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Chapter 12 Emotional Behaviors Module 11.1: What Is Emotion? Module 11.2: Attack and Escape Behaviors Module 11.3: Stress and Health What is Emotion? • An emotional state has three aspects: 1. Cognition (assessment of situation: “This is dangerous.”) 2. Feelings (“I feel scared”—requires labeling) 3. Action (involves physical response, such as running away) Common Sense View What is Emotion? • Action, or “readiness for action” is a product of the autonomic nervous system (ANS). • James-Lange theory (1884): autonomic arousal and skeletal action occur first, then come feelings/emotions. • The emotion that is felt is the label that we give the arousal of the organs and muscles. What is Emotion? • According to the James-Lange theory: 1. People with a weak autonomic or skeletal response should feel less emotion. 2. Increasing one’s response should enhance an emotion. What is Emotion?: Evidence Supporting the James-Lange Theory • People with “pure autonomic failure” report feeling emotion less intensely. – Pure autonomic failure - output from the autonomic nervous system almost entirely fails. • Botulinum toxin (BOTOX): blocks transmission at synapses and nerve-muscle junctions, resulting in temporary paralysis, resulting in weaker than usual emotional responses What is Emotion?: Evidence Supporting the James-Lange Theory • Creating certain body actions may also slightly influence emotion. – smiling slightly increases happiness. – Inducing a frown leads to the rating of stimuli as slightly less pleasant. • Indicates that perception of the body's actions do contribute to emotional feeling What is Emotion?: Evidence Refuting the James-Lange Theory Research indicates that paralyzed people report feeling emotion to the same degree as prior to their injury • Contradictory research suggests other factors are involved in the perception of emotion. What is Emotion?: Basic Emotions • Facial expressions are just one source of information about emotion • Research indicates that facial expressions, body posture, tone of voice all convey emotional meaning What is Emotion? • Emotional experiences arouse many areas of the brain. • The limbic system has traditionally been regarded as critical for emotion. • 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. What is Emotion? • Emotions tend not to be localized in specific parts of the cortex. • A single emotion increases activity in various parts of the brain. What is Emotion? • Inactivation of the medial frontal cortex appears to impair the ability to recognize angry expression. What is Emotion? • Insular cortex – strongly activated when experiencing disgust – primary taste cortex – reacts to frightening stimuli as well. What is Emotion? • The two hemispheres of the brain play different roles in emotion. • Behavioral Inhibition System (BIS): associated with increased activity of the frontal and temporal lobes of the right hemisphere – Increases attention and arousal – Inhibits action – Stimulates emotions such as fear and disgust What is Emotion? • Behavioral Activation System: increased activity of left hemisphere frontal and temporal areas – associated with “approach” – marked by low to moderate arousal – registers happiness or anger What is Emotion? • Differences in prefrontal cortex activity relates to personality. • People with greater activity in the left hemisphere tend to be happier, more outgoing and friendlier. • People with greater right hemisphere activity tend to be socially withdrawn, less satisfied with life, and prone to unpleasant emotions. What is Emotion? • The right hemisphere seems to be more responsive to emotional stimuli than the left. • Damage to the right temporal cortex causes problems in the ability to identify emotions of others. What is Emotion? • One major function of emotion is to help us make decisions. • Failure to anticipate the unpleasantness of an event can lead to bad decision making. • Low autonomic arousal is correlated with making logical moral decisions Attack and Escape Behaviors • Pain, threat or other unpleasant stimuli usually trigger an attack behavior. • Attack behaviors are associated with increased activity in the corticomedial area of the amygdala. • After experiencing a provocation, people are more likely to attack for a period of time afterwards. • An initial attack behavior increases the probability of a second attack behavior. Attack and Escape Behaviors • Twins studies suggest genetic contribution to the likelihood of violent behavior. • Smoking cigarettes while pregnant is correlated with violent behavior in offspring. • The effect is particularly strong if the mother smoked and also had complications during pregnancy. Attack and Escape Behaviors • Environmental factors can combine with genetic factors to influence behavior. • Adopted children have the highest probability of violent behavior if the biological parent has a criminal record and there is discord in the adopted family household. • A biological predisposition alone, or a troubled adoptive family by itself, produces only moderate effects. Attack and Escape Behaviors • On average, males engage in more aggressive and violent behaviors than do females. • Male aggressive behavior is influenced by the hormone testosterone. • Research shows that men with the highest rates of violent behavior also have slightly higher testosterone levels. Attack and Escape Behaviors • Studies suggest a connection between aggressive behavior and low serotonin release. • Turnover is the amount of release and resynthesis of a neurotransmitter by presynaptic neurons. • In human and animal studies, low serotonin turnover has been linked to: – violent behavior and violent crime – suicide by violent means Attack and Escape Behaviors • “Fear” is associated with a strong tendency to escape from an immediate threat. • “Anxiety” is a general sense that something dangerous might occur. – Not necessarily associated with the desire to flee. Attack and Escape Behaviors • The startle reflex is the extremely fast response to unexpected loud noises. – 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. Attack and Escape Behaviors • Stimuli previously associated with the startle response enhances the startle response. – Cells in the amygdala are responsible. • Cells in the amygdala receive