Psychology 210Psychology 210

Lecture 11Lecture 11

Kevin R SmithKevin R Smith

TodayToday

SleepSleep• Why do we need it?Why do we need it?

DreamsDreams• Why do we dream?Why do we dream?

Sleep deprivationSleep deprivation

Peter TrippPeter Tripp• 19591959• Stayed awake for 201 Stayed awake for 201

hourshours• Experienced Experienced

hallucinationshallucinations Minor sleep deprivationMinor sleep deprivation

• ExhaustionExhaustion• Trouble focusingTrouble focusing• DizzinessDizziness• AngerAnger

Correlations between Correlations between road rage and lack of road rage and lack of sleepsleep

Sleep deprivationSleep deprivation

Other Symptoms of Minor Sleep Other Symptoms of Minor Sleep DeprivationDeprivation• Memory problemsMemory problems• Speech problemsSpeech problems• Glucose metabolism reduced up to 40%Glucose metabolism reduced up to 40%

Can lead to symptoms of early onset Can lead to symptoms of early onset diabetesdiabetes

Side note:Side note:• Guinness Book of Records record is 18 Guinness Book of Records record is 18

days, 21 hours, 40 minutesdays, 21 hours, 40 minutes

Drastic Effects of Sleep Drastic Effects of Sleep DeprivationDeprivation

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Sleep deprivation implicated in major Sleep deprivation implicated in major disastersdisasters• Three Mile Island nuclear meltdownThree Mile Island nuclear meltdown• Exxon Valdez oil tanker disasterExxon Valdez oil tanker disaster• Challenger explosionChallenger explosion• Bhopal, India chemical leaksBhopal, India chemical leaks

Sleep Deprivation: AdolescentsSleep Deprivation: Adolescents

Teens don’t get Teens don’t get enough sleep enough sleep during the weekduring the week

Try to make up for Try to make up for it on the weekendsit on the weekends

Sleep is a Biological RhythmSleep is a Biological Rhythm

Seasonal migrationsSeasonal migrations Mating seasonsMating seasons MenstruationMenstruation Circadian rhythms: Circadian rhythms:

• SleepSleep

Zeitgebers: External Cues Help Zeitgebers: External Cues Help Set Circadian RhythmsSet Circadian Rhythms

Internal clocks interact with Internal clocks interact with zeitgeberszeitgebers• LightLight

Without light: Human “free-running” Without light: Human “free-running” cycle is about 25 hourscycle is about 25 hours

Blind individuals and sailors serving Blind individuals and sailors serving on submarines may experience sleep on submarines may experience sleep problemsproblems

Individual Variations in Sleep Individual Variations in Sleep PatternsPatterns

““Larks” are morning peopleLarks” are morning people ““Owls” are night peopleOwls” are night people Many people are in between these Many people are in between these

extremesextremes Most adolescents are temporarily owlsMost adolescents are temporarily owls

• Revert back to their individual preference after Revert back to their individual preference after adolescenceadolescence

• Accommodation by the schools to an Accommodation by the schools to an adolescents natural schedule is beneficialadolescents natural schedule is beneficial

Changed 7:15 start to 8:40 startChanged 7:15 start to 8:40 start• Attendance and grades increasedAttendance and grades increased

Shift WorkShift Work

Nurses, Doctors, Public Safety workersNurses, Doctors, Public Safety workers Shift workers average 1.5 hours less sleep, Shift workers average 1.5 hours less sleep,

and are more prone to sleep-related and are more prone to sleep-related illnesses and psychological disorders.illnesses and psychological disorders.

