Altered states of consciousness
Susan Blackmore, Emily T. Troscianko
March 13, 2024 DOI: 10.4324/9781003300687-19 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Review |
|---|---|
| Topics | Altered states of consciousness |
| Keywords | Consciousness Psychoanalysis |
| Citations | 46 |
| Key findings | Argues that ASCs are hard to define and measure, and that existing maps are incomplete. Reviews evidence that psychoactive drugs and meditation can induce ASCs, with brain scans revealing changes in attention and default mode network, and clinical studies showing promise for depression and anxiety, especially in the terminally ill. Highlights ongoing debates about baseline states and hypnosis. |
Abstract
Altered states of consciousness (ASCs) are surprisingly hard to define and to measure. Neither ‘subjective’ methods (like verbal reports) nor ‘objective’ measures (such as how the state is induced, or physiological and behavioural criteria) are entirely satisfactory. Attempts to map ASCs are reviewed, including two- or three-dimensional maps such as Tart&s;s and Laureys’, and Hobson&s;s AIM model, but the true space of possibilities is likely to be vast. Psychoactive drugs include stimulants (amphetamine, MDMA), anaesthetics (nitrous oxide, ketamine), cannabis, and major psychedelics (mescaline, psilocybin, DMT, ayahuasca, LSD). Experiments using these drugs were long prohibited, but brain scans are now beginning to reveal changes to attention systems and the default mode network, and clinical studies show promise in alleviating depression and anxiety, especially for the terminally ill. Meditation can also lead to ASCs: for example, the ‘jhanas’ are eight discrete states induced by deep concentrative meditation. Consideration of altered states in mental illness, such as anorexia or depression, raises further problems in deciding what counts as an altered state and what to compare it with. Is there a ‘normal’ or baseline state for comparison? Many of this chapter&s;s questions apply also to hypnosis, and we briefly review the ongoing state/non-state debate.
Comparable studies
Other narrative reviews on altered states of consciousness, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| The Subjective Effects of Psychedelics Are Necessary for Their Enduring Therapeutic Effects. | 2020 | Review | |
| Psychobiology of Altered States of Consciousness. | 2005 | Review | |
| Intrinsic Brain Activity in Altered States of Consciousness | 2008 | Review | |
| Dynamic functional connectivity and brain metastability during altered states of consciousness | 2017 | Review | |
| A default mode of brain function in altered states of consciousness. | 2013 | Review |
Citations in the library
Cited by 13
- Future directions in meditation research: Recommendations for expanding the field of contemplative science PLoS One November 7, 2018
- Health status of ayahuasca users. Drug Testing and Analysis 2012
- Lucid, Prelucid, and Nonlucid Dreams Related to the Amount of EEG Alpha Activity during REM Sleep Psychophysiology July 1, 1984
- Pattern Theory of Selflessness: How Meditation May Transform the Self-Pattern Mindfulness August 1, 2024
- The Duboisia genus, Australian aborigines and suggestibility. Journal of Psychoactive Drugs 1999
and 8 more in the library