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Chapter 12
Emotional Behaviors
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What is Emotion?
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An emotional state has three aspects:
1. Cognition
2. Readiness for action
3. Feeling
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What is Emotion?
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The “readiness for action” component of emotions is a product of the autonomic nervous
system. Each emotion evokes its own special mixture of sympathetic and parasympathetic
arousal.
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The James-Lange theory of emotion suggests that the autonomic arousal and skeletal action
occurs first in an emotion.
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The emotion that is felt is the label that we give the arousal of the organs and muscles.
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What is Emotion?
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The James-Lange theory of emotion suggests that the autonomic arousal and skeletal action
occurs first in an emotion.
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The emotion that is felt is the label that we give the arousal of the organs and muscle
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The James Lange theory leads to two predictions:
1. People with a weak autonomic or skeletal response should feel less emotion.
2. Increasing one’s response should enhance an emotion.
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What is Emotion?
Research indicates the following:
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Paralyzed people report feeling emotion to the same degree as prior to their injury
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People with “pure autonomic failure” report feeling emotion less intensely.
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Pure autonomic failure - output from the autonomic nervous system to the body fails.
Thus research is contradictory and suggests other factors are involved in the perception of
emotion.
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According to the James-Lange theory, emotional feelings result from the body’s action.
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Panic attacks are marked by extreme sympathetic nervous system arousal.
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Only if perceived as occurring spontaneously.
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What is Emotion?
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Creating certain body actions may also slightly influence emotion.
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smiling slightly increases happiness.
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Inducing a frown leads to the rating of stimuli as slightly less pleasant.
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Indicates that perception of the body's actions do contribute to emotional feeling
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What is Emotion?
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Emotional experiences arouse many areas of the brain.
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The limbic system includes the forebrain areas surrounding the thalamus and has traditionally
been regarded as critical for emotion.
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PET and fMRI studies also suggest many other areas of the cerebral cortex, especially the frontal
and temporal lobes, are activated during an emotional experience.
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What is Emotion?
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Measurement of evoked responses indicate the brain is specialized to attend strongly to facial
expressions.
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Emotions tend not to be localized in specific parts of the cortex.
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A single emotion increases activity in various parts of the brain.
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Inactivation of the medial frontal cortex appears to impair the ability to recognize angry
expression.
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What is Emotion?
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Localization in the brain seems to exist for the emotion of disgust.
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The insular cortex is strongly activated during exposure to stimuli perceived as “disgusting”.
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Also the primary taste cortex.
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Also reacts to frightening stimuli as well so not completely dedicated to disgust.
What is Emotion?
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The two hemispheres of the brain play different roles in emotion.
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Activation of the frontal and temporal areas of the left hemisphere is associated with
“approach” and the Behavioral Activation System.
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Marked by low to moderate arousal.
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Can characterize either happiness or anger.
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What is Emotion?
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The Behavioral Inhibition System (BIS) is associated with increased activity of the frontal and
temporal lobe of the right hemisphere.
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Increases attention and arousal.
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Inhibits action.
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Stimulates emotions such as fear and disgust.
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What is Emotion?
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Differences in frontal cortex activity relates to personality.
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People with greater activity in the left hemisphere tend to be happier, more out-going and
friendlier.
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People with greater right hemisphere activity tend to be socially withdrawn, less satisfied with
life, and prone to unpleasant emotions.
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The right hemisphere seems to be more responsive to emotional stimuli than the left.
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Damage to the right temporal cortex causes problems in the ability to identify emotions of
others.
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What is Emotion?
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Functions of emotions include:
1. adaptive values (fear leads to escape, anger lead to attack, etc.)
2. allow us to make quick decisions
3. help us make moral decisions.
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What is Emotion?
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The consequences of our decisions have emotional considerations.
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Emotions are an important component to moral decisions.
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Failure to anticipate the unpleasantness of an event can lead to bad decision making.
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Contemplating moral decisions activates the prefrontal cortex, cingulate gyrus, and amygdala.
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Attack and Escape Behaviors
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Attack and escape behaviors are closely related physiologically and behaviorally.
