VARIATIONS IN CONSCIOUSNESS Is this reality or just someone’s imagination of reality? VARIATIONS IN CONSCIOUSNESS

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 types 1: difficulty in falling asleep 2: difficulty maintaining sleep 3: 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