09) did not significantly improve after CCT.

CONCLUSIONS AND RELEVANCE

This meta-analysis of RCTs found that CCT programs were associated with improvements in cognitive and daily function among people living with HIV. Future studies are needed to design optimal specific training programs and use implementation science to enable the transformation of CCT from a scientific research tool to a real-world clinical intervention.

Efficacy of Interventions Based on the Use of Information and Communication Technologies for the Promotion of Active Aging

Nowadays, the study of how new media and technologies can be used to carry out health education by bringing these tools closer to the elderly population is interesting. It is a way of offering them access not only to greater knowledge, but to greater communication and relationship with their surroundings, a range of new possibilities and resources at their disposal that also represent a way to reduce the generation gap and bring them closer to the rest of the community. Objectives: to evaluate and analyze the studies that show the efficacy of interventions based on the use of information and communication technologies for the promotion of active aging in people older than or equal to 65 years who live in the community. Data sources, study eligibility criteria: the search for the articles was carried out from January 2012 to March 2021, in 6 databases (Pubmed, Cochrane Library, Scopus, Scielo, Google Academic and WOS) based on the clinical question, using the keywords derived from the DeCS and MeSH thesauri, combined with the Boolean operators “AND”, “NOT” and “OR”. The search was limited to publications from the last 9 years, in English and Spanish. Results: after applying the selection criteria and evaluating the quality of the methodology, 7.91% (n = 17) of the 215 results were included with filters: 7 systematic review, 5 of Cohorts and 5 of Randomized Controlled Trial. Conclusions and implications of key findings: the use of communication technologies reduces the feeling of loneliness, as well as the use of virtual reality to exercise, train memory or perform rehabilitation. The most difficult barrier to overcome is the prior ignorance of the majority of the elderly to the technology that is overcome by working as a team throughout the community, especially in the health and educational sector, as well as the family or social nucleus.

The Effect of Video Game-Based Interventions on Performance and Cognitive Function in Older Adults: Bayesian Network Meta-analysis

Background

The decline in performance of older people includes balance function, physical function, and fear of falling and depression. General cognitive function decline is described in terms of processing speed, working memory, attention, and executive functioning, and video game interventions may be effective.

Objective

This study evaluates the effect of video game interventions on performance and cognitive function in older participants in terms of 6 indicators: balance function, executive function, general cognitive function, physical function, processing speed, and fear of falling and depression.

Methods

Electronic databases were searched for studies from inception to June 30, 2020. Randomized controlled trials and case-controlled trials comparing video game interventions versus nonvideo game control in terms of performance and cognitive function outcomes were incorporated into a Bayesian network meta-analysis. All data were continuous variables.

Results

In total, 47 studies (3244 participants) were included. In pairwise meta-analysis, compared with nonvideo game control, video game interventions improved processing speed, general cognitive function, and depression scores. In the Bayesian network meta-analysis, interventions with video games improved balance function time (standardized mean difference [SMD] –3.34, 95% credible interval [CrI] –5.54 to –2.56), the cognitive function score (SMD 1.23, 95% CrI 0.82-1.86), processing speed time (SMD –0.29, 95% CrI –0.49 to –0.08), and processing speed number (SMD 0.72, 95% CrI 0.36-1.09), similar to the pairwise meta-analysis. Interventions with video games with strong visual senses and good interactivity ranked first, and these might be more beneficial for the elderly.

Conclusions

Our comprehensive Bayesian network meta-analysis provides evidence that video game interventions could be considered for the elderly for improving performance and cognitive function, especially general cognitive scores and processing speed. Games with better interactivity and visual stimulation have better curative effects. Based on the available evidence, we recommend video game interventions for the elderly.

Trial Registration

PROSPERO CRD42020197158; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=197158

Virtual Reality Applications in Medicine During the COVID-19 Pandemic: Systematic Review (Preprint)

Background

Virtual reality can play an important role during the COVID-19 pandemic in the health care sector. This technology has the potential to supplement the traditional in-hospital medical training and treatment, and may increase access to training and therapies in various health care settings.

Objective

This systematic review aimed to describe the literature on health care–targeted virtual reality applications during the COVID-19 crisis.

