The success of some brain training games may have nothing to do with the “training” itself, STAT reports. A new study, published in the Proceedings of the National Academy of Sciences, recruited 50 participants using two posters: one that explicitly used the terms “brain training” and “cognitive enhancement,” and one that simply asked for participants for a study. The participants who thought they were improving their brain function experienced an average five- to 10-point jump in IQ after playing the brain game, whereas the other group showed no improvement. That suggests their success might simply be a result of the placebo effect. The results aren’t all bad news for companies advertising cognitive training—they still seem to improve IQ. It may be that they’re hacking into our own expectations to do it.