Transcript Chapter 4

Topic 7
States of Consciousness:
Circadian Rhythms, Sleep &
Dreams
Topic of focus
 Stages of sleep
 Why do we sleep?
 Biological clocks
 Sleep & Consicousness
 Physiological mechanism of Sleep and waking
Consciousness
• Consciousness can take many forms, while other mental processes
occur simultaneously outside our awareness
• Consciousness changes in cycles that correspond to our biological
rhythms and the patterns of stimulation in our environment
Everything of which we are aware at any given time
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Thoughts
Feelings
Sensations
External stimuli
Altered State of Consciousness
o Changes in awareness produced by
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Sleep
Meditation
Hypnosis
Drugs
WHY DO WE NEED TO SLEEP?
Why do we sleep?
 Recuperation theories
 Sleep is needed to restore homeostasis
 Wakefulness causes a deviation from homeostasis
 Circadian theories
 Sleep is the result of an internal timing mechanism
 Sleep evolved to protect us from the dangers of the
night
Comparative Analysis of Sleep
 All mammals and birds do it – must have an
important function
 Not a special higher-order human function
 Not necessarily needed in large quantities
 No clear relationship between species’ sleep
time and activity level
BIOLOGICAL CLOCK
The Influences of Circadian Rhythms
o Environmental Cues
o The ebb and flow of circadian rhythms is not strictly
biological; environmental cues also play a part
o Bright light
o especially sunlight
o Sleep-wakefulness cycle
o Daily fluctuations of body temperature
o Sleep is best when body is at lowest temperature (97-97.5)
The Influences of Circadian Rhythms
o Control of seasonal rhythms
o Pineal Gland
o A gland attached to the dorsal tectum; produces melatonin
and plays a role in circadian and seasonal rhythms.
o Secretes melatonin from dusk until just before dawn
o Does not secrete melatonin during daylight hours
o Melatonin
o A hormone synthesized from serotonin in the pineal gland
o Secreted during the night by the pineal body;
o Melatonin levels display circadian rhythms controlled by the
SCN
o plays a role in circadian and seasonal rhythms.
o Melatonin is not a sleep aid, but may be used to shift
circadian rhythms
Disruptions in Circadian Rhythms
Jet lag
o When traveling, you reach your destination
at a time when it is daylight there, but it
would have been time to go to sleep at the
place you started
o Can produce memory deficits that may be
permanent
o Supplemental melatonin has been shown
to be an effective treatment for relapses of
psychiatric disorders induced by jet lag
o Zeitgebers are accelerated or
decelerated
o Research indicates that frequent
flyers, such as this airline employee,
are just as likely to suffer from jet lag
when crossing several time zones as
travelers who are on their first intercontinental journey.
Disruptions in Circadian Rhythms
Shift work
o When people work during the night and sleep during the day
o Shift workers average 2 to 4 hours less sleep than nonshift
workers of the same age
o Subjective night
o The time during a 24-hour period when body temperature is lowest and
when the biological clock is telling a person to go to sleep
o During subjective night, energy and efficiency are at their lowest point,
reaction time is slowest, productivity is diminished, and industrial
accidents are significantly higher Zeitgebers unchanged, but sleep-wake
cycle must be altered
o Rotating work schedules forward from days to evenings to nights
makes adjustment easier because people find it easier to go to bed
later and wake up later than the reverse
o Modafinil
o A wakefulness drug that will help people remain alert without the side
effects of stimulants such as caffeine
Can the effects be prevented or
minimized?
o Both produce a variety of deficits
o Can the effects be prevented or minimized?
 Reducing Jet Lag
 Gradually shift sleep-wake cycle prior to travel
 Administer post-flight treatments to promote the needed shift
 Phase advance following east-bound travel with intense light early in the
morning
 Hamster studies suggest a good early morning workout may also help
Can the effects be prevented or
minimized?
