Allan Cheyne

Allan Cheyne

BORNCanada

OCCUPATIONPsychologist, sleep researcher

KNOWN FORPhenomenological taxonomy of sleep paralysis hallucinations

STATUSActive

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James Allan Cheyne is a Canadian psychologist at the University of Waterloo, Ontario, whose survey-based research into sleep paralysis produced the field's most influential empirical account of why the experience so often gets described in supernatural terms.

Approach

Cheyne's contribution to anomalistic psychology rests on a methodological shift: rather than working from small clinical or field samples, as earlier researchers had, he recruited sleep paralysis experiencers through the Waterloo Unusual Sleep Experiences Questionnaire, a large-scale online survey instrument that has since been used, in whole or in part, in roughly two dozen published studies across multiple laboratories. That scale let him treat the phenomenology of the experience as a dataset — tracking which sensations occurred, how often, and in what combinations — in a way case studies alone couldn't support.

The three-category model

Cheyne's best-known work, developed across a series of studies from 1999 onward, formalised a three-part factor-analytic taxonomy of sleep paralysis hallucinations.

Intruder hallucinations

The most commonly reported experience: a "sensed presence" — an overwhelming feeling that something else is in the room, elaborated through visual, auditory, and tactile hallucinations consistent with a threatening intruder. Cheyne linked this and the incubus factor to REM-related activation of the amygdala and associated sensory cortex, with dream-like content bleeding into waking perception during paralysis.

Incubus hallucinations

Chest pressure, breathing difficulties, choking or suffocation sensations, pain, and thoughts of imminent death — often interpreted, when sufficiently elaborated, as physical or sexual assault. This factor is highly correlated with the intruder factor, and fear is consistently reported in more than 80% of episodes overall.

Vestibular-motor hallucinations

Floating, flying, falling, spinning, out-of-body experiences, and illusory limb or bodily movement. Cheyne tied these to disrupted vestibular and motor processing during the REM–wake transition, distinguishing them from the other-oriented intruder and incubus experiences as considerably more self-focused, and — unlike the fear typically associated with the other two factors — sometimes associated with feelings of bliss.

Cross-cultural significance

Cheyne's own published work situates this three-part structure within a much older literature on culturally specific interpretations of the same underlying experience — most notably folklorist David Hufford's study of the "Old Hag" tradition in Newfoundland, alongside comparable traditions including kanashibari in Japan, jinn-visitation accounts in parts of the Islamic world, and modern alien abduction narratives. Subsequent cross-cultural research has continued to find the underlying phenomenology remarkably consistent across societies, independent of which supernatural or biomedical framework a given culture uses to explain it.

That consistency — one underlying neurological process, described through whatever supernatural vocabulary a culture has on hand — is one of the clearer pieces of evidence in anomalistic psychology that ordinary brain processes can produce experiences indistinguishable, from the inside, from a genuine encounter.

Relevance to paranormal claims

Cheyne's findings give weight to the argument that a meaningful share of reported paranormal encounters — bedroom apparitions, night visitations, abduction narratives, demonic attacks — are sleep paralysis events filtered through whatever supernatural framework is culturally to hand. His work also reinforced a broader finding in hallucination research: vivid, externally projected perceptions of presences and figures are far more common in neurologically ordinary people than clinical models used to assume.

See also

• Sleep paralysis
• Hallucination
• Anomalistic Psychology
• Old Hag

External links

• University of Waterloo — Awake in a Nightmare