Higher accident ratesHigher accident rates• Swing shift is higher than day shiftSwing shift is higher than day shift• Night shift is highest overallNight shift is highest overall

More mistakes made as wellMore mistakes made as well• Nurses more likely to make errors in the Nurses more likely to make errors in the

evening than in the daytimeevening than in the daytime

Jet LagJet Lag

Internal clock and external cues Internal clock and external cues disagreedisagree

Experience fatigue, irritability, and Experience fatigue, irritability, and sleepinesssleepiness

East-west travel is BADEast-west travel is BAD• Adjustment to jet lag requires about 1 Adjustment to jet lag requires about 1

day per time zone crossed.day per time zone crossed. North-South travel is GOODNorth-South travel is GOOD

Chronic Jet-LagChronic Jet-Lag

Airline crews traveling across time Airline crews traveling across time zones vs. airline crews that don’t zones vs. airline crews that don’t travel across time zonestravel across time zones• Slower reaction timesSlower reaction times• 9% more mistakes in memory task9% more mistakes in memory task

Adjustments to Phase Delays Adjustments to Phase Delays Are Easier than Phase Are Easier than Phase

AdvancesAdvances

Daylight savingsDaylight savings

Started in WW2Started in WW2 ““Spring ahead” much worse than Spring ahead” much worse than

“Fall back”“Fall back”• Similar to jet lagSimilar to jet lag

Coren (1996)Coren (1996)• Found a 7% reduction in accidents after Found a 7% reduction in accidents after

the Fall daylight savings changethe Fall daylight savings change• Found a 7% increase in accidents after Found a 7% increase in accidents after

the Spring daylight savings changethe Spring daylight savings change

History of sleepHistory of sleep

2000 years ago2000 years ago• Noticed that after you eat, you feel Noticed that after you eat, you feel

sleepysleepy ““food coma”food coma”

• Deduced that stomach vapors cause Deduced that stomach vapors cause sleepinesssleepiness

Now we know that the brain Now we know that the brain regulates sleepregulates sleep

The Internal ClockThe Internal Clock

HypothalamusHypothalamus• Suprachiasmatic Suprachiasmatic

Nucleus (SCN)Nucleus (SCN) Light is important Light is important

for circadian for circadian rhythmsrhythms• Visual information Visual information

tied closely to SCNtied closely to SCN• RetinohypothalamRetinohypothalam

ic pathwayic pathway

SCN Activity and Light/Dark SCN Activity and Light/Dark CyclesCycles

The SCN is The SCN is active during active during the day in the day in both diurnal both diurnal and nocturnal and nocturnal animalsanimals

The SCN tells The SCN tells the animal the animal whether it’s whether it’s day or night, day or night, but not how to but not how to behavebehave

The SCN tells an animal the difference between night and day, not whether it’s time to sleep or be awake.

The SCNThe SCN Isolated SCN tissue maintains its circadian Isolated SCN tissue maintains its circadian

rhythmsrhythms Transplants of SCN establish donor rhythms Transplants of SCN establish donor rhythms

in recipient animalsin recipient animals• Breeded hamsters with 20 hour internal clockBreeded hamsters with 20 hour internal clock• Transferred into regular 24 hour internal clock Transferred into regular 24 hour internal clock

hamstershamsters• A shorter cycle ensuedA shorter cycle ensued

The SCN may control other “internal clocks”The SCN may control other “internal clocks”• Rhythmic activity found in lungs, liver and Rhythmic activity found in lungs, liver and

musclesmuscles

Origin of the Internal ClockOrigin of the Internal Clock

Lesions of the maternal SCN do not Lesions of the maternal SCN do not disrupt fetal circadian rhythmsdisrupt fetal circadian rhythms

Genetics plays a roleGenetics plays a role• Oscillations of protein production and Oscillations of protein production and

degradation serves as the “ticking” of degradation serves as the “ticking” of the internal clockthe internal clock

Light may participate in the Light may participate in the triggering of some of these protein triggering of some of these protein fluctuationsfluctuations

Protein Fluctuations and Fruit Protein Fluctuations and Fruit Fly Circadian RhythmsFly Circadian Rhythms

The Biochemistry of Circadian The Biochemistry of Circadian RhythmsRhythms

Glutamate is the Glutamate is the neurotransmitter of the neurotransmitter of the retinohypothalamic tractretinohypothalamic tract• Light signals the releaseLight signals the release• PACAP modulates PACAP modulates