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Corresponding behaviors are anger and fear.
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Pain, threat or other unpleasant stimuli usually trigger an attack behavior.
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Attack and Escape Behaviors
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Environmental factors associated with increased violent tendencies include
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Exposure to lead
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Smoking behavior of mother during pregnancy
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The effect is particularly strong if the mother smoked and also had
complications during pregnancy.
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Both may impair brain development
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Attack and Escape Behaviors
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Twins studies suggest genetic contribution to the likelihood of violent behavior.
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During childhood and adolescence, Dizygotic twins resemble each other in delinquent behaviors
just as much as monozygotic twins.
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Monozygotic twins resembled each other much more in delinquent behaviors occurring in
adulthood.
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Attack and Escape Behaviors
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On average, males engage in more aggressive and violent behaviors than do females.
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Male aggressive behavior is influenced by the hormone testosterone.
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Research shows that men with the highest rates of violent behavior also have slightly higher
testosterone levels.
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Attack and Escape Behaviors
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Violence is particularly enhanced with both a genetic predisposition and an early troubled
environment.
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Example: Interaction between MAOA levels and childhood maltreatment
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Hormones also influence aggressive behavior.
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Male aggressive behavior is influenced by the hormone testosterone.
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On average, males engage in more aggressive and violent behaviors than do females.
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Research shows that men with the highest rates of violent behavior also have slightly higher
testosterone levels.
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Attack and Escape Behaviors
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Testosterone alters the way people respond to stimuli.
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Increased testosterone levels show:
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Increases in heart rate.
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The tendency to attend longer and more vigorously to situations related to conflict and
aggression.
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Attack and Escape Behaviors
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Studies also suggest a connection between aggressive behavior and low serotonin release.
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Turnover is the amount of release and resynthesis of a neurotransmitter by presynaptic neurons.
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Valzelli’s (1973) study with mice found that isolating male mice for 4 weeks increased aggressive
behavior and decreased serotonin turnover.
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Attack and Escape Behaviors
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5-hydroxyindoleacetic acid (5-HIAA) is a serotonin metabolite found in the blood, cerebrospinal
fluid, and urine that allows researchers to infer turnover rate.
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High levels of 5-HIAA imply much serotonin release and turnover.
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Research with monkeys has demonstrated that low levels of 5-HIAA increases the probability of
attack on larger monkeys and few survived past age 6.
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Attack and Escape Behaviors
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Monkeys with high levels of 5-HIAA were more likely to survive.
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Evolution seems to select for an intermediate amount of anxiety and aggression.
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Evolution might also select for high aggressive behaviors.
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may die young, but are more likely to achieve a dominant position within the troop.
In human studies, low serotonin turnover has been linked to:
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People with a history of violent behavior and violent crime.
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People who attempt suicide by violent means.
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Recurrent violent behaviors and subsequent suicide attempts.
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Attack and Escape Behaviors
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Changes in diet can alter serotonin synthesis.
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Example: tryptophan and serotonin synthesis
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Serotonin activity an also be influenced by genetics.
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Genes control the production of tryptophan hydroxylase.
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Tryptophan hydroxylase is the enzyme that converts tryptophan into serotonin.
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People with less active form of this enzyme are more likely than others to report frequent anger
and aggression.
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Attack and Escape Behaviors
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The role of serotonin is very complicated and should not be thought of as the “anti-aggression”
transmitter.
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During aggression, the brain releases serotonin.
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Clinical depression is linked to low serotonin.
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High levels of serotonin may inhibit a variety of impulses.
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Attack and Escape Behaviors
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Proneness to approach, avoidance, and anxiety varies with the situation.
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Amygdala is one of the main areas for integrating both environmental and genetic influences
and then regulating current levels of anxiety.
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Fear and anxiety are not necessarily associated with the desire to flee.
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Attack and Escape Behaviors
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The startle reflex is the extremely fast response to unexpected loud noises.
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found in young infants and thus unlearned.
Auditory information stimulates an area of the pons that commands the tensing of the neck and
other muscles.
