Improving fluid intelligence with training on working memory: a meta-analysis (Psychonomic Bulletin & Review):
“…due to the broad interest in cognitive training, laboratories around the world are investigating the effects of training and transfer. In fact, the first study of n‑back training on Gf (fluid intelligence) was conducted in Switzerland…and from our own experiences conducting research both internationally and in the U.S., we have anecdotally observed motivational differences across cultures. Therefore, we sought to systematically test for any regional differences in Gf gains… our moderator analyses suggest several possible parameters that could be optimized in order to design more efficacious interventions that might have more substantive impacts on intellectual and societal functioning.
The most striking moderator of the observed transfer effect is geographic region. International studies tend to find more transfer than U.S. studies. There is a substantial body of literature available on the effects of culture on cognition. These effects may contribute to differences not only between international and U.S. research participants, but also between methodological practices of researchers. However, due to the plurality of cultures (mostly European and American) represented in our meta-analysis, the precise reasons for the observed regional differences are not immediately clear. There is no difference in baseline ES between international and U.S. studies, thereby ruling out preexisting differences between cultures or differences in participant characteristics due to the highly selective universities in which certain U.S. studies were conducted. One hypothesis, however, based on our own experiences with both U.S. and international populations, is that the former may be generally less compliant, a crucial factor in an intensive training program such as the one investigated here.”
From the study:
- Conclusions: Our work demonstrates the efficacy of several weeks of n‑back training in improving performance on measures of Gf. We urge that future studies move beyond attempts to answer the simple question of whether or not there is transfer and, instead, seek to explore the nature and extent of how these improved test scores may reflect “true” improvements in Gf that can translate into practical, real-world settings…Since Gf is a fundamental cognitive skill that underlies a wide range of life functions, even small improvements can have profound societal ramifications, particularly given the healthy young adults in our analyses, representative of society’s workforce. Taken together, it is becoming very clear to us that training on WM with the goal of trying to increase Gf holds much promise.
- Abstract: Working memory (WM), the ability to store and manipulate information for short periods of time, is an important predictor of scholastic aptitude and a critical bottleneck underlying higher-order cognitive processes, including controlled attention and reasoning. Recent interventions targeting WM have suggested plasticity of the WM system by demonstrating improvements in both trained and untrained WM tasks. However, evidence on transfer of improved WM into more general cognitive domains such as fluid intelligence (Gf) has been more equivocal. Therefore, we conducted a meta-analysis focusing on one specific training program, n‑back. We searched PubMed and Google Scholar for all n‑back training studies with Gf outcome measures, a control group, and healthy participants between 18 and 50 years of age. In total, we included 20 studies in our analyses that met our criteria and found a small but significant positive effect of n‑back training on improving Gf. Several factors that moderate this transfer are identified and discussed. We conclude that short-term cognitive training on the order of weeks can result in beneficial effects in important cognitive functions as measured by laboratory tests.