 Reducing the Effect of Shift Changes
 Schedule phase delays, rather than phase advances
 Move from current schedule to one that starts later
 It is easier to stay up later and get up later than to retire and arise earlier
 Phase advances are harder, explaining why east-bound travel tends
to be more problematic
 Shift workers who temporarily reside at their work
places, such as workers on offshore oil rigs, appear to
adjust more easily to the demands of night work than
those who live at home
 Exposure to appropriately timed bright light or even light
of medium intensity has been found to reset young
adults’ biological clocks and improve their performance
The Influences of Circadian Rhythms
Disruptions in Circadian Rhythms
o Subjective night
o The time during a 24-hour period when the biological clock is
telling a person to go to sleep.
o Energy and efficiency are at their lowest points
o Reaction time is slowest
o Productivity is diminished
o Industrial accidents are higher
o Daylight savings time in spring is associated with short term
6.5% increase in accidental deaths.
o Work schedules
o Moving work schedules forward from days to evenings to
nights makes adjustment easier
o Rotating shifts every three weeks lessens the effect on sleep
The Influences of Circadian Rhythms
o Circadian Rhythm
o A daily rhythmical change in behavior or physiological process.
o About a day
o Regular fluctuation from high to low points of certain bodily
functions and behaviors
o Sleep debt
o Deficiency caused by not getting the amount of sleep that one
requires for optimal functioning
o Affects psychological functions of
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Blood pressure
Heart rate
Appetite
Secretion of hormones and digestive enzymes
Sensory acuity
Elimination
Body’s response to medication
The Influences of Circadian Rhythms
o Suprachiasmatic nucleus (SCN)
o A nucleus, situated atop the optic chiasm, in the brain’s hypothalamus
that control the timing of circadian rhythms
o It contains a biological clock responsible for organizing many of the
body’s circadian rhythms.
o Lesions do not reduce sleep time, but they abolish its circadian periodicity
o Exhibit activity that can be entrained by the light-dark cycle
o Transplant SCN, transplant sleep-wake cycle
o Melanopsin
o A photopigment present in ganglion cells in the retina whose axons
transmit information to the SCN, the thalamus, and the olivary pretectal
nuclei.
o Zeitgebers
o A stimulus (usually the light of dawn) that resets the biological clock
responsible for circadian rhythms.
o Intergeniculate leaflet (IGL)
o A part of the lateral geniculate nucleus that receives information from the
retina and projects to the SCN; terminals release neuropeptide Y at the
SCN
Stages of sleep
Sleep
o Understanding of sleep increased by the study of
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Brain waves
Eye movements
Chin muscle tension
Heart rate
Respiration rate
 Electro-oculogram (EOG)
 An electrical potential from the eyes, recorded by means of electrodes
placed on the skin around them; detects eye movements.
 Electromyogram (EMG)
 An electrical potential recorded from an electrode placed on a muscle.
3 Physiological Measures of Sleep
 By means of Electroencephalogram (EEG)
 “brain waves”
 By means of EOG
 Eye movements seen during rapid eye movement
(REM) sleep
 By means of EMG
 Loss of activity in neck muscles during some
sleep stages
Sleep
Polysomnogram
o Provides brain wave sleep recordings
o Outlined REM and NREM sleep patterns
EEG
 Beta activity
 Irregular electrical activity of 13–30 Hz recorded from the brain;
generally associated with a state of arousal.
 Alpha activity
 A smooth electrical activity of 8–12 Hz recorded from the brain;
generally associated with a state of relaxation
 Eyes closed, preparing to sleep
 Theta activity
 EEG activity of 3.5-7.5 Hz that occurs intermittently during early stages
of slow-wave and REM sleep.
 Delta activity
 Regular, synchronous electrical activity of less than
4 Hz recorded from the brain; occurs during the deepest stages of
slow-wave sleep.
Stages of Sleep
o Stage 1
o A transition period of drowsiness between
waking and sleeping.
o Sleep spindles occur
o Stage 2
o Somewhat more deeply asleep.
o Delta waves slight
o Stage 3
o Slow wave sleep begins
o Delta waves reach 20%.
o Stage 4 – Delta waves reach nearly 100%.
