Chapter 12 Emotional Behaviors

1. Chapter 12Emotional Behaviors

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

3. What is Emotion? • The “readiness for action” component of emotions is a product of the autonomic nervous system. • The James-Lange theory of emotion suggests that the autonomic arousal and skeletal action occurs first in an emotion. • The emotion that is felt is the label that we give the arousal of the organs and muscles.

4. Fig. 12-1, p. 355

5. What is Emotion? • According to the James-Lange theory: • People with a weak autonomic or skeletal response should feel less emotion. • Increasing one’s response should enhance an emotion.

6. What is Emotion? Research indicates the following: • Paralyzed people report feeling emotion to the same degree as prior to their injury • People with “pure autonomic failure” report feeling emotion less intensely. • Pure autonomic failure - output from the autonomic nervous system almost entirely fails. • Thus research is contradictory and suggests other factors are involved in the perception of emotion.

7. What is Emotion? • 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 • Does not imply that feedback from the body is sufficient to distinguish emotions. • Also requires the cognitive aspect.

8. Fig. 12-3, p. 357

9. What is Emotion? • Emotional experiences arouse many areas of the brain. • The limbic system includes the forebrain areas surrounding the thalamus and 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.

10. Fig. 12-3, p. 357

11. 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. • Inactivation of the medial frontal cortex appears to impair the ability to recognize angry expression.

12. What is Emotion? • Localization in the brain seems to exist for the emotion of disgust. • The insular cortex is strongly activated during exposure to stimuli perceived as “disgusting”. • Also the primary taste cortex. • Also reacts to frightening stimuli as well.

13. What is Emotion? • The two hemispheres of the brain play different roles in emotion. • Activation of the frontal and temporal areas of the left hemisphere is associated with “approach” and the Behavioral Activation System. • Marked by low to moderate arousal. • Characterizes either happiness or anger.

14. What is Emotion? • The Behavioral Inhibition System (BIS) is associated with increased activity of the frontal and temporal lobe of the right hemisphere. • Increases attention and arousal. • Inhibits action. • Stimulates emotions such as fear and disgust.

15. What is Emotion? • Differences in frontal cortex activity relates to personality. • People with greater activity in the left hemisphere tend to be happier, more out-going and friendlier. • People with greater right hemisphere activity tend to be socially withdrawn, less satisfied with life, and prone to unpleasant emotions.

16. 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.

17. What is Emotion? • One major function of emotion is to help us make decisions. • The consequences of our decisions have emotional components. • Emotions are an important component to moral decisions. • Failure to anticipate the unpleasantness of an event can lead to bad decision making.

18. 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.

19. Fig. 12-5, p. 361

20. Attack and Escape Behaviors • Twins studies suggest genetic contribution to the likelihood of violent behavior. • During childhood and adolescence, Dizygotic twins resemble each other in delinquent behaviors just as much as monozygotic twins. • Monozygotic twins resembled each other much more in delinquent behaviors occurring in adulthood.

21. Attack and Escape Behaviors • Smoking habits of the mother have been identified as an important correlational prenatal factor as influencing violent behavior. • The effect is particularly strong if the mother smoked and also had complications during pregnancy.

22. Fig. 12-6, p. 362

23. 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.

24. 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.

25. Fig. 12-7, p. 363

26. 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.

27. 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.

28. Attack and Escape Behaviors • Intermittent explosive disorder is a condition marked by occasional outbursts of violent behavior with little or no provocation. • Sometimes linked to temporal lobe epilepsy. • Symptom include hallucinations, lip smacking, repetitive acts and occasional emotional outbursts.

29. Attack and Escape Behaviors • Studies also suggest a connection between aggressive behavior and low serotonin release. • Turnover is the amount of release and resynthesis of a neurotransmitter by presynaptic neurons. • Valzelli’s (1973) study with mice found that isolating male mice for 4 weeks increased aggressive behavior and decreased serotonin turnover.

30. Attack and Escape Behaviors • 5-hydroxyindoleacetic acid (5-HIAA) is a serotonin metabolite found in the blood, cerebrospinal fluid, and urine that allows researchers to infer turnover rate. • High levels of 5-HIAA imply much serotonin release and turnover. • 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.

31. Attack and Escape Behaviors • 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.

32. Attack and Escape Behaviors • In human studies, low serotonin turnover has been linked to: • People with a history of violent behavior and violent crime. • People who attempt suicide by violent means. • Recurrent violent behaviors and subsequent suicide attempts. • A simple blood tests does not enable the reliable identification of such people.

33. Fig. 12-9, p. 365

34. Attack and Escape Behaviors • Genes control the production of tryptophan hydroxylase. • Tryptophan hydroxylase is the enzyme that converts tryptophan into serotonin. • People with less active form of this enzyme are more likely than others to report frequent anger and aggression.

35. Attack and Escape Behaviors • Genes also control the production of the enzyme monoamine oxidase. • Monoamine oxidase breaks down serotonin into inactive chemicals. • Thus, low production of this enzyme in conjunction with mistreatment in childhood increases the probability of violence and antisocial behavior.

36. 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.

37. 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.

38. 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. • Information reaches the pons within 3 to 8 milliseconds after a loud noise. • The startle response occurs within two-tenths of a second.

39. Attack and Escape Behaviors • Stimuli previously associated with the startle response enhances the startle response. • Cells in the amygdala, especially the basal lateral and central nuclei, 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.

40. Fig. 12-10, p. 367

41. 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.

42. 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

43. Attack and Escape Behaviors • In the early 1900s, studies of monkeys with Kluver-Bucy syndrome illustrated the effects of amygdala damage. • Monkeys with this syndrome are calm and placid and display less than normal fear of snakes and larger, more dominant monkeys. • Also alters social behaviors in that they have decreased ability to interpret threat gestures. • Amygdala damage can also lead to an increase in the approach motive.

44. 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. • 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.

45. Attack and Escape Behaviors • In humans, damage to the amygdala does not result in the loss of emotion. • 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.

46. Attack and Escape Behaviors • Amygdala damage also affects the ability to recognize emotions specifically in photographs or pictures. • Effect is particularly strong for fear or disgust. • Amygdala damage does not affect the ability to recognize fear in real life. • Attention to certain aspects of the face (eyes versus mouth) may account for the difference.

47. Fig. 12-14, p. 370

48. Attack and Escape Behaviors • Genetic variations in amygdala arousal may thus underlie some of the variations of anxiety in the population and related disorders. • Arousal of the amygdala relates to the tendency to experience some negative emotions. • Excessive fear and anxiety disorders are associated with hyperactivity in the amygdala

49. Attack and Escape Behaviors • 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 trigger panic.

50. Attack and Escape Behaviors • Barbituates were a drug widely used to control anxiety in the past, but have high overdose potential. • Benzodiazepines are the most commonly used anti-anxiety drugs. • 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.