Emotion and Health

CHAPTER 8

Emotion

and Health

Emotion and Health

The prefrontal cortex is necessary for making judgments about behavior and its consequences.

People who sustain damage to this area later in life show an understanding of moral and social rules in hypothetical situations but are unable to apply these rules to real-world situations.

People who sustain damage early in life never learn these rules and, at best, are motivated only to avoid punishment.

Emotion is an increase or decrease in physiological activity that is accompanied by feelings that are characteristic of the emotion, and often accompanied by a characteristic behavior or facial expression.

According to the James-Lange theory, emotional experience results from the physiological arousal that precedes it, and different emotions are the result of different patterns of arousal.

According to Schachter and Singer’s cognitive theory, physiological arousal contributes only to the emotion’s intensity, while the identity of the emotion is based on the cognitive assessment of the situation.

Physiological feedback adds intensity to the motivation necessary for adaptive behavior. Our assessment and identification of an emotion allows us to draw on our base of knowledge and experience to plan and execute a response.

Different patterns of physical arousal during emotion may have an adaptive function aside from identifying our emotions.

Emotion is not just feelings, emotions  benefit of our position on the evolutionary tree. Emotion is a major key to our survival and success.

In the late 1930s and 40s researchers proposed that emotions originated in the limbic system, a network of structures arranged around the upper brain stem.

As complex as this system is with its looping interconnections, we now know that it is an oversimplification.

Emotion involves structures at all levels of the brain, from the prefrontal areas to the brain stem.

The hypothalamus has primary control over the autonomic nervous system, and produces a variety of emotional expression.

Septal area stimulation also produces a sense of pleasure, but the feeling is accompanied by sexual fantasies and arousal.

Two of the most reliable brain-emotion associations have been the amygdala’s role in fear and the location of disgust in the insular cortex and the basal ganglia.

Another important structure in emotion is the anterior cingulate cortex, a part of the cingulate gyrus important for attention, cognitive processing, and possibly consciousness, as well as emotion.

The anterior cingulate cortex is believed to combine emotional, attentional, and bodily information to bring about conscious emotional experience.

The prefrontal cortex is the final destination for much of the brain’s information about emotion before action is taken.

The amygdala is a small limbic system structure in each temporal lobe that is involved in negative emotions. The amygdala participates in memory formation, in particular when emotion is involved.

Although the amygdala is involved in other emotions, its role in fear and anxiety has been most thoroughly researched.

Fear is an emotional reaction to a specific immediate threat. Anxiety is an apprehension about a future, and often uncertain, event.



Patients with prefrontal damage respond emotionally to rewards and punishment, but are unable to use this information to guide their behavior.

People with damage to both amygdalas do not produce the emotional response in the first place.

Although both hemispheres are involved in the experience of emotions, the left frontal area is more active when the person is experiencing positive emotions, and the right frontal area is more active during negative emotion.

People with damage to the left hemisphere often express more anxiety and sadness about their situation, while those with right-hemisphere damage are more likely to be unperturbed or even euphoric, even when their arm or leg is paralyzed.

Autonomic responses to emotional stimuli such as facial expressions and emotional scenes are greater when the stimuli are presented to the right hemisphere.

Perception of non-verbal aspects of emotion is impaired in right-hemisphere-damaged patients.

Stress, Immunity, and Health

Stress is a condition in the environment that makes unusual demands on the organism, such as threat, failure, or bereavement.

Stress is also an internal condition, your response to a stressful situation.

The stress response includes activation of the sympathetic branch of the autonomic nervous system, which is largely under the control of the hypothalamus.

The resulting increases in heart rate, blood flow, and respiration rate help the person deal with the stressful situation.

Stress also activates the hypothalamic-pituitary-adrenal axis (HPA Axis), a group of structures that help the body cope with stress.

The hypothalamus activates the pituitary gland, which in turn releases hormones that stimulate the adrenal glands to release the stress hormones epinephrine, norepinephrine, and cortisol.

The first two hormones increase output from the heart and liberate glucose from the muscles for additional energy.

The hormone cortisol also increases energy levels by converting proteins to glucose, increasing fat availability, and increasing metabolism.

Cortisol provides a more sustained release of energy than the sympathetic nervous system does, for coping with prolonged stress.

Brief stress increases activity in the immune system, the cells and cell products that kill infected and malignant cells and protect the body against foreign substances, including bacteria and viruses.

