Sleep “… if you’re sleeping are you dreaming, if you’re dreaming are you dreaming of me? …” - Blue October “… if you’re sleeping are you dreaming, if you’re dreaming are you dreaming of me? …” - Blue October

Sleeping G Average individuals spend 1/3 of their lives asleep G Sleep is at the lowest level of the hierarchy of consciousness G Sleep allows for near immediate return to the highest level of consciousness through presentation of appropriate stimulus G Average individuals spend 1/3 of their lives asleep G Sleep is at the lowest level of the hierarchy of consciousness G Sleep allows for near immediate return to the highest level of consciousness through presentation of appropriate stimulus

Historical Development G Little scientific inquiry until late 1800s G : Two scientists separately found importance of rostral midbrain legions in lethargy syndromes G Little scientific inquiry until late 1800s G : Two scientists separately found importance of rostral midbrain legions in lethargy syndromes

Historical Development G Encephalitus Lethargica: Commonly called sleeping sickness, is a degenerative viral inflammation in the brain G Worldwide epidemic from G Search for pathological basis led to conclusions of two sleeping centers in the brain: G A Waking Center: Turns off sleep when stimulated (posterior hypothalamus and mesencephalic tegmentum) G A Sleep Center: Turns on sleep when activated (in the basal forebrain structures) G Encephalitus Lethargica: Commonly called sleeping sickness, is a degenerative viral inflammation in the brain G Worldwide epidemic from G Search for pathological basis led to conclusions of two sleeping centers in the brain: G A Waking Center: Turns off sleep when stimulated (posterior hypothalamus and mesencephalic tegmentum) G A Sleep Center: Turns on sleep when activated (in the basal forebrain structures)

Historical Development G 1930’s brought about clinical use of EEGs and different sleep brain wave patterns were labeled G 1950’s: Generally accepted that regions for both sleeping and waking existed in the pons and medulla, and that sensory input to the brain was not a necessary condition for organisms to demonstrate signs of wakefulness G 1930’s brought about clinical use of EEGs and different sleep brain wave patterns were labeled G 1950’s: Generally accepted that regions for both sleeping and waking existed in the pons and medulla, and that sensory input to the brain was not a necessary condition for organisms to demonstrate signs of wakefulness

Brain Waves G Differ in Amplitude (height of wave) and Frequency (rate of occurrence) G Desynchronization: patterns of electrical activity in a typical EEG reading. aIrregular low amplitude activity with no particular pattern G Synchronization: EEG produces distinct regular patterns of brain waves of approximately the same amplitude with a regular frequency G Differ in Amplitude (height of wave) and Frequency (rate of occurrence) G Desynchronization: patterns of electrical activity in a typical EEG reading. aIrregular low amplitude activity with no particular pattern G Synchronization: EEG produces distinct regular patterns of brain waves of approximately the same amplitude with a regular frequency

Brain Waves G Beta (14-30 Hz): Parietal and Frontal cortical regions, characteristic of wakefulness G Alpha (8-13 Hz): Individuals who are awake but in a quiet resting state with eyes shut G Theta (4-7 Hz): Commonly seen in children under 10 as well as adults under conditions as simulated diving, chemical intoxication, sleep and meditation G Delta (.5-4 Hz): Deep sleeping adults as well as children G Beta (14-30 Hz): Parietal and Frontal cortical regions, characteristic of wakefulness G Alpha (8-13 Hz): Individuals who are awake but in a quiet resting state with eyes shut G Theta (4-7 Hz): Commonly seen in children under 10 as well as adults under conditions as simulated diving, chemical intoxication, sleep and meditation G Delta (.5-4 Hz): Deep sleeping adults as well as children

How to Study Sleep: G First night effect: the first night spent in a sleep laboratory usually produces abnormal brain waves - unreliable data!

