Anomalous experiences, such as so-called benign hallucinations, may occur in a person in a state of good mental and physical health, even in the apparent absence of a transient trigger factor such as fatigue, intoxication or sensory deprivation.
However, the evidence suggests that the majority of out-of-body experiences do not occur near death, but in conditions of either very high or very low arousal.
OBEs can be regarded as hallucinatory in the sense that they are perceptual or quasi-perceptual experiences in which, by definition, the ostensible viewpoint is not coincident with the physical body of the subject.
Healthy individuals prone to hallucinations, or scoring highly on psychometric measures of positive schizotypy, tend to show a bias toward reporting stimuli that did not occur under perceptually ambiguous experimental conditions.
They add: "no less than 17.5% of the [subjects] were prepared to score the item 'I often hear a voice speaking my thoughts aloud' as 'Certainly Applies'.
This latter item is usually regarded as a first-rank symptom of schizophrenia ..." Green and McCreery[23] found that 14% of their 1800 self-selected subjects reported a purely auditory hallucination, and of these nearly half involved the hearing of articulate or inarticulate human speech sounds.
An example of the former would be the case of an engineer facing a difficult professional decision, who, while sitting in a cinema, heard a voice saying, "loudly and distinctly": 'You can't do it, you know".
"[27] The following is an example of this type of experience: "My husband died in June 1945, and 26 years afterwards when I was at Church, I felt him standing beside me during the singing of a hymn.
For example, Slade and Bentall proposed the following working definition of a hallucination: "Any percept-like experience which (a) occurs in the absence of an appropriate stimulus, (b) has the full force or impact of the corresponding actual (real) perception, and (c) is not amenable to direct and voluntary control by the experiencer.
In this respect it may be said to be more hallucinatory than, for example, some hypnagogic imagery, which may be experienced as external to the subject but located in a mental "space" of its own.
[30][31] Other explanations for this phenomenon were discussed by the psychologist Graham Reed who wrote that such experiences may involve illusion, misinterpretation or suggestion.
[34][35] Sensing the presence of the deceased may be a cross-cultural phenomenon that is, however, interpreted differently depending on the cultural context in which it occurs.
[36] For example, one of the earliest studies of the phenomenon published in a Western peer-reviewed journal investigated the grief experiences of Japanese widows and found that 90% of them reported to have sensed the deceased.
[37] It was observed that, in contrast to Western interpretations, the widows were not concerned about their sanity and made sense of the experience in religious terms.
Since then, a number of qualitative studies have been published, describing the mainly beneficial effects of these experiences, especially when they are made sense of in spiritual or religious ways.
According to the dimensional model, by contrast, the population at large is ranged along a normally distributed continuum or dimension, which has been variously labelled as psychoticism (H.J.Eysenck), schizotypy (Gordon Claridge) or psychosis-proneness.
[44] The alternative to this view requires one to posit some hidden or latent disease process, of which such experiences are a symptom or precursor, an explanation which would appear to beg the question.