Gen Psyc 05 - Mind Consciousness and Dreamimg BLACKBOARD

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The Cave Dweller Experiment
• 27 year old Stefania Follini lived in an underground cave in New Mexico from On January 13 to May 22, 1989. • All cues to passage of time eliminated • “Free running time” about 25 hours • Ms. Follini’s days shifted to 28 hour cycle • 6 weeks in, woke up one day, didn’t go back to sleep for 24 hours, went into 44 hour cycle. • Time perception had sped up: 7 hours felt like 1
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Stages of sleep over the course of the night
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Hours of Sleep
Why do we sleep?
• Conservation
– Sleep evolved because it allowed animals to conserve energy
• Stage 1 sleep
– Easily aroused – Slower synchronized waves--theta waves
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Electrical brain activity during Sleep
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• Stage 2 sleep
Stages of sleep
– Less sensitive to external stimulation – Theta waves + occasional special patterns
• Restoration
– Sleep (specifically Non-REM) occurs to provide an opportunity to repair and restore brain cells
Why do we sleep?
• Facilitation of learning
• Cultural Construction of Reality
– Ways of thinking about the world that are shared by most members of a particular group
Sleep and Dreams
• Circadian Rhythm
Contents of Consciousness
• Consciousness
– Awareness of internal events and of the external environment
• Self-awareness
– Top level of consciousness
Contents of Consciousness
– Allows strengthening of neural connections – Consolidation of learning
• Circadian rhythm theory
– “circa diem” = around a day, 24 hour cycle – Allows animals to remain inactive during vulnerable periods – “Free running” time, about 25 hours
– sends serotonin to cortex when awake
• Preoptic area in forebrain
– inhibitory signals to RAS – reduce arousal & induce sleep
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Activity in the Locus Coeruleus
• REM dreams
– Content: – Activation of brain areas associated with motivation, emotion, & reward
• Non-REM dreams
– Content:
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VIDEO
• Scientific American: “What’s in a Dream?”
• Sleeptalking
– Common & harmless – REM and non-REM sleep
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Sleep Disorders
• Night terrors
– Qualities: –: – Much more common in young children
• Insomnia
• Nonconscious processes
– Preconscious Memories
• Can be called into consciousness when necessary
– Unattended Information – Unconscious
Studying the Contents of Consciousness
• Sleep spindles: brief bursts of activity • K-complexes: large slow waves
• Stage 3 and 4 sleep
– Deep sleep – Large, slow synchronized waves
• delta waves
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Sleep Disorders
• Sleepwalking (somnambulism)
– Sleepwalking in which people leave their beds and wander while still remaining asleep – Occurs during non-REM, stage 3 or 4 sleep – Common in young children – Runs in families
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Neural mechanisms of Sleep
• Endocrine system
– Suprachiasmic nucleus (SCN) of hypothalamus, the “biological clock” – SCN receives signals about light from retina – SCN signals pineal gland to secrete melatonin (a hormone) – Melatonin helps induce sleep, recover from jet lag
– Chronic inability to sleep
• Narcolepsy
– Irresistible compulsion to sleep
• Sleep Apnea
– Stop breathing while asleep
• Dreams
Dreaming
– Altered state of reality – Images and fantasies confused with reality
Stages of sleep
• Alert wakefulness
– Extremely active brain – Beta waves: desynchronized waves
• short and frequent
• Drowsiness
– Increase in synchrony--alpha waves
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Pineal gland
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Reticular activating system (RAS)
• Locus coeruleus (in RAS)
– sends norepinephrine to many parts of brain during wakefulness
• Raphe nuclei (in RAS)
– Consistent pattern of cyclical body activities determined by internal clock – Twenty-four to twenty-five hours
• Jet Lag
– Fatigue, irresistible sleepiness, and unusual sleep-wake cycles that result when the internal circadian rhythm is out of phase with the temporal environment
Functions of Consciousness
• Aiding Survival
– Restrictive function – Selective storage function – Planning function
• Personal Construction of Reality
– Your unique interpretation of a current situation
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Electrical brain activity during Sleep
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Stages of sleep
• REM sleep (paradoxical sleep) – Rapid eye movements – Beta waves & extreme brain activity – Bodily arousal (breathing, heart rate, BP) – Body paralysis – High likelihood of dreaming – As night progresses, more REM less deep sleep – REM rebound when not enough sleep