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VARIATIONS IN CONSCIOUSNESS
Is this reality or just someone’s imagination of reality?
CONSCIOUSNESS
The awareness of internal and external stimuli
Also includes: Awareness of self as unique Awareness of experiences
VARIATIONS IN LEVELS OF AWARENESS William James---stream of
consciousness Freud believed that stream had depth
(unconscious) Conscious and unconscious are levels
of consciousness
CONSCIOUSNESS AND BRAIN ACTIVITY Consciousness is not centered in one
structure EEG is the best measurement Records brain waves 4 principle waves: beta, alpha, theta,
and delta
BIOLOGICAL RHYTHMS AND SLEEP
Biological rhythms: periodic fluctuations in physiological functioning
Circadian rhythms: 24 hour biological cycles found in humans and many other species
IGNORING CIRCADIAN RHYTHMS
Quality of sleep Crossing time zones causes jet lag Going to bed a couple of hours later
affects rhythm
THE SLEEP AND WAKE CYCLE
CONDUCTING SLEEP RESEARCH
Use EEG Electromyograph (EMG): records
muscular activity and tension Electrooculograph (EOG): records eye
movements
STAGES OF SLEEP---STAGE 1
1: lasts 1-7 minutes; drowsiness; breathing and heart rate decrease; muscle activity declines
Hypnic jerks: brief muscular contractions
Primarily theta waves
STAGES OF SLEEP---STAGE 2
10-25 minutes Sleep spindles: higher-frequency brain
waves Brain waves become higher in
amplitude and slower in frequency
STAGES OF SLEEP---STAGES 3 AND 4
Lasts c. 30 minutes Slow-wave sleep: high amp, low
frequency delta waves prominent After: cycle reverses Before reaching stage one again, ….
REM SLEEP
5th stage Irregular breathing and pulse Virtually paralyzed Beta waves High-frequency, low amp brain waves,
and vivid dreaming Non-REM (nREM): stages 1-4
REPEATING THE CYCLE
Usually repeat c. 4 times REM periods get longer; peak at 40-60
min. NREM periods get shorter Young adults: 60% in light sleep (1 and
2); 20% in slow wave sleep (3 and 4); 20% in REM
AGE AND SLEEP
Infants: 6-8 times in 24 hrs; 16+ hrs total
50% in REM As age increases, deep sleep decreases
in amt Total sleep increases w/age
CULTURE AND SLEEP
Co-sleeping: children and parents sleep together
Discouraged in western societies Napping is cultural; siesta cultures
NEURAL BASES OF SLEEP
Reticular Formation important in sleep and wakefulness
Ascending reticular activating system (ARAS): afferent fibers running through the RF that influence physiological arousal
NEURAL BASES OF SLEEP CONTINUED Pons assoc. with REM sleep Areas in medulla, thalamus,
hypothalamus, and limbic system assoc. with control of sleep and waking
NT’s involved: ACh, serotonin, norepinephrine, dopamine, and GABA
EVOLUTIONARY BASES OF SLEEP
Conserve energy Reduce exposure to predators Helps to restore energy and other
bodily resources Which do you believe?
SLEEP DEPRIVATION
Complete deprivation negatively effects mood, cognitive and perceptual-motor tasks
Difficult to go past 3 or 4 days w/o sleep
Partial deprivation: losing substantially less sleep over a period of time; very common
SLEEP DEPRIVATION CONTINUED
Selective deprivation Repeated disruption of sleep Experiments show rebound effect:
making up time in stages where sleep was interrupted
INSOMNIA
Insomnia: chronic problems in getting adequate sleep
3 main types1: difficulty in falling asleep2: difficulty maintaining sleep3: persistent early-morning waking--assoc. w/ daytime fatigue, impaired functioning, reduced productivity, increased health problems
INSOMNIA
Sleep state misperception: pseudoinsomnia
Causes: anxiety, stress, depression, various health problems
Treatment: sedatives for short term solution
OTHER SLEEP DISORDERS
Narcolepsy: sudden onset of sleep during normal waking periods
Sleep apnea: frequent, reflexive gasping for air that disrupts sleep
Nightmares: anxiety-arousing dreams that lead to awakening, usually from REM
Night terrors: abrupt awakenings from NREM sleep accompanied w/intense autonomic arousal and feelings of panic
Sleepwalking: walking around while asleep