Sleep Cycle & EEG
 Stage 1
 similar to awake EEG, but slower
 low-voltage, high-frequency
 EEG voltage increases and frequency decreases as
one progresses from stage 1 through 2, 3, and 4
 Stage 2 – characterized by
 K complexes – large negative waves
 Sleep spindles – burst of 12-14 Hz waves
 Stages 3 and 4 – delta waves, large and slow
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Progress to stage 4 sleep and then retreat to stage 1
Sleep Cycle & EEG
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Emergent stage 1 differs from initial stage 1
 REMs
 Loss of body core muscle tone
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Progress through sleep stages in 90 minute cycles
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More time spent in emergent stage 1 as night progresses
 Emergent stage 1 sleep = REM sleep
 Non-REM (NREM) sleep = all other stages
 Stage 3 + 4 = slow-wave sleep (SWS)
 During REM: REMs, loss of core muscle tone, lowamplitude/high-frequency EEG, increased cerebral
and autonomic activity, muscles may twitch
NREM Sleep
o Non-rapid eye movement sleep.
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Four sleep stages
Lightest sleep
Mid-sleep
Deep sleep
Deepest sleep
o Heart and respiration slow and
regular
o Little body movement
o Blood pressure and brain activity
at lowest points of 24 hour
period.
REM Sleep
 Non-REM sleep
 All stages of sleep except REM sleep.
 REM sleep
 A period of desynchronized EEG activity during sleep, at which time
dreaming, rapid eye movements, and muscular paralysis occur.
 80% of awakenings from REM yield reports of story-like dreams
 Slow-wave sleep
 Non-REM sleep, characterized by synchronized EEG activity during
deeper stages.
 Basic rest-activity cycle
 A 90-minute cycle (in humans) of waxing and waning alertness,
controlled by a biological clock in the caudal brain stem; controls
cycles of REM sleep and
slow-wave sleep.
REM Sleep
o Rapid eye movement
sleep
o Called “active sleep”
o 20-25% of a night’s sleep
o Internally:
o Intense brain activity
o Brain metabolism
increases
o Brain temperature rises
rapidly
o Epinephrine release
leads to increases in
o Blood pressure
o Heart rate
o respiration
o Externally:
o Body appears calm
o Large muscles become
paralyzed
o Eyes dart around
o Dreaming occurs in 80%
of people
o The brain conducts
o Consolidation of
learning (all night
studying doesn’t help)
o perceptual skills increase
after 8-10 hours of sleep
o Memory consolidation
REM Rebound
o The increased amount of REM sleep that
occurs after REM deprivation
o Intensity of REM sleep increases
o Those with Sleep Deprivation
o Proceed more rapidly into REM as REM
deprivation increases
o More time spent in REM when deprivation is over
o Often associated with unpleasant dreams or
nightmares
o Alcohol, amphetamines, cocaine, and LSD
use suppress REM sleep results in REM
rebound
o Withdrawal results in REM rebounds
 REM rebound suggests that REM sleep
serves a special function
Purpose of REM?
 Necessary for mental health
 Inconsistent with the effects of tricyclic
antidepressants – block REM
 Necessary for maintenance of normal levels of
motivation
 Necessary for processing of memories
 No clear purpose
 Default Theory of REM
 REM serves no critical function
 One can’t stay continuously in non-REM sleep, so we
switch between REM and wakefulness
 When bodily needs exist – wake up
 No immediate needs – REM
 No REM rebound seen when lost REM periods replaced
with 15-mins awake
Variations in Sleep
o Infants and young children
o have the longest sleep time
o Have the highest of REM and slow wave
sleep
o Ages 6-puberty
o Most consistent sleepers and wakers
o Sleep and awake same time daily
o Adolescents
o Sleep patterns are influenced by their
schedules
o Sleep longer when no schedule conflicts
o Poor sleep may contribute to poor school
performance
Effects of Sleep Deprivation
o Causes
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Difficulty concentrating
Attention lapse
General irritability
Decreases cognitive functioning
Impairs learning
 Recuperation theories predict:
 Long periods of wakefulness will result in
disturbances
 Disturbances will get worse as deprivation
continues
 After deprivation, much of the missed sleep will
be regained
 What does the research indicate?