The immune response involves two major types of cells:

Leukocytes, or white blood cells which recognize invaders by the unique proteins that every cell has on its surface and kills them.

Natural killer cells, the second type of immune cells which attack and destroy certain kinds of cancer cells and cells infected with viruses.

We are better equipped to deal with brief stress than with prolonged stress.

Chronic stress can interfere with memory, increase or decrease appetite, diminish sexual desire and performance, deplete energy, and cause mood disruptions.

Although brief stress enhances immune activity, prolonged stress compromises the immune system.



The cardiovascular system is particularly vulnerable to stress.

Stress increases blood pressure, and prolonged high blood pressure can damage the heart or cause a stroke.

In sudden cardiac death, stress causes excessive sympathetic activity that sends the heart into fibrillation, contracting so rapidly that it pumps little or no blood.

Extreme stress can also lead to brain damage.

Hippocampal volume was reduced in Vietnam combat veterans suffering from posttraumatic stress disorder and in victims of childhood abuse, and cortical tissue was reduced in torture victims.

There is some evidence the damage is caused by cortisol.

Whether stress has a negative impact on health depends on a variety of factors, including social support, personality, and attitude.

Social and personality influences must work through physiological mechanisms which, unfortunately, are seldom assessed in studies.

People with congenital insensitivity to pain are born unable to sense

pain.

They injure themselves repeatedly because they are not motivated to avoid dangerous situations, and they die from untreated conditions like a ruptured appendix.

The pain pathway has rich interconnections with the limbic system, where pain becomes an emotional phenomenon. We process pain as an emotion in many cases.

Besides the somatosensory area, pain particularly activates the anterior cingulate cortex, which in turn is intimately connected with other limbic structures.

If pain continues it also recruits activity in prefrontal areas where, presumably, the pain is evaluated and responses to the painful situation are planned.

In pain insensitivity disorders, it is the emotional response that is diminished rather than the sensation of pain.

The person can recognize painful stimulation, but simply isn’t bothered by it. The same is true for people who underwent prefrontal lobotomy back when that surgery was used to manage untreatable pain.

When questioned, the patients often said they still felt the “little” pain but the “big” pain was gone.

Biological Origins
of Aggression

Aggression is behavior that is intended to harm.

A distinction that has been useful in animal research is the one between predatory aggression and affective aggression.

Predatory aggression occurs when an animal attacks and kills its prey.

Affective aggression is characterized by its emotional arousal, and can be further subdivided:

An unprovoked attack on another animal is offensive aggression.

Defensive aggression occurs in response to threat and is motivated by fear.

Human aggression is less clearly categorized.

In nonprimate animals, aggression is enhanced by testosterone in males and by both testosterone and estrogen in females.

In primates, aggressiveness increases in female monkeys during the premenstrual period, a time when estrogen and progesterone are at their lowest.

Studies have also reported a doubling of crimes and violent crimes in women during this period.

Progesterone has been reported to reduce PMS-related aggressiveness, and some studies suggest that decreased levels of allopregnanolone, a metabolite of progesterone, may impair the woman’s anxiety response to stress.

Some studies have found a relationship between testosterone and violence in male prison inmates.

There is no clear evidence that aggression in humans is affected by manipulation of testosterone levels or by disorders that increase or decrease testosterone.

We know more about the brain structures involved in feline aggression and their connections than in any other animal.

The defensive pathway begins in the medial nucleus of the amygdala, travels to the medial hypothalamus, and goes from there to the dorsal part of the periaqueductal gray in the brain stem.

Control of predatory attack flows form the later nucleus and the central nucleus of the amygdala to the lateral hypothalamus and the ventral periaqueductal gray.

Research on human aggression is constrained.

Tumors can cause aggression if they are in the hypothalamus or the septal region.

Seizure activity in the area of the amygdala increases aggression, and damage to the amygdala reduces it.

The prefrontal cortex is critical in restraining aggression.

People with antisocial personality disorder behave recklessly, violate social norms, commit antisocial acts like fighting, stealing, and using drugs, and engaging in sexual promiscuity, and show little or no remorse for their behavior.

People with antisocial personality disorder are more likely to have reduced prefrontal gray matter.

Serotonin inhibits aggression, probably through its effects in the amygdala, hypothalamus, periaqueductal gray, and prefrontal area.

Low serotonin activity is specifically associated with impulsive aggression.

