Consciousness, Sleep, & Dreams. Today’s Goal Explain the sleep cycle and why sleep is important.
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Transcript of Consciousness, Sleep, & Dreams. Today’s Goal Explain the sleep cycle and why sleep is important.
What is Consciousness?• Awareness of ourselves and our environments
• Preconscious – what is not immediately in your awareness, but can easily be brought to your awareness
• Unconscious – info we are unaware of and would be difficult to become aware of (deep, hidden mind)
Dual Processing• We process information at all levels of
consciousness simultaneously= Two-track mind
Biological Rhythms
= Physiological fluctuations Circadian – 24 hour cycle (i.e. sleep-wake) Ultradian – more than 2x daily (stages of
sleep) Infradian – occur once/month or once/season
(hibernation)
Sleep DebtEffects of Sleep Debt
• Lower hormone levels– Less growth hormone
• More accidents• Hypertension & stress• Poor concentration• Irritability• Suppressed immune
system• Weight gain• Premature aging
Can I make up for sleep debt?
• Takes awhile to make up for sleep debt (not just one big sleep)
• Genetics influence how much sleep we need
So Why Do We Sleep?
• Melatonin makes us feel sleepy• Sleep protects us from harm (ecological niche)• Sleep restores the body–Muscles & tissues– Neurological repair– Growth & cognitive
development
How do we study sleep?• Electroencephalogram (EEG) detects brain wave
patterns
• Electrooculogram (EOG) detects eye movements during dreams
• Electromyogram (EMG) detects muscle tension
EEG
EMG
EOG
Awake REM Deep NREM Sleep
Two Main Types of Sleep
• 90 min. cycle• NREM (non-rapid-eye-movement)– Stages 1-4– 75% of sleep– Restores the body
• REM (rapid-eye-movement)– 25% of sleep– Restores brain– Vivid dreams– Body immobile
Stages of Wake/Sleep • Awake & alert – Beta
waves– Faster, irregular waves
• Awake but relaxed – Alpha waves– Lower frequency,
higher amplitude, more regular
NREM Stage 1• Theta waves• Transition from
wakefulness to sleep
• Frequency slows, amplitude increases
• Hypnic jerks (body shutting down)
NREM Stage 2• Theta waves• Sleep spindles – brief bursts in wave frequency• K Complexes – brief bursts in wave amplitude
REM Sleep
• Paradoxical sleep• Brain is active but
body is immobile• Vivid dreams• Cortisol (stress
hormone) drops• Helps immune
system
Narcolepsy• Sudden sleep attack when nervous
system is aroused • Fall into immediate REM sleep• Rare (1 in 2000)
Sleep Apnea• Repeated sleep interruptions due to blockage
of air passage (inability to breathe) • Usually do not know this is happening, but
may get full night’s sleep and still feel exhausted
Somnambulism (Sleepwalking)
• Not dangerous to awaken sleepwalker, but difficult (they are in stage 4 of sleep)
Night Terrors
• High arousal and fear response during stage 4 sleep (in children)
• Child rarely has memory of episode• Do not occur in REM (different from
nightmares)
Theories of Dreaming• Activation-synthesis
Random neural firing, our brains create meaning
– PhysiologicalBrain stimulation develops &
preserves neural pathways
• Cognitive developmentReflect person’s cognitive dev. & understanding