Methods

We conducted a systematic search of the literature on the PsycINFO, Web of Science, and MEDLINE databases, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The search string was as follows: “[(virtual reality)] AND [(COVID-19) OR (coronavirus) OR (SARS-CoV-2) OR (healthcare)].” Papers published in English after December 2019 in peer-reviewed journals were selected and subjected to the inclusion and exclusion criteria. We used the Mixed Methods Appraisal Tool to assess the quality of studies and the risk of bias.

Results

Thirty-nine studies met the inclusion criteria. Seventeen studies showed the usefulness of virtual reality during the COVID-19 crisis for reducing stress, anxiety, depression, and pain, and promoting physical activity. Twenty-two studies revealed that virtual reality was a helpful learning and training tool during the COVID-19 crisis in several areas, including emergency medicine, nursing, and pediatrics. This technology was also used as an educational tool for increasing public understanding of the COVID-19 pandemic. Different levels of immersion (ie, immersive and desktop virtual reality), types of head-mounted displays (ie, PC-based, mobile, and standalone), and content (ie, 360° videos and photos, virtual environments, virtual reality video games, and embodied virtual agents) have been successfully used. Virtual reality was helpful in both face-to-face and remote trials.

Conclusions

Virtual reality has been applied frequently in medicine during the COVID-19 pandemic, with positive effects for treating several health conditions and for medical education and training. Some barriers need to be overcome for the broader adoption of virtual reality in the health care panorama.

Trial Registration

International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY) INPLASY202190108; https://inplasy.com/inplasy-2021-9-0108/

Cognitive stimulation in the workplace, plasma proteins, and risk of dementia: three analyses of population cohort studies

OBJECTIVES

To examine the association between cognitively stimulating work and subsequent risk of dementia and to identify protein pathways for this association.

DESIGN

Multicohort study with three sets of analyses.

SETTING

United Kingdom, Europe, and the United States.

PARTICIPANTS

Three associations were examined: cognitive stimulation and dementia risk in 107 896 participants from seven population based prospective cohort studies from the IPD-Work consortium (individual participant data meta-analysis in working populations); cognitive stimulation and proteins in a random sample of 2261 participants from one cohort study; and proteins and dementia risk in 13 656 participants from two cohort studies.

MAIN OUTCOME MEASURES

Cognitive stimulation was measured at baseline using standard questionnaire instruments on active versus passive jobs and at baseline and over time using a job exposure matrix indicator. 4953 proteins in plasma samples were scanned. Follow-up of incident dementia varied between 13.7 to 30.1 years depending on the cohort. People with dementia were identified through linked electronic health records and repeated clinical examinations.

RESULTS

During 1.8 million person years at risk, 1143 people with dementia were recorded. The risk of dementia was found to be lower for participants with high compared with low cognitive stimulation at work (crude incidence of dementia per 10 000 person years 4.8 in the high stimulation group and 7.3 in the low stimulation group, age and sex adjusted hazard ratio 0.77, 95% confidence interval 0.65 to 0.92, heterogeneity in cohort specific estimates I²=0%, P=0.99). This association was robust to additional adjustment for education, risk factors for dementia in adulthood (smoking, heavy alcohol consumption, physical inactivity, job strain, obesity, hypertension, and prevalent diabetes at baseline), and cardiometabolic diseases (diabetes, coronary heart disease, stroke) before dementia diagnosis (fully adjusted hazard ratio 0.82, 95% confidence interval 0.68 to 0.98). The risk of dementia was also observed during the first 10 years of follow-up (hazard ratio 0.60, 95% confidence interval 0.37 to 0.95) and from year 10 onwards (0.79, 0.66 to 0.95) and replicated using a repeated job exposure matrix indicator of cognitive stimulation (hazard ratio per 1 standard deviation increase 0.77, 95% confidence interval 0.69 to 0.86). In analysis controlling for multiple testing, higher cognitive stimulation at work was associated with lower levels of proteins that inhibit central nervous system axonogenesis and synaptogenesis: slit homologue 2 (SLIT2, fully adjusted β -0.34, P<0.001), carbohydrate sulfotransferase 12 (CHSTC, fully adjusted β -0.33, P<0.001), and peptidyl-glycine α-amidating monooxygenase (AMD, fully adjusted β -0.32, P<0.001). These proteins were associated with increased dementia risk, with the fully adjusted hazard ratio per 1 SD being 1.16 (95% confidence interval 1.05 to 1.28) for SLIT2, 1.13 (1.00 to 1.27) for CHSTC, and 1.04 (0.97 to 1.13) for AMD.

