sleep and dreaming

• stages 1-4 of the sleep cycle are called NREM sleep
• stage 1 is light sleep where you go through alpha and theta brainwaves
• in stage 1 muscles are less active eye movements slow and you can suddenly twitch
• in stage 2 called the late night stage you move into sleep and your brainwaves are mainly theta waves
• in stage 2 brainwaves are slower, eye movements stop, there are bursts of brain activity, body temperature drops and heart rate slows
• stages 3 and 4 are often merged
• stage 3 is deep sleep where there are slow delta waves but also some faster waves
• stage 4 is where almost all waves are slow delta waves as it is very deep sleep
• in stage 4 there are no eye movements, very hard to wake and you can feel disorientated when woken
• REM sleep = rapid eye movement
• sensory blockade is when incoming information from the senses is blocked during REM sleep
• movement inhibition is when signals in the pons shut off neurons in the spinal cord preventing movement
• during REM sleep there is rapid shallow breathing, eyes jerking and paralysis
• a cycle of sleep lasts about 90 minutes
• circadian rhythms are daily rhythms
• ultradian rhythms are lashing less than 24 hours such as the sleep cycle
• melatonin is a hormone that signals the need for sleep and is produced in the pineal gland
• melatonin is triggered by darkness
• exogenous are external cues in the environment that affect our biological clock
• zeitgebers are external cues that synchronise our biological rhythms
• pons is the part of the brain that shuts off neurons and causes paralysis
• suprachiasmic nuclei controls the circadian rhythm and is found in the centre of the brain
• narcolepsy is the inability to control sleeping leading to sleep attacks
• cataplexy is the loss of muscle triggered by the onset of strong emotion
• hypocretin or orexin is a chemical in the brain that keeps us awake and regulates the sleep-wake cycle
• around 70% of people with narcolepsy also experience cataplexy
• according to freud the unconscious mind accounts for about 90% of our thinking
• Id is the part of freuds personality theory that is demanding “I want”
• superego is the part of freuds personality theory that is the conscience thought “you cant have”
• ego is the part of freuds personality theory that is reasoning, to balance the Id and superego
• one way balance is achieved is when the ego uses defence mechanisms such as repression
• manifest content is the story of the dream that the dreamer tells
• latent content is the hidden meaning of the dream
• dreamwork consists of condensation, displacement and secondary elaboration
• condensation is that many ideas appear as one idea in a dream
• displacement is where something unimportant seems to be important shifting attention away from the important thing
• secondary elaboration is using muddled ideas from dream work to build a whole storuy
• freuds 1909 little hans study