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
