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Published byAlexandra Reed Modified over 9 years ago
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Variations in Consciousness
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Levels of Awareness Controlled Automatic Daydreaming Altered states (meditation, hypnosis, drug use) Sleep Freud’s Unconscious Unconscious
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Biological Clocks Circadian Rhythm- biological clock that is programmed for 24-25 hours (1 Day) Light- Receptors in retina- Hypothalamus (suprachiasmatic nucleus SCN)- Pineal Gland- secretion of melatonin High levels of melatonin = drowsiness Body temperature also plays a role
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Morning or Night Person? Depends on body temperature Morning person- temp. rises more quickly and peaks earlier in the evening
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Ignoring Circadian Rhythms Jet Lag, working the Grave Yard shift, sleep deprivation Decreased productivity Accident- prone Quality of social relationships suffer Decrease immune system functioning- lower T-cell count
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Measuring the Stages of Sleep Sleep Labs EEG (brain waves) EMG (muscle tension) EOG (eye movement)
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EEG patterns in sleep
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Stages of Sleep Awake- Beta waves Drowsy- Alpha waves Stage 1- Theta waves 1-7 minutes Very light stage; easily awoken Hypnic jerks
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Stages of Sleep Stage 2- theta waves & mixed EEG Sleep spindles Respiration, heart rate, muscle tension, and body temperature continue to decline 10-25 minutes
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Stages of Sleep Stages 3 & 4- Delta (Slow-wave) sleep 30-45 minutes Deepest stage of sleep Sleepwalking (Somnambulism) can occur Secretion of growth hormones which controls levels of metabolism, physical growth, and brain development Repeat stages backwards
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Stages of Sleep Stage 5-REM Paradoxical sleep- beta waves 20% of sleep time All voluntary muscles paralyzed Occurs about 4 times a night about 15-45 min each Remembering dreams REM “Rebound Effect”
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Brain areas involved in sleep No single “sleep center” or “sleep chemical” RAS, Pons, Medulla, Thalamus, Hypothalamus Serotonin & Gaba
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Evolutionary Bases of Sleep Conservation Theory- sleep helps to conserve organisms’ energy Immobilization Theory- sleep reduces exposure to predators Restorative Theory- sleep helps to restore energy and other resources depleted during the day
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Cultural Variations in Sleep Co-sleeping Siesta Cultures
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Sleep Disorders Insomnia 35% Causes: anxiety, depression, use of stimulants Treatments: benzodiazepine medications (sedatives) effect GABA synapses Narcolepsy.05% Cause seems to be entirely genetic Treatment: stimulant drugs
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Sleep Disorders Sleep Apnea 2-4% usually between ages 30-60 Nightmares Cause: stress Frequent nightmares might reflect emotional disturbances Night/Sleep terrors Occur in NREM sleep usually stage 4 Feel panic; may wake up crying or screaming
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