Emotions and Autonomic Arousal

• Strong emotions enhance readiness for action
• Emotion theories link emotion and action
• Emotion includes cognitions, feelings, actions, and physiological changes

Emotions and Autonomic Arousal

• Emotional situations activate the sympathetic and parasympathetic nervous systems
• The sympathetic nervous system prepares for vigorous action
• The parasympathetic nervous system conserves energy
• One emotion theory suggests heart rate responds first, prompting other responses
• James-Lange theory: Autonomic arousal and skeletal action occur before emotion with emotion being just a label of physiological responses
• The emotion theory has three components: Cognitions, actions, and feelings
• Cognitive appraisal occurs first, leading to action, then emotional feelings occur later
• Emotions do not require feedback from full body muscle movements, as spinal cord injury patients still report emotions
• Pure autonomic failure is a rare condition involving complete or near-complete autonomic nervous system failure
• Those with pure autonomic failure report experiencing emotions, but with reduced intensity and no autonomic response to stress
• Decreased emotional feeling aligns with James-Lange theory

Physiological Arousal and Emotions

• Botox studies suggest body changes, like facial expressions, affect emotional experience
• Panic attacks involve extreme sympathetic nervous system arousal, sometimes from rapid breathing or a racing heartbeat
• These symptoms can trigger the belief that a panic attack is imminent
• People made to smile found a comic strip funnier than those who were not smiling
• Emotion has cognition, feeling, and action aspects, so not all aspects always co-occur
• Emotional experiences activate many brain areas, including the limbic system
• The limbic system, traditionally critical for emotion, borders the brainstem
• PET and fMRI studies reveal activation of specific cortical areas during emotional experiences

Anatomy of Emotion

• The hypothalamus sits under the thalamus at the top of the brainstem
• It controls critical bodily functions and is believed to have a role in emotion
• Lateral parts of the hypothalamus relate to pleasure and rage
• The medial part relates to aversion, displeasure, uncontrollable laughter

Thalamus

• Thalamus sits deep in the brain at the top of the brainstem, and means "inner room” in Greek
• It's called the gateway to the cerebral cortex, because most sensory inputs runs through it
• It regulates consciousness, sleep, and alertness
• Thalamus lesions are associated with changes in emotional reactivity
• Damage can lead to coma

Amygdala

• Almond-shaped nuclei mass located in the temporal lobes, near the hippocampus
• Main functions include: Memory, decision-making, and emotional reactions
• It mediates and controls major affective activities like friendship, love, affection, mood expression and mainly fear, rage and aggression
• The amygdala connects to the olfactory bulb and cortex
• Women tend to retain stronger memories for emotional events
• The amygdala is fundamental for self-preservation as the center for identifying danger
• When triggered, the amygdala causes fear and anxiety, leading to alertness as readiness to flee or fight
• Lesions in the amygdala cause humans to lose the affective meaning of outside information
• Subjects with lesions know who a person is, but can't decide if they like them
• Amygdala lesions block fear conditioning and it appears responsible for adding emotional significance to another stimulus

Insular Cortex

• Processes taste information
• Plays a role experiencing the emotion of disgust

Basic Emotions

• Support: Facial expressions exist for happiness, sadness, fear, anger, disgust, surprise, and perhaps other emotions
• Seldom is emotion interpreted solely based on expressions alone
• Two or more emotions can co-occur in a single facial expression
• Context and gestures are also important
• Emotional feelings vary along two continuous dimensions
• The alternative view with the two continuous dimensions fits physiological evidence

Hemispheres

• Left hemisphere activity (BAS) has low to moderate autonomic arousal, relating to happiness or anger
• Right hemisphere activity (BIS) raises attention/arousal, inhibits action, and stimulates fear/disgust
• Greater left frontal cortex activity is associated with being happier, more outgoing, fun-loving
• Greater right-hemisphere activity is associated with being socially withdrawn, less satisfied with life, and prone to unpleasant emotions
• The right hemisphere is more responsive to emotional stimuli and is activated by unpleasant emotions

Functions of Emotion

• Fear alerts to danger and disgust helps avoid illness
• Emotions communicate needs and help one understand others, which helps make quick “gut” decisions
• Moral decisions involve considering how outcomes will feel
• The trolley, footbridge, lifeboat, and hospital dilemmas all involve saving five people by killing one
• In the trolley dilemma, most find it right to pull the switch
• In the footbridge and lifeboat dilemmas, fewer find it to be acceptable
• Seldom is the right decision worked out rationally, but rather based on what feels right and a logical justification comes afterward

