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Susan Blackmore
Published in Skeptical Inquirer 1991, 15, 362-370
What could it mean to be conscious in your
dreams? For most of us, dreaming is something quite separate from normal
life. When we wake up from being chased by a ferocious tiger, or seduced
by a devastatingly good-looking Nobel Prize winner we realize with relief
or disappointment that "it was only a dream."
Yet there are some dreams that are not like
that. Lucid dreams are dreams in which you know at the time that you
are dreaming. That they are different from ordinary dreams is obvious
as soon as you have one. The experience is something like waking up
in your dreams. It is as though you "come to" and find you are dreaming.
Lucid dreams used to be a topic within psychical
research and parapsychology. Perhaps their incomprehensibility made
them good candidates for being thought paranormal. More recently, however,
they have begun to appear in psychology journals and have dropped out
of parapsychology—a good example of how the field of parapsychology
shrinks when any of its subject matter is actually explained.
Lucidity has also become something of a New
Age fad. There are machines and gadgets you can buy and special clubs
you can join to learn how to induce lucid dreams. But this commercialization
should not let us lose sight of the very real fascination of lucid dreaming.
It forces us to ask questions about the nature of consciousness, deliberate
control over our actions, and the nature of imaginary worlds.
A Real Dream or Not?
The term lucid dreaming was coined by the Dutch
psychiatrist Frederik van Eeden in 1913. It is something of a misnomer
since it means something quite different from just clear or vivid dreaming.
Nevertheless we are certainly stuck with it. Van Eeden explained that
in this sort of dream "the re-integration of the psychic functions is
so complete that the sleeper reaches a state of perfect awareness and
is able to direct his attention, and to attempt different acts of free
volition. Yet the sleep, as I am able confidently to state, is undisturbed,
deep, and refreshing."
This implied that there could be consciousness
during sleep, a claim many psychologists denied for more than 50 years.
Orthodox sleep researchers argued that lucid dreams could not possibly
be real dreams. If the accounts were valid, then the experiences must
have occurred during brief moments of wakefulness or in the transition
between waking and sleeping, not in the kind of deep sleep in which
rapid eye movements (REMs) and ordinary dreams usually occur. In other
words, they could not really be dreams at all.
This presented a challenge to lucid dreamers
who wanted to convince people that they really were awake in their dreams.
But of course when you are deep asleep and dreaming you cannot shout,
"Hey! Listen to me. I’m dreaming right now." All the muscles of
the body are paralyzed.
It was Keith Hearne (1978), of the University
of Hull, who first exploited the fact that not all the muscles are paralyzed.
In REM sleep the eyes move. So perhaps a lucid dreamer could signal
by moving the eyes in a predetermined pattern. Just over ten years ago,
lucid dreamer Alan Worsley first managed this in Hearne’s laboratory.
He decided to move his eyes left and right eight times in succession
whenever he became lucid. Using a polygraph, Hearne could watch the
eye movements for signs of the special signal. He found it in the midst
of REM sleep. So lucid dreams are real dreams and do occur during REM
sleep.
Further research showed that Worsley’s
lucid dreams most often occurred in the early morning, around 6:30 A
M, nearly half an hour into a REM period and toward the end of a burst
of rapid eye movements. They usually lasted for two to five minutes.
Later research showed that they occur at times of particularly high
arousal during REM sleep (Hearne 1978).
It is sometimes said that discoveries in science
happen when the time is right for them. It was one of those odd things
that at just the same time, but unbeknown to Hearne, Stephen LaBerge,
at Stanford University in California, was trying the same experiment.
He too succeeded, but resistance to the idea was very strong. In 1980,
both Science and Nature rejected his first paper on the discovery (LaBerge
1985). It was only later that it became clear what an important step
this had been.
An Identifiable State?
It would be especially interesting if lucid
dreams were associated with a unique physiological state. In fact this
has not been found, although this is not very surprising since the same
is true of other altered states, such as out-of-body experiences and
trances of various kinds. However, lucid dreams do tend to occur in
periods of higher cortical arousal. Perhaps a certain threshold of arousal
has to be reached before awareness can be sustained.
