Placebo effects in cognitive training
Cyrus Foroughi and colleagues recruited 50 participants, 25 per group, with one of two flyers. One flyer advertised brain training and stated that numerous studies have shown working memory training can increase fluid intelligence; the other was visually similar and said nothing about either. Both groups completed the same one-hour dual n-back session. The group recruited by the brain training flyer improved on two fluid intelligence tests, with effect sizes of 0.50 and 0.39, and the other group showed no significant change. The authors judged that a single hour of practice almost certainly had not changed intelligence.
Cyrus Foroughi and colleagues recruited 50 participants, 25 per group, with one of two flyers. One flyer advertised brain training and stated that numerous studies have shown working memory training can increase fluid intelligence; the other was visually similar and said nothing about either. Both groups completed the same one-hour dual n-back session. The group recruited by the brain training flyer improved on two fluid intelligence tests, with effect sizes of 0.50 and 0.39, and the other group showed no significant change. The authors judged that a single hour of practice almost certainly had not changed intelligence.
Written from the full text on PubMed Central, read 2026-10-23.
What our sources record
Recorded when this source was checked, figures included, with page references and quotation marks removed.
Foroughi, C. K., et al. (2016). Placebo effects in cognitive training. Proceedings of the National Academy of Sciences, 113(27), 7470-7474