Chapter 12Emotional 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. 12-10, 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. 12-14, 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