Associations and hallucinations in mice and men.

Powers et al. (2017, Science, 357(6351), 596-600) report that Pavlovian conditioning can result in the perception of a stimulus in its absence, and that this effect is related to hallucinations outside the laboratory. Considered alongside similar studies in animals, this suggests that associatively produced perceptual processing offers a means to study hallucination-like behaviour in the animal laboratory.