Hypnagogia is the experience of the transitional state from wakefulness to sleep: the hypnagogic
state of consciousness. The related words from the Greek are agōgos "leading", "inducing",
pompe "act of sending", and hypnos "sleep". The word hypnagogia entered the popular psychology
literature through Dr. Andreas Mavromatis in his 1983 thesis, while hypnagogic and hypnopompic
were coined by others in the 1800s and noted by Havelock Ellis. The term hypnagogic was
originally coined by Alfred Maury to name the state of consciousness during the onset
of sleep. Hypnopompic was coined by Frederic Myers soon afterwards to denote the onset
of wakefulness. The term hypnagogia is used by Dr. Mavromatis to identify the study of
the sleep-transitional consciousness states in general, and he employs hypnogogic or hypnapompic
for the purpose of identifying the specific experiences under study.
Mental phenomena that occur during this "threshold consciousness" phase include lucid dreaming,
hallucinations, and sleep paralysis.
Definitions and synonyms Sometimes the word hypnagogia is used in a
restricted sense to refer to the onset of sleep, and contrasted with hypnopompia, Frederic
Myers's term for waking up. However, hypnagogia is also regularly employed in a more general
sense that covers both falling asleep and waking up, and Havelock Ellis questioned the
need for separate terms. Indeed, it is not always possible in practice to assign a particular
episode of any given phenomenon to one or the other, given that the same kinds of experience
occur in both, and that people may drift in and out of sleep. In this article hypnagogia
will be used in the broader sense, unless otherwise stated or implied.
Other terms for hypnagogia, in one or both senses, that have been proposed include "presomnal"
or "anthypnic sensations", "visions of half-sleep", "oneirogogic images" and "phantasmata", "the
borderland of sleep", "praedormitium", "borderland state", "half-dream state", "pre-dream condition",
"sleep onset dreams", "dreamlets", and "wakefulness-sleep transition".
Threshold consciousness describes the same mental state of someone who is moving towards
sleep or wakefulness but has not yet completed the transition. Such transitions are usually
brief, but can be extended by sleep disturbance or deliberate induction, for example during
meditation. History
Early references to hypnagogia are to be found in the writings of Aristotle, Iamblichus,
Cardano, Simon Forman and Swedenborg. Romanticism brought a renewed interest in the subjective
experience of the edges of sleep. In more recent centuries, many authors have referred
to the state; Edgar Allan Poe, for example, wrote of the "fancies" he experienced "only
when I am on the brink of sleep, with the consciousness that I am so."
Serious scientific inquiry began in the 19th century with Johannes Peter Müller, Jules
Baillarger and Alfred Maury, and continued into the 20th century with Leroy.
The advent of electroencephalography has supplemented the introspective methods of these early researchers
with physiological data. The search for neural correlates for hypnagogic imagery began with
Davis et al. in the 1930s, and continues with increasing sophistication to this day. While
the dominance of the behaviorist paradigm led to a decline in research, especially in
the English speaking world, the later 20th century has seen a revival, with investigations
of hypnagogia and related altered states of consciousness playing an important role in
the emerging multidisciplinary study of consciousness. Nevertheless, much remains to be understood
about the experience and its corresponding neurology, and the topic has been somewhat
neglected in comparison with sleep and dreams; hypnagogia has been described as a "well-trodden
and yet unmapped territory". Important reviews of the scientific literature
have been made by Leaning, Schacter, Richardson and Mavromatis.
Sensory phenomena Transition to and from sleep may be attended
by a wide variety of sensory experiences. These can occur in any modality, individually
or combined, and range from the vague and barely perceptible to vivid hallucinations.
Sights Among the more commonly reported, and more
thoroughly researched, sensory features of hypnagogia are phosphenes which can manifest
as seemingly random speckles, lines or geometrical patterns, including form constants, or as
figurative images. They may be monochromatic or richly colored, still or moving, flat or
three-dimensional. Imagery representing movement through tunnels of light is also reported.
Individual images are typically fleeting and given to very rapid changes. They are said
to differ from dreams proper in that hypnagogic imagery is usually static and lacking in narrative
content, although others understand the state rather as a gradual transition from hypnagogia
to fragmentary dreams, i.e., from simple Eigenlicht to whole imagined scenes. Descriptions of
exceptionally vivid and elaborate hypnagogic visuals can be found in the work of Marie-Jean-Léon,
Marquis d'Hervey de Saint Denys. Tetris effect
People who have spent a long time at some repetitive activity before sleep, in particular
one that is new to them, may find that it dominates their imagery as they grow drowsy,
a tendency dubbed the Tetris effect. This effect has even been observed in amnesiacs
who otherwise have no memory of the original activity. When the activity involves moving
objects, as in the video game Tetris, the corresponding hypnagogic images tend to be
perceived as moving. The Tetris effect is not confined to visual imagery, but can manifest
in other modalities also. For example, Robert Stickgold recounts having experienced the
touch of rocks while falling asleep after mountain climbing. This can also occur to
people who have traveled on a small boat in rough seas, or have been swimming through
waves, shortly before going to bed, and they feel the waves as they drift to sleep, or
people who have spent the day skiing who continue to "feel snow" under their feet, also people
who have spent considerable time jumping on a trampoline will find that they can feel
the up-and-down motion before they go to sleep. Many chess players report the phenomenon of
seeing the chess board and pieces during this state. New employees working stressful and
demanding jobs often report doing work-related tasks in this period before sleep.
