Variations in Consciousness

Levels of Awareness Controlled Automatic Daydreaming Altered states (meditation, hypnosis, drug use) Sleep Freud’s Unconscious Unconscious

Biological Clocks Circadian Rhythm- biological clock that is programmed for 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

Morning or Night Person? Depends on body temperature Morning person- temp. rises more quickly and peaks earlier in the evening

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

Measuring the Stages of Sleep Sleep Labs EEG (brain waves) EMG (muscle tension) EOG (eye movement)

EEG patterns in sleep

Stages of Sleep Awake- Beta waves Drowsy- Alpha waves Stage 1- Theta waves 1-7 minutes Very light stage; easily awoken Hypnic jerks

Stages of Sleep Stage 2- theta waves & mixed EEG Sleep spindles Respiration, heart rate, muscle tension, and body temperature continue to decline minutes

Stages of Sleep Stages 3 & 4- Delta (Slow-wave) sleep 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

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 min each Remembering dreams REM “Rebound Effect”

Brain areas involved in sleep No single “sleep center” or “sleep chemical” RAS, Pons, Medulla, Thalamus, Hypothalamus Serotonin & Gaba

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

Cultural Variations in Sleep Co-sleeping Siesta Cultures

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

Sleep Disorders Sleep Apnea 2-4% usually between ages 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