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 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 NREM-2: lasts about 20 minutes See sleep spindles: rapid, rhythmic brain waves Can be easily awakened but are asleep

4 Stages Cont. 4. REM: contains most vivid dreams. 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 Protects Recuperative Restore/Rebuild memories Creative Thinking Growth