Sleeps, Dreams and Disorders #5 : Dreams (Part 1)

Crick and Mitchison's Reorganisational Theory of Dreaming (1986)

Crick and Mitchison further developed Reverse Learning Theory by incorporating it into the Reorganisational Theory of Dreaming (1986). The theory proposed that while dreams clear cognitive debris they also gave the individual a chance to recuperate from events throughout the day and to prepare them - mentally - for the following day. The theory takes a neurobiological approach suggesting that information is distributed over many synapses and that one synapse may be involved in many items of information - a bit like a spider's web. When an individual dreams the random neural activity that is generated debugs the network. This removes any unwanted connections (as with reverse learning) and consolidates the remaining memories. The theory proposes that by de-cluttering our neural memory networks we reduce the chances of system overload and overlapping memory associations. Issues which could occur without reorganisation include: Fantasies - the activation of far-fetched associations Obsession - a limited number of states arising irrelevant of input Hallucination - network activation to inappropriate signals Concepts which share a single feature can become associated (shared synapse) and begin to overload the neural network, debugging weakens this association. This should result in increased brain functioning and would lead to the prediction that failure to debug would reduce learning ability. This prediction has been supported in studies of humans and animals which have been deprived of REM sleep. Rideout (1979) tested the maze-learning ability of sleep deprived rats. The results showed that rats which had been deprived of REM sleep showed poorer learning ability than rats deprived of nREM sleep and the control group. It is difficult to know whether the results of this study are due to the effects of a lack of REM sleep rather than the failure to debug the cognitive system by dreaming during the REM stage of sleep. Smith (1995, 1996) found that when rats were conditioned to respond to a light and avoid an electric shock they spent an increased amount of time in REM sleep. If they were deprived of sleep for 4 hours after the learning episode they only remembered the learned response half as well compared to those who slept normally. If the rats where deprived of sleep 20 hours after the learning episode they showed no reduction in their learning. The assumption being that consolidation had already taken place. In Smith's (1995, 1996) study of human participants it was found that students' requirements for REM sleep increases in the week following revision for an exam. When participants were REM sleep deprived their memory for cognitive-procedural tasks (logical puzzles) was impaired while the ability to memorise word -pairs was not. Evaluation Research suggests that cognitive functioning is impaired when people are deprived of REM sleep. The theory can explain the role of dreams - neurons are fired, cognitive debris is dealt with and retained information is consolidated. However Craik and Mitchison's theory does not explain why dreams can be such an intense subjective experience or why they hold so much personal meaning to individuals. Also the theory cannot account for the differences between REM and nREM dreams.

List

- A Cognitive Theory of Dreaming (Hall, 1953) - Problem Solving Theory (Webb & Cartwright, 1987)

Symbol examples

- Powerful figures (e.g. kings, queens, prime ministers, doctors etc.) represent the mother and father. - Vermin (e.g. rats, cockroaches etc.) represent the brothers and sisters. - Water (either climbing into or out of) represents birth. - Phallic symbols are anything vaguely penis shaped e.g. baguettes, trains, cruise missiles etc. - Vaginal symbols are anything you can put something else in e.g. ovens, bowls, wardrobes etc. The hidden or latent content of the dream manifests itself into a socially acceptable story-line. At face value the story line may mean little, but a knowledgeable psychoanalyst should be able to recognise symbols disguised within the dream.

List

- Reverse Learning Theory (Crick & Mitchison, 1983) Reorganisational theory of dreaming (Crick & Mitchison, 1986) The activation-synthesis theory (Hobson & McCarley, 1977). This theory suggests that dreams are what happens when we try to make sense of brain activity during REM

We need to sleep according to Freud because...

- We need to sleep in order to rest and restore our bodies. - When we sleep, the ego (the conscious part of personality which deals with reality) lets down its guard, and the unconscious mind starts to impinge upon consciousness. - If this happened, we would wake up and hence never be able to rest. - To prevent us from being woken up, the ego does dream work. - In dream work, the ego disguises the thoughts from the unconscious using symbols. - The symbols do not disturb us, so we are able to continue sleeping.

According to Freud there are two functions of dreams:

1. To allow the expression of primitive urges e.g. sex and aggression 2. To use disguised images (symbols) to protect the sleeper from becoming aware of their latent thoughts.

Symbolism in dreams

According to Freud, an object or activity becomes a stand-in for another object or activity due to laws of association, particularly the law of resemblance. Freud suggested that the symbolism in a dream is of two types. Personal symbolism can only be understood by knowing something about the experiences and personality of the dreamer. On the other hand, universal symbols can be understood by anyone.

