Physiology of Emotions II

1. Physiology of Emotions II Class 10

2. Major Divisions of the Forebrain

3. Main Divisions of the Brain Striatal system: Reptilian brain Limbic system: Emotional center Neocortex: Reasoning

4. Striatal System Reptilian in origin MacLean extensively studies lizards to learn about the functions of striatum. Basic survival functions: hunting, territorial, mating, four basic communications: Self Identification: Hey, it’s me. Territory: Don’t lean on my wheels Courting: Hey bayybee, hey bayybee Surrender: Oh gee, Officer, was I really going 95?

5. Differences Between Lizards and Mammals Mammals Lizards Maternal care-giving X Vocalizing X Play X Terrorize Tokyo when fully grown X Limbic System in mammals provides for these unique abilities.

6. Limbic System

7. Evidence That Limbic System Regulates Behavior Electrode Studies (Hess, 1940s) 1. Superfine electrode stimulation of rats' LS 2. Rats respond to jolts as if hugely rewarding: a. Go to where jolts occurred b. Work long to get jolts c. Learn tasks paired with jolts 3. Refers to this as "self-stimulation behavior" 4. 85% of limbic system --> self stim behavior, rare outside of limbic system Rats' response to jolts is like what kind of problematic human behavior? Addiction

8. More Evidence That Limbic System Regulates Behavior Psychomotor Epilepsy 1. Occurs when brain cells in certain area fires in waves 2. Psychomotor epilepsy restricted to limbic system 3. Has similar effect in humans as electrode shocks in rats. 4. Results of limbic epilepsy (emotional auras): a. Happiness: Dostoevsky reports "indescribably happiness." b. Other emotions: Desire, sadness, affection, fear, anger. Behaviors associated with P.E. 1. Shadow boxing 2. Kissing fits

9. Amygdala • 1. Emotion central: pleasure and pain • Sensitive to unfamiliar stimuli • 3. Makes first assessment of event’s emotional significance • 4. Neural pathway to amygdala bypasses the cortex

10. Klϋver-BucySyndrome Removal of monkey amygdala leads to: 1. Lose fear to/aggressiveness towards humans 2. No facial expression 3. Examine things regardless of danger: fire, broken glass 4. Eat everything: meat, feces 5. Mate everything: other sex, same sex, inanimate objects Klϋver-Bucy Syndrome occurs when amygdala is damaged. Shows same effects in humans as amygdala removal in monkeys. What does K-B Syndrome say about emotions and judgment?

11. LeDoux’s Neural Pathways STANDARD ROUTE: SENSORY  THALAMUS  CORTEX  AMYGDALA This route indicates what comes first, thinking or feeling? Thinking: cortex precedes amygdala EMERGENCY ROUTE: SENSORY  THALAMUS  AMYGDALA This route indicates what comes first, thinking or feeling? Feeling: Direct line to amygdala

12. Amygdala and Emotions: Key Points 1. Input connections—Visual centers, auditory centers  2. Output connections—hypothalamus (directs emot. behavior)  3. Activation leads to self stimulation behavior, a range of emotions  4. Assigns emotional significance to events   * Conditioning occurs without cortex, just amygdala   * Directs attention to important events   * Sets up species specific action systems  5. Does amygdala support appraisal or separate systems?

13. The Role of the Cortex in Emotions: Hemispheric Lateralization Right Hemi. Left Hemi.

14. Hemis. Lateralization and Emotions Lateralization: L hemisphere guides right side of body R hemisphere guides left side of body Lateral functions: L hemisphere – speech, reasoning R hemisphere – emotional recognition and interpretation. All reversed if Left-handed (i.e., L hemi. guides emotion, etc.) Research on hemisphere lateralization   1. Split-brain studies of epileptics   2. Emotional ID of faces and hemi. dominance 3. Lie detection and hemisphere dominance

15. Split Brain Studies of Epileptics Epilepsy treatment—removal of corpus collosum Corpus Collosum is: Membrane connects L hemi to R hemi Removal permits exclusive presentation to L or R hemi Patients shown emotional displays to L or R side of brain Can recognize emotions when shown to: Right side Can verbalize emotions when shown to: Left side

16. Aphasia and Lie Detection a•pha•sia (uh-fay'-zhuh) n. An impairment of the ability to use or comprehend words, usually acquired as a result of a stroke or other brain injury (National Aphasia Association). Oliver Sacks and laughter from the Aphasia Ward during Ronald Reagan’s speech. Aphasiacs depend on emotional cues So good at “reading” emotions, hard to see that they don’t understand language. Respond to HOW things said, not WHAT said.

