EMOTIONS STRESS & HEALTH

1. EMOTIONSSTRESS & HEALTH

2. DEFINING EMOTIONS • Emotions constitute multiple responses • Behavioral (Actions) • Autonomic (Physiological) • Hormonal (Physiological) • Internal Subjective Experience (Psychological) Study Objective #1

3. HISTORICAL LANDMARKS IN THE STUDY OF EMOTION • Phineas Gage Case – 1848 • Darwin’s Publication On the Expression of Emotion in Man and Animals, 1872 • James/Lange theory, late 19th century • Cannon/Bard theory, early 20th century • Sham rage experiments by Bard, 1929 • Limbic System involvement in emotion as depicted by Papez, 1937 • Kluver-Bucy Syndrome described, 1939

4. THEORIES OF EMOTION • Darwin • Comparative studies of emotional expression • Evolutionary theory of emotion • James-Lange Theory • emphasis on physiological changes • stimulus-->autonomic response-->emotion • Canon-Bard Theory • emphasis on central processes • Stimulus produces simultaneous autonomic and emotional reactions that are not necessarily causally related.

5. THEORIES OF EMOTION Study Objective #2

6. THEORIES OF EMOTION • Schachter’s Cognitive Theory • The experience of emotion is influenced by cognitive appraisal/interpretation of physiological changes. • Stimuli produce nonspecific arousal that are cognitively labeled based on external cues. • Schachter and Singer (1962) • Epinephrine injections were given to participants who then witnessed either a happy or angry confederate. • The environmental context influenced participant’s interpretation/appraisal of the autonomic arousal.

7. NEUROBIOLOGY OF EMOTION • Decorticate rage (sham rage) • Bard (1929) studied decorticate cats. • Aggressive responses were poorly coordinated and not directed at particular targets • Bard concluded that the hypothalamus is critical for the expression of aggressive responses and the cortex is responsible for inhibiting and directing those responses. • Kluver-Bucy Syndrome (1939) • lesions of anterior temporal lobes/amygdala • tameness, lack of fear • hyperorality and hypersexuality • Similar syndrome has been observed in humans with amygdala damage. Study Objective #3

8. NEUROBIOLOGY OF EMOTION • LIMBIC SYSTEM (Papez’s circuit) • amygdala • hippocampus • fornix • septum • hypothalamus • cingulate gyrus • mammillary bodies Study Objective #4

9. NEUROBIOLOGY OF EMOTION • Autonomic Nervous System • Emotional Specificity?? • Uses of polygraphy • Control-question technique • Guilty-knowledge technique

10. AGGRESSION • FORMS OF AGRESSION • Offensive Behaviors • Predatory (related to feeding) • Social (establishing, maintaining social hierarchy or territory, related to reproduction) • Defensive Behaviors • Intraspecific defense • Defensive attacks • Freezing and Flight • Maternal Defensive Behaviors • Risk Assessment • Defensive Burying

11. ANDROGENS AND AGGRESSION • Castration reduces aggressive behavior in male rodents. • Testosterone injections reinstate this behavior. • Studies in human males are less convincing. • Mixed results • Correlational studies --> problematic interpretation • Testosterone and Social dominance Study Objective #8

12. ANDROGENS AND AGGRESSION Study Objective #8

13. SEROTONIN & AGGRESSION • Serotonin levels show negative correlations with aggression • Destruction of 5-HT axons in forebrain facilitates aggressive attack. • 5-HIAA levels are lower in more aggressive animals (linked to risky behavior). • Diminished 5-HIAA levels in CSF of people with history of violence and impulsive aggression. • SSRIs and violent acts • mostly anecdotal reports and media hype • SSRIs actually decrease aggressive behavior. Study Objective #7

14. FEAR CONDITIONING Study Objective #5

15. NEUROBIOLOGY OF FEAR • AMYGDALA • Subdivided into several nuclei. • Central Nucleus, Lateral Nucleus • Electrical/chemical stimulation of the amygdala elicits emotional responses • Amygdala lesions disrupt wide range of emotional behaviors and physiological responses • Lesions of the central nucleus and the lateral nucleus abolish conditioned fear.

16. NEURAL CIRCUITRY OF FEAR e.g., Freezing HR/BP Cortisol Study Objective #6

17. NEURAL CIRCUITRY OF FEAR Study Objective #6

18. STRESS & HEALTH • Defining Stress • Cluster of physiological responses to threat or harm • Both physical and psychological stressors produce similar patterns of physiological changes. • Acute stress is adaptive. • Chronic stress is maladaptive. • Stress response • First described by Hans Selye, 1950s • Activation of Hypothalamus-Anterior Pituitary-Adrenal Cortex System (HPA axis) • Feedback loop involving actions of CRH, ACTH, and cortisol

19. HPA axis Study Objective #9

20. STRESS & HEALTH • Hormonal Responses to Stress • Glucocorticoids (e.g., cortisol) from adrenal cortex • assists with metabolism to provide energy • increases blood flow • stimulates behavioral responsiveness • Sympathetic activation (norepinephrine) and epinephrine from adrenal medulla • Epinephrine influences glucose metabolism. • Catecholamines increase blood flow to muscles by increasing heart output. Study Objective #10

21. STRESS RESPONSES

22. HORMONAL RESPONSES TO SOCIAL STRESS Study Objective #13

23. ADAPTATION TO STRESS • General Adaptation Syndrome (Selye) • Alarm Stage: fight or flight reaction • Resistance: adaptation, immune responses • Exhaustion: energy depletion, immune system suppression

24. ADAPTATION TO STRESS

25. STRESS & HEALTH • Psychoneuroimmunology • CNS influences on immune function (through ANS and HPA axis) • Immune system influences on CNS (antibodies and cytokines influence brain activity) Study Objective #11

26. PSYCHONEUROIMMUNOLOGY

27. STRESS AND HEALTH • Prolonged elevations in stress hormones may cause deleterious effects: • prolonged inc. bp ---> heart disease • muscle tissue damage • growth retardation • inhibition of inflammatory responses, slower healing, immunosuppression • increased cell death in hippocampus (may accelerate aging processes) • Stress related diseases • Gastric Ulcers • Cancers • Heart Disease Study Objective #12

28. STRESS AND HEALTH Study Objective #12