Sounds Hypnagogic hallucinations are often auditory
or have an auditory component. Like the visuals, hypnagogic sounds vary in intensity from faint
impressions to loud noises, such as crashes and bangs. People may imagine their own name
called, crumpling bags, white noise, or a doorbell ringing. Snatches of imagined speech
are common. While typically nonsensical and fragmented, these speech events can occasionally
strike the individual as apt comments on — or summations of — their thoughts at the time.
They often contain word play, neologisms and made-up names. Hypnagogic speech may manifest
as the subject's own "inner voice", or as the voices of others: familiar people or strangers.
More rarely, poetry or music is heard. Sleep paralysis
Humming, roaring, hissing, rushing, zapping, and buzzing noises are frequent in conjunction
with sleep paralysis. This happens when the REM atonia sets in sooner than usual, before
the person is fully asleep, or persists longer than usual, after the person has fully awoken.
Sleep paralysis is reportedly very frequent among narcoleptics. It occurs frequently in
about 6% of the rest of the population, and occurs occasionally in 60%. In surveys from
Canada, China, England, Japan and Nigeria, 20 to 60% of individuals reported having experienced
sleep paralysis at least once in their lifetime. The paralysis itself is frequently accompanied
by additional phenomena. Typical examples include a feeling of being crushed or suffocated,
electric "tingles" or "vibrations", imagined speech and other noises, the imagined presence
of a visible or invisible entity, and sometimes intense emotion: fear or euphoria and orgasmic
feelings. Sleep paralysis has been proposed as an explanation for at least some alien
abduction experiences, the Oight Hag and shadow people hauntings.
Other sensations Gustatory, olfactory and thermal sensations
in hypnagogia have all been reported, as well as tactile sensations. Sometimes there is
synesthesia; many people report seeing a flash of light or some other visual image in response
to a real sound. Proprioceptive effects may be noticed, with numbness and changes in perceived
body size and proportions, feelings of floating or bobbing, and out-of-body experiences. Perhaps
the most common experience of this kind is the falling sensation, and associated hypnic
jerk, encountered by many people, at least occasionally, while drifting off to sleep.
Cognitive and affective phenomena Thought processes on the edge of sleep tend
to differ radically from those of ordinary wakefulness. Hypnagogia may involve a "loosening
of ego boundaries ... openness, sensitivity, internalization-subjectification of the physical
and mental environment and diffuse-absorbed attention." Hypnagogic cognition, in comparison
with that of normal, alert wakefulness, is characterized by heightened suggestibility,
illogic and a fluid association of ideas. Subjects are more receptive in the hypnagogic
state to suggestion from an experimenter than at other times, and readily incorporate external
stimuli into hypnagogic trains of thought and subsequent dreams. This receptivity has
a physiological parallel; EEG readings show elevated responsiveness to sound around the
onset of sleep. Herbert Silberer described a process he called
autosymbolism, whereby hypnagogic hallucinations seem to represent, without repression or censorship,
whatever one is thinking at the time, turning abstract ideas into a concrete image, which
may be perceived as an apt and succinct representation thereof.
The hypnagogic state can provide insight into a problem, the best-known example being August
Kekulé’s realization that the structure of benzene was a closed ring while half-asleep
in front of a fire and seeing molecules forming into snakes, one of which grabbed its tail
in its mouth. Many other artists, writers, scientists and inventors — including Beethoven,
Richard Wagner, Walter Scott, Salvador Dalí, Thomas Edison, Nikola Tesla and Isaac Newton
— have credited hypnagogia and related states with enhancing their creativity. A 2001 study
by Harvard psychologist Deirdre Barrett found that, while problems can also be solved in
full-blown dreams from later stages of sleep, hypnagogia was especially likely to solve
problems which benefit from hallucinatory images being critically examined while still
before the eyes. A feature that hypnagogia shares with other
stages of sleep is amnesia. But this is a selective forgetfulness, affecting the hippocampal
memory system, which is responsible for episodic or autobiographical memory, rather than the
neocortical memory system, responsible for semantic memory. It has been suggested that
hypnagogia and REM sleep help in the consolidation of semantic memory, but the evidence for this
has been disputed. For example, suppression of REM sleep due to antidepressants and lesions
to the brainstem has not been found to produce detrimental effects on cognition.
Hypnagogic phenomena may be interpreted as visions, prophecies, premonitions, apparitions
and inspiration, depending on the experiencers' beliefs and those of their culture.
