Hypnosis is an effective intervention with proven efficacy that is employed in clinical settings and for investigating various cognitive processes. Despite their practical success, no consensus exists regarding the mechanisms underlying well-established hypnotic phenomena. Here, we suggest a new framework called the Simulation-Adaptation Theory of Hypnosis (SATH). SATH expands the predictive coding framework by focusing on (a) redundancy elimination in generative models using intrinsically generated prediction errors, (b) adaptation due to amplified or prolonged neural activity, and (c) using internally generated predictions as a venue for learning new associations. The core of our treatise is that simulating proprioceptive, interoceptive, and exteroceptive signals, along with the top-down attenuation of the precision of sensory prediction errors due to neural adaptation, can explain objective and subjective hypnotic phenomena. Based on these postulations, we offer mechanistic explanations for critical categories of direct verbal suggestions, including (1) direct-ideomotor, (2) challenge-ideomotor, (3) perceptual, and (4) cognitive suggestions. Notably, we argue that besides explaining objective responses, SATH accounts for the subjective effects of suggestions, i.e., the change in the sense of agency and reality. Finally, we discuss individual differences in hypnotizability and how SATH accommodates them. We believe that SATH is exhaustive and parsimonious in its scope, can explain a wide range of hypnotic phenomena without contradiction, and provides a host of testable predictions for future research.
The ongoing obesity epidemic is an indicator that traditional efforts towards diet change are insufficient, and interventions focusing mainly on restrictions of unhealthy food are of limited success. Therefore, approaches targeting food preferences should be integral in counteracting the current epidemic. However, food preferences are affected by a multitude of factors and are usually resistant to changes later in life. Hence, we tested whether the food choices of preschool children can be changed by a child-appropriate, interactive, fairytale-like narrative. We used two interactive stories: the first (experimental) story was about how two protagonists of similar age as the participants saved their hometown from being drained of color with the help of magic fruits or vegetables, while the second (control) story consisted of a similar plot that did not mention food. In Experiment 1, we used a crossover design with a one-week baseline measurement. After the experimental stories, healthy food choices (i.e., pieces of fruit vs. cookies, sweets, or cake) increased significantly relative to the one-week baseline, whereas no change was observed after the control story. In preregistered Experiment 2, we replicated these results with vegetables as healthy options using a random control design and investigated the longevity of the effects. The food-story effect on vegetable choices was similar to fruits (Exp. 1) and lasted for two weeks. These findings demonstrate that appropriate narratives about food can have a strong and lasting effect on the healthy food choices of preschool children and might promote healthy food consumption if incorporated into nutrition education.