By strict dictionary definition, somnambulism means sleepwalking, and a somnambulist is a person who sleepwalks. In everyday medical and psychological usage, that remains the ordinary meaning of the terms.
In some hypnosis traditions, however, somnambulism and somnambulist have acquired a specialized meaning. They are used to describe a particularly deep or responsive hypnotic state—and, in the case of somnambulist, a person who can experience that state readily. This use of the terms should not be confused with medical sleepwalking.
The terminology can be confusing because hypnosis is often described with words associated with sleep: sleep, deep sleep, somnambulism, and awakening. In most hypnotic procedures, these words are not claims that the client has entered ordinary sleep. They are suggestions and metaphors intended to help the person relax, focus attention, and respond to the hypnotist’s instructions.
A more precise modern description is that hypnosis involves focused attention, reduced attention to competing stimuli, and increased responsiveness to suggestion.¹ The person may feel deeply relaxed or absorbed, but hypnosis and sleep are different psychological and physiological conditions.²
What does somnambulism mean in hypnosis?
In hypnosis, somnambulism generally refers to a deep, highly responsive hypnotic state in which a person can experience strong changes in perception, memory, sensation, movement, imagery, or emotion.
The word does not describe a single universally agreed-upon clinical state. Different schools and practitioners use it somewhat differently. In some traditions, it means a particular level of hypnotic depth. In others, it refers more broadly to a person who responds strongly to a range of hypnotic suggestions.
The term is also sometimes used to describe the ability to experience phenomena such as:
Amnesia: temporary difficulty remembering an instruction, event, or part of the session
Analgesia: reduced pain
Anesthesia: markedly reduced or absent sensation in a particular area
Positive hallucination: experiencing something that is not physically present, such as hearing a sound or seeing an image
Negative hallucination: failing to notice something that is physically present
Time distortion: experiencing time as passing more quickly or slowly than expected
Ideomotor response: movement that feels automatic or occurs with little deliberate effort
Posthypnotic response: carrying out a suggestion after the formal hypnotic procedure has ended
Vivid imagery: experiencing imagined events, sensations, or scenes with unusual clarity
These experiences are commonly discussed in research on hypnotic suggestibility and hypnotic phenomena. They do not all occur in every person, and their presence does not by itself establish a particular depth of trance.³
Is somnambulism the same as deep trance?
Not necessarily. “Deep trance” is a common practical expression, but it does not have one universally accepted scientific definition. Hypnotic responsiveness is better understood as a set of abilities and responses than as a single measurable depth that everyone passes through in the same order.
A person may be highly responsive to suggestions involving movement but less responsive to suggestions involving amnesia. Another person may experience vivid imagery while remaining aware of the surroundings. Someone else may show little visible relaxation yet respond strongly to suggestions. These differences are one reason researchers often measure hypnotic responsiveness with standardized suggestions rather than relying only on outward appearance.⁴
The term somnambulism can therefore be useful within a particular teaching tradition, but it should not be treated as a universally standardized diagnostic category.
Common signs and experiences
A person described as somnambulistic in hypnosis may show some of the following responses:
Rapid or smooth induction
The person may focus easily, become absorbed in the procedure, and respond quickly to instructions for relaxation or attention. This does not necessarily mean that every person who enters hypnosis quickly will experience every phenomenon associated with deep hypnosis.
Changes in sensation
Suggestions may produce warmth, coolness, heaviness, lightness, tingling, numbness, or reduced pain. Hypnotic analgesia has been studied in both laboratory and clinical settings, although results vary among individuals and hypnosis should not be used to ignore a potentially serious medical problem.⁵
Changes in movement
A hand, arm, head, or other part of the body may move in response to suggestion. The movement can feel involuntary or automatic, even though it is produced by the person’s own nervous system.
Vivid imagery
The person may imagine sights, sounds, physical sensations, or events with unusual clarity. Vivid imagery alone, however, is not proof of a specific hypnotic depth.
Altered memory access
Suggestions may affect what a person remembers during or after a session. This area requires particular care. Hypnosis can increase confidence in memories without guaranteeing that those memories are accurate, and suggestion can contribute to memory distortion.⁶ Hypnosis should therefore not be used to establish the factual accuracy of uncertain memories or to conduct an investigative “memory recovery” procedure.
Time distortion
A person may feel that a session lasted only a few minutes when more time passed, or may experience the period as unusually long. This is a subjective change in time experience, not evidence that time itself changed.
Reduced awareness of surroundings
Attention may become so concentrated on the hypnotist’s voice, internal imagery, or bodily sensations that surrounding sounds and events receive less notice. This is better described as a shift in attention than as unconsciousness.
