Dream

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For other uses, see Dream (disambiguation) and Dreams (disambiguation).

A dream is the experience of envisioned images, sounds, or other sensations during sleep. It occurs in humans, most mammals, and some birds. [1] The events of dreams are often impossible or unlikely to occur in physical reality, and are usually outside the control of the dreamer. The exception is lucid dreaming, in which dreamers realize that they are dreaming, and are sometimes capable of changing their oneiric reality and controlling various aspects of the dream, in which the suspension of disbelief is often broken.[2] Dreamers may experience strong emotions while dreaming. Frightening or upsetting dreams are referred to as nightmares. The discipline of dream research is oneirology.

Contents

[edit] Neurology of dreams

There is no universally agreed-upon biological definition of dreaming. General observation shows that dreams are associated with REM sleep. REM sleep is the state of sleep in which brain activity is most like wakefulness, which is why many researchers believe this is when dreams are strongest, although it could also mean that this is a state from which dreams are most easily remembered.[citation needed] During a typical lifespan, a human spends a total of about six years dreaming.[3] (which is about 2 hours each night[4]) It is unknown where in the brain dreams originate — if there is such a single location — or why dreams occur at all.

[edit] Discovery of REM

In 1953 Eugene Aserinsky discovered REM sleep while working in the lab of his Ph.D advisor Nathaniel Kleitman. While observing sleepers for Kleitman's sleep lab Aserinsky noticed the eyes beneath the subjects eyelids seemed to be fluttering. He proposed studying these eye movements to Kleitman, who agreed, suggesting that Aserinsky use a polygraph machine to record changes in the brain. During these sessions observing sleepers Aserinsky began to notice patterns in the brain waves of the volunteers. During one session he awakened a subject who was crying out in his sleep during REM and confirmed an earlier hunch that dreaming was occurring.[5] In 1953 Kleitman and Aserinsky published the ground breaking study in Science.[6]

[edit] Activation synthesis theory

In 1977 J. Allan Hobson and Robert McCarley proposed a new theory that changed dream research, challenging the previously held Freudian view of dreams as subconscious wishes to be interpreted. The activation synthesis theory asserts that the sensory experiences are fabricated by the cortex as a means of interpreting chaotic signals from the pons. They propose that in REM sleep, the ascending cholinergic PGO (ponto-geniculo-occipital) waves stimulate higher midbrain and forebrain cortical structures, producing rapid eye movements. The activated forebrain then synthesizes the dream out of this internally generated information. They assume that the same structures that induce REM sleep also generate sensory information.[7] Memory, attention and the other features lacking in the dream state are taken to depend on the neurotransmitters, norepinephrine and serotonin, which are present in reduced concentrations during REM sleep. This chemical change is hypothesized to produce a psychotic state, as well as a lack of orientation.

[edit] Role of forebrain

Hobson's 1977 research suggested that the signals interpreted as dreams originated in the brain stem during REM sleep. However, research by Mark Solms suggests that dreams are generated in the forebrain, and that REM sleep and dreaming are not directly related.[8] While working in the neurosurgery department at hospitals in Johannesburg and London, Solms had access to patients with various brain injuries. He began to question patients about their dreams and confirmed that patients with damage to the parietal lobe stopped dreaming; this finding was in line with Hobson's 1977 theory. However, Solms did not encounter cases of loss of dreaming with patients having brain stem damage. This observation forced him to question Hobson's prevailing theory which marked the brain stem as the source of the signals interpreted as dreams. Solms viewed the idea of dreaming as a function of many complex brain structures as validating Freudian dream theory, an idea that drew criticism from Hobson.[9]

[edit] Continual-activation theory

Combining Hobson's activation synthesis hypothesis with Solms's findings, the continual-activation theory of dreaming presented by Jie Zhang proposes that dreaming is a result of brain activation and synthesis; at the same time, dreaming and REM sleep are controlled by different brain mechanisms. Zhang hypothesizes that the function of sleep is to process, encode and transfer the data from the temporary memory to the long-term memory, though there is not much evidence backing up this so-called "consolidation." NREM sleep processes the conscious-related memory (declarative memory), and REM sleep processes the unconscious related memory (procedural memory).