Evidence favors the common-sense interpretation that alcohol facilitates aggression rather than simply being associated with it However, alcohol appears to influence aggression only in people who also have low serotonin levels, such as early-onset alcoholics, who tend to be impulsively aggressive.

After initially increasing serotonin activity, alcohol later depletes it below the original level.

The alcohol abuser is caught in a vicious cycle as alcohol consumption increases both aggression and the craving for more alcohol.

Higley and his colleagues (1996) suggest that high testosterone and low serotonin interact to produce aggression. Monkeys with low 5-HIAA levels were impulsive. They more frequently took dangerously long leaps among the treetops, and when they engaged in aggression it was more likely to accelerate into greater violence.

The most aggressive monkeys of all had both low 5-HIAA and high testosterone levels.

Reca[:

Emotion and the Nervous System

•         Sympathetic nervous system activation with emotional arousal

–       increased heart rate, respiration, perspiration and blood pressure

–       decreased digestion and blood vessel constriction

–       stimulates glucocorticoid hormone release by adrenal glands

•         Parasympathetic nervous system brings you back down and restores energy

Comparison of sympathetic activity during emotional arousal with parasympathetic activity during relaxation

Theories of Emotion

         James-Lange theory

–       nervous system activation occurs first and causes emotions

–       we fear a bear because our body reacted to seeing one

         Schachter-Singer theory

–       cognitive labeling of the physiological activation determines emotion experienced – physiological activation is the same for every emotion

Comparison of the James-Lange and the Schachter-Singer cognitive theories of emotion

Cognitive Aspects of Emotion

         Schachter-Singer's study

–       injected with epinephrine (causing sympathetic nervous system arousal)

–       some told actual effects of injection (informed), others uninformed

–       waited in room with confederate acting euphoric or angry

–       uninformed participants labeled their arousal congruent with confederate's apparent mood

Physical Patterns of Emotional Response

•         Use of polygraph (commonly called the lie detector) has demonstrated that some emotional states indeed do have distinctive patterns of physiological response

•         Some investigators looking at feedback provided from facial muscles

–       facial expressions may lead to the experience of different emotions

–       are also correlated with distinctive patterns of physiological activation

–       facial expressions are universal (even in blind individuals)

Brain Areas and Emotion

•         The limbic system

–       many parts that are interconnected

–       emotion, learning & memory, sexual activity and aggression

•         Stimulation of some parts of the hypothalamus can lead to bared teeth and claws while other parts (the septal area) produces a sense of pleasure (particularly sexual)

The Amygdala

•         Part of limbic system

•         Helps coordinate physiological and facial expressions of emotion (especially fear)

•         Damage to amygdala removes fear and aggression in animals

•         Stimulation produces fear and aggression

•         Anti-anxiety medications have some of their effects at amygdala

•         Damaged amygdala patients do not respond emotionally to rewards and punishments

Stress and the Brain

The Prefrontal Cortex and the Right Hemisphere

•         Damage to prefrontal cortex blunts emotional responding

–       inability to anticipate long-term consequences to their behavior

•         Damage to right hemisphere causes emotional suppression probably due to decreased autonomic nervous system activity

–       have difficulty recognizing emotional expressions – facial expressions and vocal tone

–       their own speech is emotionless

Stress

•         Activates the sympathetic nervous system and the hypothalamus-pituitary-adrenal cortex axis (HPA)

–       pituitary releases adrenocorticotropic hormone (ACTH) that then stimulates adrenal glands to release epinephrine, norepinephrine and cortisol – all lead to increased energy levels to fight off stress

•         Increases immune system activity

–       leucocytes recognize antigens of foreign cells; macrophages ingest them

–       T cells attack the foreign cells and B cells create antibodies to attack the cell types

–       natural killer cells destroy some cancerous cells and cells with viruses

The Hypothalamus-Pituitary-Adrenal Cortex Axis

Negative Effects of Stress

•         Memory impairment, appetite changes, decreased sex drive and energy, and mood disruptions

•         Decreased B cells, T cells and natural killer cells

–       immunoredistribution hypothesis

•         Increased blood pressure potentially causing heart attack or stroke

•         Sudden cardiac death where sympathetic nervous system so activated it sends the heart into fibrillation

•         Decreased hippocampal volume and cortical tissue in brain

–       probably caused by the increased cortisol

Social and Personality Variables

•         Social support lowers death rate and stress hormone levels

•         Hostility associated with greater cardiac risk

•         Depressed individuals have lower natural killer cells

•         These results are correlational, not causal!

