The Sleep CycleThe Sleep Cycle

Unit 3Unit 3

Lesson 2Lesson 2

Objectives:Objectives:

• Define sleepDefine sleep

• Identify the main theories of sleepIdentify the main theories of sleep

• Differentiate between the stages of Differentiate between the stages of sleepsleep

Warm UpWarm Up

• Describe two of the Describe two of the five different levels five different levels of consciousness of consciousness we talked about we talked about yesterday.yesterday.

What Is Sleep?What Is Sleep?

• An altered state in An altered state in which people which people become relatively become relatively unaware of unaware of external external stimulationstimulation

Studying SleepStudying Sleep

• (1953) EEG records (1953) EEG records brain wave activitybrain wave activity– Frequency and Frequency and

strengthstrength

• EOG record eye EOG record eye movementsmovements

• EMG record muscle EMG record muscle movementsmovements

• EKG records activity of EKG records activity of the heartthe heart

Online ActivityOnline Activity

• Use PsychSim 5.0 “EEG & Sleep Use PsychSim 5.0 “EEG & Sleep Stages” atStages” at

http://www.worthpublishers.com/http://www.worthpublishers.com/exploring5e/content/psychsim5/EEGexploring5e/content/psychsim5/EEG%20and%20Sleep%20Stages/%20and%20Sleep%20Stages/PsychSim_Shell.htmlPsychSim_Shell.html

EEG and Sleep StagesEEG and Sleep Stages

• Awake = Beta WavesAwake = Beta Waves

• Stage 1 = Theta WavesStage 1 = Theta Waves– Hypnagogic StateHypnagogic State

• Stage 2 = Theta WavesStage 2 = Theta Waves– Sleep SpindlesSleep Spindles

• Stage 3 = Delta WavesStage 3 = Delta Waves

• Stage 4 = Delta WavesStage 4 = Delta Waves– Bedwetting, Sleep talk/walkBedwetting, Sleep talk/walk– Night TerrorsNight Terrors

• REM = Mimic’s Beta WavesREM = Mimic’s Beta Waves– Atonia, DREAMING!Atonia, DREAMING!

Sleep CycleSleep Cycle

• Roughly 5 periods Roughly 5 periods of REM sleep per of REM sleep per nightnight– Sleep becomes Sleep becomes

lighter as night lighter as night wears onwears on

– REM sleep REM sleep becomes longer becomes longer towards amtowards am

Why Do We Sleep?Why Do We Sleep?

• Evolutionary TheoryEvolutionary Theory: Protective function, keeps : Protective function, keeps people tucking away at night, safe from predators.people tucking away at night, safe from predators.

• Recuperative TheoryRecuperative Theory: Conserves energy, restores : Conserves energy, restores body tissues depleted during daily activitybody tissues depleted during daily activity– REM: hormones released that influence thinking REM: hormones released that influence thinking

& memory formation, mental organization; & memory formation, mental organization; counteract fatigue, irritability, inattentioncounteract fatigue, irritability, inattention

– NREM: body replenishes itself (tissue restoration NREM: body replenishes itself (tissue restoration and release of growth hormone)and release of growth hormone)

Why Do We Sleep At Night?Why Do We Sleep At Night?

• Circadian RhythmCircadian Rhythm– Internally Internally

generated generated sleep/wake cycle sleep/wake cycle connected to 24-connected to 24-hour pd of earth’s hour pd of earth’s rotationrotation

How Much Sleep Do I Need?How Much Sleep Do I Need?

• InfantsInfants– 20 hours20 hours

• 50% REM50% REM

• Children/AdolescentsChildren/Adolescents– 10 hours10 hours

• 25-30% REM25-30% REM– Bed Later, Up LaterBed Later, Up Later

• AdultsAdults– 8 hours8 hours

• 20% or less REM20% or less REM

• Elderly Elderly – 6 hours6 hours– Bed Later, Up EarlierBed Later, Up Earlier

What If I Miss Sleep?What If I Miss Sleep?

• Effects On BodyEffects On Body

– Immune system Immune system weakensweakens

– Metabolic Metabolic malfunctionmalfunction

– Varied body tempVaried body temp

• Effects On BrainEffects On Brain– MoodinessMoodiness– Decreased cognitive Decreased cognitive

performanceperformance• Learn slower, Learn slower,

remember less, loss remember less, loss concentration & concentration & creativitycreativity

– Blurred visionBlurred vision– Disorganized speechDisorganized speech– HallucinationsHallucinations

Sleep ActivitiesSleep Activities

• Am I Sleep Am I Sleep Deprived?Deprived?

• Sleep Myths QuizSleep Myths Quiz

Am I Sleep Deprived? Am I Sleep Deprived? Yes/NoYes/No• I need an alarm clock to I need an alarm clock to

wake up for school.wake up for school.

• It’s a struggle to get out of It’s a struggle to get out of bed in the morning.bed in the morning.

• I hit the snooze bar several I hit the snooze bar several times to get more sleep.times to get more sleep.

• I feel tired, irritable and I feel tired, irritable and stressed out during the stressed out during the week.week.

• I have trouble concentrating I have trouble concentrating and remembering.and remembering.

• I feel slow with critical I feel slow with critical thinking, problem solving thinking, problem solving and being creative.and being creative.

• I often fall asleep in boring I often fall asleep in boring classes or warm rooms.classes or warm rooms.

• I often fall asleep within 5 I often fall asleep within 5 minutes of getting into bed.minutes of getting into bed.

• I often feel drowsy while I often feel drowsy while driving.driving.

• I often sleep extra hours on I often sleep extra hours on weekend mornings.weekend mornings.

• I often need a nap when I I often need a nap when I get home from school.get home from school.

• I have pink circles around or I have pink circles around or dark circles under my eyes.dark circles under my eyes.

Am I Sleep Deprived? Am I Sleep Deprived? Yes/NoYes/No• An answer of “yes” to An answer of “yes” to

three or more of the three or more of the previous questions previous questions indicates sleep indicates sleep deprivation.deprivation.

• You can easily You can easily improve your mood, improve your mood, performance and performance and health by getting health by getting more sleepmore sleep!!

Closure

•How has sleep deprivation affected your life? Which activities contribute most to your sleep deprivation?