Chapter 12: Chapter 12: Wakefulness and SleepWakefulness and Sleep

Endogenous CyclesEndogenous Cycles

1.1. Many animals have a circannual Many animals have a circannual rhythm rhythm

2.2. Most animals, including humans Most animals, including humans have a circadian rhythmhave a circadian rhythm

What do you think this means?What do you think this means?

How long is the How long is the natural natural Human Circadian Human Circadian Rhythm?Rhythm?1.1. Our internal daily rhythm actually Our internal daily rhythm actually lasts a little longer than 24 hours.lasts a little longer than 24 hours.

2.2. How do we know that?How do we know that?

What is the Biological What is the Biological Clock?Clock?

1.1. This internal, daily rhythm is what This internal, daily rhythm is what psychologists refer to as the psychologists refer to as the biological clockbiological clock

Different from the way it is used in Different from the way it is used in Hollywood!!Hollywood!!

2.2. While it can be manipulated by While it can be manipulated by external factors, the clock is an external factors, the clock is an INTERNAL mechanismINTERNAL mechanism

What Controls the What Controls the Biological Clock?Biological Clock?

1.1. Brain areasBrain areas

2.2. GlandsGlands

3.3. HormonesHormones

4.4. NeurotransmittersNeurotransmitters

5.5. External influencesExternal influences

Suprachiasmatic Suprachiasmatic NucleusNucleus

1.1. The hypothalamus is responsible for The hypothalamus is responsible for controlling the internal mechanisms controlling the internal mechanisms of hunger, sexual arousal, body of hunger, sexual arousal, body temp, etc.temp, etc.

2.2. The suprachiasmatic Nucleus (The suprachiasmatic Nucleus (SCNSCN) ) is an area of the hypothalamus that is an area of the hypothalamus that controls the biological clockcontrols the biological clock

How would you guess we know that?How would you guess we know that? Damage and… hamstersDamage and… hamsters

MelatoninMelatonin1.1. Part of the SCN’s function is to Part of the SCN’s function is to

control glands that release control glands that release hormones hormones pineal gland pineal gland

2.2. The pineal gland controls the The pineal gland controls the release of melatoninrelease of melatonin

3.3. What would you guess melatonin’s What would you guess melatonin’s function is?function is?

Can we Manipulate the Can we Manipulate the Clock?Clock?

1.1. First, what ‘sets’ the clock?First, what ‘sets’ the clock? The The zeitgeberzeitgeber Location of the SCN & link to the retinaLocation of the SCN & link to the retina How can animals who can’t see light set How can animals who can’t see light set

the clock?the clock?

2.2. Can you think of any circumstances Can you think of any circumstances where you would want to manipulate where you would want to manipulate the clock?the clock?

Traveling to other time zonesTraveling to other time zones Shift workShift work NewbornsNewborns

Jet LagJet Lag1.1. Has everyone here experienced Jet Has everyone here experienced Jet

Lag?Lag? When does it happen?When does it happen? What does it feel like?What does it feel like?

2.2. Constantly adjusting and re-Constantly adjusting and re-adjusting can actually be bad for adjusting can actually be bad for the bodythe body

Stress hormones increase – heart Stress hormones increase – heart problemsproblems

Even brain changes with functional Even brain changes with functional consequencesconsequences

Shift workShift work1.1. Can we effectively override the Can we effectively override the

circadian rhythm and shift our circadian rhythm and shift our bodies to be awake at night and bodies to be awake at night and sleep all day?sleep all day?

2.2. While we CAN do it, we never do it While we CAN do it, we never do it very well (no matter how long we very well (no matter how long we are on that schedule)are on that schedule)

What is Sleep?What is Sleep? Can anyone describe it to me? Can anyone describe it to me?

Sleep is …Sleep is …

Sleep has a distinct biological Sleep has a distinct biological rhythmrhythm

About every 90 minutes we cycle About every 90 minutes we cycle through 5 stages of sleepthrough 5 stages of sleep

How do we get to How do we get to sleep?sleep?

1.1. Decreasing stimulationDecreasing stimulation

2.2. Temperature changesTemperature changes

3.3. Inhibit the arousal centers of the Inhibit the arousal centers of the brain, namely the forebrainbrain, namely the forebrain

The Stages of SleepThe Stages of Sleep

Stage oneStage one

Stage twoStage two

SLOW-WAVE SLEEPSLOW-WAVE SLEEP Stage threeStage three Stage fourStage four

The ‘5The ‘5thth’ Stage ’ Stage REM sleepREM sleep We know that activity in the pons is We know that activity in the pons is

what ‘triggers’ REM sleepwhat ‘triggers’ REM sleep There is a pattern of brain activity There is a pattern of brain activity

from pons to the thalamus and from pons to the thalamus and then to the occipital cortexthen to the occipital cortex

The limbic system is also activated The limbic system is also activated during REMduring REM

The CycleThe Cycle 11 2 2 3 3 4 4 3 3 2 2 REM REM

In other words, the ‘5In other words, the ‘5thth stage’ of stage’ of sleep doesn’t happen right after sleep doesn’t happen right after stage 4! stage 4! We cycle back up & have REM We cycle back up & have REM

instead of stage 1instead of stage 1

We don’t spend equal amounts of We don’t spend equal amounts of time in each stage during the nighttime in each stage during the night

How much Sleep do we How much Sleep do we Need?Need?