Sleep Stages G Stage 1: G Body begins to show signs of relaxation, muscle tonus diminishes, heart rate slows, and breathing becomes deeper and more regular G Brain wave activity is desynchronous, Hz is most prominent frequency G Not difficult to arouse a person in stage 1 sleep G Only happens as you are first falling asleep G Stage 1: G Body begins to show signs of relaxation, muscle tonus diminishes, heart rate slows, and breathing becomes deeper and more regular G Brain wave activity is desynchronous, Hz is most prominent frequency G Not difficult to arouse a person in stage 1 sleep G Only happens as you are first falling asleep

Sleep Stages G Stage 2: G Sleep Spindles: Sinusoidal wave with frequency Hz. Associated with loss of perceptual awareness and occur in transition between stage 1 and stage 2 G K-Complex: Biphasic wave form beginning with an initial, sharp negative wave followed by positive components G Stage 2: G Sleep Spindles: Sinusoidal wave with frequency Hz. Associated with loss of perceptual awareness and occur in transition between stage 1 and stage 2 G K-Complex: Biphasic wave form beginning with an initial, sharp negative wave followed by positive components

Sleep Stages G Stage 3: G Muscle Tonus, heart rate, blood pressure ad body temperature all show signs of decreasing G Takes relatively large stimulus to awaken someone G Onset and termination defined by percentage of delta wave activity G Consists of the times when 20-50% of EEGs are delta wave G Stage 3: G Muscle Tonus, heart rate, blood pressure ad body temperature all show signs of decreasing G Takes relatively large stimulus to awaken someone G Onset and termination defined by percentage of delta wave activity G Consists of the times when 20-50% of EEGs are delta wave

Sleep Stages G Stage 4 G Begins when over 50% of EEG activity is delta waves G Very deep stage of sleep and extremely difficult to awaken G If allowed to sleep interrupted, will go from stage 4 to stage 3 to stage 2 G Night terrors occur during this stage of sleep G Stage 4 G Begins when over 50% of EEG activity is delta waves G Very deep stage of sleep and extremely difficult to awaken G If allowed to sleep interrupted, will go from stage 4 to stage 3 to stage 2 G Night terrors occur during this stage of sleep

Sleep Stages G REM Sleep G Occurs ever minutes throughotu the night, sleeping subjets go from stage 2 to REM G Low voltage, mixed frequncies, punctated by occastional bursts of alpha activity G Eyes dart back and forth behind closed eyelids about times per minute (gives REM its name) G REM Sleep G Occurs ever minutes throughotu the night, sleeping subjets go from stage 2 to REM G Low voltage, mixed frequncies, punctated by occastional bursts of alpha activity G Eyes dart back and forth behind closed eyelids about times per minute (gives REM its name)

Sleep Stages G REM Sleep G Respiration and pulse rates increase and become irregular, blood pressure increases G Male subjects often experience erections G This is when dreaming occurs (though it can sometimes occur in NREM sleep, just unlikely they will be remembered) G Greater right hemispheric involvement in REM sleep while greater left hemispheric activation in NREM sleep G REM Sleep G Respiration and pulse rates increase and become irregular, blood pressure increases G Male subjects often experience erections G This is when dreaming occurs (though it can sometimes occur in NREM sleep, just unlikely they will be remembered) G Greater right hemispheric involvement in REM sleep while greater left hemispheric activation in NREM sleep

Age Related Changes G Age related changes contribute to the excessive daytime sleepiness observed in the elderly G Total time spent in stage 4 and REM decreases with age G Lack of flexibility in sleep patterns as people age G Age related changes contribute to the excessive daytime sleepiness observed in the elderly G Total time spent in stage 4 and REM decreases with age G Lack of flexibility in sleep patterns as people age

Hypnopedia G Hypnopedia: The possibility of learning during sleep G No study has been able to show convincingly an ability to learn complex verbal material during sleep G Learning such material when awake appears to be facilitated slightly as compared with the rate that similar (but new) material is learned G Hypnopedia: The possibility of learning during sleep G No study has been able to show convincingly an ability to learn complex verbal material during sleep G Learning such material when awake appears to be facilitated slightly as compared with the rate that similar (but new) material is learned

Other things in the book: G Sleep deprivation G Sleeping Disorders G Theories of Sleep: Answers to why do we sleep? G When do we dream and what is it about? G Theories on Dreaming (Freud etc) G Day dreaming G Sexual fantasies G Sleep deprivation G Sleeping Disorders G Theories of Sleep: Answers to why do we sleep? G When do we dream and what is it about? G Theories on Dreaming (Freud etc) G Day dreaming G Sexual fantasies