The authors suggest that they have found what could be considered the Holy Grail of cognitive research—a means to enhance intelligence. There is some hope from the article, as results on a task considered to measure fluid intelligence are improved, even if the subjects are not trained on this specific task. The “dual n-back” training task, although not pure working memory (as the authors acknowledge), is a very interesting experimental paradigm. Unfortunately, the authors fail to convince us of its usefulness in enhancing “fluid intelligence.” When a drug is tested, any effect, to be convincingly supported, must be demonstrated in a double-blind, randomized, placebo (or standard treatment)-controlled trial. The same should be true for any (pharmacological or otherwise) means aimed at enhancing cognition.

As for the issue of whether this training will have the same effects in schizophrenic subjects as it had in these normal, motivated controls, that is an entirely different question that is not addressed in the article. I think that future studies have to address all those limitations (randomization of subjects, a similar amount of training with a different task in controls, a double-blind design) before any firm conclusions could be drawn.

View all comments by Andrei Szoke