Zhang assumes that during REM sleep, the unconscious part of a brain is busy processing the procedural memory; meanwhile, the level of activation in the conscious part of the brain will descend to a very low level as the inputs from the sensory are basically disconnected. This will trigger the "continual-activation" mechanism to generate a data stream from the memory stores to flow through the conscious part of the brain. Zhang suggests that this pulse-like brain activation is the inducer of each dream. He proposes that, with the involvement of the brain associative thinking system, dreaming is, thereafter, self-maintained with the dreamer's own thinking until the next pulse of memory insertion. This explains why dreams have both characteristics of continuity (within a dream) and sudden changes (between two dreams).[10][11]

[edit] Dreams and memory

Eugen Tarnow suggests that dreams are ever-present excitations of long-term memory, even during waking life. The strangeness of dreams is due to the format of long-term memory, reminiscent of Penfield & Rasmussen’s findings that electrical excitations of the cortex give rise to experiences similar to dreams. During waking life an executive function interprets long term memory consistent with reality checking. Tarnow's theory is a reworking of Freud's theory of dreams in which Freud's unconscious is replaced with the long-term memory system and Freud's “Dream Work” describes the structure of long-term memory.[12]

[edit] Hippocampus and memory

A 2001 study showed evidence that illogical locations, characters, and dream flow may help the brain strengthen the linking and consolidation of semantic memories. These conditions may occur because during REM sleep the flow of information between the hippocampus and neocortex is reduced.[13] Increasing levels of the stress hormone Cortisol late in sleep (often during REM sleep) cause this decreased communication. One stage of memory consolidation is the linking of distant but related memories. Payne and Nadal hypothesize that these memories are then consolidated into a smooth narrative, similar to a process that happens when memories are created under stress.[14]

[edit] Cultural history

Dreams have a long history both as a subject of conjecture and as a source of inspiration. Throughout their history, people have sought meaning in dreams. They have been described physiologically as a response to neural processes during sleep, psychologically as reflections of the subconscious, and spiritually as messages from God or predictions of the future.

Oneiromancy deals with the use of dreams for divination. In ancient Judeo-Christianity: in the Tanakh, Jacob, Joseph and Daniel are given the ability to interpret dreams by Yahweh; in the New Testament, divine inspiration comes as a dream to Saint Joseph, the husband of Mary, when the Angel Gabriel spoke to him in a dream and told him that the baby Mary was carrying was the Son of God. After the visit of the Three Wise Men to them in Bethlehem, an angel appeared to him and told him to take Mary and Jesus to Egypt for their safety. The angel appeared again in a dream to tell him when it was safe to return to Israel. The story of Saint Patrick and his conversion of the people of Ireland also features dreaming. When Patrick was enslaved in Antrim he was told by God in a dream that there was a boat waiting in Wicklow to bring him back to his homeland.

Dreams were thought to be part of a spiritual world, and were seen as messages from the gods. Likewise, the Torah (known in Christianity as the first five books of the Old Testament) and the Qur'ān tell the same story of Joseph, who was given the power to interpret dreams and act accordingly. Biblical stories and actions that came from dreams (and visions) form about one-third of the entire Bible (383 References to "Dream" "Vision" and "Seer" / 74 times alone for "Dream" in the King James Bible: Gen 20:3; Gen 31:10; Gen 31:11; Gen 31:21; Gen 37:5 etc). Many cultures practiced dream incubation, with the intention of cultivating dreams that were prophetic or contained messages from the divine. In Islam, good dreams are considered to be from Allah and bad dreams from Satan [2].

The belief that dreams were part of a spiritual world continued into the Early Middle Ages. A story from Nevers, which is reproduced in the Golden Legend, states that one night the Emperor Charlemagne dreamed that he was saved from being killed by a wild boar during a hunt by the appearance of a child, who had promised to save the emperor from death if he would give him clothes to cover his nakedness. The bishop of Nevers interpreted this dream to mean that he wanted the emperor to repair the roof of the cathedral dedicated to the boy-saint Saint Cyricus.

[edit] Dream content

From the 1940s to 1985, Calvin S. Hall collected more than 50,000 dream reports at Western Reserve University. In 1966 Hall and Van De Castle published The content analysis of dreams in which they outlined a coding system to study 1,000 dream reports from college students.[15] It was found that people all over the world dream of mostly the same things. Hall's complete dream reports became publicly available in the mid-1990's by Hall's protoege William Domhoff allowing further content analysis.

[edit] Emotions

The most common emotion experienced in dreams was anxiety. Negative emotions are more common than positive feelings. Some ethnic groups like the Yir Yiront showed an abnormally high percentage of dreams of an aggressive nature. The U.S. ranks the highest amongst industrialized nations for aggression in dreams with 50 percent of U.S. males reporting aggression in dreams, compared to 32 percent for Dutch men.

