Enhancing Cognitive Abilities with Comprehensive Training: A Large, Online, Randomized, Active-Controlled Trial

PLoS One. 2015 Sep 2;10(9):e0134467. doi: 10.1371/journal.pone.0134467. eCollection 2015.


Background: A variety of studies have demonstrated gains in cognitive ability following cognitive training interventions. However, other studies have not shown such gains, and questions remain regarding the efficacy of specific cognitive training interventions. Cognitive training research often involves programs made up of just one or a few exercises, targeting limited and specific cognitive endpoints. In addition, cognitive training studies typically involve small samples that may be insufficient for reliable measurement of change. Other studies have utilized training periods that were too short to generate reliable gains in cognitive performance.

Methods: The present study evaluated an online cognitive training program comprised of 49 exercises targeting a variety of cognitive capacities. The cognitive training program was compared to an active control condition in which participants completed crossword puzzles. All participants were recruited, trained, and tested online (N = 4,715 fully evaluable participants). Participants in both groups were instructed to complete one approximately 15-minute session at least 5 days per week for 10 weeks.

Results: Participants randomly assigned to the treatment group improved significantly more on the primary outcome measure, an aggregate measure of neuropsychological performance, than did the active control group (Cohen's d effect size = 0.255; 95% confidence interval = [0.198, 0.312]). Treatment participants showed greater improvements than controls on speed of processing, short-term memory, working memory, problem solving, and fluid reasoning assessments. Participants in the treatment group also showed greater improvements on self-reported measures of cognitive functioning, particularly on those items related to concentration compared to the control group (Cohen's d = 0.249; 95% confidence interval = [0.191, 0.306]).

Conclusion: Taken together, these results indicate that a varied training program composed of a number of tasks targeted to different cognitive functions can show transfer to a wide range of untrained measures of cognitive performance.

Trial registration: ClinicalTrials.gov NCT-02367898.

Trial registration: ClinicalTrials.gov NCT02367898.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Attention / physiology*
  • Cognition / physiology*
  • Female
  • Humans
  • Internet
  • Male
  • Memory, Short-Term / physiology*
  • Middle Aged
  • Neuropsychological Tests
  • Practice, Psychological*
  • Problem Solving / physiology*
  • Young Adult

Associated data

  • ClinicalTrials.gov/NCT02367898

Grants and funding

No external funding contributed to this research; Lumos Labs, Inc. funded the research through the development of its software tools and through the employment of JLH, DAS, KK, FF and MS and through the consulting services of RAN. The specific roles of these authors are articulated in the “Author Contributions” section. Other members of the company contributed suggestions and ideas during the design of the study and preparation of the manuscript, and provided support and advice to the authors during the process of submitting the manuscript for publication. Lumos Labs had no other role in the study design, data collection and analysis, decision to publish, and preparation of the manuscript. Legal approval for publication before submission of the manuscript was obtained from Lumos Labs.