1. 4/26/2017
Sleeping and Dreaming

2. Electroencephalogram (EEG)
4/26/2017
Electroencephalogram (EEG)
Electrodes placed on the scalp provide a gross record of the electrical activity of the brain
EEG recordings are a rough index of psychological states
Keywords: electroencephalogram, EEG

3. EEG Waves of Wakefulness
4/26/2017
EEG Waves of Wakefulness
Awake, but non-attentive - large, regular alpha waves
1 second
Alpha waves
Awake, nonattentive
Awake and attentive - low amplitude, fast, irregular beta waves
Keywords: EEG, alpha waves, beta waves, wakefulness
1 second
Beta waves
Awake, attentive

4. 4/26/2017
Stages of Sleep
Sleep stage 1 - brief transition stage when first falling asleep
Stages 2 through 4 (slow-wave sleep) - successively deeper stages of sleep
Characterized by an 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)
Keywords: sleep stage 1, sleep stage 2, sleep stage 3, sleep stage 4, delta waves

5. 4/26/2017
Stages of Sleep
Upon reaching stage 4 and after about 80 to 100 minutes of total sleep time, sleep lightens, returns through stages 3 and 2
REM sleep emerges, characterized by EEG patterns that resemble beta waves of alert wakefulness
muscles most relaxed
rapid eye movements occur
dreams occur
Four or five sleep cycles occur in a typical night’s sleep - less time is spent in slow-wave, more is spent in REM
Keywords: REM sleep, sleep cycles

6. 4/26/2017
Functions of Sleep
Restoration theory - body wears out during the day and sleep is necessary to put it back in shape
Preservation 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
Keywords: restoration theory, preservation and protection theory

7. 4/26/2017
Circadian Rhythm
Any rhythmic change that continues at close to a 24-hour cycle in the absence of 24-hour cues
body temperature
cortisol secretion
sleep and wakefulness
In the absence of time cues, the cycle period will become somewhat longer than 24 hours
Keywords: circadian rhythm

8. 4/26/2017
Sleep Deprivation
Has little effect on performance of tasks requiring physical skill or intellectual judgment
Hurts performance on simple, boring tasks more than challenging ones
Most reliable effect is sleepiness itself
Keywords: sleep deprivation

9. Individual Differences in Sleep Drive
4/26/2017
Individual Differences in Sleep Drive
Some individuals need more and some less than the typical 8 hours per night
Nonsomniacs - sleep far less than most, but do not feel tired during the day
Insomniacs - has a normal desire for sleep, but is unable to and feels tired during the day
Keywords: nonsomniacs, insomniacs

10. Sleep Disorders Somnambulism - sleepwalking
4/26/2017
Sleep Disorders
Somnambulism - sleepwalking
Nightmares - frightening dreams that wake a sleeper from REM
Night terrors - sudden arousal from sleep and intense fear accompanied by physiological reactions (e.g., rapid heart rate, perspiration) that occur during slow-wave sleep
Narcolepsy - overpowering urge to fall asleep that may occur while talking or standing up
Sleep apnea - failure to breathe when asleep
Keywords: somnambulism, nightmares, night terrors, narcolepsy, sleep apnea

11. Dreams and REM Sleep Everyone dreams several times a night
4/26/2017
Dreams and REM Sleep
Everyone dreams several times a night
true dream - vivid, detailed dreams consisting of sensory and motor sensations experienced during REM
sleep thought - lacks vivid sensory and motor sensations, is more similar to daytime thinking, and occurs during slow-wave sleep
Keywords: true dream, sleep thought

12. Dreams and REM Sleep What are true dreams for?
4/26/2017
Dreams and REM Sleep
What are true dreams for?
Although research has yet to answer this question, a prevalent view today is that dreams don’t serve any purpose at all, but are side effects of REM
to exercise groups of neurons during sleep
some are in perceptual and motor areas
REM occurs in other mammals and to a much greater extent in fetuses and infants than adults
REM sleep may help consolidate memories
Keywords: side effect view of dreaming

13. Brain Mechanisms Controlling Sleep
4/26/2017
Brain Mechanisms Controlling Sleep
Sleep is promoted by a complex set of neural and chemical mechanisms
Daily rhythm of sleep and arousal
suprachiasmatic nucleus of the hypothalamus
pineal gland’s secretion of melatonin
Slow-wave sleep
raphe nuclei of the medulla and pons and the secretion of serotonin
REM sleep
neurons of the pons
Keywords: suprachiasmatic nucleus, pineal gland, raphe nuclei, medulla, pons, hypothalamus, melatonin, serotonin