Lucid dreams are those in which a person becomes aware that he is dreaming. As he realises this the character of the dream changes, and as long as he remains aware of his state, he continues to be in a lucid dream. A lucid dream differs in many respects from an ordinary dream; it may be extremely realistic and provide the dreamer with a strikingly convincing imitation of waking life, and its emotional tone is often positive, sometimes to the point of elation.
The following lucid dream, reported by Oliver Fox, the author of a book about his own lucid dreams and out-of-the-body experiences,1
illustrates some of the characteristic features of lucid dreams. It will be seen that Fox reports what appears to be a relatively high level of cognitive functioning, with insight into his condition and memory of the basic facts of his life, including the position of his physical body.
I dreamed that I was walking, by day, through some unfamiliar street containing very fine buildings. There were plenty of people about in ordinary attire. Some incident or incongruous detail, which I cannot remember, told me I was dreaming, and I decided to experiment in prolonging the dream. I just walked on, like a visitor to a strange town. I noticed that I was dressed in the uniform of an army officer; so when I passed a very fine War Memorial, I played my part by giving it ‘eyes left’ and saluting. I also returned the salute of a soldier who happened to pass me. The uniform was brown, but I am not sure whether it was British. Nevertheless I had perfect consciousness of my real physical condition. I knew I
was a Clerical Officer at the—Dept, and that my body was at home in Worple Road. I knew also that in my army days I was only a private.
By and by I left the street and found myself on a pretty country road. The hedgerows and trees were in full leaf, and the sky blue and sunlit. I had my usual feeling (in these experiments) of wonderful health and vitality, and the atmosphere was charged with beauty and the sense of coming adventure.
(Fox, 1962, pp. 111–12)
Lucid dreams have only recently gained recognition as a phenomenon which has to be considered separately from ordinary dreaming, and it is only in the last fifteen years or so that they have started to be the subject of research by psychologists and physiologists. It seems a strange phenomenon in itself that they should have remained almost unrecognised for so long, since they seem to be fairly easy for people to learn to have, and are usually valued as an interesting experience by those who have them.
Lucid dreams appear to be accessible to a fair proportion of the population, and a great many people experience them spontaneously at some stage of their lives. There is also a small number of individuals who experience lucid dreams regularly. It appears to be rare, however, for a person to become a habitual lucid dreamer without some deliberate intention to cultivate them. On the other hand, people who have never had them before (as far as they remember) may find that reading a book about them and applying some analytical thought to their possibilities is sufficient for them to start dreaming in this way.
The following dream is from one of our subjects who came to have lucid dreams as a result of reading about them. It illustrates the positive emotions which may be experienced in lucid dreams, though not all lucid dreamers report such a high degree of elation.
I was in a strange country-style kitchen, sitting at the table and looking at the notepaper which I had bought yesterday in real life. As I opened the box, I noticed that instead of blank stationery, it contained already sealed and addressed envelopes (the first was for a friend in America). I thought, ‘but that’s not possible, I only bought these today and I know they were blank then.’ Then suddenly light dawns and I think ‘BUT
THIS MUST BE A DREAM THEN!’ I am elated at finally understanding why things are so ridiculous, and my overall feeling is of being tremendously happy at this release from worrying about the illogic around me. I start to rise up after this realisation comes and I fly towards the window. I go out ‘swimming’ through the air, having decided to see if breast stroke is possible in thin air. As I fly, I can remember all my intentions about lucid dream experimentation. I laugh at my scepticism at how exhilarating flying dreams could be. The most important thing is that throughout I am in control.
(Subject S. R.)
In her earlier study of the present topic, Green (1968a) adopted the term ‘lucid dream’, which was used by van Eeden (1913) to designate dreams in which he knew he was dreaming, in preference to the names given by some other lucid dreamers, such as Oliver Fox, who called them ‘dreams of knowledge’. This terminology has now been generally adopted. We think it is important to restrict the definition of a lucid dream entirely to the presence or absence of this one factor, the dreamer’s awareness of his state.
Because dreams in which a person knows he or she is dreaming tend, as a group, to have other characteristic features which distinguish them from ordinary dreams, and also because they are in the literal sense of the word ‘lucid’, in that the dreamer seems to be rational and dear-headed, it has sometimes been suggested that the definition of a lucid dream should be made to depend on some composite of these other qualities. For example, it has been suggested that a dream should be regarded as lucid only if, in addition to the dreamer’s preserving awareness that he is dreaming, he also has complete memory of his waking life and a high level of control of the developments within the dream (Tart, 1988).
