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Chapter 12 Emotional Behaviors. What is Emotion?. An emotional state has three aspects: Cognition Readiness for action Feeling. What is Emotion?. Autonomic nervous system arousal James-Lange theory. Fig. 12-1, p. 355. Cannon-Bard Theory. 2 factor (cognitive) theory Schacter-Singer.
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What is Emotion? • An emotional state has three aspects: • Cognition • Readiness for action • Feeling
What is Emotion? • Autonomic nervous system arousal • James-Lange theory
2 factor (cognitive) theory • Schacter-Singer
What is Emotion? • Emotional experiences arouse many areas of the brain • The limbic system • PET and fMRI studies
What is Emotion? • Most emotions tend not to be localized in specific parts of the cortex.
What is Emotion? • BUT localization in the brain seems to exist for the emotion of disgust. • The insular cortex
What is Emotion? • The two hemispheres of the brain play different roles in emotion.
What is Emotion? • The Behavioral Inhibition System (BIS)
What is Emotion? • Differences in frontal cortex activity relates to personality. • left hemisphere • right hemisphere
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? • Function of emotion
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 • genetic contribution • Dizygotic twins • Monozygotic twins
Attack and Escape Behaviors • Smoking habits of the mother
Attack and Escape Behaviors • Nature versus Nurture
Attack and Escape Behaviors • males versus females. • testosterone.
Attack and Escape Behaviors • Testosterone alters the way people respond to stimuli. • Increased testosterone levels show: • Increases in heart rate. • The tendency to attend longer and more vigorously to situations related to conflict and aggression.
Attack and Escape Behaviors • Electrical stimulation of certain areas of the brain can evoke aggressive behaviors. • The exact area of the stimulation affects the type of response: • Ranging from attack to facial movements or growls in animals.
Attack and Escape Behaviors • Intermittent explosive disorder
Attack and Escape Behaviors • Studies also suggest a connection between aggressive behavior and low serotonin release. • Turnover • Valzelli’s (1973) study with mice found that isolating male mice for 4 weeks increased aggressive behavior and decreased serotonin turnover.
Attack and Escape Behaviors • 5-hydroxyindoleacetic acid (5-HIAA) • High levels of 5-HIAA imply much serotonin release and turnover.
Attack and Escape Behaviors • 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. • Monkeys with high levels of 5-HIAA were more likely to survive.
Evolution seems to select for an intermediate amount of anxiety and aggression. • Evolution might also select for high aggressive behaviors. • may die young, but are more likely to achieve a dominant position within the troop.
Attack and Escape Behaviors • In human studies, low serotonin turnover has been linked to:
Attack and Escape Behaviors • Genes control the production of tryptophan hydroxylase.
Attack and Escape Behaviors • Genes also control the production of the enzyme monoamine oxidase.
Attack and Escape Behaviors • The role of serotonin is very complicated and should not be thought of as the “anti-aggression” transmitter. • During aggression, the brain, in fact, releases serotonin.
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 • 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 • Damage to the amygdala interferes with: • the learning of fear responses • retention of fear responses previously learned • interpreting or understanding stimuli with emotional consequences
Attack and Escape Behaviors • In the early 1900s, studies of monkeys with Kluver-Bucy syndrome illustrated the effects of amygdala damage.
Attack and Escape Behaviors • fMRI studies of humans suggest the amygdala responds strongly to emotional stimuli and facial expressions. • Not necessarily associated with just fear.
Attack and Escape Behaviors • In humans, damage to the amygdala does not result in the loss of emotion.
Attack and Escape Behaviors • Amygdala damage
Attack and Escape Behaviors • Genetic variations in amygdala
Attack and Escape Behaviors • Drugs intended to control anxiety alter activity at amygdala synapses.
Attack and Escape Behaviors • Barbituates • Benzodiazepines
Attack and Escape Behaviors • Diazepam-binding inhibitor (DBI)
Attack and Escape Behaviors • Ethyl alcohol • Cross-tolerance