The Science of Sleep

Sleep Patterns Weekdays: What time do you go to bed? What time do you wake up? Weekend days: What time do you go to bed? What time do you wake up? Do you think you get enough sleep?

Question # 8 Sleep is a time for the body and brain to shut down for rest. Disagree Sleep is a dynamic process:  Some increased brain activity  Endocrine systems increases secretions of certain hormones What is sleep video

How much sleep did you get last night? How much should you have? How much should a teenager have?

Would you believe 9 to 10 hours?

Agree  Teens do need at least 9 hours of sleep per night  Teens need more sleep than adults  Most teens do not get enough sleep Question # 6 Most teens need at least nine hours of sleep each night.

Did you know? 85% of adolescents get less than recommended sleep on school nights 56% of teens report getting less sleep than they need By 12 th grade average sleep on school nights is 6.9 hrs. –By end of week sleep debt = 10.5 hours

Good Sleep Healthier Attractive Taller Stronger Faster More athletic Smarter

NSF poll 28% fall asleep at least one time per week 22% fall asleep doing homework Less sleep –Lower grades –Depressed mood “A” Students –Sleep 15 min more than B students –26 min more than C students –36 min more than D students Teachers were able to predict students sleep amounts by academic and classroom behavior

Attention Deficit Hyperactivity Disorder Primary Symptoms of ADHD Hyperactivity Inattention Impulsivity Distractibility Difficulty concentrating Forgetful Difficulty waiting or taking turns Sleep Deprivation in Kids Hyperactivity Inattention Impulsivity Distractibility Difficulty concentrating Forgetful Oppositional behavior Moodiness and irritability

Did you know? It is estimated that at least 50% of kids diagnosed with ADHD actually have sleep disorder.

Why is sleep important? Memory Concentration Motor response/reaction Controlling emotions School/work/athletic performance

Sleep Regulation Regulated by: Circadian system (Biological clock) Homeostatic mechanism Sleep variables: Duration Sleep intensity ( Tobler and Achermann)

Sleep Cycles 1.Biological clock – when 2.NREM/REM – how 3.Sleep Homeostasis - need

Question #1 Everyone has a biological clock. True  The timing of sleep in humans is regulated by our biological clock

(1) Biological Clock Cycle: a little longer than 24 hour period “CIRCADIAN CLOCK” circa=about diem=day Clock Regulates: –Seasonal reproductive cycles –Sleep/wake cycles External and internal rhythms.

Question # 9 The body quickly adjusts to different sleep schedules? False  Circadian clock works on day/night schedule, despite attempts to change it  Clock can sometimes be reset, but only by an hour or two. (1) Biological Clock

Circadian Rhythms Two Clock Rhythms  External (environmental) rhythm  Internal rhythm (1) Biological Clock

 Clock location: suprachiasmatic nucleus (SCN) of the hypothalamus in the brain  At SCN signals interact with genes (active/inactive) to serve as “pacemakers” External rhythm LIGHT (1) Biological Clock

Internal rhythm  Rhythm continues in absence of environmental cues  Cycles just over 24 hours, bedtime 1 hour later each night.  24 days back to same bedtime. Biological Clock Video (1) Biological Clock

(2) NREM/REM (Ultradian Rhythm)  Slow wave - Non Rapid Eye Movement (NREM)  Rapid Eye Movement (REM)

NREM Slow wave –Low muscle movement –Limited eye movement (2) NREM/REM  Brain distributes information into networks & categories. (FRONTLINE)  Connections between nerve cells strengthen - consolidating new skills. (FRONTLINE)

REM –Burst of rapid eye movement –Almost paralyzed (2) NREM/REM  Brain re-enacts previous day (FRONTLINE)  Solidifies newly made connections through memory banks (FRONTLINE)

Practice makes perfect!! (2) NREM/REM

What happens when you don’t sleep?