This proposal, however, seems to us unsatisfactory in a number of ways. First, it would shift the basis of classification from a simple all-or-none factor to something which has to be subjectively assessed on some kind of sliding scale. Secondly, it is not a realistic proposal that a lucid dreamer should assess whether, or to what extent, he really has access to his full range of waking memories, or to what extent he is able to influence the dream events. He may have a strong sense that he is particularly
‘all there’ in a certain dream, and might therefore be tempted to classify it as ‘more lucid’ than one in which he feels this less strongly, but it is actually only by experiment within the dream that it is possible to discover restrictions which may actually be present upon his ability to recall his normal life or his control of the dream, and there is no scope within any given dream for more than a limited number of experiments bearing upon these points.
It seems to us more satisfactory to retain the original definition of a lucid dream as depending on one factor only. This, of course, leaves the way open for research into the extent to which this factor is found in combination with different degrees of memory and intellectual functioning.
It may be helpful to characterise the status of lucid dream reports at the time of the first author’s book Lucid Dreams. Certain individuals had reported that they occasionally had dreams in which they were aware of their situation and were able to remember and reason in a normal way. But were they really doing this, or were they only dreaming about doing it? The idea of lucid dreaming aroused resistance in various quarters because dreams were felt to be an essentially irrational state, and some philosophers took refuge in the suggestion that lucid dreams were merely a variant on the common dream feature of ‘dreaming that x’, where x in this case equated with ‘one is dreaming’ rather than, say, ‘one is flying’. Lucid dreamers were not, it was sometimes suggested to us, aware that they were dreaming, but dreaming that they were aware.
The resistance to the idea of lucid dreaming was associated, for some people, with a generalised deprecation of the dream state. Rationality, according to this mode of thought, is inseparable from the reality in which it functions, and in particular with the waking state in which communication with others takes place. Some philosophers, such as Malcolm (1959), went so far as seemingly to doubt that a dream ever happened (that, at least, is the message which Malcolm’s book Dreaming
suggests, even if Malcolm himself never explicitly admits that this is the implication of his arguments). According to Macolm, the ‘real’ world is that in which people communicate with one another and confirm one another’s observations. In this world, all that verifiably takes
place is that people sometimes feel inclined on waking to narrate a sequence of experiences which they say they have just had.
Alternatively, some psychologists, such as Hartmann (1975), suggested that reports of lucid dreams were really reports of brief periods of wakefulness, or ‘brief partial arousals’, and hence closer to daydreams than to a true dream. This is a proposal which would probably only seem plausible to someone who had never experienced lucidity in the dream state. It seems to us that anyone who had ever become lucid during a dream would consider it inapplicable, if only because he would know that one remains fully immersed in the perceptual world of the dream, and does not suddenly become aware instead, or as well, of the real world or any part of it, such as the feel of the bed in which one is lying. This point will be illustrated by several examples later in this book, in which it is clear that lucid dreamers may be quite uncertain of the location of their physical body while they are lucid. For example, on page 107 we quote a case in which a lucid dreamer, who is dreaming of being at his desk in a chair, wonders if his physical body is in that position in reality (in fact he is lying in bed in the normal way). Indeed it seems to be particularly difficult for some lucid dreamers to recall the immediate circumstances of their waking life, such as where they went to sleep the night before.
The fact that scepticism about the possibility of lucidity in dreams may be linked to the fact of a person’s never having experienced it is illustrated by the following passage by a writer on dreams from the early years of this century, Havelock Ellis. It will be seen that the statement of his sceptical position immediately follows his admission that he himself has never experienced lucidity. It is also interesting to note that he produced what is essentially the same hypothesis as Hartmann to explain those statements he knew of by other writers that they have indeed at times been lucid while dreaming.
I have never detected in my own dreams any recognition that they are dreams. I may say, indeed, that I do not consider that such a thing is really possible, although it has been borne witness to by many philosophers and others from Aristotle and Synesius and Gassendi onwards. The phenomenon occurs; the person who says to himself that he is dreaming believes that he is still dreaming, but one may be permitted to
doubt that he is. It seems far more probable that he has for a moment, without realising it, emerged at the waking surface of consciousness.
