More than meets the eye: The role of sensory dimensions in psychedelic brain dynamics, experience, and therapeutics.
Neuropharmacology February 1, 2023 Peer reviewed DOI: 10.1016/j.neuropharm.2022.109300 via PubMed
Summary
Psychedelics can alter low-level sensory experiences, particularly in the visual cortex, and these changes are likely important for understanding their therapeutic effects. The study suggests that these low-level alterations do not merely result from higher-level changes but interact with them, influencing therapeutic outcomes. Reevaluating the role of sensory dimensions in psychedelic experiences could enhance both neuroscience and clinical practice.
Study at a glance
| Design | review |
|---|---|
| Key finding | Psychedelic-induced alterations in low-level sensory dimensions are likely to play a causally relevant role in determining high-level alterations and therapeutic outcomes. |
Abstract
Psychedelics are undergoing a major resurgence of scientific and clinical interest. While multiple theories and frameworks have been proposed, there is yet no universal agreement on the mechanisms underlying the complex effects of psychedelics on subjective experience and brain dynamics, nor their therapeutic benefits. Despite being prominent in psychedelic phenomenology and distinct from those elicited by other classes of hallucinogens, the effects of psychedelics on low-level sensory - particularly visual - dimensions of experience, and corresponding brain dynamics, have often been disregarded by contemporary research as 'epiphenomenal byproducts'. Here, we review available evidence from neuroimaging, pharmacology, questionnaires, and clinical studies; we propose extensions to existing models, provide testable hypotheses for the potential therapeutic roles of psychedelic-induced visual hallucinations, and simulations of visual phenomena relying on low-level cortical dynamics. In sum, we show that psychedelic-induced alterations in low-level sensory dimensions 1) are unlikely to be entirely causally reconducible to high-level alterations, but rather co-occur with them in a dialogical interplay, and 2) are likely to play a causally relevant role in determining high-level alterations and therapeutic outcomes. We conclude that reevaluating the currently underappreciated role of sensory dimensions in psychedelic states will be highly valuable for neuroscience and clinical practice, and that integrating low-level and domain-specific aspects of psychedelic effects into existing nonspecific models is a necessary step to further understand how these substances effect both acute and long-term change in the human brain.