MODULE 23 SLEEP PATTERNS AND SLEEP THEORIESUnit 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