Consequences of Sleep Deprivation Cognitive and social impairment Decreases ability to think –Creative –Problem solving –Abstract thought –Decision making/judgement Mood and depression Reduced endurance Increased risk seeking behavior Impaired motor function –Decreased coordination –Blurred vision –Prolonged reaction time Delayed visual reaction time Delayed auditory reaction time

Fatigue vs. Alcohol  17 hours sustained wakefulness produces performance impairment =.08% BAC  24 hours =.10% BAC (Dawson & Reid, 1997; Williamson & Feyer, 2000).  Synergistic effect  On 4 hours sleep, 1 beer can have the impact of a six- pack (Roehrs et al., 1994)

*Approximate breath ethanol concentration (BrEC) at peak; † Above 0.05% for legal intoxication in many states. N=32 healthy subjects without prior sleep deprivation and with  85% sleep efficiency. Sleep loss group (n=12) was tested in all 4 conditions, with 3 to 7 days of recovery time between tests, and compared with ethanol group (n=20). Roehrs T, et al. Sleep. 2003;26: BrEC, %* Sleep time (hours in bed) Legal Intoxication † Hours of Sleep and Equivalent Blood Alcohol Level for Sedative Effects

Why don’t you get enough sleep? Not a priority

Not enough sleep Sleep just is not set as a priority –School –Homework –Sports –Social life –Television –Internet –Etc all get in the way

They want to sleep, but aren’t able Their internal clock is shifted several hours later. –Bedtimes shifts to 11-1am Trying to go to bed at 10 is similar to adult trying to go to bed at 8 pm –Wake up times shift accordingly Shortened sleep time

Junk sleep 98.5% have at least one electronic device in their bedroom (TV, Phone or mp3 player) –65% had all 3 –Greater number of items Less amount of sleep Greater amount of daytime sleepiness

Sleep Disorders Obstructive sleep apnea syndrome Restless Legs/Periodic Limb Movement Parasomnias Insomnia –Stress/worry/body clock

Tips to help sleep Make sleep a priority!!!!! Establish regular sleep schedule and routine –Encourage relaxing, non-alerting activity Read Write Avoid TV and PC Make Bedroom a NO gadget zone. –Place recharging station in kitchen not bedroom. Avoid Caffeine. Expose yourself to light in the morning. Exercise, but not too close to bedtime. Avoid late naps

(3) Sleep Homeostasis (Homeostatic “rhythm”) Homeostasis: maintaining internal equilibrium by adjusting internal processes  Sleep pressure increases when awake  Sleep pressure decreases during sleep

Sleep Homeostasis  Molecule Adenosine: Keep tracks of sleep loss May induce sleep Caffeine binds and blocks receptors  Hormone melatonin: Levels rise during the night Levels decline at dawn Controlled by the clock (3) Homeostasis Sleep Homeostasis Video

Circadian patterns typical of someone who rises early in morning, eats lunch around noon, and sleeps at night (10 p.m.) 1)Biological Clock - when 2)NREM/REM - how 3)Homeostasis - need Sleep Cycles

Why is sleep important? Memory Concentration Motor response/reaction Controlling emotions School/work/athletic performance

Question #10 Getting one hour less sleep per night than I need will not have any effect on my daytime performance. False  small, regular, decreases can effect daytime performance.

What are good and bad sleep habits? Good Sleep HabitsBad Sleep Habits

What are some consequences of bad sleep habits? IndividuallySocially

Question #3 Safe drivers don’t have to worry about being sleepy? False  Sleepiness = decrease in alertness  Decrease in alertness ≠ safe driving

Question # 7 Driving makes you sleepy. False  Driving makes your level of sleepiness apparent  Safest to drive during alert times

Sleep Prepares for Learning Too little sleep impairs information acquisition – Sleepiness – Irritability – Distractibility – Inattention – Motivation That is, ability to process input is diminished

References Unless otherwise noted within the presentation, information, charts and graphs have been obtained from NIH Curriculum Supplements for Grades Sleep Disorders and Biological Rhythms. 1.NIH Curriculum Supplement Series for Grades Sleep Disorders and Biological Rhythms. National Institutes of Health FRONTLINE. Adolescents and Sleep, A Summary of What Researchers Know About Teenagers’ Need for Sleep and Why Sleep Affects Memory and Learning Jenni OG., Achermann P. and Carskadon MA. Homeostatic sleep regulation in adolescents. SLEEP 28 (2005) Tobler, Irene and Achermann, Peter, Sleep homeostasis. 5.What is Sleep, Biological Clock and Homeostasis videos: Biological clock diagram Nova sleep movie: