Stages of Consciousness

History

• Wundt - __________________• James – ___________________• Behaviorism - _______________• Consciousness – able to study using ________– More scientific

Stages of Consciousness

• Controlled processes – __________________• Automatic processes ex. _____________• Daydreaming - __________________• Sleeping• Anesthesia • Unconsciousness

Circadian Rhythms

• The cyclical daily fluctuations in biological and psychological processes

• Light resets biological clock– Hormone melatonin– Light tweaks the circadean clock by activating light-sensitive retinal

proteins. These proteins tigger signals to the brain’s suprachiasmatic nucleus – causing the brain’s pineal gland to decrease secretion of melatonin in the morning or increase the secretion of melatonin in the evening which causes slowing of biological activity

– Shift to 25 hour clock due to electric lights– Easier to adjust to later shifts than earlier ones

Why do we sleep?

– Evolutionary psychology – sleep protects; better to be safe in cave than vulnerable in dark

– Physiological psychology – sleep frees up energy to restore body and brain and allow for growth

– Sleep helps us recuperate – restore and repair brain tissue, building memories

Sleep Stages

Brain Waves

• Beta – alert wakefulness, small, fast brain waves• Alpha – relaxed wakefulness, drowsy, relatively

slow brain waves• Delta – large, slow brain waves associated with

deep sleep• K complex – single, high voltage spike of brain

activity• REM – rapid eye movement, alpha waves, rapid

breathing, “REM paralysis”, dreaming

Stages of Sleep

• Stage 1: Small, irregular waves produced in light sleep (people may or may not say they were asleep)– Hypnic Jerk: Reflex muscle contraction

• Stage 2: Deeper sleep; sleep spindles (short bursts of distinctive brain-wave activity) appear, K complex – single high voltage spike of brain activity

• Stage 3: Deeper sleep; Delta waves appear; very large and slow

• Stage 4: Deepest level of normal sleep; almost purely Delta waves

(a) Average proportion of time adults spend daily in REM sleep and NREM sleep. REM periods add up to about 20 percent of total sleep time. (b) Typical changes in stages of sleep during the night. Notice that dreams mostly coincide with REM periods.

Typical Night Sleep

• 0 • 1 • 2 • 3 • 4 • 5 • 6 • 7

• 4

• 3

• 2

• 1

• Sleep• stages

• Awake

• Hours of sleep

• REM

Typical Night Sleep

• Hours of sleep

• Minutes

• of • Stag

e 4 and

• REM

• 1 • 2 • 3 • 4 • 5 • 6 • 7 • 8• 0

• 10

• 15

• 20

• 25

• 5

• Decreasing • Stage 4

• Increasing • REM

Sleep Disorders• Insomnia

– persistent problems in falling or staying asleep• Narcolepsy

– uncontrollable sleep attacks• Sleep Apnea

– cessation of breathing– often associated with snoring– repeatedly awakes sufferer

• Night Terrors– high levels of arousal– Stage 4– heart rate and breathing rate double

• Sleepwalking (Somnambulism)– Occurs in NREM sleep during Stages 3 and 4

• Sleeptalking– Speaking while asleep; occurs in NREM sleep

Sleep Deprivation

• Create sleep debt if sleep is missed

• Lost sleep changes behavior– Irritable

– Fatigued

– Inattentive and inefficient