The Spiegel eye roll
Some hypnotists refer to an upward movement of the eyes beneath the eyelids as the Spiegel eye roll. It is named after psychiatrist Herbert Spiegel, who used eye-related observations in his work on hypnotic ability.⁷
An upward eye movement may occur during hypnosis, but it is not a reliable stand-alone measure of hypnotic depth. People vary in their eye movements, and an observer cannot determine the full quality of someone’s experience from this sign alone. A person may respond strongly to suggestion without showing a prominent eye roll, while another person may show the movement without demonstrating every phenomenon traditionally associated with somnambulism.
For that reason, eye position should be treated as one possible observation—not as a test that proves whether someone is deeply hypnotized.
What is a somnambulist?
In hypnosis terminology, a somnambulist is usually described as a person who can enter a highly responsive hypnotic state relatively easily and may experience a broad range of hypnotic phenomena.
A person may be called a somnambulist if they:
enter an absorbed state quickly;
respond readily to hypnotic suggestions;
experience changes in sensation, movement, imagery, or perception;
can follow both direct and indirect suggestions;
experience amnesia or other suggested memory changes;
move relatively easily between ordinary alertness and focused hypnotic attention.
This label is used differently by different practitioners. It should not be treated as a formal medical diagnosis or as a permanent psychological type.
Are people born somnambulists?
Some people appear to be highly responsive to hypnosis from their first experience. Others become more comfortable and responsive with practice. Research suggests that hypnotic responsiveness is influenced by several factors, including attention, expectations, motivation, absorption—the capacity to become deeply involved in an experience—and the fit between the person and the procedure. At the same time, individual differences in hypnotic responsiveness can remain relatively stable over time.⁸
It is therefore too simple to say that a person is either permanently capable or permanently incapable of somnambulistic hypnosis. A first session can reveal important tendencies, but it is not always a final measurement of what someone can experience under different circumstances.
A person’s response may also be affected by:
how safe and comfortable the setting feels;
the quality of communication and rapport;
fatigue, stress, pain, or distraction;
expectations about hypnosis;
the wording and timing of suggestions;
previous experience with relaxation or focused attention;
the person’s willingness to participate.
No one should feel pressured to demonstrate a particular response. Hypnosis is cooperative: the hypnotist offers instructions and suggestions, while the client remains an active participant.
“Natural somnambulist” and the Analytical–Physical distinction
In some Kappasinian hypnosis terminology, a natural somnambulist is someone who appears able to reach a somnambulistic level of hypnosis without extensive prior training or repeated practice. In that system, the term may also be connected with a person’s pattern of suggestibility.
John Kappas described two broad suggestibility types: Emotional and Physical. In modern explanatory language, these are often discussed as Analytical (or Emotional) and Physical patterns. The model proposes that people may respond more readily to suggestions framed through feelings, meaning, and emotional experience, or to suggestions involving bodily sensations and physical responses. A person with a relatively balanced pattern may appear responsive to both kinds of suggestion.
This is a theory-specific classification, not a universally accepted psychological taxonomy. It should be presented as a model used in a particular hypnosis tradition rather than as an established clinical diagnosis or fixed personality category. Readers interested in that terminology can review the Kappasinian E&P model.
Even within this model, “natural” should not be taken to mean that a person has unusual powers or that hypnosis will work automatically for every goal. Responsiveness can vary by suggestion, context, relationship, and purpose.
Can somnambulism be developed?
Many people become more comfortable with hypnosis through repeated experience. Practice may make it easier to focus attention, recognize the sensations of trance, use imagery, and respond to suggestions. This does not mean that practice guarantees a particular response or that everyone will develop the same abilities.
A responsible practitioner should avoid presenting somnambulism as a competition. There is no therapeutic prize for reaching a supposedly deeper level, and a dramatic outward response is not required for hypnosis to be useful. For many goals, the relevant question is not “How deep did the person go?” but “Was the person able to use the suggestions in a safe and meaningful way?”
Hypnosis is not sleep
Although hypnotists may say “sleep” during an induction, hypnosis is not ordinary sleep.
During hypnosis, a person may:
hear and understand the hypnotist;
notice some or most surrounding sounds;
remain able to speak or move;
reject a suggestion that conflicts with their wishes;
remember the session afterward;
experience focused attention rather than unconsciousness.
Some people feel heavy, relaxed, drowsy, or detached from the surroundings. Others feel alert and mentally active. Both experiences can occur in hypnosis.
Sleep and hypnosis also differ in brain and behavioral measures. Hypnosis is not simply a person being asleep while another person talks. Research comparing hypnosis with sleep and ordinary relaxation has found differences in attention, responsiveness, and physiological measures, although the exact nature of hypnotic states remains a subject of ongoing research.⁹
Does hypnosis remove free will?
Somnambulistic hypnosis does not give the hypnotist unlimited control over another person. A client remains an active participant and generally does not lose all judgment or become compelled to follow every instruction. People can refuse suggestions, interrupt the session, and respond in ways that reflect their own goals and boundaries.
