The Journal of Parapsychology, June 2002, published a research paper on the relationship between the not quite dreamlike states that occur in the moments between waking and sleep and reports of seemingly paranormal, or anomalous, experiences. A range of anomalous experiences has been reported during these borderline states, both between waking and sleep, termed hypnagogic, and between sleep and waking, termed hypnopompic, that surround periods of sleep. Researchers suggest that these states are sometimes conducive to extraordinary or anomalous subjective phenomena. These periods feature an increase in alpha activity (8-12 Hz), and slower and less frequent eye movements, compared to the usual waking state. Especially during hypnagogic states, people can experience brief and vivid imagery or sensations in one or more different sensory modalities or temporary paralysis. Visual and auditory are two of the most common forms of both hypnagogic imagery, but sensations of smell, taste, touching things, temperature change, bodily movement, and/or synesthetic experiences, in which sensations that first seem to come from one sense subsequently trigger sensations from a different sense, may also occur. A sense of presence is also a common feature of these borderline states. Visual hypnagogic/hypnopompic imagery is often pleasant, even humorous, but it can also be terrifying. The following types are most common: (a) formless (e.g., waves, clouds of color); (b) designs (e.g., geometric and symmetrical patterns and shapes); (c) faces, figures, animals, and objects; (d) nature scenes (e.g., landscapes, seascapes, gardens); (e) scenes with people; and (f) print and writing (e.g., in real or imaginary languages). Auditory phenomena can include the hearing of crashing noises, one's name being called, a doorbell ringing, new words or expressions, irrelevant sentences containing unrecognizable names, pompous nonsense, quotations, references to spoken conversations, remarks directed to oneself, and even meaningful responses to one's thought of the moment. Visual hypnagogic/hypnopompic imagery has often been referred to as the "faces in the dark" phenomenon because the seeing of faces is so common. Faces may range from the beautiful and the pleasant to the hideous and the terrifying (Mavromatis, 1987; McKellar, 1957). These faces are often characterized as being extremely lifelike and often seem to be looking at the observer ( Leaning, 1925). These faces can also develop into figures that may move towards the observer. Such faces or figures can be singular or in groups, of known or unknown, living or dead persons and may sometimes seem to represent particular moods and emotions (Leaning, 1925; Mavromatis, 1987). People undergoing such experiences may also hear their names being called, which might be interpreted as attempts at communication by deceased persons. Although hypnagogic/hypnopompic imagery and sleep paralysis are relatively normal experiences, occasionally they may be influenced by anomalous processes (e.g., extra-sensory perception, ESP) or may facilitate anomalous experiences. This is especially true for hypnagogic imageries that are extremely vivid. They may occur in more than one sensory modality, sometimes simultaneously, and may have some significance for the person experiencing them. For example, some experimental studies have found that hypnagogic imagery is conducive to telepathy (Gertz, 1983; Schacter & Kelly, 1975). In terms of spontaneous cases, there are a number of well documented cases of ESP and crisis apparitions that have occurred during the hypnagogic/hypnopompic states (e.g., Gurney et al., 1886, Chapter IX, "Borderland" Cases, pp. 251-285). For example, a father reported a hypnopompic image involving his son: I was suddenly awakened by hearing his voice, as I fancied, very near me. I saw a bright, opaque, white mass before my eyes, and in the centre of this light I saw the face of my little darling, his eyes bright, his mouth smiling. The apparition, accompanied by the sound of his voice, was too short and too sudden to be called a dream: it was too clear, too decided, to be called an effect of imagination. So distinctly did I hear his voice that I looked around the room to see whether he was actually there. (p. 277) The father received a letter the following day informing him that his son was ill but later found out that his son had died at the time of the apparition. Another well-documented spontaneous case involving hypnagogic phenomena was the haunting of the Mill House at Willington in northeast England (MacKenzie, 1982). The haunting lasted for about 13 years. It was well documented, partly by a diary kept by the owner, and phenomena were observed at different times and in different locations by a variety of witnesses, sometimes simultaneously. The phenomena included shadowy figures, apparitions, the sound of footsteps, strange voices and doors opening, people feeling pressure on parts of their body as they lay in bed, and, in particular, the feeling of the bed and/or bedclothes being moved up and down. It is also possible that hypnagogic/hypnopompic imagery and sleep paralysis may account for some intense UFO reports and abductions (e.g., Sherwood, 2000; Spanos et al., 1993). Abductions are often reported around the time of sleep and may feature paralysis, awareness of surroundings, a sense of presence, bright lights and figures in the room, humming and buzzing sounds, and sensations of floating (e.g., Mack, 1994). There are also hypnagogic features that might facilitate ESP interpretations. Hypnopompic imagery, in particular, tends to anticipate forthcoming daily events, and in connection with actual later events it may be considered to be precognitive (Zusne & Jones, 1989). Hypnopompic imagery may also appear to be warning of imminent or future danger. Visual imagery involving complex scenes characterized by movement and life may also be experienced (Leaning, 1925; Mavromatis, 1987). Evidence for the conduciveness of the hypnagogic states to anomalous processes comes from the fact that these states have physiological and psychological features believed to be psi-conducive in other contexts, from experimental studies using both naturally occurring and induced states, from spontaneous case reports of a variety of different phenomena, and from biographical accounts of gifted subjects and psychics. Why do these phenomena occur? It is possible that, in such a state information from the physical world of molecules, the dimension that regular people can see, will have less influence on people's consciousness. Thus, the existence in other dimension may have a chance to be reflected in people's minds.