For instance, when we make a movement, our brain predicts the sensory consequences of the movement so that we experience the movement, as self-caused. If these predictions go awry, the brain may falsely attribute control to some external source, leading to a ‘delusion of control’. Recently, the theory has been extended to explain perceptual hallucinations, using the idea that perceptions are also based on predictions. This implies that schizophrenics, unlike most, should be able to tickle themselves, which turns out to be true.