1. 1 Sleeping and Dreaming

2. 2 Electroencephalogram (EEG) zElectrodes placed on scalp provide gross record of electrical activity of brain zEEG :rough index of psychological states

3. 3 EEG Waves of Wakefulness zlarge, regular alpha waves 1 second Awake, nonattentive 1 second Awake, attentive zfast, irregular beta waves

4. 4 Stages of Sleep zStage 1 - brief transition stage when first falling asleep zStages 2 - 4 (slow-wave sleep) - successively deeper stages of sleep zCharacterized by increasing percentage of slow, irregular, high- amplitude delta waves Delta waves Sleep stage 1 1 second Sleep stage 4 Sleep stage 2 Spindlers (bursts of activity)

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6. 6 EEG (De)-Synchronization zSynchronized activity: ylow frequency yhigh amplitude zDesynchronized activity: yhigh frequency ylow amplitude

7. 7 REM sleep (paradoxical sleep) Characteristics EEG waves-irregular, low-amplitude, high frequency waves (like beta waves) Postural muscle paralysis Rapid Eye Movements genital arousal irregular heart rate, blood pressure, breathing Dreams

8. 8 Sleep during a typical night 4- 5 cycles; Duration :About 90 minutes REM sleep takes up increasing amounts of cycle as night progresses

9. 9 Functions of Sleep zRestoration theory zPreservation and protection theory - sleep emerged in evolution to preserve energy and protect during the time of day when there is little value and considerable danger

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11. 11 Sleep Deprivation zHas little effect on performance of tasks requiring physical skill or intellectual judgment zHurts performance on simple, boring tasks more than challenging ones zMost reliable effect is sleepiness itself

12. 12 Dreams and REM Sleep zEveryone dreams several times a night ytrue dream - vivid, detailed dreams consisting of sensory and motor sensations experienced during REM ysleep thought - lacks vivid sensory and motor sensations, is more similar to daytime thinking, and occurs during slow- wave sleep

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14. 14 Dreams and REM Sleep zFunction?? zview today : dreams don’t serve any purpose, but are side effects of REM zPurpose of REM? yto exercise groups of neurons during sleep? ysome are in perceptual and motor areas zREM rebound: shows significance of REM zREM occurs in other mammals zMore REM in fetuses and infants zREM sleep may help consolidate memories

15. 15 Circadian Rhythm zAny rhythmic change that continues at close to a 24-hour cycle in the absence of 24-hour cues ybody temperature ycortisol secretion ysleep and wakefulness zNo time cues: cycle becomes longer than 24 hours

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18. 18 Brain Mechanisms Controlling Sleep zDaily rhythm of sleep and arousal ysuprachiasmatic nucleus of the hypothalamus ypineal gland’s secretion of melatonin zSlow-wave sleep yraphe nuclei of the medulla and pons ysecretion of serotonin zREM sleep yneurons of the pons

19. 19 Sleep Disorders zSomnambulism - sleepwalking zNightmares - frightening dreams that wake a sleeper from REM zNight terrors - sudden arousal from sleep and intense fear accompanied by physiological reactions (e.g., rapid heart rate, perspiration) that occur during slow-wave sleep zNarcolepsy - overpowering urge to fall asleep that may occur while talking or standing up zSleep apnea - failure to breathe when asleep