EXPLORING
PSYCHOLOGY
EIGHTH EDITION IN MODULES
David Myers
PowerPoint Slides
Aneeq Ahmad
Henderson State University
Worth Publishers, © 2011
Consciousness and the
Two-Track Mind
Dual-Processing, Sleep, and
Dreams
Module 5
The Brain and Consciousness
 Dual Processing
 Selective Attention
Sleep
 Biological Rhythms and Sleep
 Why Do We Sleep?
 Sleep Disorders
 Dreams
States of Consciousness
AP Photo/ Ricardo Mazalan
Stuart Franklin/ Magnum Photos
Christine Brune
Bill Ling/ Digital Vision/ Getty Images
Consciousness is our awareness of ourselves and our
environment. In addition to normal, waking awareness, it can
come to us in altered states.
Dual Processing
Through dual processing, we are
simultaneously processing information
through both conscious and unconscious
tracks.
Perception, memory, thinking, language,
and attitudes all operate on these two levels.
Selective Attention
Through selective attention, your conscious
awareness focuses on only a very limited aspect of
all that you experience.
While driving and talking on the phone, your
selective attention must shift focus from one to the
other, which can make you slower to respond to a
demanding situation.
Inattentional Blindness
Inattentional blindness refers to the inability to see
an object or a person in our midst. Simons &
Chabris (1999) showed that half of the observers
failed to see the gorilla-suited assistant in a ball
passing game.
Change Blindness
Change blindness is a form of inattentional
blindness in which two-thirds of individuals
giving directions failed to notice a change in the
individual asking for directions.
Sleep & Dreams
Sleep – the irresistible tempter to whom we
inevitably succumb. Sleep—the equalizer
of presidents and peasants. Sleep—sweet,
renewing, mysterious sleep.
Mysteries about sleep and dreams have just started
unraveling in sleep laboratories around the world.
Biological Rhythms and Sleep
Circadian Rhythms occur on a 24-hour cycle and include
sleep and wakefulness. Termed our “biological clock,” it
can be altered by artificial light.
Light triggers the suprachiasmatic nucleus to decrease
(morning) melatonin from the pineal gland
and increase (evening) it at nightfall.
Sleep Stages
REM sleep rapid eye movement sleep: a recurring sleep
stage during which vivid dreams commonly occur. Also
known as paradoxical sleep, because the muscles are relaxed
(except for minor twitches) but other body systems are
active.
Alpha waves: the relatively slow brain waves of a relaxed,
awake state.
Sleep: periodic, natural loss of consciousness—as distinct
from unconsciousness resulting from a coma, general
anesthesia, or hibernation.
Sleep Stages
Hallucinations, false sensory experiences, can
occur during the brief Stage 1 sleep.
Delta waves, the large, slow brain waves
associated with deep sleep begin in Stage 3 and
increase in Stage 4.
Measuring Sleep Activity
Sleep researchers measure brain-wave activity, eye
movements, and muscle tension by electrodes that pick up
weak electrical signals from the brain, eye, and facial muscles.
Brain Waves and Sleep Stages
The regular alpha waves of an
awake, relaxed state are quite
different from the slower, larger
delta waves of deep Stage 4
sleep.
Although the saw-toothed REM
sleep waves resemble the near waking Stage 1 sleep waves, the
body is more aroused during
REM sleep than during Stage 1
sleep. (From Dement, 1978.)
90-Minute Cycles During Sleep
With each 90-minute cycle, stage 4 sleep decreases
and the duration of REM sleep increases.
Why do we sleep?
The Effects of Sleep Loss
We spend roughly onethird of our lives sleeping.
Jose Luis Pelaez, Inc./ Corbis
A sleep-deprived person
may experience a
depressed immune system,
impaired concentration,
and a greater vulnerability
to accidents.
Canadian Traffic Accidents
Frequency of accidents increase with loss of sleep
Sleep Theories
1. Sleep Protects: Sleeping in the darkness when
predators loomed about kept our ancestors out
of harm’s way.
2. Sleep Helps us Recover: Sleep helps restore and
repair brain tissue.
3. Sleep Helps us Remember: Sleep restores and
rebuilds our fading memories.
4. Sleep may play a role in the growth process:
During sleep, the pituitary gland releases
growth hormone. Older people release less of
this hormone and sleep less.
Sleep Disorders
1. Insomnia: A persistent inability to fall
asleep.
2. Narcolepsy: Overpowering urge to fall
asleep that may occur while talking or
standing up.
3. Sleep apnea: Failure to breathe when
asleep.
Sleep Disorders
Children are most prone to:



Night terrors: The sudden arousal from sleep
with intense fear accompanied by
physiological reactions (e.g., rapid heart rate,
perspiration) which occur during Stage 4 sleep.
Sleepwalking: A Stage 4 disorder which is
usually harmless and unrecalled the next day.
Sleeptalking: A condition that runs in families,
like sleepwalking.
Dreams
A dream is a sequence of images, emotions,
and thoughts passing through a sleeping
person’s mind.
Why Do We Dream?
To satisfy our own wishes…
Freud believed that dreams provide an outlet for
otherwise unacceptable feelings.
Manifest content: the remembered story line of a
dream
Latent content: the underlying meaning of a
dream
Why We Dream
To develop and preserve neural pathways…
Some researchers speculate that dreams may serve a
physiological function.
To make sense of neural static…
Other theories propose that dreams erupt from neural
activity spreading upward from the brainstem
To reflect cognitive development…
Others see dreams as part of brain maturation and
cognitive development. REM rebound, the tendency for
REM sleep to increase following REM sleep deprivation,
supports this view.
Dream Theories
Summary