Short- and long-term benefits of cognitive training

Abstract

Does cognitive training work? There are numerous commercial training interventions claiming to improve general mental capacity; however, the scientific evidence for such claims is sparse. Nevertheless, there is accumulating evidence that certain cognitive interventions are effective. Here we provide evidence for the effectiveness of cognitive (often called "brain") training. However, we demonstrate that there are important individual differences that determine training and transfer. We trained elementary and middle school children by means of a videogame-like working memory task. We found that only children who considerably improved on the training task showed a performance increase on untrained fluid intelligence tasks. This improvement was larger than the improvement of a control group who trained on a knowledge-based task that did not engage working memory; further, this differential pattern remained intact even after a 3-mo hiatus from training. We conclude that cognitive training can be effective and long-lasting, but that there are limiting factors that must be considered to evaluate the effects of this training, one of which is individual differences in training performance. We propose that future research should not investigate whether cognitive training works, but rather should determine what training regimens and what training conditions result in the best transfer effects, investigate the underlying neural and cognitive mechanisms, and finally, investigate for whom cognitive training is most useful.

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.

N-back training task. Example of some two-back trials (i.e., level 2), along with feedback screens shown at the end of each round (Materials and Methods).

Fig. 2.

Task themes. Outline of the four different training game themes. The treasure chest shown in the center is presented after each round and at the end of the training session when participants could trade in coins earned for token prizes (Materials and Methods).

Fig. 3.

Training performance. Training outcome plotted as a function of performance group. Each dot represents the average n-back level reached per training session. The lines represent the linear regression functions for each of the two groups. ***P < 0.001.

Fig. 4.

Transfer effect on Gf. (A) Immediate transfer. The columns represent the standardized gain scores (posttest minus pretest, divided by the SD of the pretest) for the group with large training gain, the group with small training gain, and the active control group. (B) Long-term effects. Standardized gain scores for the three groups comparing performance at follow-up (3 mo after training completion) with the pretest. Error bars represent SEMs. Effect sizes for group differences are given as Cohen's d.