Studies of Sleep Deprivation in
Humans
 Does sleep loss affect your
performance?
 We tend to be poor judges
of the effects of sleep
deprivation on our
performance
 3-4 hours of deprivation in
one night
 Increased sleepiness
 Disturbances displayed on
written tests of mood
 Perform poorly on tests of
vigilance
 2-3 days of continuous
deprivation
 Experience microsleeps,
naps of 2-3 seconds
 Effects on complex
cognitive function, motor
performance, and
physiological function are
less consistent
Sleep-Deprivation Studies with Lab
Animals
 Carousel apparatus used to
deprive rats of sleep
 When the experimental rat’s
EEG indicates sleep, the
chamber floor moves – if the
rat does not awaken, it falls
into water
 Yoked controls – subjected
to the same floor rotations
 Experimental rats typically die
after several days
 Postmortem studies reveal
the extreme stress
experienced by the
experimental rats
Carousel apparatus
Theories of Sleep Function
o Restorative theory, holds that being awake
produces wear and tear on the body and brain,
and sleep serves the function of restoring the
body and mind.
o Circadian theory of sleep is based on the
premise that sleep evolved to keep humans out
of harm’s way during the dark of night and
possibly from becoming prey of some nocturnal
predator.
Sleep Disorders - Parasomnias
o Somnambulism (sleepwalking)
o occurs during partial arousal from stage 4 sleep.
o Sleep terror
o happens during partial arousal from stage 4 sleep
o usually begins with a piercing scream.
o Nightmares
o are frightening dreams that occur during REM sleep.
o Somniloquy (Sleeptalking)
o occurs during any sleep stage
o is more frequent among children.
Major Sleep Disorders
o Insomnia
 A sleep disorder characterized by
 Disorders of sleep initiation and maintenance
o Difficulty falling or staying asleep
o Waking too early
o Sleep that is light, restless, or of poor quality
 Symptoms can lead to distress and impairment in
daytime functioning
o Hypersomnia
o Disorders of excessive sleep or sleepiness
Major Sleep Disorders
o Sleep apnea
 Periods during sleep when breathing stops and the individual
must awaken briefly in order to breathe
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o 2 types
1. Caused by muscle spasms or atonia
2. Failure of the CNS to stimulate breathing
Most commonly seen in males, the overweight, and in the
elderly
The major symptoms are excessive daytime sleepiness and
extremely loud snoring, often accompanied by snorts, gasps,
and choking noises
Alcohol and sedatives aggravate the condition
Can lead to chronic high blood pressure, heart problems, and
even death
Neuroscientists have also found that it can cause mild brain
damage
The interrupted sleep experienced by individuals with this
disorder affects cognitive as well as physiological functioning
Major Sleep Disorders
o Narcolepsy
o Also a form of hypersomnia
o Characterized by excessive daytime sleepiness and repeated
brief uncontrollable attacks of daytime REM sleep, usually
lasting 10 – 20 minutes
o An incurable sleep disorder
o Cataplexy – loss of muscle tone while awake
o Sleep paralysis – paralyzed while falling asleep or upon
waking
o Hypnagogic hallucinations – dreaming while awake
o Appears to be an abnormality in the mechanisms that triggers
REM
o Dreaming and loss of muscle tone while awake – suggest
REM intruding into wakefulness
o REM without atonia – able to act out dreams – possibly caused by
damage to the nucleus magnocellularis or its output
What Other Forms Can
Consciousness Take?
