Eminent scholars from around the world last month signed a statement on the 'brain training' industry (see go.nature.com/d2bpuj ). They point out discrepancies between current scientific understanding of cognitive enhancement and advertising claims for commercial cognitive-training software. But it should not be inferred that software can never improve cognition (see D. Bavelier et al . Nature Rev. Neurosci. 12 , 763–768; 2011).

The effectiveness of 'brain-training' software may differ, so product claims might not always be exaggerated. And, given that new training programs are compared with results from control groups engaging in other stimulating activities, the absence of any effect after training can be relative, and is not necessarily definitive. Cognitive enhancement is a vast enterprise that has not yet been clearly defined, and finding optimal ways to train the brain is still a promising area of research.