The beginning of lucidity (marked by eye signals,
of course) is associated with pauses in breathing, brief changes in
heart rate, and skin response changes, but there is no unique combination
that allows the lucidity to be identified by an observer.
In terms of the dream itself, there are several
features that seem to provoke lucidity. Sometimes heightened anxiety
or stress precedes it. More often there is a kind of intellectual recognition
that something "dreamlike" or incongruous is going on (Fox 1962; Green
1968; LaBerge 1985).
It is common to wake from an ordinary dream
and wonder, "How on earth could I have been fooled into thinking that
I was really doing pushups on a blue beach?" A little more awareness
is shown when we realize this in the dream. If you ask yourself, "Could
this be a dream?" and answer "No" (or don’t answer at all), this
is called a pre-lucid dream. Finally, if you answer "Yes," it becomes
a fully lucid dream.
It could be that once there is sufficient cortical
arousal it is possible to apply a bit of critical thought; to remember
enough about how the world ought to be to recognize the dream world
as ridiculous, or perhaps to remember enough about oneself to know that
these events can’t be continuous with normal waking life. However,
tempting as it is to conclude that the critical insight produces the
lucidity, we have only an apparent correlation and cannot deduce cause
and effect from it.
Becoming a Lucid Dreamer
Surveys have shown that about 50 percent of
people (and in some cases more) have had at least one lucid dream in
their lives. (See, for example, Blackmore 1982; Gackenbach and LaBerge
1988; Green 1968.) Of course surveys are unreliable in that many people
may not understand the question. In particular, if you have never had
a lucid dream, it is easy to misunderstand what is meant by the term.
So overestimates might be expected. Beyond this, it does not seem that
surveys can find out much. There are no very consistent differences
between lucid dreamers and others in terms of age, sex, education, and
so on (Green 1968; Gackenbach and LaBerge 1988).
For many people, having lucid dreams is fun,
and they want to learn how to have more or to induce them at will. One
finding from early experimental work was that high levels of physical
(and emotional) activity during the day tend to precede lucidity at
night. Waking during the night and carrying out some kind of activity
before falling asleep again can also encourage a lucid dream during
the next REM period and is the basis of some induction techniques.
Many methods have been developed (Gackenbach
and Bosveld 1989; Tart 1988; Price and Cohen 1988). They roughly fall
into three categories.
One of the best known is LaBerge’s MILD
(Mnemonic Induction of Lucid Dreaming). This is done on waking in the
early morning from a dream. You should wake up fully, engage in some
activity like reading or walking about, and then lie down to go to sleep
again. Then you must imagine yourself asleep and dreaming, rehearse
the dream from which you woke, and remind yourself, "Next time I dream
this I want to remember I’m dreaming."
A second approach involves constantly reminding
yourself to become lucid throughout the day rather than the night. This
is based on the idea that we spend most of our time in a kind of waking
daze. If we could be more lucid in waking life, perhaps we could be
more lucid while dreaming. German psychologist Paul Tholey suggests
asking yourself many times every day, "Am I dreaming or not?" This sounds
easy but is not. It takes a lot of determination and persistence not
to forget all about it. For those who do forget, French researcher Clerc
suggests writing a large "C" on your hand (for "conscious") to remind
you (Tholey 1983; Gackenbach and Bosveld 1989).
This kind of method is similar to the age-old
technique for increasing awareness by meditation and mindfulness. Advanced
practitioners of meditation claim to maintain awareness through a large
proportion of their sleep. TM is often claimed to lead to sleep awareness.
So perhaps it is not surprising that some recent research finds associations
between meditation and increased lucidity (Gackenbach and Bosveld 1989).
The third and final approach requires a variety
of gadgets. The idea is to use some sort of external signal to remind
people, while they are actually in REM sleep, that they are dreaming.
Hearne first tried spraying water onto sleepers’ faces or hands
but found it too unreliable. This sometimes caused them to incorporate
water imagery into their dreams, but they rarely became lucid. He eventually
decided to use a mild electric shock to the wrist. His "dream machine"
detects changes in breathing rate (which accompany the onset of REM)
and then automatically delivers a shock to the wrist (Hearne 1990).
Meanwhile, in California, LaBerge was rejecting
taped voices and vibrations and working instead with flashing lights.