Brain Damage and Decision Making

• People with prefrontal damage are more likely to choose the utilitarian option (killing one to save five)
• This is seen even in situations most people find emotionally unacceptable
• Phineas Gage had prefrontal damage, survived, but became impulsive with poor decisions
• Antonio Damasio also had prefrontal cortex damage; it resulted in bad decisions that cost him his job, marriage, and savings
• Damage to the ventromedial prefrontal cortex causes loss of guilt
• Damage to the prefrontal cortex or amygdala slows emotional information processing

Attack and Escape Behaviors

• Attack and escape (fear) behaviors are related physiologically and behaviorally
• They depend on the individual and the situation

Heredity and Environment in Violence

• Individual differences in aggressive, violent, or antisocial behavior depend on both heredity and environment
• The environment's role involves witnessing/experiencing violence in childhood, living in a violent neighborhood, and lead exposure as a child
• Twin studies point to heritability, but with experimental design debate
• Individuals with the low-activity form of the MAOA gene tend to act more aggressively
• A person raised is still a high interaction between genetics and the environment

Hormonal Effects

• Male aggression and social dominance depend on testosterone
• Men with more testosterone have more violent activities and criminal behaviors
• Women injected with testosterone were less accurate at identifying angry facial expressions
• Testosterone raises amygdala response to angry expressions
• Women injected with testosterone were also more likely to argue

Serotonin and Aggressive Behavior

• Impulsiveness and aggression are linked to low serotonin release
• Serotonin release is measured by serotonin turnover, noted as 5-HIAA concentration in cerebrospinal fluid
• Decreased serotonin turnover in mice led to more aggressive behavior
• Serotonin turnover is inferred by measuring 5-hydroxyindoleacetic acid (5-HIAA), a serotonin metabolite.
• Social isolation induced a serotonin turnover drop in male mice brains, further increasing aggression toward other males
• These effects are not found in female mice.
• Lower-than-normal serotonin turnover can be found in those convicted of violent crimes or who attempted suicide
• Those released with lower serotonin turnover have higher probability of further convictions
• Serotonin/aggression relationship is small and can't be used to make predictions about an individual

Chemicals

• Aggressive behavior does not correlate strongly with any single chemical, but rather a combination
• Testosterone facilitates aggressive, assertive, and dominant behaviors
• Serotonin tends to inhibit impulsive behaviors
• Cortisol inhibits aggression
• Aggressive behavior depends on ratio of testosterone to cortisol

Role of the Amygdala

• It is involved with fear and anxiety
• Startle reflex is the response to a sudden, unexpected loud noise
• People with post-traumatic stress disorder show a much enhanced startle reflex

Rodents

• The amygdala enhances the startle reflex via hypothalamus axons (controlling autonomic fear responses)
• Relaying of the information to the pons, which is in the midbrain, triggers the reflex
• Toxoplasma gondii is a protozoan exploits the consequences of amygdala damage
• The parasite enters a rat and migrates to the brain, damaging the amygdala
• The rat fearlessly approaches a cat, so that the parasite will enter into the cat to reproduce and excrete in the feces.
• Rats learn to fear stimulus, as well as the cage, new cages, and new situations if they get shocks after fear conditioning
• When attached or having traumatic experiences the humans can also become more fearful
• The amygdala knows what to fear
• Long-term, generalized emotional arousal depends on the bed nucleus of the stria terminalis

Studies of Monkeys

• Klüver-Bucy syndrome is tameness and placidity in monkeys following damage or removal of the amygdala
• Monkeys with amygdala lesions are more likely to approach an object they normally avoid
• It leads to decreased fear, while other monkeys are withdrawn and fearful
• Those with a more vigorously reactive amygdala show greater fear response to a noise or an intruder

Response of the Human Amygdala to Visual Stimuli

• Amygdala is activated in response to emotional expressions, especially fear and anger
• It also responds to faces showing happiness or sadness to a lesser extent
• The Amygdala responds the most when a facial expression is a bit ambiguous or difficult to interpret
• Arousal indicates that it is working harder to make sense of the stimulus

Amygdala Response and Anxiety

• Amygdala activity correlated highly with the number of unpleasant emotions college students recorded
• Unpleasant emotions are biologically predisposed
• Soldiers with the greatest amygdala response to unpleasant faces reported greatest combat stress
• The amygdala is strongly associated with fear responses
• People with a highly reactive amygdala are likely to perceive dangers
• This supports strong protection against those dangers

Damage to the Amygdala

• Some can still continue to experience the cognitive aspect of emotions when they have this damage
• They are still able to classify emotional photos as pleasant or unpleasant, but not the feeling aspect
• Urbach-Wiethe disease is a genetic disorder that causes gradual atrophy of the amygdala
• The people are curious when touching exotic and venomous snakes, views scary movies
• When getting held up at gun point and knife point only remembers being angry, not scared
• Those with damage don't recognize emotional expressions in faces, especially expressions of fear and disgust
• She always looks at peoples nose and to recognize fear, make sure to look at the eyes so SM can quickly recognize it
• The research suggests that it directs other brain areas to pay attention to it in the proper way
• It may not be responsible for feeling fear, but for detecting emotional information