[edit] Gender differences

In men's dreams 70 percent of the characters are other men, while a female's dreams contain an equal number of men and women. Men generally had more aggressive feelings in their dreams than women, and children's dreams did not have very much aggression until they reached teen age.[15] Recent research has shown that gender differences are not innate biological differences but rather reflective of each gender's role in society. For example, a woman with a more masculine personality is more likely to experience aggressive dreams.[16]

[edit] Sexual content

Sexual content is not as prevalent in dreams as one might expect. The Hall data analysis shows that sexual dreams show up no more than 10 percent of the time.[15]

[edit] Recurring dreams

While the content of most dreams is dreamt only once, most people experience recurring dreams—that is, the same dream narrative is experienced over different occasions of sleep. Up to 70% of females and 65% of males report recurrent dreams.[17] Such dream patterns are often associated with stressful events, and for some dreamers have been prodromal—that is, indicative of a health problem.

[edit] Common themes

Through content-analysis studies scientists have identified recurring themes in dreams. Common reported themes have been shown to be: themes relating to school, being chased, sexual experiences, falling, arriving too late, a person now alive being dead, flying, and failing an examination.[18]

[edit] Understanding dreams

[edit] Psychodynamic interpretation of dreams

Main article: Dream interpretation

Both Sigmund Freud and Carl Jung identify dreams as an interaction between the unconscious and the conscious. They also assert together that the unconscious is the dominant force of the dream, and in dreams it conveys its own mental activity to the perceptive faculty. While Freud felt that there was an active censorship against the unconscious even during sleep, Jung argued that the dream's bizarre quality is an efficient language, comparable to poetry and uniquely capable of revealing the underlying meaning. Fritz Perls presented his theory of dreams following the holistic nature of gestalt therapy. Dreams are seen as being projections of parts of oneself. Often these are parts that have been ignored, rejected or even suppressed. One aim of gestalt dream analysis is to accept and reintegrate these. According to Perls, the dream needs to be accepted in its own right - not broken down and analysed out of existence.

[edit] Other associated phenomena

[edit] Lucid dreaming

Main article: Lucid dreaming

Lucid dreaming is the conscious perception of one's state while dreaming.[19]The occurrence of lucid dreaming has been scientifically verified.[20]

[edit] Dreams of absent-minded transgression

Dreams of absent-minded transgression (DAMT) are dreams wherein the dreamer absentmindedly performs an action that he or she has been trying to stop (one classic example is of a quitting smoker having dreams of lighting a cigarette). Subjects who have had DAMT have reported awaking with intense feelings of guilt. Some studies have shown that DAMT are positively related with successfully stopping the behaviour, when compared to control subjects who did not experience these dreams.[21]

[edit] Dreaming as a skeptical argument

Main article: dream argument

While one dreams a non-lucid dream, one will not realize one is dreaming. This has led philosophers to the idea that one could be dreaming right now (or at least one cannot be certain that they are not dreaming). First formally introduced by Hindu beliefs,[citation needed] the dream argument has become one of the most popular skeptical hypotheses.

[edit] Recalling dreams

According to Craig Hamilton-Parker, [3] author of Fantasy Dreaming, many humans find certain dreams extremely difficult to recall. According to David Koulack in "To Catch A Dream," researchers refer to these types of dreams as "no content dream reports." It is thought that such dreams are characterized by relatively little affect. According to Koulack, factors such as salience, arousal and interference play a role in dream recall and dream recall failure. According to Henry Reed, author of Dream Medicine, a useful technique to improve dream recall is to keep a dream journal. Stephen LaBerge, author of Exploring the World of Lucid Dreaming, also suggests that one must lie perfectly still upon awaking from a dream, not letting concerns of the day occupy the mind. It is quite common to not remember much of what has just been dreamed, but LaBerge maintains that with sufficient concentration, the entire dream may be recalled.

[edit] Déjà vu

Main article: Déjà vu

The theory of déjà vu dealing with dreams indicates that the feeling of having previously seen or experienced something could be attributed to having dreamed about a similar situation or place, and forgetting about it until one seems to be mysteriously reminded of the situation or place while awake.

[edit] Dream incorporation

In one use of the term, "dream incorporation" is a phenomenon whereby an external stimulus, usually an auditory one, becomes a part of a dream, eventually then awakening the dreamer. There is a famous painting by Salvador Dalí that depicts this concept, entitled "Dream Caused by the Flight of a Bee around a Pomegranate a Second Before Awakening" (1944).