(Ellis, 1911, p. 65)
Perhaps part of the reason for the lateness with which lucid dreaming has come to be recognised as a real phenomenon, and as one worthy of the attention of philosophers and psychologists, lies in the difficulty, which we apparently all experience to a greater or lesser degree, of imagining that other people’s subjective experience may differ in significant and permanent ways from our own. In other words, it may be generally under-appreciated that there are considerable differences between individuals on the phenomenological as well as the behavioural level. This idea was well expressed by Galton towards the end of the last century, in his book Inquiries into Human Faculty:
In future chapters I shall give accounts of persons who have unusual mental characteristics as regards imagery, visualised numerals, colours connected with sounds and special associations of ideas, being unconscious of their peculiarities. … It will be seen in the end how greatly metaphysicians and psychologists may err, who assume their own mental operations, instincts, and axioms to be identical with those of the rest of mankind, instead of being special to themselves. The differences between men are profound, and we can only be saved from living in blind unconsciousness of our own mental peculiarities by the habit of informing ourselves as well as we can of those of others.
(Galton, 1883, p. 32)
In Lucid Dreams
Green (1968a) suggested that, if lucid dreamers were as rational as they believed they were, it might be possible to communicate with them while they were actually dreaming lucidly. Perhaps it would be possible for lucid dreamers to learn to exercise sufficient motor control to signal to an experimenter. She also predicted that lucid dreams would be found to be associated with the ‘paradoxical’ phase of sleep, characterised by low-voltage, fast waves in the electroencephalogram (EEG), muscular relaxation, and the
rapid eye movements – REMs – which have given this phase the name ‘REM sleep’. One of the reasons given for this proposal was the fact that lucid dreamers often reported lucidity arising out of a preceding non-lucid dream, and the latter sort of dream had already been associated with the REM phase of sleep.
At first sight these two suggestions in combination present us with a difficulty, however. This is that in REM sleep the sleeper has no apparent control of his body. It is the association of this state of physical paralysis with an EEG similar to that of an awake person which has led to this being designated as a ‘paradoxical’ stage of sleep. (Moreover, in the REM stage, despite the apparent activation of his brain, the sleeper is paradoxically more inaccessible to external stimuli and more difficult to arouse than at other stages of sleep.)
The same solution to this difficulty was arrived at independently by two researchers, Keith Hearne working at Liverpool University (Hearne, 1978), and Stephen LaBerge of Stanford University’s sleep research laboratory (LaBerge et al., 1981). The signalling method that both reseachers evolved depends on the fact that the eye muscles, unlike all other muscles during the REM phase, are, as the name implies, liable to be extremely active. It was found that if the lucid dreamer ‘looked’ right or left within his dream, this caused actual movements of a corresponding kind in his physical eyes, which could be picked up and measured by electrodes attached near the eye muscles. This makes it possible for simple messages to be transmitted. The dreamer can indicate by eye movements when he has become lucid, or when he is beginning or ending a task which he has been asked to carry out in the dream, and he can signal ‘yes’ or ‘no’ to a question which corresponds to a prolonged signal from the experimenter.
When experiments of this kind began to develop, the position of the sceptics incidentally became much less tenable. If it was possible to communicate rationally with a dreaming person, even if only to this limited extent, it was difficult to deny that he or she was what we would normally call conscious.
Experiments using this method of signalling by means of eye movements from within the dream suggested that lucid dreams do indeed take place, as predicted, predominantly during REM sleep; that they last from one to six minutes; and that they occur mostly in the early morning, towards the end of the sleeping period, when REM sleep is relatively abundant.
As a lucid dreamer is able to recall in the lucid state instructions which have been given to him while he was awake, he is able to carry out predetermined tasks. By this means it was possible to carry out experiments on the extent to which the lucid dreamer’s waking report about the events in his dream tallied with the signals which he made about them while they were happening. From these experiments it appeared that the sequence of dream events which he reported as having happened when he woke up had indeed happened in the sequence that he described. An extensive series of experiments of this sort was carried out at St Thomas’s Hospital in London, using as the subject Alan Worsley, who incidentally had been Keith Hearne’s subject in the first successful eye-signalling experiments at Liverpool. For example, Worsley was able to draw triangles on the walls in his dreams, following the movement of his hand visually as he did so, and it was ascertained that this produced movements of his physical eyes corresponding to those which would have occurred if he had been following triangular movements in the waking state (Schatzman et al
Another finding has been that the length of the various parts of a lucid dreamer’s experience corresponded fairly well with his or her subjective impression of their duration. For example, LaBerge asked his subjects to signa...