Glutamate activity in the Glutamate activity in the SCNSCN

Melatonin is released only Melatonin is released only at night (by the retina and at night (by the retina and the pineal gland)the pineal gland)• Peak is around 4amPeak is around 4am• Blind individuals peak at Blind individuals peak at

different times every daydifferent times every day• Used to treat insomnia Used to treat insomnia

and jet lagand jet lag

Biochemistry of Circadian RhythmsBiochemistry of Circadian Rhythms

Growth hormone is Growth hormone is released during deep released during deep sleepsleep

Cortisol release is Cortisol release is highest in the morning highest in the morning and drops during the and drops during the dayday• Released during times Released during times

of stressof stress• Possibly why it is hard Possibly why it is hard

to sleep when stressedto sleep when stressed

Seasonal Affective Disorder Seasonal Affective Disorder (SAD)(SAD)

Depression related to the season:Depression related to the season:• 1.4% of Florida residents experience SAD1.4% of Florida residents experience SAD• 9.7% of New Hampshire residents experience SAD9.7% of New Hampshire residents experience SAD• Icelanders may enjoy some genetic immunityIcelanders may enjoy some genetic immunity

Serotonin levels normally drop in late fall Serotonin levels normally drop in late fall through winter—people with SAD may through winter—people with SAD may experience too much of a dropexperience too much of a drop

Light therapy uses lights of 2500 lux (normal Light therapy uses lights of 2500 lux (normal indoor light is about 100 lux, sunlight is about indoor light is about 100 lux, sunlight is about 10,000 lux)10,000 lux)

Evaluating Sleep and Evaluating Sleep and WakefulnessWakefulness

Electroencephalogram (EEG)Electroencephalogram (EEG) Evaluation of muscle toneEvaluation of muscle tone Evaluation of eye movementEvaluation of eye movement

© Lester Lefkowitz/CORBIS

Stages of Waking and SleepingStages of Waking and Sleeping Wakefulness is characterized by relatively Wakefulness is characterized by relatively

desynchronized alpha and beta wavesdesynchronized alpha and beta waves Slow-wave sleep (SWS) is characterized by Slow-wave sleep (SWS) is characterized by

relatively synchronized theta and delta waves.relatively synchronized theta and delta waves. Rapid-eye-movement sleep (REM) is characterized Rapid-eye-movement sleep (REM) is characterized

by an EEG resembling wakefulnessby an EEG resembling wakefulness• 90-120 minute cycles90-120 minute cycles

90–120 minute ultradian cycles characterize both 90–120 minute ultradian cycles characterize both sleep and wakefulness sleep and wakefulness

EEG During Wakefulness and EEG During Wakefulness and SleepSleep

Stage 2:Stage 2:• Spindles: bursts of Spindles: bursts of

activityactivity• K-Complex: responses K-Complex: responses

to outside stimulito outside stimuli Stages 3 and 4 show Stages 3 and 4 show

larger percentages of larger percentages of delta wavesdelta waves

REM sleep combines an REM sleep combines an active EEG, eyeactive EEG, eye movements and movements and muscular paralysismuscular paralysis

Sleep Patterns in a Typical Sleep Patterns in a Typical NightNight

The first 4 hours The first 4 hours contain more Slow contain more Slow Wave Sleep, Wave Sleep, especially Stages 3 especially Stages 3 and 4and 4

The second 4 hours The second 4 hours contain more REMcontain more REM

REM episodes occur REM episodes occur approximately approximately every 90every 90––120 120 minutesminutes

Brain Activity in Wakefulness, SWS Brain Activity in Wakefulness, SWS and REMand REM

REM vs. waking (top):REM vs. waking (top):• Frontal Lobe more active Frontal Lobe more active

during wakefulnessduring wakefulness• primary visual cortex primary visual cortex

equally activeequally active• limbic system more active limbic system more active

during REMduring REM

REM vs. SWS (lower):REM vs. SWS (lower):• most of the brain is most of the brain is

more active during more active during REM than during REM than during SWSSWS

• primary visual primary visual cortex is more cortex is more active during SWSactive during SWS

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Sleep Patterns Across the Sleep Patterns Across the LifespanLifespan

