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Consciousness
Chapter 4
Consciousness
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Personal awareness of mental activities,
internal sensations, and the external
environment
William James (1892) described it as a
“stream” or “river”
Allows us to integrate past, present, and
future behavior
Attention
The capacity to selectively focus
awareness on particular stimuli in your
external environment or on you internal
thoughts or sensations.
 You are always paying attention to
something- but it’s not always the stimuli
that you’re supposed to be paying
attention to.
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Characteristics of Attention
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Attention has a limited capacity:
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Attention is selective:
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Compared to a spotlight that we shine on a particular stimuli or
thought.
Cocktail party effect: able to talk to one person even though you
are surrounded by a lot of noise.
Attention can be blind:
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We are faced with more information than we can process.
We can’t pay attention to everything.
We sometimes miss completely obvious stimuli in our vison or
hearing.
Multi-Tasking divides our attention and gives less
attention to each task.
Circadian Rhythm
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A cycle or rhythm that is roughly 24 hours long: the
cyclical daily fluctuations in biological and psychological
processes.
 body temperature
 Sleep/Wake cycle
In the absence of time cues, the cycle period will
become somewhat longer than 24 hours.
The Suprachiasmatic Nucleus
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SCN: cluster of neurons in the
hypothalamus that governs the
timing of circadian rhythms.
 Also involves environmental
cues- sun
Melatonin: hormone
manufactured by the pineal
gland that produces sleepiness.
Stages of Sleep
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Defined in terms of brain-wave patterns.
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Measured by an electroencephalograph or
EEG.
 Electrodes
placed on the scalp provide a gross
record of the electrical activity of the brain.
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4 different brain-wave patterns:
Beta
 Alpha
 Theta
 Delta
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Stages of Sleep
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When you are awake and aware your brain
emits beta waves.
When you become relaxed and drowsy your
brain switches to alpha waves.
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Hypnagogic hallucinations: vivid sensory phenomena
that occur during the onset of sleep.
Stages of Sleep
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Stage 1 NREM:
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Drowsiness occurs and theta waves start (can
still quickly wake if needed).
Stages 2 NREM:
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Onset of true sleep.
Defined by appearance of sleep spindles.
Brief bursts of brain activity that last a second
or two.
K complexes: single but large high-voltage
spike of brain activity.
Awake
Low-voltage, high-frequency beta waves
Drowsy
Alpha waves
Stage 1 Sleep
Theta waves
Stage 2 Sleep
mixed EEG activity
Slow wave sleep
(stage 3 and stage 4 sleep)
Progressively more delta waves (stage 4 shown)
REM sleep
Low-voltage, high-frequency waves
Stages of Sleep
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Upon reaching stage 4 and after about 80 to 100 minutes of
total sleep time, sleep lightens, returns through stages 3 and
2
REM sleep emerges, characterized by EEG patterns that
resemble beta waves of alert wakefulness
 muscles most relaxed
 rapid eye movements occur
 dreams occur
Four or five sleep cycles occur in a typical night’s
sleep; less time is spent in slow-wave, more is spent
in REM
Stages of Sleep
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Stage 3 & 4 NREM:
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Slow-wave sleep
When Delta waves represent more than 20% of brain
activity, sleeper is in stage 3.
When Delta waves exceed 50%, sleeper is in stage 4.
REM Sleep:
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Brain becomes more active, smaller and faster brain
waves.
Visual and motor neurons activate.
Dreams occur
Sleep Across the Lifespan
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Sleep cycles emerge during prenatal
development.
Newborns sleep about 16 hours per day.
By age 2, 75-minute sleep cycles are
experienced.
By age 5, typical 90-minute sleep cycles of
alternating REM and NREM sleep emerge.
Deeper slow-wave sleep decreases with age.
Time in REM sleep increases during childhood
and adolescence, remains stable throughout
adulthood, and decreases during late adulthood.
Sleep Deprivation
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Some individuals need more and some
less than the typical 8 hours per night.
