Altered states of consciousness

The new lower-order scales of the OAV have desirable psychometric properties and are better suited for assessing drug-induced altered states of consciousness.

psychometric study

Argues that current knowledge on altered states of consciousness should be organized into a consistent theoretical system to understand their emergence, manifestations, commonalities, and functions.

theoretical or philosophical paper

Altered states of consciousness share three oblique dimensions—Oceanic Boundlessness, Dread of Ego Dissolution, and Visionary Restructuralization—regardless of induction method.

experimental and field study Sample size: 1133

Subjective effects of psychedelics are necessary for their enduring beneficial effects and account for the majority of those benefits.

review

Proposes that transient hypofrontality is the unifying feature of all altered states of consciousness, with each state's uniqueness resulting from differential viability of frontal circuits.

theoretical or philosophical paper

Altered states of consciousness can be characterized by four dimensions—activation, awareness span, self-awareness, and sensory dynamics—and arise from neurophysiological changes including brain structure compromise, disconnectivity, and neurochemical/metabolic processes.

review

The 5-HT2A receptor is critical for LSD's subjective and neural effects, as ketanserin fully blocked both.

double-blind, randomized, counterbalanced, cross-over study Sample size: 24

Coherent spontaneous BOLD fluctuations, particularly in the default-mode network, persist across various states of unconsciousness, suggesting they reflect default brain connectivity rather than conscious mental activity alone.

review

DMT reduced alpha and beta oscillatory power and increased signal diversity, with delta and theta activity correlating with the peak of the subjective visual experience.

observational cohort Sample size: 13

LSD increased effective connectivity from the thalamus to the posterior cingulate cortex via serotonin 2A receptor activation and decreased connectivity from the ventral striatum to the thalamus independently of those receptors.

double-blind, randomized, placebo-controlled, cross-over study Sample size: 25

Different subjective meditation states are associated with distinct patterns of brain neuronal activity, as measured by EEG gamma-band source localization.

case study Sample size: 1

Dynamic neuroimaging data reveals non-trivial temporal fluctuations compatible with a discrete repertoire of brain states, supporting the dynamic core hypothesis of consciousness.

review

Proposes that a neurophenomenological approach to non-ordinary states of consciousness can serve as a unifying framework for studying their role as catalysts of transformation in clinical practice.

theoretical or philosophical paper

The VR group scored significantly higher than the screen group on all dimensions of the MEQ30, indicating that VR can elicit mystical-type experiences.

controlled experiment Sample size: 70

Proposes that 'noopoietics' and 'doxolysis' provide a metaphysically austere, process-oriented vocabulary for altered states of consciousness, avoiding the evaluative baggage of inherited terms.

theoretical or philosophical paper

Pharmacological and pathological loss of responsiveness involve distinct neurotransmitter system contributions across basal ganglia nuclei, with different correlations in anaesthesia versus patients.

observational cohort study with fMRI Sample size: 38

Lower experiential avoidance during a high ventilation breathwork session significantly predicted higher mental well-being after the session, and altered states of consciousness during the session significantly predicted lower experiential avoidance.

cross-sectional online study Sample size: 324

Proposes that intentional sensory overstimulation in a neurogastronomic setting may inhibit analytical processing and reduce Default Mode Network activity, potentially shifting brain oscillatory states from alpha toward theta.

theoretical or philosophical paper

Music-induced trance across traditional shamanism and contemporary rave culture engages partially overlapping neural dynamics, including increased low-frequency synchronization and shifts from executive control to limbic and default mode networks.

review

Non-ordinary states of consciousness involve coordinated shifts across brain, body, and lived experience that may contribute to psychological transformation by loosening ordinary patterns of self-reference and opening access to expanded awareness, meaning, connection, and potential.

narrative literature review

Guided meditation significantly reduced arousal and time-related thoughts compared to both the control and Ganzfeld conditions, and higher trait absorption predicted diminished body boundary salience in the control and Ganzfeld conditions.

within-subjects design Sample size: 48