Unit 8: Consciousness

Consciousness: Our awareness of ourselves and our environment.
Biological Rhythms: Periodic physiological fluctuations.
Circadian Rhythm: The biological clock.  It involves regular body rhythms (ex: temperature & sleep) that occur on a 24-hour cycle.
                       STAGES OF SLEEP
Stage 1:
Alpha waves; hypnogogic hallucinations; sleep talking; hypnic jerk; slow down of biological functions (e.g., blood pressure, heart rate, respiration) & a decrease in temperature.
Stage 2: Waves are slower (see some theta waves); sleep spindles; K-complexes; sleep talking; biological functions continue to slow.
Stage 3: Transition stage.  See first signs of delta waves; biological functions continue to slow.
Stage 4: Deep sleep. All delta waves; bedwetting & sleep walking most likely.  Biological functions are at there lowest.

After stage 4, the sleeper moves back to stages 3, stage 2, & then into REM sleep.
REM Sleep: Rapid eye movement; dreaming; erections in males; paralysis.  Also called "paradoxical sleep" because while the person is totally asleep, there biological function and brain waves appear more like a person who is awake.
A full sleep-cycle takes about 90 minutes.  As the cycles continue throughout the night, stage 4 sleep gets shorter and REM sleep gets longer.
                         SLEEP THEORIES
1. Possibly certain chemicals depleted during the day are restored during sleep.
2. A build-up of "s-factor" during the day causes sleep at night.         
3. Pituitary gland more active during deep sleep. So, sleep may be involved in growth process. (Babies and young people spend more time in deep sleep than older people).

4. Evolutionary view: Sleeping when it was dark kept us safe.
                  DREAM THEORIES
Freudian Theory:
Dreams help disguise unconscious conflicts and motives.
      Manifest Content: According to Freud, the remembered storyline of a dream.
      Latent Content: According to Freud, the underlying "meaning" of a dream.
Activation-synthesis Theory: Dreams spring from the mind's relentless effort to make sense of random visual bursts of electrical activity which originate in the brainstem and are given their emotional tone as they pass through the limbic system.
Memory Consolidation Theory: The parts of the brain active when we learn something are similarly active later when we sleep and dream.
Brain-Stimulation Theory:  Periodic stimulation during dreaming helps form neural connections.  Especially important in infants.

Regardless, if we don't get enough REM sleep, we will go into
REM Rebound: The tendency for REM sleep to increase following a period of REM deprivation.
                      SLEEP DISORDERS
Recurring problems in falling or staying asleep.
Narcolepsy: Disorder characterized by uncontrollable sleep attacks.  The sufferer may lapse directly into REM sleep at inopportune time.
Sleep Apnea: Disorder characterized by temporary cessation of breathing during sleep and momentary awakenings throughout the night.
Night Terror: Disorder characterized by high arousal and an appearance of being terrified.  Unlike nightmares, these occur during stage 4 sleep and are typically not remembered.    NEXT PAGE

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