CONCLUSIONS

The risk of dementia in old age was found to be lower in people with cognitively stimulating jobs than in those with non-stimulating jobs. The findings that cognitive stimulation is associated with lower levels of plasma proteins that potentially inhibit axonogenesis and synaptogenesis and increase the risk of dementia might provide clues to underlying biological mechanisms.

Evaluating the relationship between citation set size, team size and screening methods used in systematic reviews: a cross-sectional study

Background

Standard practice for conducting systematic reviews (SRs) is time consuming and involves the study team screening hundreds or thousands of citations. As the volume of medical literature grows, the citation set sizes and corresponding screening efforts increase. While larger team size and alternate screening methods have the potential to reduce workload and decrease SR completion times, it is unknown whether investigators adapt team size or methods in response to citation set sizes. Using a cross-sectional design, we sought to understand how citation set size impacts (1) the total number of authors or individuals contributing to screening and (2) screening methods.

Methods

MEDLINE was searched in April 2019 for SRs on any health topic. A total of 1880 unique publications were identified and sorted into five citation set size categories (after deduplication): < 1,000, 1,001–2,500, 2,501–5,000, 5,001–10,000, and > 10,000. A random sample of 259 SRs were selected (~ 50 per category) for data extraction and analysis.

Results

With the exception of the pairwise t test comparing the under 1000 and over 10,000 categories (median 5 vs. 6, p = 0.049) no statistically significant relationship was evident between author number and citation set size. While visual inspection was suggestive, statistical testing did not consistently identify a relationship between citation set size and number of screeners (title-abstract, full text) or data extractors. However, logistic regression identified investigators were significantly more likely to deviate from gold-standard screening methods (i.e. independent duplicate screening) with larger citation sets. For every doubling of citation size, the odds of using gold-standard screening decreased by 15 and 20% at title-abstract and full text review, respectively. Finally, few SRs reported using crowdsourcing (n = 2) or computer-assisted screening (n = 1).

Conclusions

Large citation set sizes present a challenge to SR teams, especially when faced with time-sensitive health policy questions. Our study suggests that with increasing citation set size, authors are less likely to adhere to gold-standard screening methods. It is possible that adjunct screening methods, such as crowdsourcing (large team) and computer-assisted technologies, may provide a viable solution for authors to complete their SRs in a timely manner.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-021-01335-5.

Short-Term Touch-Screen Video Game Playing Improves the Inhibition Ability

There is mixed evidence regarding whether video games affect executive function. The inconsistent results in this area may have to do with researchers’ conceptualizations of executive function as a unified construct or as a set of independent skills. In the current study, 120 university students were randomly assigned to play a video game or to watch a screen record of the video game. They then completed a series of behavioral tasks to assess the shifting, updating and inhibiting subcomponents of executive function. Scores on these tasks were also used as indicators of a component-general latent variable. Results based on analysis of covariance showed that, as predicted, the inhibition subcomponent, but not the updating or the shifting subcomponent, was significantly enhanced after gaming. The component-general executive function was not enhanced after gaming once the results were controlled for other subcomponents. The results were unrelated to participants’ self-reported positive and negative affect. The findings add key evidence to the literature on executive function and potentially contribute to the therapeutic use of video games to maintain executive function in the aged population.

Retinal Imaging Techniques Based on Machine Learning Models in Recognition and Prediction of Mild Cognitive Impairment

BACKGROUND AND PURPOSE

Mild Cognitive Impairment (MCI) is thought to be the signal of many progressive diseases but is easily ignored. Therefore, a simple and easy screening method for recognizing and predicting MCI is urgently needed. The study aimed to establish machine learning models of retinal vascular features to categorize and predict MCI.

PATIENTS AND METHODS

Subjects enrolled underwent cognitive function assessment and were divided into a normal group, an MCI group, and a dementia group, and fundus photography was performed. MATLAB 2019b was used for fundus image preprocessing and vascular segmentation. Via the Green channel, adaptive histogram equalization (AHE), image binarization, and median filtering, we obtained the original and segmentation retinal vessel images. Afterwards, the histogram of oriented gradient (HOG) was used for image feature extraction. Support vector machine (SVM) and extreme learning machine (ELM) were selected for training models in the fundus original images and fundus vascular segmentation images, respectively. Among the three cognitive groups, sensitivity, specificity, the receiver operating characteristic (ROC) curves, and the area under the curve (AUC) were used to evaluate and compare the predictive performance of the two models in the fundus original and vascular segmentation images, respectively.