Pain and Emotion

•         Pain is adaptive

–       congenital insensitivity to pain leads to repeated injuries and death

•         Extent of pain perception influenced by meaningful context

•         Pain pathway activates the anterior cingulated cortex (ACC)

–       many connections to limbic system (emotion)

–       responsible for the emotional aspect of pain

•         May also involve the prefrontal cortex

–       planned responses to painful stimulation

Types of Aggression

•         Offensive aggression – unprovoked attack on another

•         Defensive aggression – response to threat – fear motivated

•         Predatory aggression – animal attacks, kills and consumes its prey

•         Hormones tend to influence offensive aggression more than other types

–       testosterone in males and testosterone & estrogen in females

>     premenstrual syndrome may be due to increased estrogens

–       relationship between testosterone and aggression is correlational

The Brain and Aggression

•         Defensive aggression

–       pathway from medial amygdala to dorsal periaqueductal gray

•         Predatory aggression

–       pathway from lateral and central amygdala to lateral hypothalamus and ventral periaqueductal grey

•         Seizures in amygdala increase aggression

•         Tumors in hypothalamus (septal region) increase aggression

•         Decreased activity in prefrontal cortex correlated with increased aggression

–       difficulty controlling impulses (antisocial personality disorder (APD)

Serotonin and Aggression

•         Low serotonin associated with impulsive aggression

–       particularly in prefrontal cortex

•         Alcohol increases aggression in low serotonin individuals (early-onset alcoholics)

•         Low serotonin and high testosterone interact to produce aggression

•         There does appear to be a genetic basis for aggression

–       genes that control three serotonin receptor subtypes

CHAPTER 8

Emotion

and Health

Emotion and Health

The prefrontal cortex is necessary for making judgments about behavior and its consequences.

People who sustain damage to this area later in life show an understanding of moral and social rules in hypothetical situations but are unable to apply these rules to real-world situations.

People who sustain damage early in life never learn these rules and, at best, are motivated only to avoid punishment.

Emotion is an increase or decrease in physiological activity that is accompanied by feelings that are characteristic of the emotion, and often accompanied by a characteristic behavior or facial expression.

According to the James-Lange theory, emotional experience results from the physiological arousal that precedes it, and different emotions are the result of different patterns of arousal.

According to Schachter and Singer’s cognitive theory, physiological arousal contributes only to the emotion’s intensity, while the identity of the emotion is based on the cognitive assessment of the situation.

Physiological feedback adds intensity to the motivation necessary for adaptive behavior. Our assessment and identification of an emotion allows us to draw on our base of knowledge and experience to plan and execute a response.

Different patterns of physical arousal during emotion may have an adaptive function aside from identifying our emotions.

Emotion is not just feelings, emotions benefit of our position on the evolutionary tree. Emotion is a major key to our survival and success.

In the late 1930s and 40s researchers proposed that emotions originated in the limbic system, a network of structures arranged around the upper brain stem.

As complex as this system is with its looping interconnections, we now know that it is an oversimplification.

Emotion involves structures at all levels of the brain, from the prefrontal areas to the brain stem.

The hypothalamus has primary control over the autonomic nervous system, and produces a variety of emotional expression.

Septal area stimulation also produces a sense of pleasure, but the feeling is accompanied by sexual fantasies and arousal.

Two of the most reliable brain-emotion associations have been the amygdala’s role in fear and the location of disgust in the insular cortex and the basal ganglia.

Another important structure in emotion is the anterior cingulate cortex, a part of the cingulate gyrus important for attention, cognitive processing, and possibly consciousness, as well as emotion.

The anterior cingulate cortex is believed to combine emotional, attentional, and bodily information to bring about conscious emotional experience.

The prefrontal cortex is the final destination for much of the brain’s information about emotion before action is taken.

The amygdala is a small limbic system structure in each temporal lobe that is involved in negative emotions. The amygdala participates in memory formation, in particular when emotion is involved.

Although the amygdala is involved in other emotions, its role in fear and anxiety has been most thoroughly researched.

Fear is an emotional reaction to a specific immediate threat. Anxiety is an apprehension about a future, and often uncertain, event.

Patients with prefrontal damage respond emotionally to rewards and punishment, but are unable to use this information to guide their behavior.

People with damage to both amygdalas do not produce the emotional response in the first place.