REM sleep is more prevalent in infancyREM sleep is more prevalent in infancy Aging is associated with drops in overall Aging is associated with drops in overall

sleep and proportion of SWSsleep and proportion of SWS

Stage 3 and 4 sleep decreases from 20% of a 25 year old’s sleep to 5% of a 35 year old’s sleep

DreamingDreaming

Dreams occur during both SWS and Dreams occur during both SWS and REMREM

REM dreaming is more vivid, less REM dreaming is more vivid, less logical, story-like and longerlogical, story-like and longer

Calvin Hall found that we usually Calvin Hall found that we usually dream about familiar places and dream about familiar places and routine activities, but unfamiliar routine activities, but unfamiliar peoplepeople

Theories of DreamsTheories of Dreams

Hobson-McCarley: Dreams Hobson-McCarley: Dreams incorporate ongoing functions (e.g. incorporate ongoing functions (e.g. vestibular activity) and/or vestibular activity) and/or environmental events (e.g. your environmental events (e.g. your alarm clock)alarm clock)

Crick-Mitchison: Dreaming is a way Crick-Mitchison: Dreaming is a way to forget irrelevant informationto forget irrelevant information

Winson’s evolutionary approach: Winson’s evolutionary approach: Animals integrate memories and Animals integrate memories and experience while dreamingexperience while dreaming

A Freudian ApproachA Freudian Approach

Believed the ID was freely expressed Believed the ID was freely expressed in dreamsin dreams

The ID is a biologically driven The ID is a biologically driven mechanismmechanism

Common dream interpretationsCommon dream interpretations• Circular items such as apples, oranges, Circular items such as apples, oranges,

balls: breastsballs: breasts• Snakes and longer items: phallic Snakes and longer items: phallic

symbolssymbols

Random Dream NotesRandom Dream Notes

70% of dreams have negative 70% of dreams have negative emotional contentemotional content• Being chasedBeing chased• FallingFalling• Appearing nakedAppearing naked• Needing to take an exam, but being Needing to take an exam, but being

unpreparedunprepared

Lucid DreamingLucid Dreaming

Having the realization that you are Having the realization that you are dreaming during the dreamdreaming during the dream

Typically can change the dreamTypically can change the dream May have uses in psychological May have uses in psychological

therapy therapy • Getting people to face their fears in their Getting people to face their fears in their

dreamsdreams

Nightmares and Night TerrorsNightmares and Night Terrors

Nightmares: bad dreams during REM Nightmares: bad dreams during REM sleepsleep

Night Terrors: during Slow wave Night Terrors: during Slow wave sleepsleep• Start with a screamStart with a scream• May situp and moveMay situp and move• Not responsive until woken upNot responsive until woken up

Nightmares vs. Night TerrorsNightmares vs. Night Terrors

Why Do We Sleep?Why Do We Sleep?

Sleep Sleep keeps us keeps us safesafe

Sleep Sleep preserves preserves energyenergy

Sleep Sleep restores restores our bodiesour bodies

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Functions of SWSFunctions of SWS

Rest, repair bodyRest, repair body Human growth hormone (HGH) is Human growth hormone (HGH) is

released during Stages 3 and 4 SWSreleased during Stages 3 and 4 SWS Deprivation produces joint and Deprivation produces joint and

muscle painmuscle pain

Functions of REMFunctions of REM Birds and mammals (except the echidna) Birds and mammals (except the echidna)

show REMshow REM REM increases after learning has occurredREM increases after learning has occurred REM rebound after deprivationREM rebound after deprivation People can live and learn without REMPeople can live and learn without REM

• brain injurybrain injury• SSRIs suppress REMSSRIs suppress REM

REM deprivation REM deprivation improves moodimproves mood

© Staffan Widstrand/CORBIS

What Parts of the Brain Manage What Parts of the Brain Manage Sleep Phenomena?Sleep Phenomena?