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Information reaches the pons within 3 to 8 milliseconds after a loud noise.
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The startle response occurs within two-tenths of a second.
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Attack and Escape Behaviors
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Cells in the amygdala, especially the basal lateral and central nuclei, receive information from
pain, vision, and hearing circuits.
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Axons extend to areas in the midbrain that relay information to the nucleus in the pons.
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The relay enhances the startle reflex.
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Attack and Escape Behaviors
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Output from the amygdala to the hypothalamus controls autonomic fear responses.
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Axons extending from the amygdala to the prefrontal cortex regulate approach and avoidance
responses.
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Attack and Escape Behaviors
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Damage to the amygdala interferes with:
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the learning of fear responses
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retention of fear responses previously learned
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interpreting or understanding stimuli with emotional consequences
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Attack and Escape Behaviors
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In the early 1900s, studies of monkeys with Kluver-Bucy syndrome illustrated the effects of
amygdala damage.
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Monkeys with this syndrome are calm and placid and display less than normal fear of snakes and
larger, more dominant monkeys.
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Also alters social behaviors in that they have decreased ability to interpret threat gestures.
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Amygdala damage can also lead to an increase in the approach motive.
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Attack and Escape Behaviors
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fMRI studies of humans suggest the amygdala responds strongly to emotional stimuli and facial
expressions.
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Not necessarily associated with just fear.
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Activity is strongest when the meaning is unclear and requires some processing.
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With some exceptions, looking at happy faces activates the amygdala only weakly.
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Amygdala also responds to stimuli not consciously perceived.
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Attack and Escape Behaviors
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In humans, damage to the amygdala does not result in the loss of emotion.
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Damage to the amygdala impairs the processing of emotional information when the signals are
subtle or complicated.
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Amygdala damage affects the ability to judge “trustworthiness” in people.
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People with amygdala damage focus on emotional stimuli the same as irrelevant stimuli or
details.
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Amygdala damage also affects the ability to recognize emotions specifically in photographs or
pictures.
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Effect is particularly strong for fear or disgust.
Amygdala damage does not affect the ability to recognize fear in real life.
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Attention to certain aspects of the face (eyes versus mouth) may account for the
difference.
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Attack and Escape Behaviors
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Genetic variations in amygdala arousal may thus underlie some of the variations of anxiety in
the population and related disorders.
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Arousal of the amygdala relates to the tendency to experience some negative emotions.
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Excessive fear and anxiety disorders are associated with hyperactivity in the amygdala
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Attack and Escape Behaviors
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Drugs intended to control anxiety alter activity at amygdala synapses.
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The main excitatory neuromodulator in the amygdala is CCK, and the main inhibitory transmitter
is GABA.
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Injections of CCK-stimulating drugs into the amygdala enhance the startle response.
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Drugs that increase GABA activity trigger panic.
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Attack and Escape Behaviors
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Barbituates were a drug widely used to control anxiety in the past, but have high overdose
potential.
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Benzodiazepines are the most commonly used anti-anxiety drugs.
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Benzodiazepines bind to the GABAA receptor complex, and facilitate the effects of GABA.
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Benzodiazepines exert their effects in the amygdala, hypothalamus, midbrain, and other areas.
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Attack and Escape Behaviors
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Diazepam-binding inhibitor (DBI) is a naturally occurring protein which attaches to the same
sites as benzodiazepines and blocks their effects.
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Endozepines are neuromodulators that include DBI and other related proteins that work to
increase levels of fear and anxiety.
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Attack and Escape Behaviors
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Ethyl alcohol has behavioral effects similar to benzodiazepines.
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Alcohol enhances GABA effects.
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An experimental drug Ro-15-4513 blocks the effect of alcohol on the GABAA receptors complex.
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Stress and Health
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Behavioral medicine emphasizes the effects of diet, smoking, exercise, stressful experiences,
and other behaviors on health.
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Emotions and other experiences influence illness and pattern of recovery.
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Stress and Health
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Hans Selye (1979) defined stress as the non-specific response of the body to any demand made
upon it.
