Dreams Nature of Dreams Functions of Dreams Objectives
Dreams Nature of Dreams Functions of Dreams
Objectives Lesson 1 • To consider key questions in relation to dreaming. • To be able to describe common features of the content and duration of dreams • To begin to consider the purpose of dreaming and what different explanations their might be.
Content of Dreams • Dreams frequently involve other people & the dreamer is nearly always personally involved. • Kahn et al (2000) found that half the characters in dreams were known to the dreamer, about a third were more generic characters. Fewer than one in six were completely unknown or novel. • Dreams have an emotional content. PET scans taken during REM sleep show that the brain regions most associated with emotions are very active.
Content of Dreams • Evidence for gender differences show that males dream about other males more than females dream of males (Martin, 2002). This appears to hold across all different cultures & is present in children & adults (Hall, 1984) • Cartwright et al (1984) studied 90 people who were undergoing marital separation & divorce. Their dream content gave evidence of a strong correlation.
Different kinds of dream REM dreams • Dement & Kleitman (1957) showed that sleepers who were awoken during REM sleep reported dreaming 80% of the time. NREM dreams • People reported dreams during NREM sleep but far less (7%). They tend to be shorter, more mundane and more like fragments of ideas similar to waking thoughts.
Hypnagogic & Hypnopompic states • Dream like experiences that occur in the transitional state between wakefulness and sleep. • People who play a lot of computer games experience ‘screen dreams’ as they fall asleep. • Pps played tetris for several hours. Many players later reported vivid dreams about it as they fell asleep.
Lucid Dreams Dreamers have self-awareness. Fully aware of being in a dream and can control the events taking place. Dreams are pleasant and straightforward. Sex is a common theme.
Duration of Dreams • Every 90 minutes = REM sleep • Dreams run in ‘real time’, some lasting for half an hour (Horne, 1999) • Dreams fade rapidly unless awoken suddenly • REM dreams vivid relatively long run through ‘real time’ • NREM mundane short, less intense
Test Yourself • What do PET scans show about the content of dreams? • What did Cartwright’s evidence suggest about the content of dreams? • Is it true that time runs slower in dreams? • What kind of biological rhythm could we call dream cycles? How long between each cycle?
Objectives Lesson 2 • To be able to describe Psychological theories of the function of dreams (Freud and Cartwright) • To evaluate these theories • To be able to use supporting/opposing evidence to evaluate theories
Explanations of dreaming • Psychological theories (Dreams have meaning) • Physiological/Neurobiological theories (Dreams have no meaning) – Reverse learning (Crick & Mitchison) – Activation synthesis (Hobson & Mc. Carley) psychlotron. org. uk – Ego defence (Freud) – Problem solving (Cartwright)
Freud and Dreams • Dreams protect sleeper from irrational urges coming from id. They allow the release of potentially dangerous energy which would otherwise lead to insanity. • Dreams therefore mainly ‘wish fulfullment’ • Dreams nature made up of manifest and latent content. • Dreams ‘royal road’ into the unconscious mind
Cartwright and Problem Solving • Cartwright dreams directly reflect our major emotional concerns • Problem solving takes place during dreaming—deal with preoccupations of waking life. • Dreams provide solutions for work-Kekule and structure of benzene • Dreams provide coping strategies for emotional problems. Mind finds symbols that fit the pressures of the moment.
Commentary Freud • Theory difficult to falsify • Theory based on culturally and historically biased sample of neurotics Viennese woman. • However, PET scans show rational brain switched off during dreaming while forebrain—centre of motivation memory is fully activated—so no ego but id active. • Solms shows dreams activated by forebrain not brain stem. • Dreamwork - Condensation supported by computer simulation research. • Are all dreams wish fulfillments—i. e nightmares?
Commentary on Cartwright • Barrett 1993 studied students who were instructed to solve a problem. Over a week a panel of independent judges found 50% dreamt a solution. • Stickgold 2000 found Tetris players dreamt solutions to problems connected to the game. • Cartwright 1984 found couples separating had dreams relating to their waking coping strategies
Objectives Lesson 3 • To be able to describe Neurobiological theories of the function of dreams • To evaluate these theories • To be able to use supporting/opposing evidence to evaluate theories
Hobson and Mc. Carley • Activation-Synthesis. Random internally generated signals from brainstem are ‘synthesized’ by frontal cortex. • Bizarre nature of dreams is the lack of information that brain does its best to interpret and give meaning. • Conclusion personal but meaningless.
Crick and Mitchison • Reverse Learning—we dream to forget. • Parasitic associations clog up our processing mechanisms making us function inefficiently • Dreaming clears out these unwanted memories • Other unwanted memories are also expelled including those that might be pathological—that is obsessional. • Neural networks are kept compact and efficient
Crick and Mitchison • Reverse Learning—What happens? • The BRAINSTEM bombards the FOREBRAIN • This excites the neurons in the FOREBRAIN and loosens the conections responsible for unnecessary “parasitic” memories • Dreams are the “By-product” of this process
Commentary on Neurobiological Theories • Goertzel 1997 estimates 100 billion bits of information taken in by brain during a lifetime but brain has only space for 100 billion bits • Negative correlations between brain size and REM sleep predicted by theory and found. • Mammals without REM sleep have larger brains. • However, Reverse learning can not explain why dreams are meaningful • Christos 1996 has shown that computer simulations give little support for theory • Capacity of storage for human brain may be underestimated.
• Pet scans give support to Activation-Synthesis—ie. Brain stem active prefrontal cortex not active—frontal lobe active • Explains why dreams are without ‘smell’ as that part of brain inactive. • Animal studies show acetylcholine is the ‘firing’ agent in the brain stem. No acetylcholine no dreams. • However, Solms 2000 found injuries to brain stem REM stopped but dreaming did not.
Essay Plan – Discuss the nature of dreams (25) • • • Intro – Briefly discuss the nature and content of dreams. Distinguish between REM and NREM dreams. Controversial question is whether dreams have significant meaning or not – explain there are two theories to support both sides of this argument Psychological (Meaning) and Neurobiological (No meaning). AO 1 Describe Freudian theory AO 2 Evaluate Freudian theory with supporting and opposing evidence AO 1 Describe Cartwright’s theory AO 2 Evaluate Cartwright’s theory with supporting and opposing evidence AO 1 Describe Activation-Synthesis AO 2 Evaluate Activation synthesis with supporting and opposing evidence AO 1 Describe Reverse Learning Theory AO 2 Evaluate Reverse Learning Theory with supporting and opposing evidence Summarise points and make point about problem with both theories.
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