Consciousness, Sleep, & Dreams

Today’s Goal  Explain the sleep cycle and why sleep is important.

What is Consciousness? Awareness of ourselves and our environments Awareness of ourselves and our environments Preconscious – what is not immediately in your awareness, but can easily be brought to your awareness 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) 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 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 Debt Effects of Sleep Debt Lower hormone levels Lower hormone levels – Less growth hormone More accidents More accidents Hypertension & stress Hypertension & stress Poor concentration Poor concentration Irritability Irritability Suppressed immune system Suppressed immune system Weight gain Weight gain Premature aging Premature aging Can I make up for sleep debt? Takes awhile to make up for sleep debt (not just one big sleep) Takes awhile to make up for sleep debt (not just one big sleep) Genetics influence how much sleep we need Genetics influence how much sleep we need

So Why Do We Sleep? Melatonin makes us feel sleepy Melatonin makes us feel sleepy Sleep protects us from harm (ecological niche) Sleep protects us from harm (ecological niche) Sleep restores the body 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 REMDeep NREM Sleep

Two Main Types of Sleep 90 min. cycle 90 min. cycle NREM (non-rapid-eye-movement) NREM (non-rapid-eye-movement) – Stages 1-4 – 75% of sleep – Restores the body REM (rapid-eye-movement) REM (rapid-eye-movement) – 25% of sleep – Restores brain – Vivid dreams – Body immobile

Stages of Wake/Sleep Awake & alert – Beta waves Awake & alert – Beta waves – Faster, irregular waves Awake but relaxed – Alpha waves Awake but relaxed – Alpha waves – Lower frequency, higher amplitude, more regular

NREM Stage 1 Theta waves Theta waves Transition from wakefulness to sleep Transition from wakefulness to sleep Frequency slows, amplitude increases Frequency slows, amplitude increases Hypnic jerks (body shutting down) Hypnic jerks (body shutting down)

NREM Stage 2 Theta waves Sleep spindles – brief bursts in wave frequency K Complexes – brief bursts in wave amplitude

Stages 3 & 4: Slow-wave Sleep Delta waves Delta waves Blood pressure drops Blood pressure drops Slowed breathing Slowed breathing

REM Sleep Paradoxical sleep Paradoxical sleep Brain is active but body is immobile Brain is active but body is immobile Vivid dreams Vivid dreams Cortisol (stress hormone) drops Cortisol (stress hormone) drops Helps immune system Helps immune system

Stage 2 & REM get longer as sleep cycle repeats Stage 2 & REM get longer as sleep cycle repeats

Insomnia Difficulty falling asleep & staying asleep Difficulty falling asleep & staying asleep Oral medications, alcohol worsen the problem Oral medications, alcohol worsen the problem

Narcolepsy Sudden sleep attack when nervous system is aroused Sudden sleep attack when nervous system is aroused Fall into immediate REM sleep Fall into immediate REM sleep Rare (1 in 2000) Rare (1 in 2000)

Sleep Apnea Repeated sleep interruptions due to blockage of air passage (inability to breathe) 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 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) High arousal and fear response during stage 4 sleep (in children) Child rarely has memory of episode Child rarely has memory of episode Do not occur in REM (different from nightmares) Do not occur in REM (different from nightmares)

Theories of Dreaming Activation-synthesis Random neural firing, our brains create meaning – Physiological Brain stimulation develops & preserves neural pathways Cognitive development Reflect person’s cognitive dev. & understanding

Theories of Dreaming Info-processing Sort out day’s events & experiences, make memories Freud’s wish-fulfillment Manifest content  storyline of dream Latent content  underlying meaning, reveals the unconscious