Abstract

The terms 'hypnagogic imagery' and `hypnopompic imagery' were introduced by Maury (1848) and Myers (1903), respectively, and refer to imagery of varying sensory modalities that is experienced in the borderline states just as one is falling asleep or awakening from sleep. Previous research into hypnagogic/hypnopompic imagery has tended to focus on hypnagogic (HG) imagery and the visual and auditory modalities in particular. Comparatively little is known about hypnopompic (HP) imagery and other sensory modalities. Although it is known that a range of anomalous experiences have been reported during the HG/HP states, there has not been much research into the range of interpretations that people may give to their HG/HP experiences. A WWW survey, with 492 respondents, was conducted in order to investigate the relative frequency of various sensory modalities for HG and HP imagery, the content of each type of imagery and how these experiences have been interpreted.

The results suggest that HG is more common than HP imagery and visual, falling and sense of presence sensations are the most common forms of HG/HP imagery followed by auditory, tactile, bodily and movement sensations. Olfactory and gustatory imagery is relatively rare. However, one should note that the sample was self-selected and taken from the WWW-user population, which limits the generalisability of the findings. Although the range of HG/HP imagery content is quite broad, a qualitative thematic analysis of the survey data revealed a wide range of common themes that apply to both HG/HP experiences. However, there are some themes and features that seem to only occur in either the HG or HP state but not both. The main difference between HG and HP content is that HP content is often (but not always) related to previous dreams whereas HG tends not to be. In a temporal sense, there is also some indication that HG imagery may relate to events prior to sleep whereas HP imagery may have a tendency to anticipate daily events that may follow sleep (McKellar, 1957).The survey has also identified a range of possible interpretations of HG/HP experiences: some people seem not to pay too much attention to them or are not sure what they are; some consider them to be normal aspects of mind/body functioning; a few are concerned about possible physical or mental health problems. Others consider their HG/HP experiences to have some kind of paranormal, spiritual, mystical or supernatural cause or significance. Paranormal interpretations of HG/HP experiences tend to be associated with ESP or possible survival-related experiences, which might include communication with the dead, ghosts and hauntings, past-life experiences and out-of-body experiences. Spiritual, mystical and supernatural interpretations involve gods or angels, an unknown force or forces of nature, or beings from other dimensions. Although there is evidence to suggest that the HG/HP might be conducive to a range of anomalous experiences, that normal HG/HP experiences might be misinterpreted, or both (Sherwood, 1998, 2000, in press), the next step is to try to identify what distinguishes normal from apparently anomalous HG/HP experiences.