After being deprived of sleep for just one night,
microsleeps develop-episodes of sleep lasting a
few seconds during wakefulness.
Disruptions in mood, mental abilities, reaction
time, perceptual skills, and complex motor skills
occur with sleep deprivation.
Most people are not good at judging the extent
to which their performance is impaired by
inadequate sleep.
Effects of Sleep Deprivation
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Moods become more volatile
Harmful changes in levels of stress hormones
Immune system compromised
REM deprivation often results in REM rebound
increasing REM by 50%
Changes become more pronounced the longer
the sleep deprivation
The brain needs to experience the full range of
sleep states, compensating when possible.
http://www.cbsnews.com/news/the-science-of-sleep/
Dreams and REM Sleep
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Dream: An unfolding sequence of
thoughts, perceptions, and emotions that
typically occurs during REM
Sleep thought—Vague, bland, thought
like occurrences about real-life events that
occur during NREM sleep.
Psychoanalytic Interpretation
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Manifest content—elements of the dream
that are consciously experienced and
remembered
Latent content—the unconscious wishes
that are concealed in the manifest content
Dreams as “wish fulfillments”
Activation Synthesis Model
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Brain activity during sleep produces dream
images (activation) that are combined by
the brain into a dream story (synthesis).
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Meaning is to be found by analyzing the
way the dreamer makes sense of the
progression of chaotic dream images.
Neurocognitive Model
Emphasizes the continuity of waking and
dreaming cognition.
 States that dreaming is like thinking under
conditions of reduced sensory input and
the absence of voluntary control.
 Dreams reflect our interests, personality
and individual worries.
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Sleep Disorders
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Dyssomnias: category of disorders involving
disruption in the amount, quality, or timing of
sleep.
Insomnia—inability to fall asleep or stay asleep
Narcolepsy—overpowering urge to fall asleep
that may occur while talking or standing up
Sleep Apnea
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Breathing interruption that occurs during sleep.
Do not start breathing again until they suddenly
sit up and gasp for air.
Once they start breathing again they go back to
sleep.
They are often tired throughout the day because
they were waking up all night.
Occurs when a person’s air passage is blocked.
Associated with obesity and snoring.
Can lead to heart attacks and strokes.
Parasomnias
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Undesirable physical arousal, behaviors,
or events during sleep or sleep transitions
Nightmare—different than sleep terror
Sleepsex—involves abnormal sexual behaviors and
experiences during sleep
Sleepwalking—an episode involving walking or
performing other actions during sleep
Sleep-related eating disorder (SRED)—the sleeper will
sleepwalk and eat compulsively
REM sleep behavior disorder—a failure of the brain
mechanisms that normal suppress voluntary actions
during REM sleep
Night terrors—sudden arousal from sleep and intense
fear accompanied by physiological reactions (eg, rapid
heart rate, perspiration) that occurs during slow-wave
sleep
Hypnosis
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State of awareness
Highly focused attention
Increased responsiveness to suggestion
Vivid imagery
Willingness to accept distortions of logic
Alteration of sensation and perception
Meditation
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Sustained concentration that focuses
attention and heightens awareness
Lowered physiological arousal
decreased heart rate
 decreased blood pressure
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Predominance of alpha brain waves
Psychoactive Drugs
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Depressants—inhibit brain activity
Opiates—pain relief and euphoria
Stimulants—increase brain activity
Psychedelics—distort sensory perceptions
Drug Abuse: Recurrent drug use that results
in disruption of academic, social, or
occupational functioning, or in legal or
psychological problems
Common Properties
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Physical dependence: person has physically adapted to
a drug so that he or she must take the drug in order to
avoid withdrawal
Tolerance: increasing amount of a drug are needed to
produce desired effect
Withdrawal symptoms: physical reactions that occur
when a person stops using a drug that they are
physically dependent on
Drug rebound effect: withdrawl symptoms that are the
opposite of a physically addictive drug’s actions
Approximately 23 million Americans age 12 and older
abuse or are dependent on psychoactive drugs (National
Survey on Drug Abuse and Health).