This does not make suggestion powerless. Expectation, social context, focused attention, imagination, and the relationship with the practitioner can all influence experience. It does mean that popular images of hypnosis as total mind control are misleading.¹⁰
A professional hypnotist should explain the procedure clearly, obtain informed consent, respect boundaries, and avoid suggestions that are deceptive, coercive, or outside the agreed purpose of the session.
Why the terminology matters
Using somnambulism in hypnosis can be practical when a practitioner and client share the same definition. It becomes misleading when the word is presented as though it has one precise scientific meaning or as though it refers to literal sleepwalking.
A careful explanation distinguishes three ideas:
Medical somnambulism: sleepwalking, a sleep-related behavior.
Traditional hypnosis usage: a deep or highly responsive hypnotic state.
Individual response: the particular suggestions and experiences a person can produce in a given setting.
Keeping those meanings separate helps clients understand what hypnosis can involve without creating unrealistic expectations.
A concise definition
In hypnosis, somnambulism refers to a traditionally described deep or highly responsive hypnotic state—not literal sleepwalking. A somnambulist is a person who can enter that state relatively easily and may experience phenomena such as amnesia, analgesia, anesthesia, altered sensation, vivid imagery, time distortion, or automatic movement. A natural somnambulist is someone who appears able to reach that level without extensive prior practice.
The terms describe patterns of hypnotic response, not medical diagnoses, proof of unconsciousness, or evidence that a person has surrendered control.
If you would like to explore the Kappasinian terminology, you can take the Hypnotechs E&P Suggestibility Assessment. You can also read about the Arons Scale of Hypnotic Depth and find the Hypnotechs personality assessments. These tools are intended for education and self-exploration, not diagnosis.
Notes
Gary R. Elkins, Mark P. Barabasz, David C. Council, and David Spiegel, “Advancing Research and Practice: The Revised APA Division 30 Definition of Hypnosis,” International Journal of Clinical and Experimental Hypnosis 63, no. 1 (2015): 1–9.
David Spiegel and Herbert Spiegel, Trance and Treatment: Clinical Uses of Hypnosis, 2nd ed. (Washington, DC: American Psychiatric Press, 2004).
Michael R. Nash and Amanda J. Barnier, eds., The Oxford Handbook of Hypnosis: Theory, Research, and Practice (Oxford: Oxford University Press, 2008).
Peter B. Shor, “Three Dimensions of Hypnotic Depth,” International Journal of Clinical and Experimental Hypnosis 16, no. 1 (1968): 23–38; Theodore X. Barber, “Hypnosis: A Scientific Approach,” in Handbook of Clinical Hypnosis, edited by John W. Rhue, Steven J. Lynn, and Irving Kirsch (Washington, DC: American Psychological Association, 1993).
Mark P. Jensen, Hypnosis for Chronic Pain Management: Therapist Guide (New York: Oxford University Press, 2011).
Steven J. Lynn, Elizabeth F. Krackow, Scott W. Loftus, Giuseppe Lilienfeld, and Elizabeth M. Lock, “Remembering and Forgetting: Applications to the Study of Hypnosis and Psychotherapy,” International Journal of Clinical and Experimental Hypnosis 56, no. 2 (2008): 97–125.
Herbert Spiegel, “An Eye-Roll Test for Hypnotizability,” American Journal of Clinical Hypnosis 15, no. 1 (1972): 25–29.
David A. Oakley and Peter W. Halligan, “Hypnotic Suggestion: Opportunities for Cognitive Neuroscience,” Nature Reviews Neuroscience 14, no. 8 (2013): 565–576; Joseph P. Green, Deirdre Barrett, and Steven J. Lynn, “Hypnotic Responsiveness: Expectancy, Attitudes, and the Role of Context,” in The Oxford Handbook of Hypnosis: Theory, Research, and Practice, edited by Michael R. Nash and Amanda J. Barnier (Oxford: Oxford University Press, 2008).
Amir Raz and Lyn M. Campbell, “Can We Use Hypnosis to Enhance Learning and Memory?,” International Journal of Clinical and Experimental Hypnosis 56, no. 2 (2008): 103–116; David Spiegel, “Neurophysiological Correlates of Hypnosis,” in Handbook of Clinical Hypnosis, edited by John W. Rhue, Steven J. Lynn, and Irving Kirsch (Washington, DC: American Psychological Association, 1993).
Theodore X. Barber, “Hypnosis, Suggestion, and Suggestibility: An Integrative Review of 40 Years of Research,” in International Handbook of Clinical Hypnosis, edited by Graham D. Burrows, Robert O. Stanley, and Peter B. Bloom (Chichester: Wiley, 2001).