1.1. The answer varies based on factors The answer varies based on factors such as agesuch as age

Newborns spendNewborns spend Older adultsOlder adults TeenagersTeenagers

2.2. Most adults allowed to sleep as long Most adults allowed to sleep as long as they like will tend to go about 9 as they like will tend to go about 9 hourshours

Theories about why we Theories about why we SleepSleep

1.1. As an evolutionary protective As an evolutionary protective mechanismmechanism

2.2. Sleep is a restorative functionSleep is a restorative function

3.3. Growth may occur during sleepGrowth may occur during sleep

Why REM?Why REM?1.1. REM is necessary, with out it we REM is necessary, with out it we

become irritable and ADD-likebecome irritable and ADD-like

2.2. Maybe involved in learning and Maybe involved in learning and memorymemory

The consolidation process is a good The consolidation process is a good candidatecandidate

Research is mixedResearch is mixed

3.3. Weird Eyeball theoryWeird Eyeball theory

Why Dreams?Why Dreams?1.1. Activation-synthesis hypothesisActivation-synthesis hypothesis

2.2. Clinico-anatomical hypothesisClinico-anatomical hypothesis

InsomniaInsomnia InsomniaInsomnia, three kinds:, three kinds:

1.1. ONSET insomniaONSET insomnia

2.2. MAINTENANCE insomniaMAINTENANCE insomnia

3.3. TERMINATION insomniaTERMINATION insomnia Screw-ups in the body’s temperature Screw-ups in the body’s temperature

change are associated with onset at change are associated with onset at termination insomniatermination insomnia

1.1. Phase delayed = warmer than normal at Phase delayed = warmer than normal at night = onsetnight = onset

2.2. Phase advanced = warmer than normal in Phase advanced = warmer than normal in the morning = terminationthe morning = termination

Treatments for Treatments for InsomniaInsomnia

1.1. What have you guys tried when you What have you guys tried when you can’t sleep?can’t sleep?

2.2. Sleeping pills and alcoholSleeping pills and alcohol

3.3. Insomnia is often a behavioral issue Insomnia is often a behavioral issue & can be fixed with behavioral & can be fixed with behavioral interventionsinterventions

Sleep ApneaSleep Apnea Sleep apneaSleep apnea

1.1. You are basically waking up every few You are basically waking up every few minutes all night, every nightminutes all night, every night

2.2. You never feel restedYou never feel rested

3.3. Your family will often tell you that you Your family will often tell you that you snore like a bansheesnore like a banshee

Often caused by obesity, related to Often caused by obesity, related to heart damageheart damage

Treatments for Sleep Treatments for Sleep ApneaApnea

1.1. If obesity is a factor, lose weightIf obesity is a factor, lose weight

2.2. Cut down on alcohol and other Cut down on alcohol and other depressantsdepressants

3.3. Oxygen Delivery MaskOxygen Delivery Mask Basically forces air into your lungsBasically forces air into your lungs Looks really uncomfortable, but allows Looks really uncomfortable, but allows

people to remain asleeppeople to remain asleep

4.4. SurgerySurgery Kids – adenoids/tonsils Kids – adenoids/tonsils Adults – excess tissueAdults – excess tissue

NarcolepsyNarcolepsy1.1. NarcolepsyNarcolepsy

Not as uncommon as you might think – 1 Not as uncommon as you might think – 1 in 1000in 1000

Associated with Associated with cataplexycataplexy, , sleep sleep paralysisparalysis, & , & hypnagogic hallucinationshypnagogic hallucinations

2.2. Attacks are often brought on by emotionsAttacks are often brought on by emotions

3.3. Cause may be linked to neurotransmitter Cause may be linked to neurotransmitter problems – ACh (stem) & Hypocretin problems – ACh (stem) & Hypocretin (hypothalamus)(hypothalamus)

Treatments for Treatments for NarcolepsyNarcolepsy

1.1. You’d think treatments would focus You’d think treatments would focus on the proposed causes, right?on the proposed causes, right?

What would this entail?What would this entail? Why can’t we do that?Why can’t we do that?

2.2. Treatment at this point is basically Treatment at this point is basically to load these folks up with to load these folks up with stimulants stimulants

Restless Leg SyndromeRestless Leg Syndrome1.1. Your book calls this ‘periodic limb Your book calls this ‘periodic limb

movement disorder’movement disorder’

2.2. It is where as you are falling asleep It is where as you are falling asleep your legs kick involuntarily, waking your legs kick involuntarily, waking you upyou up

3.3. Pharmacological interventionsPharmacological interventions

REM Behavior DisorderREM Behavior Disorder1.1. This is a relatively newly recognized This is a relatively newly recognized

disorder in which the normal REM disorder in which the normal REM paralysis does not occurparalysis does not occur

Occurs most frequently in older men Occurs most frequently in older men with other brain disorder (like with other brain disorder (like Parkinson’s/Alzheimer’s)Parkinson’s/Alzheimer’s)

2.2. They frequently have aggressive They frequently have aggressive dreams & act them out, injuring dreams & act them out, injuring themselves or their sleeping themselves or their sleeping partnerspartners

3.3. It has been used as a defense for It has been used as a defense for ‘sleep-walking crime’ ‘sleep-walking crime’

Night Terrors, etc.Night Terrors, etc.1.1. Night terrors are different than your Night terrors are different than your

typical nightmaretypical nightmare

2.2. Sleep walking often runs in familiesSleep walking often runs in families