RESULTS

A total of 86 eligible subjects were enrolled in the study. After a clinical cognitive assessment, the participants were divided into the normal group (N = 38), the MCI group (N = 26), and the dementia group (N = 22). A total of 332 qualified fundus images were adopted after screening. Comparing the models among the three groups showed that the SVM model had more advantages than the ELM model in the fundus original images and vascular segmentation images. Meanwhile, we found that the original images performed better than the segmentation images in the same prediction model. Among the three groups, the SVM model of the fundus original images had the best performance.

CONCLUSION

The establishment of a predictive model based on vascular-related feature extraction from fundus images has high recognition and prediction abilities for cognitive function and can be used as a screening method for MCI.

CLINICAL TRIAL REGISTRATION

ChiCTR.org.cn (ChiCTR1900027404), Registered on Nov 12, 2019.

Computerised cognitive training for 12 or more weeks for maintaining cognitive function in cognitively healthy people in late life

BACKGROUND

Increasing age is associated with a natural decline in cognitive function and is the greatest risk factor for dementia. Cognitive decline and dementia are significant threats to independence and quality of life in older adults. Therefore, identifying interventions that help to maintain cognitive function in older adults or that reduce the risk of dementia is a research priority. Cognitive training uses repeated practice on standardised exercises targeting one or more cognitive domains and may be intended to improve or maintain optimal cognitive function. This review examines the effects of computerised cognitive training interventions lasting at least 12 weeks on the cognitive function of healthy adults aged 65 or older and has formed part of a wider project about modifying lifestyle to maintain cognitive function. We chose a minimum 12 weeks duration as a trade-off between adequate exposure to a sustainable intervention and feasibility in a trial setting.

OBJECTIVES

To evaluate the effects of computerised cognitive training interventions lasting at least 12 weeks on cognitive function in cognitively healthy people in late life.

SEARCH METHODS

We searched to 31 March 2018 in ALOIS (www.medicine.ox.ac.uk/alois), and we performed additional searches of MEDLINE, Embase, PsycINFO, CINAHL, ClinicalTrials.gov, and the WHO Portal/ICTRP (www.apps.who.int/trialsearch), to ensure that the search was as comprehensive and as up-to-date as possible to identify published, unpublished, and ongoing trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs, published or unpublished, reported in any language. Participants were cognitively healthy people, and at least 80% of the study population had to be aged 65 or older. Experimental interventions adhered to the following criteria: intervention was any form of interactive computerised cognitive intervention - including computer exercises, computer games, mobile devices, gaming console, and virtual reality - that involved repeated practice on standardised exercises of specified cognitive domain(s) for the purpose of enhancing cognitive function; the duration of the intervention was at least 12 weeks; cognitive outcomes were measured; and cognitive training interventions were compared with active or inactive control interventions.

DATA COLLECTION AND ANALYSIS

We performed preliminary screening of search results using a 'crowdsourcing' method to identify RCTs. At least two review authors working independently screened the remaining citations against inclusion criteria. At least two review authors also independently extracted data and assessed the risk of bias of included RCTs. Where appropriate, we synthesised data in random-effects meta-analyses, comparing computerised cognitive training (CCT) separately with active and inactive controls. We expressed treatment effects as standardised mean differences (SMDs) with 95% confidence intervals (CIs). We used GRADE methods to describe the overall quality of the evidence for each outcome.