Frédéric Brémer proved that sleep is a Frédéric Brémer proved that sleep is a behavior, not just the lack of brain activitybehavior, not just the lack of brain activity

Brémer’s sections identified parts of the Brémer’s sections identified parts of the brain responsible for sleep mechanismsbrain responsible for sleep mechanisms• Basal forebrain: responsible for SWSBasal forebrain: responsible for SWS• Raphe Nuclei in brainstem: play a role in Raphe Nuclei in brainstem: play a role in

SWSSWS• Reticular Formation: also plays a role in Reticular Formation: also plays a role in

arousalarousal Inhibited by the raphe nucleiInhibited by the raphe nuclei

The Control of WakefulnessThe Control of Wakefulness

Reticular formation activity wakes Reticular formation activity wakes animalsanimals

Locus coeruleus (pons) Locus coeruleus (pons) (norepinephrine)(norepinephrine)

Raphe nuclei may promote sleep by Raphe nuclei may promote sleep by inhibiting the reticular formationinhibiting the reticular formation

Control of REM SleepControl of REM Sleep

PGO Waves (Pons-PGO Waves (Pons-Geniculate-Occipital)Geniculate-Occipital)• Occur with eye Occur with eye

movementsmovements Caudal reticular Caudal reticular

formation (Pons) formation (Pons) controls REM controls REM phenomenaphenomena

REM sleep is inhibited REM sleep is inhibited by both the raphe nuclei by both the raphe nuclei and the locus coeruleusand the locus coeruleus• Active during SWSActive during SWS

Summary of Sleep ControlSummary of Sleep Control

Biochemical Correlates of SleepBiochemical Correlates of Sleep

Not well understoodNot well understood Reticular formationReticular formation

• Arousal: dopamineArousal: dopamine Raphe nucleiRaphe nuclei

• Serotonin: promotes sleepinessSerotonin: promotes sleepiness• Trytophan: a serotonin agonistTrytophan: a serotonin agonist

Locus coeruleusLocus coeruleus• Norepinephrine: inhibits REM sleepNorepinephrine: inhibits REM sleep

Biochemical Correlates of SleepBiochemical Correlates of Sleep

Sleep DisordersSleep Disorders

DyssomniasDyssomnias involve difficulties with involve difficulties with the initiation, maintenance, timing the initiation, maintenance, timing and quality of sleepand quality of sleep

ParasomniasParasomnias involve unusual involve unusual behaviors that intrude on normal behaviors that intrude on normal sleepsleep

DyssomniasDyssomnias

InsomniaInsomnia• Onset insomniaOnset insomnia• Maintenance Maintenance

insomniainsomnia Sleep apneaSleep apnea

• Ceasing to breathe Ceasing to breathe during sleepduring sleep

NarcolepsyNarcolepsy

Harriet Tubman may have had narcolepsy.

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NarcolepsyNarcolepsy

Sleep attacks: episodes and features of Sleep attacks: episodes and features of REM sleep occur during wakefulnessREM sleep occur during wakefulness• CataplexyCataplexy

Muscle paralysis during wakefulnessMuscle paralysis during wakefulness Triggered by a stressorTriggered by a stressor

• Sleep paralysisSleep paralysis Muscle paralysis immediately before or after sleepingMuscle paralysis immediately before or after sleeping

• Hypnogogic and hypnopompic hallucinationsHypnogogic and hypnopompic hallucinations Dreaming immediately after or before sleepingDreaming immediately after or before sleeping

Cause of NarcolepsyCause of Narcolepsy

Highly geneticHighly genetic• Can breed for a narcoleptic gene in dogsCan breed for a narcoleptic gene in dogs

Brainstem functioning abnormallyBrainstem functioning abnormally Due to abnormal amounts of certain Due to abnormal amounts of certain

neurotransmittersneurotransmitters

ParasomniasParasomnias NightmaresNightmares Night terrorsNight terrors Sudden infant death Sudden infant death

syndrome (SIDS)syndrome (SIDS) Sleep talkingSleep talking Sleep walkingSleep walking Enuresis (bedwetting)Enuresis (bedwetting) REM behavior disorderREM behavior disorder Restless leg syndromeRestless leg syndrome

© Roy Morsch/CORBIS