Dreams Nature of Dreams Functions of Dreams Nature

Dreams Nature of Dreams Functions of Dreams

Nature of Dreams • Most dreams occur during REM sleep but not all! Exam hint: do not discuss REM sleep when asked about dreams!! • Dream content has a deep psychological core. Cartwright 1984 dreams of divorcing couples • Dreams have a noticeable emotional content. Hobson 2000 PET scans show ‘emotional’ sections of brain activated • REM dreams vivid relatively long run through ‘real time’ • NREM mundane short less intense • Dreams full of often bizarre images.

Function of Dreams • Psychological theories assume the meaning of the dream is the function of the dream—Dreams provide a psychological service • Neurobiological theories include Activation-Synthesis Theory and Reverse Learning Theory • Former suggest random electrical activity during REM sleep experienced as a dream • Latter claims brain requires memory consolidation to function effectively and during this process the associated electrical activity produces dreams.

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. • 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

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 are the content of dreams and they are discarded during this process. • Other unwanted memories are also expelled including those that might by pathological—that is obsessional. • Neural networks are kept compact and efficient

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 sized 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.