MAIN RESULTS

We identified eight RCTs with a total of 1183 participants. The duration of the interventions ranged from 12 to 26 weeks; in five trials, the duration of intervention was 12 or 13 weeks. The included studies had moderate risk of bias, and the overall quality of evidence was low or very low for all outcomes. We compared CCT first against active control interventions, such as watching educational videos. Negative SMDs favour CCT over control. Trial results suggest slight improvement in global cognitive function at the end of the intervention period (12 weeks) (standardised mean difference (SMD) -0.31, 95% confidence interval (CI) -0.57 to -0.05; 232 participants; 2 studies; low-quality evidence). One of these trials also assessed global cognitive function 12 months after the end of the intervention; this trial provided no clear evidence of a persistent effect (SMD -0.21, 95% CI -0.66 to 0.24; 77 participants; 1 study; low-quality evidence). CCT may result in little or no difference at the end of the intervention period in episodic memory (12 to 17 weeks) (SMD 0.06, 95% CI -0.14 to 0.26; 439 participants; 4 studies; low-quality evidence) or working memory (12 to 16 weeks) (SMD -0.17, 95% CI -0.36 to 0.02; 392 participants; 3 studies; low-quality evidence). Because of the very low quality of the evidence, we are very uncertain about the effects of CCT on speed of processing and executive function. We also compared CCT to inactive control (no interventions). We found no data on our primary outcome of global cognitive function. At the end of the intervention, CCT may lead to slight improvement in episodic memory (6 months) (mean difference (MD) in Rivermead Behavioural Memory Test (RBMT) -0.90 points, 95% confidence interval (CI) -1.73 to -0.07; 150 participants; 1 study; low-quality evidence) but can have little or no effect on executive function (12 weeks to 6 months) (SMD -0.08, 95% CI -0.31 to 0.15; 292 participants; 2 studies; low-quality evidence), working memory (16 weeks) (MD -0.08, 95% CI -0.43 to 0.27; 60 participants; 1 study; low-quality evidence), or verbal fluency (6 months) (MD -0.11, 95% CI -1.58 to 1.36; 150 participants; 1 study; low-quality evidence). We could not determine any effects on speed of processing because the evidence was of very low quality. We found no evidence on quality of life, activities of daily living, or adverse effects in either comparison.

AUTHORS' CONCLUSIONS

We found low-quality evidence suggesting that immediately after completion of the intervention, small benefits of CCT may be seen for global cognitive function when compared with active controls, and for episodic memory when compared with an inactive control. These benefits are of uncertain clinical importance. We found no evidence that the effect on global cognitive function persisted 12 months later. Our confidence in the results was low, reflecting the overall quality of the evidence. In five of the eight trials, the duration of the intervention was just three months. The possibility that more extensive training could yield larger benefit remains to be more fully explored. We found substantial literature on cognitive training, and collating all available scientific information posed problems. Duration of treatment may not be the best way to categorise interventions for inclusion. As the primary interest of older people and of guideline writers and policymakers involves sustained cognitive benefit, an alternative would be to categorise by length of follow-up after selecting studies that assess longer-term effects.

Effects of Combined Aerobic Exercise and Cognitive Training on Verbal Fluency in Older Adults

We have previously shown that aerobic exercise improves measures of verbal fluency in older adults, and such an improvement is correlated with improved cardiovascular reserve (i.e., estimates of VO2). Due to increasing popularity in computer-based cognitive training, we explored whether the addition of cognitive training to aerobic exercise would further enhance the beneficial cognitive impact of exercise. Therefore, this study sought to test the hypothesis that a cognitive training regimen alone would directly improve executive function and that this effect would be potentiated with the addition of aerobic exercise. The interventions lasted 12 weeks, and cognitive assessments were taken immediately prior to and after the interventions. We found that only the groups employing aerobic exercise showed improvements in verbal fluency (semantic and letter) and cardiovascular fitness with no other executive functions being significantly impacted. Cognitive training alone was associated with decreased verbal fluency. These data replicate previous findings which indicate that aerobic exercise may have a remedial or mitigating effect of cognitive decline. In addition, they provide evidence that the addition of concurrent cognitive training to an aerobic exercise program does not provide synergistic improvement in executive functions.

Reward motivation and neurostimulation interact to improve working memory performance in healthy older adults: A simultaneous tDCS-fNIRS study

Several studies have evaluated the effect of anodal transcranial direct current stimulation (tDCS) over the prefrontal cortex (PFC) for the enhancement of working memory (WM) performance in healthy older adults. However, the mixed results obtained so far suggest the need for concurrent brain imaging, in order to more directly examine tDCS effects. The present study adopted a continuous multimodal approach utilizing functional near-infrared spectroscopy (fNIRS) to examine the interactive effects of tDCS combined with manipulations of reward motivation. Twenty-one older adults (mean age = 69.7 years; SD = 5.05) performed an experimental visuo-spatial WM task before, during and after the delivery of 1.5 mA anodal tDCS/sham over the left prefrontal cortex (PFC). During stimulation, participants received performance-contingent reward for every fast and correct response during the WM task. In both sessions, hemodynamic activity of the bilateral frontal, motor and parietal areas was recorded across the entire duration of the WM task. Cognitive functions and reward sensitivity were also assessed with standard measures. Results demonstrated a significant impact of tDCS on both WM performance and hemodynamic activity. Specifically, faster responses in the WM task were observed both during and after anodal tDCS, while no differences were found under sham control conditions. However, these effects emerged only when taking into account individual visuo-spatial WM capacity. Additionally, during and after the anodal tDCS, increased hemodynamic activity relative to sham was observed in the bilateral PFC, while no effects of tDCS were detected in the motor and parietal areas. These results provide the first evidence of tDCS-dependent functional changes in PFC activity in healthy older adults during the execution of a WM task. Moreover, they highlight the utility of combining reward motivation with prefrontal anodal tDCS, as a potential strategy to improve WM efficiency in low performing healthy older adults.

