Brain training is all in your head.

In Brain Circuitry, Brain Science, Memory and Learning by Brainy Days Ahead

A study finds that people who do a mere hour of brain training have a bump in their IQ by five to 10 points–but only if they believe the training will have an effect on their cognition, in other words, the placebo effect. A lot of the benefit of these games may be “all in our heads.”