• An altered state of consciousness
• A mental state other than ordinary waking consciousness, such
as sleep, meditation, hypnosis, or a drug-induced state
• occurs when some aspect of normal consciousness is modified
by mental, behavioral, or chemical means
• Hypnosis
• Induced state of altered awareness, characterized by
heightened suggestibility and deep relaxation
• Meditation
• Form of consciousness change induced by focusing on a
repetitive behavior, assuming certain body positions and
minimizing external stimulation
• Psychoactive drug states
• Chemicals that affect mental processes and behavior by their
effects on the nervous system
Hypnosis
A procedure through which one person,
thehypnotist, uses the power of suggestion to
induce changes in a person’s:
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Thoughts
FeelingsSensations
Perceptions
Behavior
Hypnotizability – Degree to which an individual is
responsive to hypnotic suggestions
o 80-95% of people are hypnotizable to some degree
o About 5% can reach deepest levels
Misconceptions About Hypnosis
o Hypnotized people are under the complete
control of the hypnotists and will violate their
moral values
o People can demonstrate superhuman strength
and perform amazing feats under hypnosis
o Subjects are not stronger or more powerful under
hypnosis
o Memory is more accurate under hypnosis
o Pseudomemories – false memories constructed
through guidance.
o People under hypnosis will reveal embarrassing
secrets
o Hypnosis is not like a truth serum
o Subjects can keep secrets or lie under hypnosis
o People under hypnosis can relive an event that
occurred when they were children and can
function mentally as if they were that age.
 Careful reviews of studies on hypnotic age regression
have found no evidence to support this claim
Meditation
A group of techniques that involve
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focusing attention on
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an object
a word
one’s breathing,
one’s body movements
An effort to block out all distractions
Enhance well-being
Achieve an altered state of consciousness.
Includes: Yoga, Zen, and transcendental meditation
 Yoga
 A meditator typically assumes a cross-legged position known as the
lotus and gazes at a visual stimulus
 Zen
 The individual counts breaths or concentrates on the breathing process
o Can be helpful with physical and psychological problems
o Lower blood pressure
o Learn how to control emotions
Physiological Mechanisms of Sleep
and Waking
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Types of neurotransmitter involved
1. Acetylcholine
 One of the most important neurotransmitters involved in arousal.
 Two groups of acetylcholinergic neurons located in the pons and basal
forebrain. They produce activation and cortical desynchrony when they are
stimulated.
2. Norepinephrine
 Catecholamine agonists produce arousal and sleeplessness; effects appear to be
mediated by the locus coeruleus in the dorsal pons.
3. Serotonin (5-HT)
 Appears to play a role in activating behavior; almost all of the brain’s serotonergic
neurons are found in the raphe nucleus. These neurons are located in the
medullary and pontine regions of the brain.
4. Histamine
 A neurotransmitter implicated in the control of wakefulness and arousal; a
compound synthesized from histidine, an amino acid.
Physiological Mechanisms of Sleep
and Waking
 Neural control of arousal
 Locus coeruleus
 A dark color group of noradrenergic cell bodies located in the pons near
the rostral end of the floor of the fourth ventricle; involved in arousal and
vigilance.
 Raphe nucleus
 A group of nuclei located in the reticular formation of the medulla, pons,
and midbrain, situated along the midline; contains serotonergic neurons.
 Tuberomammillary nucleus
 A nucleus in the ventral posterior hypothalamus, just rostral to the
mammillary bodies; contains histaminergic neurons involved in cortical
activation and behavioral arousal.
 Hypocretin
 A peptide also known as orexin, produced by neurons whose cell bodies
are located in the hypothalamus; their destruction causes narcolepsy.
Physiological Mechanisms of Sleep
and Waking
 Neural control of slow-wave sleep
 Ventrolateral preoptic area (VLPA)
 A group of GABAergic neurons in the preoptic area whose
activity suppresses alertness and behavioral arousal and
promotes sleep.
 Destruction of this area has been reported to result
in total insomnia, coma, and eventual death in rats.
Physiological Mechanisms of Sleep
and Waking
 Neural control of REM
sleep
 PGO wave (pontine,
geniculate, occipital):
 Bursts of phasic electrical
activity originating in the
pons, followed by activity
in the lateral geniculate
nucleus and visual cortex,
a characteristic of REM
sleep.
