Original title: REBUS and the Anarchic Brain: Toward a Unified Model of the Brain Action of Psychedelics
The brain uses strong expectations, called priors, to make sense of incoming information. This paper proposes that psychedelics make some high-level expectations less dominant, so signals from lower brain systems, including the limbic systemA group of brain structures involved in processes including emotion., can have more influence. That could make entrenched patterns linked to mental illness easier to revise. The authors also suggest the same process might affect political, religious, or philosophical beliefs.
Imagine following a recipe you know by heart while cooking dinner. If you trust your usual method too much, you may ignore a smell that tells you something is burning. In this paper, the familiar recipe is a strong expectation, and the smell is a signal from within the brain; psychedelics are proposed to make the expectation less dominant, so the signal can change what you do.
The model offers one way to explain how psychedelics might help with mental illness: by loosening strongly held patterns of thought so they can be reconsidered. It also warns that this process could affect other deeply held beliefs, and says that intention, care, and context matter.
The abstract presents a model and says the authors assemble evidence to support it; it does not establish that the proposed mechanism is proven or that psychedelic therapy works for every mental illness. It does not specify which beliefs can be changed, how often change occurs, or what treatment conditions are required beyond noting the importance of intention, care, and context.
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REBUS and the Anarchic Brain: Toward a Unified Model of the Brain Action of Psychedelics — Robin Lester Carhart-Harris, Karl John Friston — Pharmacological Reviews — doi:10.1124/pr.118.017160
Abstract licence: CC BY
Explanation generated by Synthesis from the abstract — it is not the original paper.