States of Consciousness

• Sleep: a state of consciousness. We are less aware of our surroundings.
• Conscious, subconscious, unconscious
• Biological Rhythms
• Annual Cycles: seasonal variations (bears hibernation, seasonal affective disorder)
• 28 day cycles: menstrual cycle
• 24 hour cycle: our circadian rhythm
• 90 minute cycle: sleep cycle
• Circadian Rhythm: our 24 hour biological clock. Our body temperature and awareness changes throughout the day.
• Sleep Stages: there are 5 identified stages of sleep. It takes about 90-100 minutes to pass through the 5 stages. The brain's waves will change according to the sleep stage you are in. The first four stages are known as NREM sleep. The fifth stage is called REM sleep.
• Stage 1: kind of awake and kind of asleep. Only lasts a few minutes, and you usually only experience it once a night. Your brain produces Theta waves (high amplitude, low frequency (slow))
• Stage 2: "baseline" of sleep. Part of the 90 minute cycle and occupies approximately 45-60% of sleep. More Theta waves that get progressively slower. Show sleep spindles... short bursts of rapid brain waves.
• Stage 3 & 4: slow wave sleep. Produce Delta waves. If awoken you will be very groggy. Vital for restoring body's growth hormones and good overall health. May last 15-30 minutes. "Slow wave" sleep because brain activity slows down dramatically from the "theta" rhythm of Stage 2 to a much slower rhythm called "delta" and the height. Delta sleep is the "deepest" stage of sleep and the most restorative. Brain craves delta sleep first and foremost.
• REM Sleep: Rapid Eye Movement. Brain is very active. Dram usually occur in REM. Body is essentially paralyzed.
• Stage 5: composes 20-25% of a normal night sleep. Breathing, heart rate and brain wave activity quicken. Vivid dreams can occur. From REM, you go back to Stage 2.
• Sleep Disorders
• Insomnia: recurring problems in falling or staying asleep.
• Narcolepsy: characterized by uncontrollable sleep attacks. Lapses directly into REM sleep (usually during times of stress or joy).
• Sleep Apnea: a sleep disorder characterized by temporary cessations of breathing during sleep and consequent momentary reawakening.
• Night Terrors: a sleep disorder characterized by high arousal and an appearance of being terrified. Occur in Stage 4, not REM, and are not often remembered.
• Sleepwalking (Somnambulism): sleep walking most often occurs during deep non-REM sleep (stage 3 or 4 sleep) early in the night.
• Dreams: a sequence of images, emotions, and thoughts passing through a sleeping person's mind.
• Manifest Content: the remembered storyline of a dream.
• Latent Content: the underlying meaning of a dream.
• Why do we Dream? Three Theories
• Freud's Wish-Fulfilling Theory: dreams are the key to understanding our inner conflicts. Ideas and thoughts that are hidden in our unconsciousness.
• Information-Processing Theory: dreams act to sort out and understand the memories that you experience.
• Physiological Function Theories
  Activation-Synthesis Theory: during the night our brainstem releases random neural activity, dreams may be a way to make sense of that activity.