Suggestion of cognitive enhancement improves emotion regulation.

Cognitive training seems a promising approach to enhance emotion regulation. To establish a causal connection, researchers must compare the training intervention with a control group that accounts for improvements induced by some factors other than the training. Despite this familiar methodology, the influence of expectations on the transfer effects of training remains poorly understood. We tested this possibility in 2 experiments, where a procedure was designed to intentionally induce a placebo effect via the suggestion of cognitive enhancement to evaluate the role of expectation in emotion regulation gains from cognitive training. Both the Placebo and Control groups completed the identical short-term working memory training (20 min) in Experiment 1. New participants were recruited to complete a long-term pseudotraining program (7 days) in Experiment 2. The results from the 2 experiments consistently showed that the Placebo group, who expected benefits from the training, unlike the Control group, showed less negative emotion and better regulatory effects after pseudotraining, irrespective of the duration of the training. Thus, inadequate control of expectation is a fundamental design flaw that potentially undermines any causal inferences. These findings also suggest a novel perspective for optimizing the experimental designs in psychological interventions and advancing the understanding of emotion regulation enhancement. (PsycInfo Database Record (c) 2020 APA, all rights reserved).