Physiology Physiological studies have tended to concentrate
on hypnagogia in the strict sense of spontaneous sleep onset experiences. Such experiences
are associated especially with stage 1 of NREM sleep, but may also occur with pre-sleep
alpha waves. Davis et al. found short flashes of dreamlike imagery at the onset of sleep
to correlate with drop-offs in alpha EEG activity. Hori et al. regard sleep onset hypnagogia
as a state distinct from both wakefulness and sleep with unique electrophysiological,
behavioral and subjective characteristics, while Germaine et al. have demonstrated a
resemblance between the EEG power spectra of spontaneously occurring hypnagogic images,
on the one hand, and those of both REM sleep and relaxed wakefulness, on the other.
To identify more precisely the nature of the EEG state which accompanies imagery in the
transition from wakefulness to sleep, Hori et al. proposed a scheme of 9 EEG stages defined
by varying proportions of alpha, suppressed waves of less than 20μV, theta ripples, proportions
of sawtooth waves, and presence of spindles. Germaine and Nielsen found spontaneous hypnagogic
imagery to occur mainly during Hori sleep onset stages 4 and 5.
The "covert-rapid-eye-movement" hypothesis proposes that hidden elements of REM sleep
emerge during the wakefulness-sleep transition stage. Support for this comes from Bódicz
et al., who note a greater similarity between WST EEG and REM sleep EEG than between the
former and stage 2 sleep. Respiratory pattern changes have also been
noted in the hypnagogic state, in addition to a lowered rate of frontalis muscle activity.
Daydreaming and waking reveries Microsleep may intrude into wakefulness at
any time in the wakefulness-sleep cycle, due to sleep deprivation and other conditions,
resulting in impaired cognition, amnesia. Gurstelle and Oliveira distinguish a state
which they call daytime parahypnagogia, the spontaneous intrusion of a flash image or
dreamlike thought or insight into one's waking consciousness. DPH is typically encountered
when one is "tired, bored, suffering from attention fatigue, and/or engaged in a passive
activity." The exact nature of the waking dream may be forgotten even though the individual
remembers having had such an experience. Gustelle and Oliveira define DPH as "dissociative,
trance-like, [...] but, unlike a daydream, [...] not self-directed"—however, daydreams
and waking reveries are often characterised as "passive", "effortless", and "spontaneous",
while hypnagogia itself can sometimes be influenced by a form of autosuggestion, or "passive concentration",
so these sorts of episode may in fact constitute a continuum between directed fantasy and the
more spontaneous varieties of hypnagogia. Others have emphasized the connections between
fantasy, daydreaming, dreams and hypnosis. In his book, Zen and the Brain, James H. Austin
cites speculation that regular meditation develops a specialized skill of "freezing
the hypnagogic process at later and later stages" of the onset of sleep, initially in
the alpha wave stage and later in theta. Investigative methodology
Self-observation was the primary tool of the early researchers. Since the late 20th century,
this has been joined by questionnaire surveys and experimental studies. All three methods
have their disadvantages as well as points to recommend them.
Naturally, amnesia contributes to the difficulty of studying hypnagogia, as does the typically
fleeting nature of hypnagogic experiences. These problems have been tackled by experimenters
in a number of ways, including voluntary or induced interruptions, sleep manipulation,
the use of techniques to "hover on the edge of sleep" thereby extending the duration of
the hypnagogic state, and training in the art of introspection to heighten the subject's
powers of observation and attention. Techniques for extending hypnagogia range
from informal ones, to the use of biofeedback devices to induce a "theta" state, characterized
by relaxation and theta EEG activity. The theta state is produced naturally the most
when we are dreaming. It has also been linked to paranormal activities, and Rick Strassman
has argued that it triggers the release of DMT from the pineal gland, causing a dreaming
state. Another method is to induce a state said to
be subjectively similar to sleep onset in a Ganzfeld setting, a form of sensory deprivation.
But the assumption of identity between the two states may be unfounded. The average EEG
spectrum in Ganzfeld is more similar to that of the relaxed waking state than to that of
sleep onset. Wackerman et al. conclude that "the Ganzfeld imagery, although subjectively
very similar to that at sleep onset, should not be labeled as 'hypnagogic'. Perhaps a
broader category of 'hypnagoid experience' should be considered, covering true hypnagogic
imagery as well as subjectively similar imagery produced in other states."
Hypnagogia in film Dracula
Ghostbusters Marianne
Paranormal Activity Delicacies of Molten Horror Synapse, by the
highly esteemed avant-garde filmmaker Stan Brakhage. Brakhage states that he shaped this
film to look like "what hypnagogic vision might see while watching television".
See also
References
Further reading Leaning, F.E.. "An introductory study of hypnagogic
phenomena". Proceedings of the Society for Psychical Research, 35, 289-409.
Mavromatis, A.. Hypnagogia: the Unique State of Consciousness Between Wakefulness and Sleep.
London: Routledge and Kegan Paul. Warren, Jeff. "The Hypnagogic". The Head Trip:
Adventures on the Wheel of Consciousness. ISBN 978-0-679-31408-0.
External links "Hypnagogic and hypnopompic hallucinations:
pathological phenomena?" in the British Journal of Psychiatry
"Hypnagogia" by Gary Lachman in Fortean Times