PSYC 211 Chapter Notes - Chapter 9: Multiple System Atrophy, Melanopsin, Genetic Disorder
22 Aug 2013
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Stages of sleep: electrodes monitor eeg, muscle activity recorded as electromyogram emg, eye movement recorded as electro-oculogram eog. During wakefulness, there is alpha activity: regular, medium-frequency waves 8-12 hz, eyes closed. Beta activity is irregular, low amplitude waves 13-30 haz, shows desynchrony many neural circuits actively processing info, person alert and attentive. Stage 1: theta activity, transition between sleep/wakefulness, eyes open/close, roll up/down. After 15 minutes, stage 3 has high-amplitude delta activity, 3. 5 hz, also in stage 5. After 45 minutes of stage 4, eeg becomes desynchronizes, some theta waves, eyes rapidly move, person paralyzed rem sleep. Cycles are 90 minutes long, 20-30 minutes rem, becomes longer, more rem and stage 2. Basic rest-activity cycle: 90 minutes cycle of waxing and waning alertness, controlled by biological clock in caudal brain stem, controls rem cycles and slow-wave sleep. Rem we are paralyzed, but brain very active accelerated cerebral blood flow, oxygen consumption.
