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Presentation on theme: "Sleep."— Presentation transcript:

1 Sleep

2 Variations in Consciousness
Consciousness – Awareness of internal and external stimuli “personal awareness” Example

3 Variation in levels of awareness
Consciousness is not all or none We still have some level of awareness during sleep and even while under anesthesia during surgery Examples

4 Studying states of consciousness
Electroencephalograph (EEG) –a device that monitors electrical activity of the brain over time Records electrodes attached to surface of scalp This shows the rhythm of activity of brain (brain waves)


6 Biological Rhythms and Sleep
Circadian Rhythm – 24 hour biological cycles found in humans and other species Influential in sleep regulation These rhythms prime us to fall asleep easily at a certain point in day “ideal” time

7 Ignoring Rhythms (Ideal Sleep)
What happens when we ignore our biological clocks and sleep at an unusual time? Quality suffers Tired, sluggish, irritable for days, lower cognitive performance Equates with “jet lag” This is especially problematic for workers constantly switching and working odd shifts. What some studies show

8 Realigning Circadian Rhythms
Researchers have studied methods to get over this feeling of “jet lag” Options Certain type of drug (melanonin) Carefully timed exposure to bright light Carefully plan rotation schedules at work Problem with options

9 The Sleep and Waking Cycle
Former thoughts about sleep… Now realize that much physical and mental activity happens during sleep How did we form this understanding? Sleep Laboratories Volunteer patients spend night What happens in these labs? Video clip

10 Sleep Stages Sleep onset is gradual
Once we fall asleep, humans progress through different stages Stages 1-4- Commonly referred to as non- REM sleep Respiration, heart rate, and body temperature decrease with each stage Brain waves increase as we progress

11 REM Sleep This is the fifth and final sleep stage
REM= Rapid eye movements How are these measured? How were they discovered? REM is the deepest form of sleep Rapid eye movements High frequency brain waves Dreaming Sleep cycle (Stages 1-5) repeat during night

12 Cultural Variations in sleep
Cultures mostly similar in terms of sleep experience and activity Differ on other matters Co-sleeping- children and parents sleeping together More accepted in other cultures Examples Napping Some societies close shops and activities during day to permit naps for an hour or two examples

13 Sleep Deprivation Research has focused on sleep restriction – partial sleep deprivation Seems that much of the U.S. are chronic sufferers Effects our attention, reaction time, decision making Night time workers fall asleep on job Numerous accidents are result of sleep deprivation Examples

14 Selective Deprivation
Many lab studies awake participants whenever they begin to go into REM Selectively deprived of REM As nights go by, need to awaken more and more REM begins to happen more spontaneously in these patients now Following deprivation: Rebound Effect- patients spend extra time in REM sleep for one to three nights

15 Sleep Problems Insomnia- chronic problems getting adequate sleep
15-17% of adults suffer from severe insomnia Narcolepsy- marked by sudden, irresistible onsets of sleep during normal waking periods. Awake directly to REM sleep Very rare Sleep Apnea- frequent, reflexive gasping for air that awakens person and disrupts sleep Person literally stops breathing for 10 seconds Clips (if time)

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