The original version was laboratory based and used a personal computer
to detect the eye movements of REM sleep and to turn on flashing lights
whenever the REMs reached a certain level. Eventually, however, all
the circuitry was incorporated into a pair of goggles. The idea is to
put the goggles on at night, and the lights will flash only when you
are asleep and dreaming. The user can even control the level of eye
movements at which the lights begin to flash.
The newest version has a chip incorporated
into the goggles. This will not only control the lights but will store
data on eye-movement density during the night and when and for how long
the lights were flashing, making fine tuning possible. At the moment,
the first users have to join in workshops at LaBerge’s Lucidity
Institute and learn how to adjust the settings, but within a few months
he hopes the whole process will be fully automated. (See LaBerge’s
magazine, DreamLight. )
LaBerge tested the effectiveness of the Dream
Light on 44 subjects who came into the laboratory, most for just one
night. Fifty-five percent had at least one lucid dream and two had their
first-ever lucid dream this way. The results suggested that this method
is about as successful as MILD, but using the two together is the most
effective (LaBerge 1985).
Lucid Dreams as an Experimental Tool
There are a few people who can have lucid dreams
at will. And the increase in induction techniques has provided many
more subjects who have them frequently. This has opened the way to using
lucid dreams to answer some of the most interesting questions about
sleep and dreaming.
How long do dreams take? In the last century,
Alfred Maury had a long and complicated dream that led to his being
beheaded by a guillotine. He woke up terrified, and found that the headboard
of his bed had fallen on his neck. From this, the story goes, he concluded
that the whole dream had been created in the moment of awakening.
This idea seems to have got into popular folklore
but was very hard to test. Researchers woke dreamers at various stages
of their REM period and found that those who had been longer in REM
claimed longer dreams. However, accurate timing became possible only
when lucid dreamers could send "markers" from the dream state.
LaBerge asked his subjects to signal when they
became lucid and then count a ten-second period and signal again. Their
average interval was 13 seconds, the same as they gave when awake. Lucid
dreamers, like Alan Worsley, have also been able to give accurate estimates
of the length of whole dreams or dream segments (Schatzman, Worsley,
and Fenwick 1988).
Dream Actions
As we watch sleeping animals it is often tempting
to conclude that they are moving their eyes in response to watching
a dream, or twitching their legs as they dream of chasing prey. But
do physical movements actually relate to the dream events?
Early sleep researchers occasionally reported
examples like a long series of left-right eye movements when a dreamer
had been dreaming of watching a ping-pong game, but they could do no
more than wait until the right sort of dream came along.
Lucid dreaming made proper experimentation
possible, for the subjects could be asked to perform a whole range of
tasks in their dreams. In one experiment with researchers Morton Schatzman
and Peter Fenwick, in London, Worsley planned to draw large triangles
and to signal with flicks of his eyes every time he did so. While he
dreamed, the electromyogram, recording small muscle movements, showed
not only the eye signals but spikes of electrical activity in the right
forearm just afterward. This showed that the preplanned actions in the
dream produced corresponding muscle movements (Schatzman, Worsley, and
Fenwick 1988).
Further experiments, with Worsley kicking dream
objects, writing with umbrellas, and snapping his fingers, all confirmed
that the muscles of the body show small movements corresponding to the
body’s actions in the dream. The question about eye movements was
also answered. The eyes do track dream objects. Worsley could even produce
slow scanning movements, which are very difficult to produce in the
absence of a "real" stimulus (Schatzman, Worsley, and Fenwick 1g88).
LaBerge was especially interested in breathing
during dreams. This stemmed from his experiences at age five when he
had dreamed of being an undersea pirate who could stay under water for
very long periods without drowning. Thirty years later he wanted to
find out whether dreamers holding their breath in dreams do so physically
as well. The answer was yes. He and other lucid dreamers were able to
signal from the dream and then hold their breath. They could also breathe
rapidly in their dreams, as revealed on the monitors. Studying breathing
during dreamed speech, he found that the person begins to breathe out
at the start of an utterance just as in real speech (LaBerge and Dement
1982a).
Hemispheric Differences
It is known that the left and right hemispheres
are activated differently during different kinds of tasks. For example,
singing uses the right hemisphere more, while counting and other, more
analytical tasks use the left hemisphere more. By using lucid dreams,
LaBerge was able to find out whether the same is true in dreaming.
In one dream he found himself flying over a
field. (Flying is commonly associated with lucid dreaming.) He signaled
with his eyes and began to sing "Row, row, row your boat...." He then
made another signal and counted slowly to ten before signaling again.
The brainwave records showed just the same patterns of activation that
you would expect if he had done these tasks while awake (LaBerge and
Dement 1982b).
Dream Sex
Although it is not often asked experimentally,
I am sure plenty of people have wondered what is happening in their
bodies while they have their most erotic dreams.
LaBerge tested a woman who could dream lucidly
at will and could direct her dreams to create the sexual experiences
she wanted. (What a skill!) Using appropriate physiological recording,
he was able to show that her dream orgasms were matched by true orgasms
(LaBerge, Greenleaf, and Kedzierski 1983).
Experiments like these show that there is a
close correspondence between actions of the dreamer and, if not real
movements, at least electrical responses. This puts lucid dreaming somewhere
between real actions, in which the muscles work to move the body, and
waking imagery, in which they are rarely involved at all. So what exactly
is the status of the dream world?
The Nature of the Dream World
It is tempting to think that the real world
and the world of dreams are totally separate. Some of the experiments
already mentioned show that there is no absolute dividing line. There
are also plenty of stories that show the penetrability of the boundary.
Alan Worsley describes one experiment in which
his task was to give himself a prearranged number of small electric
shocks by means of a machine measuring his eye movements. He went to
sleep and began dreaming that it was raining and he was in a sleeping
bag by a fence with a gate in it. He began to wonder whether he was
dreaming and thought it would be cheating to activate the shocks if
he was awake. Then, while making the signals, he worried about the machine,
for it was out there with him in the rain and might get wet (Schatzman,
Worsley, and Fenwick 1988).
This kind of interference is amusing, but there
are dreams of confusion that are not. The most common and distinct are
called false awakenings. You dream of waking up but in fact, of course,
are still asleep. Van Eeden (1913) called these "wrong waking up" and
described them as "demoniacal, uncanny, and very vivid and bright, with
. . . a strong diabolical light." The French zoologist Yves Delage,
writing in 1919, described how he had heard a knock at his door and
a friend calling for his help. He jumped out of bed, went to wash quickly
with cold water, and when that woke him up he realized he had been dreaming.
The sequence repeated four times before he finally actually woke up—still
in bed.
A student of mine described her infuriating
recurrent dream of getting up, cleaning her teeth, getting dressed,
and then cycling all the way to the medical school at the top of a long
hill, where she finally would realize that she had dreamed it all, was
late for lectures, and would have to do it all over again for real.
The one positive benefit of false awakenings
is that they can sometimes be used to induce out-of-body experiences
(OBEs). Indeed, Oliver Fox (1962) recommends this as a method for achieving
the OBE. For many people OBEs and lucid dreams are practically indistinguishable.
If you dream of leaving your body, the experience is much the same.
Also recent research suggests that the same people tend to have both
lucid dreams and OBEs (Blackmore 1988; Irwin 1988).
All of these experiences have something in
common. In all of them the "real" world has been replaced by some kind
of imaginary replica. Celia Green, of the Institute of Psychophysical
Research at Oxford, refers to all such states as "metachoric experiences."
Jayne Gackenbach, a psychologist from the University
of Alberta, Canada, relates these experiences to UFO abduction stories
and near-death experiences (NDEs). The UFO abductions are the most bizarre
but are similar in that they too involve the replacement of the perceived
world by a hallucinatory replica.
There is an important difference between lucid
dreams and these other states. In the lucid dream one has insight into
the state (in fact that defines it). In false awakening, one does not
(again by definition). In typical OBEs, people think they have really
left their bodies. In UFO "abductions" they believe the little green
men are "really there"; and in NDEs, they are convinced they are rushing
down a real tunnel toward a real light and into the next world. It is
only in the lucid dream that one realizes it is a dream.
I have often wondered whether insight into
these other experiences is possible and what the consequences might
be. So far I don’t have any answers.
Waking Up
The oddest thing about lucid dreams— and,
to many people who have them, the most compelling—is how it feels
when you wake up. Upon waking up from a normal dream, you usually think,
"Oh, that was only a dream." Waking up from a lucid dream is more continuous.
It feels more real, it feels as though you were conscious in the dream.
Why is this? I think the reason can be found by looking at the mental
models the brain constructs in waking, in ordinary dreaming, and in
lucid dreams.
I have previously argued that what seems real
is the most stable mental model in the system at any time. In waking
life, this is almost always the input-driven model, the one that is
built up from the sensory input. It is firmly linked to the body image
to make a stable model of "me, here, now." It is easy to decide that
this represents "reality" while all the other models being used at the
same time are "just imagination" (Blackmore 1988).
Now consider an ordinary dream. In that case
there are lots of models being built but no input-driven model. In addition
there is no adequate selfmodel or body image. There is just not enough
access to memory to construct it. This means, if my hypothesis is right,
that whatever model is most stable at any time will seem real. But there
is no recognizable self to whom it seems real. There will just be a
series of competing models coming and going. Is this what dreaming feels
like?
Finally, we know from research that in the
lucid dream there is higher arousal. Perhaps this is sufficient to construct
a better model of self. It is one that includes such important facts
as that you have gone to sleep, that you intended to signal with your
eyes, and so on. It is also more similar to the normal waking self than
those fleeting constructions of the ordinary dream. This, I suggest,
is what makes the dream seem more real on waking up. Because the you
who remembers the dream is more similar to the you in the dream. Indeed,
because there was a better model of you, you were more conscious.
If this is right, it means that lucid dreams
are potentially even more interesting than we thought. As well as providing
insight into the nature of sleep and dreams, they may give clues to
the nature of consciousness itself.
References
Blackmore, S. J. 1982. Beyond the Body. London:
Heinemann.
———. 1988. A theory of lucid dreams
and OBEs. In Conscious Mind, Sleeping Brain, 373-387, ed. J. Gackenbach
and S. LaBerge. New York: Plenum.
Delage, Y. 1919. Le Revel Paris: Les Presses Universitaires
de France.
Fox, O. 1962. Astral Projection. New York: 370 University
Books.
Gackenbach, J., and J. Bosveld. 1989. Control Your
Dreams. New York: Harper & Row.
Gackenbach, J., and S. LaBerge, eds. 1988. Conscious
Mind, Sleeping Brain. New York: Plenum.
Green, C. E. 1968. Lucid Dreams. London: Hamish
Hamilton.
Hearne, K. 1978. Lucid Dreams: An Electrophysiological
and Psychological Study. Unpublished Ph.D. thesis, University of Hull.
———. 1990. The Dream Machine. Northants:
Aquarian.
Irwin, H. J. 1988. Out-of-body experiences and dream
lucidity: Empirical perspectives. In Conscious Mind, Sleeping Brain,
353-371, ed. J. Gackenbach and S. LaBerge. New York: Plenum.
LaBerge, S. 1985. Lucid Dreaming. Los Angeles: Tarcher.
LaBerge, S. and W. Dement. 1982a. Voluntary control
of respiration during REM sleep. Sleep Research, 11:107.
———.1982b Lateralization of alpha
activity for dreamed singing and counting during REM sleep. Psychophysiology,
19:331-332.
LaBerge, S., W. Greenleaf, and B. Kedzierski. 1983.
Physiological responses to dreamed sexual activity during lucid REM
sleep. Psychophysiology, 20 454-45s.
Price, R. F., and D. B. Cohen. 1988. Lucid dream
induction: An empirical evaluation. In Conscious Mind, Sleeping Brain,
105-134, ed. J. Gackenbach and S. LaBerge. New York: Plenum.
Schatzman, M., A. Worsley, and P. Fenwick. 1988.
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LaBerge. New York: Plenum.
Tart, C. 1988. From spontaneous event to lucidity:
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York: Plenum.
Tholey, P. 1983. Techniques for controlling and
manipulating lucid dreams. Perceptual and Motor Skills, 57:79-90.
Van Eeden, F. 1913. A study of dreams. Proceedings
of the Society for Psychical Research, 26:431-461.
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