Karteikarten
Sleep
Karten in diesem Stapel (25)
- 1EEGCells in brain fire in mass that discharges little charges that we can detect in scalp; neurons in grey matter are vertical and discharge a positive and negative charge
- 2beta wavesday to day wakefulness; high frequency, low amp
- 3alpha wavesrelaxation state; slower, increase in amp
- 4stage 1hard to differentiate between this and relaxation but theta waves are present; somewhat conscious; hypnotism, lucid dreams
- 5stage 2theta waves still there but also sleep spindles (burst of oscillatory activity; inc in wave freq) and k complex (inc in wave amp; works to suppress cortical arousal and stimulates memory consolidation)
- 6stage 3/4delta waves (slowest and highest amp); very hard to arouse, groggy-headed when wake up in this stage
- 7REM sleepsawtooth waves, similar to beta waves; paradoxical sleep because brain seems to be functioning as if it is awake
- 8who sleeps?Almost all mammals show REM sleep and similar brain activity patterns
Birds also show REM sleep, little more than few minutes each night
Reptiles and amphibians don’t show REM sleep but do show some of the other stages
Insects and fish show behavioral sleep (reduced motor activity, increased input of sensory info to respond, need to rest)
Plants also show some sort of circadian cycles.
Predators tend to sleep more; prey do not. - 9circadian rhythmnaturally occurring 24 hr cycle
- 10thalamus activity during sleepThalamus is relay station and during phase, thalamus is very busy communicating with cortex; as we sleep, thalamus ramps down relay station, activity wanes; as sink deeper and deeper, thalamus shuts out some incoming information
- 11pons activity during REMDuring REM, pons keeps regular timing, Every 90 mins, pons sends signal to thalamus to change its activity and send different info to cortex
- Changes activity in visual, motor, emotion/social areas
- Thalamus gates down activity in prefrontal cortex
- Pons prevents brain from sending motor signals down spinal chord - 12loss of REM-related atoniaresearchers prevented pons from shutting off motor activity, cats do not experience REM-related atonia, cats begin to act out their dreams; rare cases in humans can happen in old men
- 13narcolepsydisorder in which sudden sleep attacks occur in middle of waking activities; really strong emotional reaction triggers sleep
- 14myotonia congenita (fainting goat syndrome)sudden onset of muscle rigidity/ paralysis after strong environmental stimulus
- 15YH CaseShrapnel injury to pons
Reported never dreaming
Never entered REM sleep
No real cognitive consequences without REM sleep - 16Why sleep?preservation and protection theory
restoration theory
memory consolidation and insight - 17preservation and protection theorysleep emerged in evolution to preserve energy and protect during day when there is little value and considerable danger
- 18restoration theorybody wears out during day, need time to repair (growth-producing hormone only emitted during sleep, restoration of brain and other organs, immune system doesn’t function as well without sleep)
- 19memory consolidation and insightsleep enhances procedural memory
hippocampus is convergence zone - 20sleep deprivation experiments-EEG systems connected to rat, rats sleep deprived
Sleep-deprived rates didn’t fare too well: disheveled, clumped, yellowing fur despite continued grooming; rapid decrease of weight, despite increased consumption of food, hypothermia, lesions on feet and tail, no rat survived more than 3 weeks of total sleep deprivation - 21why dream?two theories:
Freud: dreams are guardians of sleep
Hobson: activation-synthesis model - 22latent thoughtwhat the unconscious is trying to convey
- 23manifest contentwhat we are actually dreaming about; psychoanalysis used to uncover latent content
- 24activation-synthesis modeldreams are produced when the mind attempts to make sense out of the random neuronal activity that occurs in brain during sleep
- 25cardinal cognitive features of dreamssensation
highly intense emotional content (ventromedial PFC)
loss of directed thought/self-reflection (deactivation of dlPFC)
reduction in logical reasoning
poor memory