MODULE 23 SLEEP PATTERNS AND SLEEP THEORIES Unit

MODULE 23 SLEEP PATTERNS AND SLEEP THEORIES Unit 5 States of Consciousness

Biological Rhythms and Sleep Circadian Rhythm: regulates bodily rhythms including temp and sleep over 24 hr cycle • Ultradian • Infradian • Thinking and memory sharpest at YOUR daily peek • Altered by age and experiences • Owls and Larks

Sleep Stages • 90 minute cycles with 4 distinct stages • Measure changes in sleep stages using EEG on scalp, chin, corner of eyes • Alpha Waves: slow, when you’re awake but calm • Beta Waves: awake and alert • Sleep: natural loss of consciousness

4 Stages of Sleep 1. NREM-1: twilight sleep, slowed breathing irregular brain waves. Lasts a few minutes. Can have hallucinations: false sensory experiences (sense of falling) • • • Also known as hypnagogic sleep Can be incorporated into memories 2. NREM-2: lasts about 20 minutes • See sleep spindles: rapid, rhythmic brain waves • Can be easily awakened but are asleep

4 Stages Cont. 3. NREM-3: lasts about 30 min. • Deep sleep, delta waves 4. REM: contains most vivid dreams. • Paradoxical: brain looks like it’s awake but muscles are relaxed • Heart rate increases, rapid breathing, eyes dart, genital arousal=beginning of dreams • Active motor cortex but brainstem blocks messages • Sleep paralysis

Stages Cont. • Hour into cycle, you go back down the cycle • NREM-1 NREM-2 NREM-3 NREM-2 REM • Spend half of the night’s sleep in NREM-2 • At 90 minutes, NREM-3 grows shorter and disappears • 20 -25% in REM sleep each night

What Affects Our Sleep Patterns? • Genetically and culturally influenced • Bright lights “tweak” circadian rhythms • Suprachiasmatic nucleus (SCN): in hypothalamus causes pineal gland to decrease melatonin due to light

Sleep Theories 5 Reasons for Sleep 1. Protects 2. Recuperative 3. Restore/Rebuild memories 4. Creative Thinking 5. Growth