Crick and Mitchison's (1983) Reverse learning Theory

Dreams allow useless, unwanted or irrelevant information to be removed. During waking, brain takes in lots of info, not all of which is important During dreaming, such 'parasitic' info is cleared out, allowing more efficient access to important information 'Storage space' is freed up, like defragging a hard-drive Dreaming is a meaningless by-product of this process You will have noticed the cognitive element (information-processing) of this theory even though it is in the biological section. This theory focuses on the biological processes which underlie cognition. The brain's neural memory systems can easily become overloaded, the dreams we have in REM sleep help to eliminate any cognitive debris. Evaluation Dolphins and spiny anteaters have a particularly large brain cortex for their size. It is suggested that the size could be due to the need to store useless memories due to the lack of dream activity, and therefore lack of 'clearing up'. However, contrary to the theory dreams very often have meaningful content and don't always contain information which is unwanted or irrelevant. The Crick & Mitchison (1983) article The Function of Dream Sleep Article is available in the Additional Resources: Dreams section

Freud's Ego Defence Theory

Dreams have been considered important since ancient times. Dreams were thought to prophesise the future and contain important hidden meanings. Image: Sigmund Freud developed a particularly influential and controversial theory of dreams, which proposed that dreams are a result of our inner conflicts. Freud (1900) believed that our conscious experience was just a small part of what actually takes place in our minds. Much of what goes on is hidden 'below the surface' in the unconscious. The unconscious mind includes all of the unacceptable thoughts and impulses that our conscious mind cannot deal with. The contents of the unconscious are always trying to 'break through' into the conscious mind. However, this cannot be allowed to happen, as if it did, we would become very disturbed.

Freud's study

Freud (1900) Aim: to understand the content of a patient's dream. Sample: one young man. Method: A case study using psychoanalysis, the man kept a record of his dreams. These were reported to Freud, who interpreted them. Result: the man had a dream in which he had a secret affair with a woman who was engaged to someone else. He was worried about the other man finding out and therefore behaved in a very affectionate way towards him. Conclusion: this dream relates to the man's Oedipus complex. The woman symbolises his mother, whom he desires and the 'other man' his father. In order to prevent his father from discovering his desire for his mother, he pretends to love him. Although Freud provided plenty of this sort of evidence, there are a number of problems with it. These include: - His sample was small and consisted mainly of middle class women with psychological problems. It is not wise to generalise from this kind of sample. - The dreams were recorded or recalled by the patients, making them retrospective data, which is often unreliable. - The method of interpretation is very subjective (i.e. it relied on Freud's own personal opinions). This does not mean that Freud was wrong, but it makes it impossible to check his conclusions. - The theory as a whole is difficult to test, because it relies on ideas (such as the unconscious mind) whose existence is difficult to prove.

Two types of Dream Content

Freud believed that the content of dreams is related to wish fulfilment and suggested that dreams have two types of content: manifest content and latent content. The manifest content is the actual literal subject matter of the dream, while the latent content is the underlying meaning of these symbols. The latent content of a dream is the hidden psychological meaning of the dream.

Hall (1953) A cognitive theory of dreams

Hall was an American psychologist who used the technique of content analysis to study dream images. He believed that dreams were an extension of thought processes and therefore part of our cognitive processes. In his The Meaning of Dreams (1966), Hall even writes, "The images of a dream are the concrete embodiments of the dreamer's thoughts; these images give visual expression to that which is invisible, namely, conceptions." (p. 95). Hall proposes that the images in our dreams can be separated into 5 categories which each relate to a part of our lives: Conceptions of self: our self-concept, how we see ourselves and the roles we play in our life Conceptions of others: the people in our lives, how we respond to them and their desires Conceptions of the world: Our environment and how it relates to our personality development and emotional connections Conception of penalties: how do we behave in our dreams when something is allowed or forbidden? How do the penalties within the dream influence our behaviour? Conceptions of conflict: Our problems and inner conflicts and how we should act to resolve these. Hall (1996) proposes that while symbols can be found in dreams, they are not usually hidden. Each individual uses symbols which are relevant to them; they represent what the individual thinks and are therefore not hidden from the dreamer. For example a person may have a dream where they engage in sexual intercourse, a subsequent dream may involve firing a gun. It is unlikely that a clearly undisguised dream of sexual intercourse would be followed by a dream where sexual desires are 'hidden' in the symbolism of a gun. Think about how society has changed since Freud's time. Are people likely to have to repress their sexual desires in a society which celebrates and in many ways promotes sexuality? Hall maintains that dream actions are a direct projection of how an individual would act in the real world and are a way of mapping out any future actions. He concludes that "with these maps we are able to follow the course of man's behaviour, to understand why he selects one road rather than another, to anticipate the difficulties and obstacles he will encounter, and to predict his destinations." In the 1960's Hall worked in partnership with Van de Castle to develop the Hall-Van de Castle scale. This is an empirical dream content analysis tool which classifies a dream report based on a collection of 16 quantitative scales. Some of the scales consist of physical conceptions such as people and objects while others include subjective conceptions such as emotions. Hall's work has been particularly influential as it has allowed dreams to be studied quantitatively - whereby data can be measured and re-tested. From an applied standpoint the Hall-Van de Castle scale allows therapists to compare the dream reports of specific patients - such as children suffering from neglect or abuse - with those reported by 'average' children.