17. Valence Lateralization Emotional Perception: R hemi is superior to L hemi Does one side FEEL more emotion than the other? NO Hemis differ in type, or “valence” of emotions they favor. Negative emotions felt mainly on?  Right Side Positive emotions felt mainly on?  Left Side

18. Chimeric Faces

19. EEG Evidence of Lateralization EEG = Electroencephalogram Electrodes placed on scalp, record brain activity Subjects see funny or gruesome movie, facial expression and EEG are recorded. EXPRESSION HEMI ACTIVATED MOVIE Funny  Smiling, happy Left Side Gruesome  Nose wrinkle, disgust Right Side

20. Muscle Contraction and Mood States Ss contract L-side/R-side of face or squeeze ball in R or L hand. These actions activate (R-hemi/L-hemi)—per handedness. These actions, in turn, lead to mood changes: L-side activity  Right Hemi  sadness Hemi  positive, assertive R-Side activity  Left

21. Hemispheric Activation and Social Judgment: TAT Study TAT = Thematic Apperception Test People see pictures, and tell stories about them. Commonly used as a clinical psychology device   L-side activity  R-hemi  R-side activity  L-hemi  More negative interpretations More positive interpretations

25. Why Are Emotions Lateralized? What kind of emotions leads to approach, positive or negative? Positive Which hemi controls these kinds of emotions, right or left? Left With which hand to we approach things, Left or Right? Right (dominant) Which hemi controls Right hand, Left or Right? Left Conclusion: Emotions help guide approach/avoidance

26. Emotional Lives of Stroke Patients Clinical Condition Stroke to Left Hemisphere  ? Depression Stroke to Right Hemisphere  ? Mania Chronically depressed people show less Left Frontal Activation

27. Neurological Development and the Limbic System R-Hemi has closer connections to limbic system than L-Hemi. R-Hemi develops earlier in infancy than L-Hemi Emotions appear in babies before language Emotionally expressive babies start talking later When babies start to talk, don’t show emotion 13 mos—talk, no emotion 19 mos—talk + emotion What does this say about separate systems?

28. Are Affective Styles Genetic? Davidsons, Kagan et al. 1993 Subs: 2.5 year olds (N = 386) tested with moms present.   Start (“T”): Hang out with mom T + 10: Talking robot appears   T+ 13: Robot leaves to “take a nap”   T+ 20: Stranger with fun toys “Want to play?”   T + 23: Stranger leaves  Three types of children identified: 1. Inhibited: hover near mom, quiet, avoid robot, stranger 2. Un-inhibited: Less time w’ mom, engage in activities 3. In-betweeners: Between inhibs and un-inhibs

29. Hemisphere Activation and Temperament:Kagan, et al. Study of Inhibited/Uninhibited Kids Implications for shyness: Learned or inherited?

30. Heart #1 Heart #2 OTTO LOEWI AND DISCOVERY OF NEURO-CHEMICALS Otto Loewi and Discovery of Neuro Chemicals • Stim vagus nerve, slows Heart 1 2. Extract fluid from Heart 1 bath 3. Apply H1 fluid to H2. H2 slows

31. Neurochemicals 1. Neurotransmitters: Fast, nerve-to-nerve 2. Hormones: Slower, longer-lasting. Endocrine-based 3. Neuromoderators: Endorphins (body’s opiate) Relevance to emotions * Different emotional systems employ different neuro-chemical messengers  * Different chemicals lead to different emotional states

32. l-Dopa 1. Precursor to dopamine, a neurotransmitter 2. Acts on striatum—motor activity 3. “Re-awakens” sleeping sickness patients Revived emotions: joy, excitement, also extreme mood swings, powerful passions.

33. CCK (cholecytokinin) 1. Tied to panic attacks * Spontaneous rush of fear, 15-30 minutes * Come out of nowhere, apparently * Feel like will have a heart attack, lose control * Lead to agoraphobia; fear of fear 2. CCK is peptide, large molecule neurotransmitter 3. CCK --> increased blood to limbic system 4. Give CCK to humans, monkeys, rats --> panic attack

34. Rats’ Maternal Behavior: Example of an Emotional System Female becomes pregnant  Pregnancy hormones: prolactin, estradiol, less progesterone  Birth hormone: oxytocin  Hormones affect arousal in mothers --Most aroused when around own pups vs. with other rats, around food, or alone. --Affects virgin females: become more nurturing to pups. Maternal cue sensitivity increases: to separation squeaks, pup odor  Maternal behaviors: Nursing, cleaning, protection.

35. Neurogastroenterology: “Gut Brain” Features of "gut brain"   * More neural fibers than spinal cord * The fibers are non-mylinated, like neurons in "big brain" * Neural fibers surrounded by neurochem. as in "big brain" * Suffers damage during diseases that attack CNS: -- Alzheimers -- Parkinsons * Responsive to psychotropic drugs -- Prozac over-activates gut -- Anti-psychotic meds heal gut ailments

36. Neurogasterentology and Intuition * Big brain and gut brain communicate * Gut brain remembers big brain experiences * “Gut feeling” occurs when gut brain reacts to past experience (e.g., tightening of stomach)