Chapter 12 Emotional Behaviors

What is Emotion? An emotional state has three aspects: 1.Cognition 2.Readiness for action 3.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

What is Emotion? Emotional experiences arouse many areas of the brain The limbic system PET and fMRI studies

Fig. 12-3, p. 357

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.

Fig. 12-5, p. 361

Attack and Escape Behaviors genetic contribution Dizygotic twins Monozygotic twins

Attack and Escape Behaviors Smoking habits of the mother

Fig. 12-6, p. 362

Attack and Escape Behaviors Nature versus Nurture

Attack and Escape Behaviors males versus females. –testosterone.

Fig. 12-7, p. 363

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:

Fig. 12-9, p. 365

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.

Fig , p. 367

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

Fig , p. 370

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