Depressants
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Alcohol—CNS depressant
Barbiturates—downers; perscription
sedatives; induce sleep
Inhalants—inhaled; can cause
relaxation or hallucinations
Tranquilizers—xanax; relieve anxiety
Alcohol
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About 17 million Americans have problems with
alcohols.
They drink heavily on a regular basis and suffer
social, occupational, and health problems as a
result of their drinking (Substance Abuse and
Mental Health Services Administration, 2008).
Alcohol lessens inhibitions by depressing the
brain centers responsible for judgment and selfcontrol.
Reduced inhibitions and self-control contribute
to aggressive and violent behavior.
Opiates
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Chemically similar to morphine and have
strong pain-relieving properties
Mimic the brain’s endorphins
Heroin, methadone
Percodan, Demerol
Opiates
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Morphine, heroin, codeine.
Morphine introduced during the Civil War to deaden the
pain from battle wounds.
 Known as “soldier’s disease”
Causes a surge of pleasure.
Heroin was introduced in the West during the 1800’s.
 Was the “hero” that would cure morphine addiction.
 Named because it made people feel “heroic”
Coming down can make a person have deep
depression.
Impair judgment, memory, cause drowsiness, and
depress the respiratory system.
Stimulants
Increase activity of the nervous system.
 Speed up heart rate.
 Sense of well being or euphoria, or an
enhanced ability to think and function.
 Can also cause anxiety, paranoia, reduced
appetite, restlessness, and insomnia.
 Nicotine
 Amphetamines
 Cocaine
 Caffeine
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Caffeine
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The most widely used psychoactive drug in the
world
Found in coffee, tea, cola drinks, chocolate, and
certain over-the-counter medications
Stimulates the release of dopamine in the
brain’s prefrontal cortex.
Is physically addictive, withdrawal symptoms can
be seen: headaches, irritability, drowsiness, and
fatigue can last a week or longer
Excess caffeine use can produce anxiety,
restlessness, increased heart rate, and disrupt
normal sleep patterns
Nicotine
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Drug found in tobacco leaves.
Spurs the release of the hormone adrenaline.
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Causes heart rate to increase.
As addictive as the use of heroin.
12-20 times as likely as non-smokers to die of
lung cancer.
Linked to death from heart disease, chronic lung
and respiratory diseases, and other illnesses.
Amphetamines
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Methamphetamine is highly addictive and can cause
extensive brain damage and tissue loss.
First used by soldiers during WWII to stay awake and
alert during the night.
Destroys the neurotransmitter Dopamine in the brain
Behavioral effects of losing dopamine receptors and
transporters involve memory and motor skill and social
skill problems.
Depression, emotional instability, and impulsive and
violent behavior are also common.
http://www.rehabs.com/explore/meth-before-and-afterdrugs/infographic.html#.VgLpOdJVhBc
Cocaine
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An illegal stimulant derived from the leaves of the coca
plant, which is found in South America.
Produces intense euphoria, mental alertness, selfconfidence, reduces hunger and raises blood pressure.
Cocaine blocks the reuptake of three different
neurotransmitters – dopamine, serotonin, and
norepinephrine.
Cocaine reaches the brain in seconds and its effects
peak in about 5 minutes.
Schizophrenia-like symptoms develop from prolonged
use (auditory hallucinations of voices and bizarrely
paranoid ideas).
Psychedelics
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Cause an overall change in perception,
consciousness, thought and emotion.
“Mixes up” the central nervous system, speeds
things up and then slows things down randomly.
Increases blood pressure, increased heart rate,
and increased appetite.
Flashback reactions and psychotic episodes
Examples: Mescaline, LSD, Marijuana
“Club” Drugs
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Ecstasy (MDMA)—feelings of euphoria,
increased well-being
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Side effects—dehydration, hyperthermia,
tremor, rapid heartbeat
Dissociative anesthetics (include PCP
and Ketamine)—deaden pain, produce
stupor or coma, may induce hallucinations