Although both hemispheres are involved in the experience of emotions, the left frontal area is more active when the person is experiencing positive emotions, and the right frontal area is more active during negative emotion.

People with damage to the left hemisphere often express more anxiety and sadness about their situation, while those with right-hemisphere damage are more likely to be unperturbed or even euphoric, even when their arm or leg is paralyzed.

Autonomic responses to emotional stimuli such as facial expressions and emotional scenes are greater when the stimuli are presented to the right hemisphere.

Perception of non-verbal aspects of emotion is impaired in right-hemisphere-damaged patients.

Stress, Immunity, and Health

Stress is a condition in the environment that makes unusual demands on the organism, such as threat, failure, or bereavement.

Stress is also an internal condition, your response to a stressful situation.

The stress response includes activation of the sympathetic branch of the autonomic nervous system, which is largely under the control of the hypothalamus.

The resulting increases in heart rate, blood flow, and respiration rate help the person deal with the stressful situation.

Stress also activates the hypothalamic-pituitary-adrenal axis (HPA Axis), a group of structures that help the body cope with stress.

The hypothalamus activates the pituitary gland, which in turn releases hormones that stimulate the adrenal glands to release the stress hormones epinephrine, norepinephrine, and cortisol.

The first two hormones increase output from the heart and liberate glucose from the muscles for additional energy.

The hormone cortisol also increases energy levels by converting proteins to glucose, increasing fat availability, and increasing metabolism.

Cortisol provides a more sustained release of energy than the sympathetic nervous system does, for coping with prolonged stress.

Brief stress increases activity in the immune system, the cells and cell products that kill infected and malignant cells and protect the body against foreign substances, including bacteria and viruses.

The immune response involves two major types of cells:

Leukocytes, or white blood cells which recognize invaders by the unique proteins that every cell has on its surface and kills them.

Natural killer cells, the second type of immune cells which attack and destroy certain kinds of cancer cells and cells infected with viruses.

We are better equipped to deal with brief stress than with prolonged stress.

Chronic stress can interfere with memory, increase or decrease appetite, diminish sexual desire and performance, deplete energy, and cause mood disruptions.

Although brief stress enhances immune activity, prolonged stress compromises the immune system.

The cardiovascular system is particularly vulnerable to stress.

Stress increases blood pressure, and prolonged high blood pressure can damage the heart or cause a stroke.

In sudden cardiac death, stress causes excessive sympathetic activity that sends the heart into fibrillation, contracting so rapidly that it pumps little or no blood.

Extreme stress can also lead to brain damage.

Hippocampal volume was reduced in Vietnam combat veterans suffering from posttraumatic stress disorder and in victims of childhood abuse, and cortical tissue was reduced in torture victims.

There is some evidence the damage is caused by cortisol.

Whether stress has a negative impact on health depends on a variety of factors, including social support, personality, and attitude.

Social and personality influences must work through physiological mechanisms which, unfortunately, are seldom assessed in studies.

People with congenital insensitivity to pain are born unable to sense

pain.

They injure themselves repeatedly because they are not motivated to avoid dangerous situations, and they die from untreated conditions like a ruptured appendix.

The pain pathway has rich interconnections with the limbic system, where pain becomes an emotional phenomenon. We process pain as an emotion in many cases.

Besides the somatosensory area, pain particularly activates the anterior cingulate cortex, which in turn is intimately connected with other limbic structures.

If pain continues it also recruits activity in prefrontal areas where, presumably, the pain is evaluated and responses to the painful situation are planned.

In pain insensitivity disorders, it is the emotional response that is diminished rather than the sensation of pain.

The person can recognize painful stimulation, but simply isn’t bothered by it. The same is true for people who underwent prefrontal lobotomy back when that surgery was used to manage untreatable pain.

When questioned, the patients often said they still felt the “little” pain but the “big” pain was gone.

Biological Origins of Aggression

Aggression is behavior that is intended to harm.

A distinction that has been useful in animal research is the one between predatory aggression and affective aggression.

Predatory aggression occurs when an animal attacks and kills its prey.

Affective aggression is characterized by its emotional arousal, and can be further subdivided:

An unprovoked attack on another animal is offensive aggression.

Defensive aggression occurs in response to threat and is motivated by fear.

Human aggression is less clearly categorized.

In nonprimate animals, aggression is enhanced by testosterone in males and by both testosterone and estrogen in females.

Biological Origins
of Aggression