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



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.


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 (, and we performed additional searches of MEDLINE, Embase, PsycINFO, CINAHL,, and the WHO Portal/ICTRP (, to ensure that the search was as comprehensive and as up‐to‐date as possible to identify published, unpublished, and ongoing trials.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We included randomised controlled trials (RCTs) and quasi‐RCTs, published or unpublished, reported in any language.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.

Plain language summary

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


The terms ‘cognition’ and ‘cognitive function’ describe all of the mental activities related to thinking, learning, remembering, and communicating. Normal changes in cognition occur with ageing. There are also diseases that affect cognition, principally dementia, which becomes increasingly common with increasing age from about 65 years onwards. It is known that being mentally active throughout life is associated with lower risk of dementia. Therefore, it has been suggested that encouraging mental activity might be an effective way of maintaining good cognitive function as people age. Cognitive training comprises a set of standardised tasks intended to ‘exercise the brain’ in various ways. Programmes of cognitive training are often delivered by computers or mobile technology, so that people can do this training on their own at home. Increasingly, these are available as commercial packages that are advertised to the general public. We wanted to know whether long‐term use of computerised cognitive training (CCT) is an effective way for people aged 65 and older to maintain good cognitive function as they age.

What we did

We searched the medical literature up to 15 March 2018 for trials that compared cognitive function of people aged 65 or older who had taken part in computerised cognitive training for a minimum of 12 weeks with cognitive function of a control group that had not done so. All participants should have been cognitively healthy at the start of the trials. For the comparison to be as fair as possible, it should have been decided randomly whether participants were in the cognitive training group or in the control group. We were primarily interested in overall measures of cognition. The choice of three months for the intervention was somewhat arbitrary, but we thought very short interventions were unlikely to have lasting effects, and we were interested in interventions that could be sustained over time.

What we found

We found eight trials with a total of 1183 participants to include in the review. Five trials provided CCT for three months, two for four months, and one for six months. We compared CCT with other activities, such as watching educational videos, and with no activity. We looked for effects on overall cognitive function and on specific cognitive functions, such as memory and thinking speed. All of the included studies had some design problems, which could have biased the results. Overall, we thought the quality of the evidence that we found was low or very low. This means we cannot be confident in the results, and that future research might well find something different. CCT may slightly improve overall cognitive function after 12 weeks of training; however, we found no evidence of a persistent effect 12 months after the intervention. We were unable to comment or found little evidence that CCT when compared with other activities may have a relevant effect on most of the specific cognitive functions that we examined. The longest trial found that compared to doing nothing, completing six months of CCT may have had a beneficial effect on memory. None of the included trials reported effects of cognitive training on quality of life or on daily activities, and none reported harmful effects of training.

Our conclusions

Compared to other activities, CCT may lead to slightly better overall cognitive function at the end of 12 weeks of training, but we found no evidence that the effect persists a year later. Compared to doing nothing, CCT may slightly improve memory at the end of six months of training. Although we excluded trials with less than 12 weeks of training, the trials that we included were still quite short for examining long‐term effects as people age. A limitation of our review is that we did not include some trials with shorter training periods that did look for long‐lasting effects, so it is possible that we missed some useful evidence. Many published studies have looked at computer training. Making sense of this substantial literature is difficult. It may be more helpful in the future to categorise trials by the duration of effects of training rather than by the duration of the training itself.

Authors’ conclusions

Implications for practice

At the current time, there is a lack of high‐quality evidence to show that computerised cognitive training (CCT) for 12 or more weeks helps to maintain cognitive function in healthy older adults. It is important to emphasise that our conclusions are applicable only to studies that delivered cognitive training over at least 12 weeks. There may be important and relevant evidence from studies with shorter intervention periods. Despite our intention to examine generalisation of effects to objective measures of everyday functioning, we are able to comment only on training effects on cognitive outcomes.Clinicians and consumers may find the field confusing and may note contradictory messages about research evidence and divisive debates in the research community (e.g. Lampit 2015Ratner 2015). Fear of developing dementia is common among older adults, and there is increasing demand for interventions to address age‐related and non‐pathological cognitive decline. This goes along with the development and commercialisation of brain training products targeting older consumers. Although we found no strong evidence in support of CCT in this review, it remains possible that longer interventions ‐ or shorter, higher‐dose interventions ‐ could help to maintain cognitive function.

Implications for research

Studies of CCT in cognitively healthy adults could be improved by careful consideration given to study design, including choice and measurement of outcomes and time points of follow‐up. Selection of outcomes ought to address the principal objective of CCT ‐ not only that training benefits the specific skills trained but also that those benefits transfer to improvement or maintenance of function on non‐trained cognitive tasks, and generalise to non‐cognitive domains such as daily functioning (Kelly 2014a), although the topic of transfer is debated (Zelinski 2009). In this review, we found that measures of functional performance that may indicate generalisation were absent from the identified studies. Inclusion of outcomes that could demonstrate effects on quality of life, psychiatric symptoms, mood, and daily functioning should be encouraged in future studies.To accurately measure change in cognitive function, and to identify transfer and generalisation, selected outcomes should be sensitive to subtle and possibly non‐linear changes, should have high reliability, should have alternate forms or be psychometrically robust for repeated use, and should have low risk of floor and ceiling effects. This is particularly relevant for cognitively healthy adults, in whom ceiling effects may dominate (i.e. how do you improve on normal?). We advocate for establishment of an international multi‐disciplinary panel to develop a standardised core outcome set for cognitive assessments in older individuals with and without cognitive decline, to improve outcome reporting and facilitate evidence synthesis. Ideally, studies should measure change immediately after an intervention ends and then should monitor function over time. Future research studies should move towards investigating different types of training exercises, differential effects of training on separate cognitive domains, and the impact of variability on the frequency, intensity, and duration of interventions. Furthermore, it would be helpful to assess effectiveness of training in realistic situations, including participants with health risk factors, comorbidities, and barriers to participation. Inactive controls are suitable for research examining possible neuroplastic mechanisms and brain reserve, and for inclusion in simple efficacy studies, and the clinical effectiveness and comparative studies described above will require an active control arm.

Improved reporting of study methods should be a priority because of the high proportion of unclear risks of bias, which could be improved through simple steps, such as adherence to CONSORT, improved data management to reduce the quantity of incomplete data, and development of methods to facilitate blinding of participants and personnel. Blinding of participants is especially important given the commercialisation of CCT, advertisements, and widespread community exposure, and an active control may partially address this potential bias.

The process of conducting this review has highlighted important methodological considerations for future updates and for other systematic reviews in this field. With hindsight, our 12 weeks duration inclusion criterion did not achieve what we hoped for. We had wanted to exclude studies in which exposure to training was modest and was unlikely to have meaningful, lasting effects. However, as is evident from comparisons of included and excluded studies, some excluded studies offered high‐intensity training and hence an overall ‘dose’ of training that was higher than in many included studies. For future updates, various options are possible; it may be useful to consider dose of training and perhaps to perform meta‐regression to look at the effects of dose on outcomes. Alternatively, length of follow‐up may be a more useful inclusion criterion than duration of intervention. Although short‐term effects are of scientific interest, for older people and for clinicians and policy makers, it is sustained benefits that matter most.

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