Anxiety Disorders

• They are characterized as such when the major symptom is increased anxiety.
• It includes panic disorder, generalized anxiety disorder, and phobias
• Panic disorder is characterized by frequent periods of anxiety and occasional attacks of rapid breathing Increased heart rate, sweating, and trembling
• Adolescent and young adults are more common than other adults
• Post-traumatic stress disorder is a psychiatric disorder that occurs when the person has has a traumatic experience
• PTSD lasts at least a month, and includes frequent distressing recollections and nightmares about the traumatic event
• Avoidance of reminders of it, and exaggerated arousal in response to noises and other stimuli
• Victims have a smaller than average hippocampus , lower than normal cortisol levels, and there are differences in vulnerability to PTSD.

Pharmacological Relief from Anxiety

• GABA (gamma amino butyric acid) is the main inhibitory neurotransmitter found in the amygdala
• Injections of GABA blockers can induce outright panic
• Benzodiazepines are commonly used class of anti-anxiety drugs
• It includes diazepam, chlordiazepoxide, and alprazolam
• These drugs bind to a receptor site on the GABAA receptor, allows GABA to attach more easily, and more tightly bind to it
• The antianxiety effects takes place in the amygdala and hypothalamus, midbrain, and several other areas
• It produces a variety of effects, including the possibility of addiction
• Some people self-medicate with alcohol since alcohol has effects on GABA receptors responsible for the anti-anxiety and intoxicating effect
• The experimental drug Ro-15-4513 blocks the effect of alcohol on the GABAA receptors complex

Stress and Health

• Behavioral medicine focuses on effects of diet, smoking, exercise, and other behaviors on health

Stress and Adaptation

• Stress is the nonspecific response of the body to any demand made upon it
• Events interpreted as threatening and elicit physiological/behavioral responses
• General adaptation syndrome refers to the generalized response to stress that includes 3 stages
• Alarm is characterized by increased activity of the sympathetic nervous system
• Resistance involves adrenal cortex secreting cortisol and other hormones
• Allowing the body to maintain prolonged alertness, fight infections, and heal wounds.
• Exhaustion refers to when the individual is tired, inactive, and vulnerable
• It no longer has the energy to sustain heightened responses
• Life changes can cause stress, such as getting fired or promoted

HPA Axis

• Stress activates both the autonomic nervous system and the HPA axis: hypothalamus, pituitary gland, and adrenal cortex
• Prolong stress increasingly activates the axis
• Stress activates the hypothalamus, which sends messages to the anterior pituitary gland and secrete adrenocorticotropic hormone
• ACTH is the hormone that stimulates the adrenal cortex to secrete cortisol, increases blood sugar levels and enhances metabolism
• Brief and moderate stress helps attention and memory, performance on tasks, and enhances activity of the immune system

Immune System

• The immune system is comprised of cells that protect the body against intruders such as bacteria and viruses
• A type of disorder called autoimmune disease is a result of the immune system attacking normal cells
• Leukocytes are types of white blood cells, looks for intruders and is produced in the none marrow
• There are B cells: Leukocytes that mature in the bone marrow and produce specific antibodies to attack an antigen
• The body develops antibodies against antigens that it encountered in the past and Y-shaped proteins, called antibodies, circulate in the blood and attach specifically to one kind of antigen
• Antigens are also known as antibody-generator molecules and located on a cell surface
• Leukocytes attack cell with antigens that are different from the rest of the body

T Cells

• Leukocytes mature in the thymus
• Cytotoxic T cells are a type of T cells and directly attacks intruder cells
• Helper T cells are a type and stimulate other T cells or B cells to multiply more rapidly
• Natural killer cells are blood cells that attach to cells infected with viruses and certain kinds of tumor cells
• Cytokines are chemicals released by the immune system that cross the blood-brain barrier and influence neuronal function

Effects of Stress

• Psychoneuroimmunology studies how experiences, especially stressful ones, alter the immune system
• This also studies how the immune system, in turn influences the central nervous system
• In response to stress the nervous system activates and secretes cytokines, it is triggered to produce the same symptoms as if one were ill.
• Results of reports from studies shows that there is no more risk when briefly stressful, but lasting over a month will increase the risk with illness
• High concentration levels of cortisol impair memory and increase the vulnerability of neurons leading to toxins that will kill the neurons in the hippocampus

Stress Control

• Resilience during stress correlates with stronger connections between the amygdala and the prefrontal cortex
• People have developed to control stress by methods of breathing routines, exercises, and social support from a loved has increased reduction with stress