Computerised cognitive training for maintaining cognitive function in cognitively healthy people in late life

BACKGROUND

Increasing age is associated with a natural decline in cognitive function and is also the greatest risk factor for dementia. Cognitive decline and dementia are significant threats to independence and quality of life in older adults. Therefore, identifying interventions that help to maintain cognitive function in older adults or to reduce the risk of dementia is a research priority. Cognitive training uses repeated practice on standardised exercises targeting one or more cognitive domains and is intended to maintain optimum cognitive function. This review examines the effect of computerised cognitive training interventions lasting at least 12 weeks on the cognitive function of healthy adults aged 65 or older.

OBJECTIVES

To evaluate the effects of computerised cognitive training interventions lasting at least 12 weeks for the maintenance or improvement of cognitive function in cognitively healthy people in late life.

SEARCH METHODS

We searched to 31 March 2018 in ALOIS (www.medicine.ox.ac.uk/alois) and performed additional searches of MEDLINE, Embase, PsycINFO, CINAHL, ClinicalTrials.gov, and the WHO Portal/ICTRP (www.apps.who.int/trialsearch) to ensure that the search was as comprehensive and as up-to-date as possible, to identify published, unpublished, and ongoing trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs, published or unpublished, reported in any language. Participants were cognitively healthy people, and at least 80% of the study population had to be aged 65 or older. Experimental interventions adhered to the following criteria: intervention was any form of interactive computerised cognitive intervention - including computer exercises, computer games, mobile devices, gaming console, and virtual reality - that involved repeated practice on standardised exercises of specified cognitive domain(s) for the purpose of enhancing cognitive function; duration of the intervention was at least 12 weeks; cognitive outcomes were measured; and cognitive training interventions were compared with active or inactive control interventions.

DATA COLLECTION AND ANALYSIS

We performed preliminary screening of search results using a 'crowdsourcing' method to identify RCTs. At least two review authors working independently screened the remaining citations against inclusion criteria. At least two review authors also independently extracted data and assessed the risk of bias of included RCTs. Where appropriate, we synthesised data in random-effect meta-analyses, comparing computerised cognitive training (CCT) separately with active and inactive controls. We expressed treatment effects as standardised mean differences (SMDs) with 95% confidence intervals (CIs). We used GRADE methods to describe the overall quality of the evidence for each outcome.

MAIN RESULTS

We identified eight RCTs with a total of 1183 participants. Researchers provided interventions over 12 to 26 weeks; in five trials, the duration of intervention was 12 or 13 weeks. The included studies had a moderate risk of bias. Review authors noted a lot of inconsistency between trial results. The overall quality of evidence was low or very low for all outcomes.We compared CCT first against active control interventions, such as watching educational videos. Because of the very low quality of the evidence, we were unable to determine any effect of CCT on our primary outcome of global cognitive function or on secondary outcomes of episodic memory, speed of processing, executive function, and working memory.We also compared CCT versus inactive control (no interventions). Negative SMDs favour CCT over control. We found no studies on our primary outcome of global cognitive function. In terms of our secondary outcomes, trial results suggest slight improvement in episodic memory (mean difference (MD) -0.90, 95% confidence interval (CI) -1.73 to -0.07; 150 participants; 1 study; low-quality evidence) and no effect on executive function (SMD -0.08, 95% CI -0.31 to 0.15; 292 participants; 2 studies; low-quality evidence), working memory (MD -0.08, 95% CI -0.43 to 0.27; 60 participants; 1 study; low-quality evidence), or verbal fluency (MD -0.11, 95% CI -1.58 to 1.36; 150 participants; 1 study; low-quality evidence). We could not determine any effects on speed of processing at trial endpoints because the evidence was of very low quality.We found no evidence on quality of life, activities of daily living, or adverse effects in either comparison.

