Celia Green - Empirical Research

Empirical Research

Green’s empirical work, some of it undertaken in collaboration with an Oxford psychologist, Charles McCreery, has focussed mainly on hallucinatory experiences in ostensibly normal people.

In 1968 Green published Lucid Dreams, a study of dreams in which the subject is aware that he or she is asleep and dreaming. The possibility of conscious insight during dreams had previously been treated with skepticism by some philosophers and psychologists. However, Green collated both previously published first-hand accounts and the results of longitudinal studies of four subjects of her own. She predicted that lucid dreams would be found to be correlated with the rapid eye movement (REM) stage of sleep, a prediction which was subsequently confirmed by experiment.

Green also speculated that it might be possible to set up a rudimentary two-way signaling system between the lucid dreamer and a waking observer, a possibility which was subsequently realized, independently of each other, by researchers in two different laboratories.

In 1968 Green published an analysis of 400 first-hand accounts of out-of-body experiences. This represented the first attempt to provide a taxonomy of such experiences, viewed simply as anomalous perceptual experiences, or hallucinations.

In 1975 Green and McCreery published a similar taxonomy of 'apparitions', or hallucinations in which the viewpoint of the subject was not ostensibly displaced, based on a collection of 1500 first-hand accounts.

Green has put forward the idea that lucid dreams, out-of-body experiences and apparitional experiences have something in common, namely that in all three types of case the subject’s field of perception is entirely replaced by a hallucinatory one. In the first two types of case this is self-evident from the nature of the experience, but in the case of apparitional experiences in the waking state the idea is far from obvious. The hypothesis, and the evidence and arguments for it, were first put forward in her book Apparitions, and later developed in her book Lucid Dreaming, the Paradox of Consciousness during Sleep, both of which she co-authored with Charles McCreery.

This preoccupation with the extent of the hallucinatory element in various anomalous perceptual experiences is an indication that for Green the main interest of all these experiences is in the light they shed on normal perception, and on our theories of such perception, both philosophical and psychological. Prior to Green’s work these various hallucinatory phenomena had been of interest only to parapsychologists, who had studied them with a view to seeing, either whether they provided evidence for extra-sensory perception, or whether they shed light on the question of whether human beings could be said to survive death.

Despite Green's work, this latter, survival issue, rather than questions about the nature of perception, has remained the main focus of public interest in out-of-body experiences due to the popularisation of the concept of the near-death experience. In reality it appears that only a minority of out-of-body experiences occur in states which could be called near death.