JMIR Publications

ABSTRACT

Background:

Computerized cognitive training has been proposed as a potential solution to age-related cognitive decline. However, published findings from evaluation studies of cognitive training games, including from meta-studies and systematic reviews, provide evidence both for and against transferability from trained tasks to untrained cognitive ability. There continues to be no consensus on this issue from the scientific community. A number of researchers have proposed that the number of results supporting the efficacy of cognitive training may be inflated due to placebo effects. Boot et al. [1] (2013) suggest that placebo effects need to be better controlled by using an active control and measuring participant expectations for improvement on outcome measures.

Objective:

This review examines placebo control methodology for recent evaluation studies of computerized cognitive training programs with older adult subjects, specifically looking for use of active control and measurement of expectations.

Methods:

Data sources: PubMed. Study eligibility criteria: Studies of computerized cognitive training published between 2016 and 2018. Participants and interventions: Evaluation studies of computerized cognitive training with older adult subjects (age 50+). Study appraisal and synthesis methods: Methods sections of studies were searched for (1) control type (active or passive) and sub-type (active: active-ingredient or similar-form; passive: no-contact or passive-task); (2) if expectations were measured: how were they measured, and whether they were used in analysis; (3) whether researchers acknowledged lack of active control and lack of expectation measurement as limitations (where appropriate).

Results:

Results:

4 of 19 (~21%) of eligible studies measured expectations. 9 of 19 (~47%) included an active control condition, all of which were of the similar-form type. The majority (10 studies, or ~53%) used only a passive control. 9 of these studies found results supporting efficacy of cognitive training, 5 of which were for far transfer effects.

Conclusions:

Conclusions:

47% of reviewed studies had poor placebo control, yet still published results supporting the effectiveness of cognitive training programs. 5 of these positive results were for far transfer effects, which form the basis for broad claims by cognitive training game makers about the scientific validity of their product. For a minimum level of placebo control, future evaluation studies should use a similar-form active control and administer a questionnaire to participants at the end of the training period about their own perceptions of improvement. Researchers are encouraged to think of more methods for the valid measure of expectations at other time points in the training.