The term "dream incorporation" is also used in research examining the degree to which preceding daytime events become elements of dreams. Recent studies suggest that events in the day immediately preceding, and those about a week before, have the most influence [4].

[edit] See also

[edit] References

[edit] Cited

  1. ^ Animals have complex dreams, MIT researcher proves
  2. ^ What are lucid dreams? Explanation for lucid dreaming
  3. ^ (2006) How Dream Works. Retrieved on 2006-05-04. 
  4. ^ (2006) Brain Basics: Understanding Sleep. Retrieved on 2006-05-04. 
  5. ^ Dement, William (1996). The Sleepwatchers. Springer-Verlag. ISBN 0964933802. 
  6. ^ Aserinsky and Kleitman (September 1953). "[1]". Science 4: 273-274. DOI:10.1126/science.118.3062.273. 
  7. ^ Hobson, J.A.; McCarley, R. (1977). "The brain as a dream state generator: An activation-synthesis hypothesis of the dream process". American Journal of Psychiatry 134: 1335-1348. 
  8. ^ Solms, M. (2000). Dreaming and REM sleep are controlled by different brain mechanisms, 23(6), Behavioral and Brain Sciences, 793-1121. 
  9. ^ Rock, Andrea (2004). "3", The Mind at Night: The New Science of How and Why we Dream. Basic Books. ISBN 0465070698. 
  10. ^ Zhang, Jie (2004). Memory process and the function of sleep, 6-6, Journal of Theoretics. Retrieved on 2006-03-13. 
  11. ^ Zhang, Jie (2005). Continual-activation theory of dreaming, Dynamical Psychology. Retrieved on 2006-03-13. 
  12. ^ Tarnow, Eugen (2003). How Dreams And Memory May Be Related, 5(2), NEURO-PSYCHOANALYSIS. 
  13. ^ R. Stickgold, J. A. Hobson, R. Fosse, M. Fosse1 (November 2001). "Sleep, Learning, and Dreams: Off-line Memory Reprocessing". Science 294 (5544): 1052 - 1057. DOI:10.1126. 
  14. ^ Jessica D. Payne and Lynn Nadel1 (2004). "Sleep, dreams, and memory consolidation: The role of the stress hormone cortisol". LEARNING & MEMORY: 671-678. ISSN 1072-0502. 
  15. ^ a b c Hall, C., & Van de Castle, R. (1966). The Content Analysis of Dreams. New York: Appleton-Century-Crofts.
  16. ^ Bursik, Krisanne (Feb 1, 1998). "Moving beyond gender differences: gender role comparisons of manifest dream content.". Sex Roles: A Journal of Research 38: 203. 
  17. ^ Van de Castle, p. 340.
  18. ^ Michael Schredl, Petra Ciric, Simon Götz, Lutz Wittmann (November, 2004). "Typical Dreams: Stability and Gender Differences". The Journal of Psychology 138 (6): 485. 
  19. ^ Lucid dreaming FAQ by The Lucidity Institute at Psych Web.
  20. ^ Watanabe, Tsuneo (Mar 2003). "Lucid Dreaming: Its Experimental Proof and Psychological Conditions.". Journal-of-International-Society-of-Life-Information-Science 21(1): 159-162. 
  21. ^ Hajek P, Belcher M. (1991). Dream of absent-minded transgression: an empirical study of a cognitive withdrawal symptom. Journal of Abnormal Psychology. Retrieved on 25 Feb 2006.

[edit] General

  • Crick, F. & Mitchinson, G. (1983) "The function of dream sleep." Nature 304, pp. 111-114.
  • Tarnow, E. (2003) "How Dreams And Memory May Be Related." Neuro-Psychoanalysis 5(2), pp. 177-182.
  • Van de Castle, Robert L. (1994). Our Dreaming Mind. New York: Ballantine Books. ISBN 0345396669. 

[edit] Literature

[edit] Classical texts

[edit] Cultural and literary history of the dream

  • Bernard Dieterle, Manfred Engel (ed.): The Dream and the Enlightenment / Le Rêve et les Lumières. Paris: Honoré Champion 2003; ISBN 2-7453-0672-3.

[edit] Pyschology and psychotherapy

  • Clara E. Hill, Working with Dreams in Psychotherapy (1996) ISBN 1-57230-092-2
  • Koulack, David "To Catch A Dream: Explorations of Dreaming," SUNY Press, New York (1991).

[edit] Lucid dreaming

[edit] Dream and esoterics

[edit] External links

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