Psychoactive Drugs
Any substance that has
powerful effects on the
brain and alters:
o Consciousness
Psychoactive drugs are:
o Controlled substances
o approved for medical use
o Illicit drugs
o Mood
o drugs that are illegal
o Perception
o Over-the counter drugs
o Thought
o Antihistamines
o Decongestants
Hallucinogens
o Herbal preparations
Depressants
Opiates
Stimulants
o Certain foods
o chocolate
How Drugs Affect The Brain
All physical pleasure has a neurological basis:
Brought about by increase of dopamine in limbic system known as
the Nucleus Accumbens
A surge of dopamine has a
o reward and motivational effects
o produced by psychoactive drugs.
The effects of drugs cascades down involving the
brain’s entire neurotransmitter system.
How Drugs Affect The Brain
Hallucinogens
Alter perceptions of the external
environment and inner awareness (also
called psychedelics)
• Mescaline
• LSD
• PCP
• Cannabis
How Drugs Affect The Brain
Opiates
Highly addictive; produce a
sense of well-being and have
strong pain-relieving properties
Heroin, Morphine, Heroin and
Methadone
o Mimic the effects of the brain’s own
endorphins
o Chemicals in the brain with pain relieving
properties
o Produce feelings of well-being
o Useful in pain management
How Drugs Affect The Brain
Depressants
Slow down mental and physical activity
by inhibiting transmission of nerve
impulses in the central nervous system
o Alcohol
o Barbiturates
o Benzodiazepines (Tranquilizers)
oValium and Librium
o Act on GABA receptors to produce a
calming, sedating effects.
o Useful in reducing a patient’s
nervousness prior to undergoing a medical
procedure.
How Drugs Affect The Brain
Stimulants
Arouse the central nervous system, speeding up mental and
physical responses
o Mimics the effects of epinephrine
o The neurotransmitter that triggers the nervous system
o Caffeine
o Nicotine
o Amphetamines
o Cocaine
o MDMA (ecstasy)
o Benefits include suppression of hunger and digestion
o Often found in “diet pills”
How Drugs Affect The Brain
Amphetamines affect the parts of the
brain that control attention and
concentration, as well as
the nucleus accumbens.
o Stimulate the release of dopamine in
frontal cortex improving attention and
concentration
This helps explain why these stimulants
are useful in the treatment of attention
problems in school children (i.e. ADHD).
Substance Abuse
A continued use of a substance after several episodes in which
use of the substance has negatively affected an individual's
work, education, and social relationships.
o People progress from substance “use” to “abuse” by
o The physical pleasure
o Genetically based differences in people’s responses to
drugs
o e.g. People who drink more to “feel the effect” are more
likely to become alcoholics
o Personality and social factors
o e.g. Impulsiveness
o Stress related variables
o e.g. Victim of child abuse or domestic violence
o Social and cultural factors
o e.g. Associating with peers who abuse drugs
Drug Dependence
Commonly called “addiction”
o Physical drug dependence
o A compulsive pattern of drug use in which
o the user develops a drug tolerance
o coupled with unpleasant withdrawal symptoms
when the drug is discontinued.
o Drug Tolerance
o A condition in which the user becomes
o progressively less affected by the drug
o must take increasingly larger doses
to maintain the same effect or high.
Drug Dependence
o Withdrawal Symptoms
o The physical and psychological symptoms that occur
when a regularly used drug is discontinued
o Usually the exact opposite of the effects produced by the
drugs
o Symptoms terminate when drug is taken again.
o Psychological Drug Dependence
o A craving or irresistible urge for the drug’s pleasurable
effects.