information from pain, vision, and hearing circuits. • Axons extend to areas in the midbrain that relay information to the nucleus in the pons. – The relay enhances the startle reflex. Attack and Escape Behaviors • Output from the amygdala to the hypothalamus controls autonomic fear responses. • Axons extending from the amygdala to the prefrontal cortex regulate approach and avoidance responses. Attack and Escape Behaviors • fMRI studies of humans suggest the amygdala responds strongly to emotional stimuli and facial expressions. – Activity is strongest when the meaning is unclear and requires some processing. – With some exceptions, looking at happy faces activates the amygdala only weakly. • Amygdala also responds to stimuli not consciously perceived. Attack and Escape Behaviors Damage to the amygdala interferes with: • learning of fear responses • retention of fear responses previously learned • interpreting or understanding stimuli with emotional consequences Attack and Escape Behaviors: Anxiety Disorders • Damage to the amygdala impairs the processing of emotional information when the signals are subtle or complicated. • Amygdala damage affects the ability to judge “trustworthiness” in people. • People with amygdala damage focus on emotional stimuli the same as irrelevant stimuli or details. Attack and Escape Behaviors • People with overactive amygdalae may experience anxiety: – physical distress, including muscle tension, heart palpitations, sweating, rapid breathing – emotional distress, including worry, etc. • Panic Disorder: episodes of extreme anxiety • Generalized Anxiety Disorder: recurrent/continuous anxiety with no identifiable cause • Phobias: fear of a specific place, thing, or situation • Post-traumatic Stress Disorder (PTSD): anxiety that occurs after experiencing a traumatic event Attack and Escape Behaviors • Excessive fear and anxiety disorders are associated with hyperactivity in the amygdala • Drugs intended to control anxiety alter activity at amygdala synapses. • The main excitatory neuromodulator in the amygdala is CCK, and the main inhibitory transmitter is GABA. – Injections of CCK-stimulating drugs into the amygdala enhance the startle response. – Drugs that increase GABA activity decrease panic. GABA =STOP CCK/Orexin=GO Attack and Escape Behaviors • Benzodiazepines are the most commonly used anti-anxiety drugs (anxiolytics or tranquilizers). • Benzodiazepines bind to the GABAA receptor complex, and facilitate the effects of GABA. • Benzodiazepines exert their effects in the amygdala, hypothalamus, midbrain, and other areas. Attack and Escape Behaviors • Ethyl alcohol has behavioral effects similar to benzodiazepines. • Alcohol enhances GABA effects. Stress and Health • Behavioral medicine emphasizes the effects of diet, smoking, exercise, stressful experiences, and other behaviors on health. • Emotions and other experiences influence illness and pattern of recovery. Stress and Health • Hans Selye (1979) defined stress as the nonspecific response of the body to any demand made upon it. • Threats on the body activate a general response to stress called the general adaptation syndrome. Stress and Health The General Adaptation Syndrome: • Alarm stage - characterized by increased sympathetic nervous system activity. • Resistance stage - sympathetic response declines, the adrenal cortex releases cortisol and other hormones that enable the body to maintain prolonged alertness. • Exhaustion stage - occurs after prolonged stress and is characterized by inactivity and decreased immune system. Stress and Health Stress activates two systems in the body: 1. The autonomic nervous system “fight or flight” response that prepares the body for brief emergency responses 2. The HPA axis - the hypothalamus, pituitary gland, and adrenal cortex. Stress and Health • The HPA axis becomes the dominant response to prolonged stressors. • Activation of the hypothalamus induces the pituitary gland to secrete adrenocorticotropic hormone (ACTH). • ACTH stimulates the adrenal cortex to secrete cortisol. • Cortisol enhances metabolic activity and elevates blood levels of sugars and other nutrients to mobilize energies. Stress and Health • Prolonged increased cortisol levels impair the immune system. • The immune system consists of cells that protect the body against viruses and bacteria. – Leukocytes – white blood cells. Stress and Health • During an infection, leukocytes and other cells produce small proteins called cytokines. – Combat infection and communicate with the brain to inform of illness. • Cytokines in the brain produce symptoms of illness. – Fever, sleepiness, lack of energy etc. – Sleep and inactivity are the body’s way of conserving energy to fight illness. Stress and Health • Psychoneuroimmunology is the study of the relationship between the nervous system and the immune system. • Deals with the way in which experiences, especially stressful ones, alter the immune system. • Also deals with how the immune system influences the central nervous system. Stress and Health Prolonged stress response is damaging to the body: • Increase of cortisol detracts from the synthesis of proteins of the immune system. • Cortisol enhances metabolic activity in the body. • Significantly increases the likelihood of illness, including autoimmune disease (immune system attacks normal cells) Stress and Health • Prolonged stress response is damaging to the body: – Can be harmful to hippocampus and can affect memory. – When metabolic activity is high in the hippocampus, the neurons are more sensitive to damage by toxins or over-stimulation. – Stress also impairs the adaptability and the production of new hippocampal neurons. Stress and Health • Posttraumatic stress disorder (PTSD) occurs in some people after terrifying experiences and includes the following symptoms: – Frequent distressing recollections – Nightmares – Avoidance of reminders of the event – Exaggerated arousal in response to noises and other stimuli Stress and Health • Studies have revealed most PTSD victims have a smaller than average hippocampus. • PTSD victims show lower than normal cortisol levels after the trauma. – People with low cortisol levels may be ill-equipped to combat stress and more prone to the damaging effects of stress. Stress and Health • There are many ways to combat and manage stress!