This author-copy (pre-pre-print) proposes a new way of looking at previously proposed REBUS and SEBUS models under the name ‘Altered Beliefs Under Psychedelics’ (ALBUS). ALBUS predicts that there will be strengthening of beliefs under psychedelics (SEBUS) and that relaxed beliefs (REBUS) dynamics also involve SEBUS effects.
Abstract
(from the conclusion) “While SEBUS and REBUS effects may converge with moderate-to-high levels of 5-HT2a agonism, we might expect qualitatively different effects with low-to-moderate doses of psychedelics. Under a regime characteristic of micro-dosing or threshold experiences, consciousness may be elevated without substantially altering normative belief dynamics. In these ways, micro-dosing may provide a promising and overlooked therapeutic intervention for depression (e.g. anhedonia), autism, Alzheimer’s disease, and other disorders of consciousness. In contrast to a purely REBUS model, a SEBUSinvolving ALBUS model makes different predictions for the potential utility of various psychedelic interventions for these often debilitating conditions, for which advances in treatment could have impacts on public health that may be difficult to overstate. In Tables 1 and 2 we begin to explore ways in which SEBUS and REBUS models may suggest different therapeutic use cases and explanations for phenomena associated with psychedelics. While informed by commonly reported effects in psychedelic interventions as well as theoretical considerations, these suggestions should all be understood as extremely tentative, with a systematic research program being required for either their verification or falsification. However, given the immense potential of 5- HT2a agonists—and perhaps also NMDA receptor antagonists—for both clinical and basic science, we believe substantial further work (and funding) is warranted to explore the conditions under which we might expect both relaxed and strengthened beliefs under psychedelics.”
Author: Adam Safron
Summary of On the Varieties of Conscious Experiences: Altered Beliefs Under Psychedelics (ALBUS)
Figure 1 shows how SEBUS and REBUS effects in hierarchical predictive processing (HPP) work. Prediction errors are propagated up cortical hierarchies in predictive coding, and the precision weighting of these predictions determines the degree to which higher-level predictions are updated to more accurately account for sensory observations. A REBUS effect involves a weakening of priors, whereas a SEBUS effect involves a strengthening of priors, which is more effective at suppressing ascending prediction errors. An additional SEBUS effect involves a default reduction in precision-weighting and reduced updating from sense data.
Figure 2 depicts the integration of sense data into a coherent field of experience, with smaller and faster forming beliefs communicated at lower beta frequencies and larger and slower forming beliefs communicated at higher frequencies. The left-most panel depicts modeling via fast and small beta complexes, with the middle panel depicting more complex compositions, including object information as modeled by each modality. This visuospatial sketchpad, or “mind’s eye,” is likely heavily dependent upon posterior medial cortices, and may also be coupled with lateral parietal cortices in complex ways that could influence things like awareness of minimal embodied selfhood, coherent tracking of causal sequences, and senses of ownership for actions.
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On the Varieties of Conscious Experiences: Altered Beliefs Under Psychedelics (ALBUS)
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