o More difficult to combat than physical dependence
o Drugs that may not be physically addictive may be due
to psychological dependence
o Learning processes (classical conditioning) are
important elements in development and maintenance
of psychological dependence
The Behavioral Effects of
Psychoactive Drugs
DETAILED DESCRIPTION
The Behavioral Effects of
Psychoactive Drugs
o Stimulants
o Speed up activity in the central nervous system
o Increase blood pressure, pulse rate, respiration rate, and
reduce cerebral blood flow
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Suppress appetite
Help ‘feel’ more awake and energetic
Also called “uppers”
High doses make people “feel” more
o Nervous
o Jittery
o Restless
o Shaky or trembling
o Interfere with sleep
Stimulants Continued
o Caffeine
o Coffee, tea, cola, chocolate, and 100+ prescriptions and overthe-counter drugs
o May improve visual acuity
o Withdrawal for moderate to heavy use induces
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Nervousness
Instability
Headaches, drowsiness
Decreased alertness
o EEG’s confirm withdrawal effects on the brain
o Significant increases in blood pressure and velocity of blood flow
in all four cerebral arteries
o Increase in slower brain waves causing decreased alertness and
drowsiness
Stimulants Continued
o Nicotine
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Increases alertness
Suppresses appetite in some people
Highly addictive
Hypnosis treatments are largely ineffective
Nicotine patches help 1 in 5 smokers quit
Stimulants Continued
o Amphetamines
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Increase arousal
Relieve fatigue
Improve alertness
Suppress appetite
Give a rush of energy
Stimulate the release of dopamine in frontal cortex
improving attention and concentration
o (helping with ADHD )
o Can cause confused and disorganized behaviors
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Extreme fears and suspiciousness
Delusions and hallucinations
Aggressive and antisocial behaviors
Manic behaviors and paranoia
Stimulants Continued
o Cocaine
o Stimulant derived from coca leaves
o Can be sniffed, injected, or smoked as crack
o Euphoria is followed by an equally intensive crash marked by
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Depression
Anxiety
Agitation
A powerful craving for more drug
o Stimulate the reward (pleasure) pathways in brain
o Reward pathways fail with continued use so no pleasure is felt
except when taking the drug
o Main withdrawal symptoms are psychological
o Inability to feel pleasure
o Strong desire for more drug
Depressants
o Alcohol
o Depresses central nervous system
o Increased drinking causes
o Slurred speech
o Poor coordination
o Staggering
o Impaired depth perception
o Men tend to become aggressive and sexually aroused yet
less able to perform sexually
o Decreases ability to form new memories
o Drinker’s expectations of alcohol effects also contribute to
alcohol’s effect
Depressants
o Barbiturates
o Depress central nervous system
o Act as sedative or sleeping pill dependent on amount taken
o Abusers become
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Drowsy and confused
Thinking and judgment suffer
Coordination and reflexes are affected
Can kill if taken in overdose (as little as three times regular dose)
When taken with alcohol are potentially fatal
o Minor Tranquilizers
o Benzodiazepines (valium, Librium, dalmane, xanax)
o Abuse is associated with
o temporary and permanent impairment of memory and other
cognitive functions
Hallucinogens (psychedelics)
o Drugs that alter and distort perceptions of time and space, alter
mood, produce feelings of unreality, and cause hallucinations.
o Marijuana (THC tetrahydrocannabinol)
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Produces a high
Remains in the body for days or even weeks
Impairs attention and coordination
Slows reaction time after intoxication feeling has passed
Interferes with concentration, logical thinking, and ability to
form new memories
Produces fragmentation in thought
Confusion in remembering recent occurrences
Chronic use associated with loss of motivation, general
apathy, and decline in school/work performance
Medical benefits include treatment of glaucoma, controlling
nausea in cancer patients, and improving appetite and
controlling weight loss in AIDS patients
Hallucinogens (psychedelics)
o LSD (Llysergic Acid Diethylamide)
o Often referred to as “acid”
o A “trip” lasts 10-12 hours and produces
o extreme perceptual and emotional changes
o Visual hallucinations
o Feelings of panic
o Bad “trips” are associated with
o Accidents, death, or suicide
o Flashbacks or ‘hallucinogen persisting disorder’
o Designer Drugs
o
o
o
o
Mimic pleasurable effects of other drugs
STP and Ecstasy
Derived from amphetamines
Have hallucinogenic and stimulant effect