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Threats on the body activate a general response to stress called the general adaptation
syndrome.
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Stress and Health
The General Adaptation Syndrome:
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Alarm stage - characterized by increased sympathetic nervous system activity.
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Resistance stage - sympathetic response declines, the adrenal cortex releases cortisol
and other hormones that enable the body to maintain prolonged alertness.
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Exhaustion stage - occurs after prolonged stress and is characterized by inactivity and
decreased immune system.
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Stress and Health
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Sapolsky (1998) argues that the nature of today’s crises are more prolonged.
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Accounts for widespread stress-related illnesses and psychiatric problems in industrial
societies.
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Long-term, inescapable issues activate the general adaptation syndrome which is harmful to our
health over time.
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Stress and Health
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Stress activates two systems in the body:
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The autonomic nervous system - “fight or flight” response that prepares the body for
brief emergency responses
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The HPA axis - the hypothalamus, pituitary gland, and adrenal cortex.
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Stress and Health
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The HPA axis becomes the dominant response to prolonged stressors.
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Activation of the hypothalamus induces the pituitary gland to secrete adrenocorticotropic
hormone (ACTH).
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ACTH stimulates the adrenal cortex to secrete cortisol.
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Cortisol enhances metabolic activity and elevates blood levels of sugars and other nutrients to
mobilize energies.
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Stress and Health
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The immune system consists of cells that protect the body against viruses and bacteria.
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Leukocytes – white blood cells.
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B-cells – leukocytes that mature in the bone marrow and secrete antibodies.
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Antibodies – Y-shaped proteins that attach to particular kinds of antigens.
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Antigens – surface proteins that are antibody-generator molecules.
Stress and Health
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T cells – attack intruders directly and help other T cells or B cells to multiply.
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Natural killer cells – leukocytes that attack tumor cells and cells that are infected with
viruses.
Prolonged increased cortisol levels impair the immune system.
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During an infection, leukocytes and other cells produce small proteins called cytokines.
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Stress and Health
Combat infection and communicate with the brain to inform of illness.
Cytokines in the brain produce symptoms of illness.
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Fever, sleepiness, lack of energy etc.
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Sleep and inactivity are the bodies way of conserving energy to fight illness.
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Stress and Health
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Psychoneuroimmunology is the study of the relationship between the nervous system and the
immune system.
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Deals with the way in which experiences, especially stressful ones, alter the immune system.
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Also deals with how the immune system influences the central nervous system.
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Stress and Health
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In response to a stressful experience, the nervous system activates the immune system.
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Immune system increases production of natural killer cells, leukocytes and cytokines.
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The cytokines can trigger symptom of illness as a reaction to the stress itself.
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Stress and Health
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Prolonged stress response is damaging to the body.
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Prolonged increase of cortisol detracts from the synthesis of proteins of the immune system.
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Prolonged stress of longer than a month significantly increases the likelihood of illness.
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Stress and Health
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Prolonged stress can also be harmful to the hippocampus and can affect memory.
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Cortical enhances metabolic activity in the body.
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When metabolic activity is high in the hippocampus, the neurons are more sensitive to damage
by toxins or over-stimulation.
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Stress also impairs the adaptability and the production of new hippocampal neurons.
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Stress and Health
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A variety of ways exist to reduce stress or control our response to it:
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Breathing routines, exercise, meditation, distraction, dealing with the problem.
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Social support from a loved one helps to reduce stress.
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Reduces response in several brain areas including the prefrontal cortex.
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Stress and Health
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Posttraumatic stress disorder (PTSD) occurs in some people after terrifying experiences and
includes the following symptoms:
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Frequent distressing recollections.
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Nightmares.
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Avoidance of reminders of the event.
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Exaggerated arousal in response to noises and other stimuli.
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Stress and Health
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Studies have revealed most PTSD victims have a smaller than average hippocampus.
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PTSD victims show lower than normal cortisol levels after the trauma.
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People with low cortisol levels may be ill-equipped to combat stress and more prone to the
damaging effects of stress.