AUTHORS' CONCLUSIONS

We found little evidence from the included studies to suggest that 12 or more weeks of CCT improves cognition in healthy older adults. However, our limited confidence in the results reflects the overall quality of the evidence. Inconsistency between trials was a major limitation. In five of the eight trials, the duration of intervention was just three months. The possibility that longer periods of training could be beneficial remains to be more fully explored.

Computerised cognitive training for preventing dementia in people with mild cognitive impairment

BACKGROUND

The number of people living with dementia is increasing rapidly. Clinical dementia does not develop suddenly, but rather is preceded by a period of cognitive decline beyond normal age-related change. People at this intermediate stage between normal cognitive function and clinical dementia are often described as having mild cognitive impairment (MCI). Considerable research and clinical efforts have been directed toward finding disease-modifying interventions that may prevent or delay progression from MCI to clinical dementia.

OBJECTIVES

To evaluate the effects of at least 12 weeks of computerised cognitive training (CCT) on maintaining or improving cognitive function and preventing dementia in people with mild cognitive impairment.

SEARCH METHODS

We searched to 31 May 2018 in ALOIS (www.medicine.ox.ac.uk/alois) and ran additional searches in MEDLINE, Embase, PsycINFO, CINAHL, ClinicalTrials.gov, and the WHO portal/ICTRP (www.apps.who.int/trialsearch) to identify published, unpublished, and ongoing trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs in which cognitive training via interactive computerised technology was compared with an active or inactive control intervention. Experimental computerised cognitive training (CCT) interventions had to adhere to the following criteria: minimum intervention duration of 12 weeks; any form of interactive computerised cognitive training, including computer exercises, computer games, mobile devices, gaming console, and virtual reality. Participants were adults with a diagnosis of mild cognitive impairment (MCI) or mild neurocognitive disorder (MND), or otherwise at high risk of cognitive decline.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias of the included RCTs. We expressed treatment effects as mean differences (MDs) or standardised mean differences (SMDs) for continuous outcomes and as risk ratios (RRs) for dichotomous outcomes. We used the GRADE approach to describe the overall quality of evidence for each outcome.

MAIN RESULTS

Eight RCTs with a total of 660 participants met review inclusion criteria. Duration of the included trials varied from 12 weeks to 18 months. Only one trial used an inactive control. Most studies were at unclear or high risk of bias in several domains. Overall, our ability to draw conclusions was hampered by very low-quality evidence. Almost all results were very imprecise; there were also problems related to risk of bias, inconsistency between trials, and indirectness of the evidence.No trial provided data on incident dementia. For comparisons of CCT with both active and inactive controls, the quality of evidence on our other primary outcome of global cognitive function immediately after the intervention period was very low. Therefore, we were unable to draw any conclusions about this outcome.Due to very low quality of evidence, we were also unable to determine whether there was any effect of CCT compared to active control on our secondary outcomes of episodic memory, working memory, executive function, depression, functional performance, and mortality. We found low-quality evidence suggesting that there is probably no effect on speed of processing (SMD 0.20, 95% confidence interval (CI) -0.16 to 0.56; 2 studies; 119 participants), verbal fluency (SMD -0.16, 95% CI -0.76 to 0.44; 3 studies; 150 participants), or quality of life (mean difference (MD) 0.40, 95% CI -1.85 to 2.65; 1 study; 19 participants).When CCT was compared with inactive control, we obtained data on five secondary outcomes, including episodic memory, executive function, verbal fluency, depression, and functional performance. We found very low-quality evidence; therefore, we were unable to draw any conclusions about these outcomes.

AUTHORS' CONCLUSIONS

Currently available evidence does not allow us to determine whether or not computerised cognitive training will prevent clinical dementia or improve or maintain cognitive function in those who already have evidence of cognitive impairment. Small numbers of trials, small samples, risk of bias, inconsistency between trials, and highly imprecise results mean that it is not possible to derive any implications for clinical practice, despite some observed large effect sizes from individual studies. Direct adverse events are unlikely to occur, although the time and sometimes the money involved in computerised cognitive training programmes may represent significant burdens. Further research is necessary and should concentrate on improving methodological rigour, selecting suitable outcomes measures, and assessing generalisability and persistence of any effects. Trials with long-term follow-up are needed to determine the potential of this intervention to reduce the risk of dementia.