Pillar 1 of 9

Foundations of Altered States

Altered states of consciousness are temporary shifts in perception, cognition, and self-awareness produced by substances, breathwork, meditation, sensory deprivation, and other means. This pillar covers the receptor pharmacology (5-HT2A, NMDA, kappa-opioid), brain networks (default mode network, claustrum, thalamocortical connectivity), and conceptual models (REBUS, entropic brain, predictive processing) that ground current scientific understanding of how consciousness shifts.

In this pillar

10 topics

Altered States of Consciousness

The spectrum of non-ordinary consciousness accessible through psychedelics and other practices, covering types of experiences, phenomenology, and meaning-making.

Baseline States and Why They Matter

Why the psychological, physical, and emotional state a person brings into an experience shapes what unfolds - and why baseline stability matters more than most people expect.

Brain and Psychedelics

How psychedelics affect brain function and structure, covering the default mode network, neuroplasticity, serotonin receptors, and what imaging studies reveal.

Default Mode Network

The brain network most associated with self-referential thought, rumination, and the narrating self. Psychedelics consistently suppress its activity, which may underlie experiences of self-dissolution.

Dose-Response and Thresholds

How psychedelic effects change with dose, where the threshold for qualitative shifts lies, and how rapid tolerance affects the relationship between use and effect.

Models of Consciousness

The major scientific frameworks for understanding consciousness and how psychedelics challenge them - from predictive processing to integrated information theory and the entropic brain hypothesis.

Neuroimaging Psychedelic States

What brain scans reveal when someone takes a psychedelic - the reorganization of neural networks, changes in connectivity, and what the imaging data does and does not tell us.

Neuroplasticity

How psychedelics promote structural and functional changes in the brain, what the BDNF and TrkB research shows, and why the post-experience window may matter as much as the experience itself.

Serotonin and the 5-HT2A Receptor

The primary receptor through which classical psychedelics act - how 5-HT2A activation in the prefrontal cortex triggers the cascade of perceptual and cognitive changes that define the psychedelic experience.

Tolerance and Cross-Tolerance

How rapidly tolerance develops with classical psychedelics, why cross-tolerance exists between substances like psilocybin and LSD, and what this means for frequency of use.

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