Hobson & McCarley's Activation-Synthesis Theory

Hobson & McCarley (1977) take the view that dreams are what happen when the mind tries to make sense of the brain activity that occurs during sleep. They believe this brain activity (especially during REM) has some other purpose, probably to do with brain restoration and protein synthesis. Their theory suggests that during sleep, the brain tries to make sense of random neural activity, and this synthesis is expressed as a dream. - During sleep, the information from the senses does not reach the brain areas that usually interpret it (input attenuation). Additionally, during REM, the skeletal muscles are paralysed (output inhibition). - The pons starts generating ponto-geniculo-occipital (PGO) waves. - The PGO waves travel up through the brain and reach the brain areas that would normally interpret sensory information. - These areas in the cerebral cortex treat the incoming activity as if it was real sensory information. - In interpreting the stimulation, the mind tries to form it together into a coherent whole (a process called synthesis). In order to produce synthesis, the brain draws upon its own stored memories. - However, because the PGO waves activate many different brain areas simultaneously, the result is highly changeable and often rather strange. Evaluation The main strength of the activation synthesis theory is that it is consistent with what we know about brain activity during REM sleep, and what we know about how the mind works. In general, the mind always tries to make the most amount of sense out of whatever it is presented with. For example, in Bartlett's work on schema driven processing he showed that people would distort information until it fitted with their schemas. Activation synthesis is also consistent with what is happening in the brain during REM sleep. For example: The higher level of brain activity during REM explains why we are more likely to remember dreams that occur then. The fact that visual, auditory and motor areas are activated during REM explains why dreams usually involve seeing, hearing and moving. However, the fact that brain areas to do with smell and taste are not activated explains why dreams rarely involve these senses. It can explain why we have dreams about recent events (recent neural activity) It has been found that when individuals are injected with acetylcholine (a neurotransmitter which initiates REM sleep) it increased REM sleep and dream activity. Main predictions of neurobiological theories Dreams will be meaningless & bizarre Dreams will be quickly forgotten Mammals that do not have REM sleep will have large brains (or large cortexes) A study by Dement (1974) found that the eye movements made during REM sleep corresponded reasonably well with the content of the dream. Cortical activation is likely to trigger images from recent episodes in the person's life or things they have been thinking about recently. It is likely that these memories are triggered more easily as they have been recently active. Hobson suggests that this imagery is likely to be fragmentary with our brain creating a narrative to make sense of the images. It is worth remembering that the activation synthesis theory is not incompatible with other theories. Dreaming may have all sorts of functions besides being a by-product of biological processes. Besides Freud's ideas, for example, it has been suggested that dreams are there to help us sort out the events of the day (Ornstein, 1986) or, alternately, that dream are there to help us get rid of unwanted memories (Crick and Watson, 1983). As Gross (1994) concludes: '[activation-synthesis] may account for where dreams come from, but not what dreams are for.'

Problems with Freud's dream theory

Much of the evidence for Freud's theory comes from his own cases studies. Hall notes several problems with Freud's dream theory: 1. Freud's theory of symbols-as-disguises is difficult to prove when one night a person has a symbolic dream and the next night they may have an explicit sexual dream. Why would wishes be concealed at some times and not at others? 2. Many people have a real talent for dream interpretation although they may have little or no information about Freudian symbolism. Why would a person bother to deceive them self by dreaming in symbols when dreams can be translated so readily by the dreamer them self? 3. People have been using symbolism in their speech for centuries in the use of slang, many of which are sexual in character. How can these symbols be effective as disguises in dreams when they are used in waking life? 4. The theory does not deal adequately with the question of why there should be multiple symbols for the same object 5. It assumes that the mind during sleep is capable of performing exceptionally complex operations.

Theories

Psychodynamic The ego-defence theory (Freud, 1900 Psychodynamic Approach). This theory suggests that dreams are related to the unconscious mind. Cognitive A Cognitive Theory of Dreaming (Hall, 1953) Problem Solving Theory (Webb & Cartwright, 1987) Neurobiological Reverse Learning Theory (Crick & Mitchison, 1983) Reorganisational theory of dreaming (Crick & Mitchison, 1986) The activation-synthesis theory (Hobson & McCarley, 1977). This theory suggests that dreams are what happens when we try to make sense of brain activity during REM

Webb & Cartwright's (1987) Problem solving Theory

The theory proposes that if we sleep on a problem it will help us to come up with a solution. The theory: Agrees with idea that subjective dream content is significant Disagrees with idea that meaning is hidden behind symbolism Suggests a direct relationship between dream content & problems in waking life Suggests dreaming allows the mind to form new associations to help solve problems Evaluation Research suggests that more realistic solutions to problems occur after REM sleep. Individuals with relationship or work problems have been found to have longer periods of REM sleep. However, sleeping on a problem is time-consuming - problems can be solved more quickly whilst awake. Main predictions of the psychological theories Brain systems involved with emotion will be active; those involved with rationality will not Dreams will reflect current problems Dreams will provide solutions Dreams will be remembered