4/26/2017 Sleeping and Dreaming

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

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

4/26/2017 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

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

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

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

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

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

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

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

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

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