Physiology of Emotions IIClass 09

Differences Between Lizards and MammalsMaternal care-givingMammals LizardsXVocalizingXPlayXTerrorize Tokyo when fully grownXLimbic System in mammals provides for these unique abilities.

Limbic System

Evidence That Limbic System Regulates BehaviorElectrode Studies (Hess, 1940s)1. Superfine electrode stimulation of rats' LS2. Rats respond to jolts as if hugely rewarding:a. Go to where jolts occurredb. Work long to get joltsc. Learn tasks paired with jolts3. Refers to this as "self-stimulation behavior"4. 85% of limbic system --> self stim behavior, rare outside of limbic systemRats' response to jolts is like what kind of problematic human behavior? Addiction

More Evidence That Limbic System Regulates BehaviorPsychomotor Epilepsy 1. Occurs when brain cells in certain area fires in waves2. Psychomotor epilepsy restricted to limbic system3. Has similar effect in humans as electrode shocks in rats.4. Results of limbic epilepsy:a. Happiness: Dostoevsky reports "indescribably happiness."b. Other emotions: Desire, sadness, affection, fear, anger.Behaviors associated with P.E. 1. Shadow boxing2. Kissing fits

Amygdala1. Emotion central: pleasure and painSensitive to unfamiliar stimuli

3. Makes first assessment of events emotional significance

4. Neural pathway to amygdala bypasses the cortex

Klver-Bucy SyndromeRemoval of monkey amygdala leads to:1. Lose fear to/aggressiveness towards humans2. No facial expression3. Examine things regardless of danger: fire, broken glass4. Eat everything: meat, feces5. Mate everything: other sex, same sex, inanimate objectsKlver-Bucy Syndrome occurs when amygdala is damaged. Shows same effects in humans as amygdala removal in monkeys.

LeDouxs Neural PathwaysSTANDARD ROUTE: SENSORY THALAMUS CORTEX AMYGDALAEMERGENCY ROUTE: SENSORY THALAMUS AMYGDALAThis route indicates what comes first, thinking or feeling?This route indicates what comes first, thinking or feeling?Thinking: cortex precedes amygdala Feeling: Direct line to amygdala

The Role of the Cortex in Emotions: Hemispheric LateralizationRight Hemi.Left Hemi.

Hemis. Lateralization and EmotionsLateralization: L hemisphere guides right side of body R hemisphere guides left side of bodyLateral 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 lateralization1. Split-brain studies of epileptics2. Emotional ID of faces and hemi. dominance3. Lie detection and hemisphere dominance

Split Brain Studies of EpilepticsEpilepsy treatmentremoval of corpus collosumCorpus Collosum is: Membrane connects L hemi to R hemiRemoval permits exclusive presentation to L or R hemiPatients shown emotional displays to L or R side of brainCan recognize emotions when shown to:Can verbalize emotions when shown to:Right sideLeft side

Aphasia and Lie Detectionaphasia (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 Reagans speech.Aphasiacs depend on emotional cuesSo good at reading emotions, hard to see that they dont understandlanguage.Respond to HOW things said, not WHAT said.

Valence LateralizationEmotional Perception: R hemi is superior to L hemiDoes one side FEEL more emotion than the other?NOHemis differ in type, or valence of emotions they favor.Negative emotions felt mainly on? Positive emotions felt mainly on? Right SideLeft Side

The Role of the Cortex in Emotions: Hemispheric LateralizationRight Hemi.Left Hemi.

Fact 1Right hemispheric dominance for emotion processing

Fact 2Emotions are expressed more intensely in the left hemiface (LHF). Because most facial muscles, particularly in the lower part, are innervated by the contralateral hemisphere

Fact 3Emotions are expressed more intensely in the left hemiface for all emotions and conditionsEvoked anger is more intensely expressed in the right hemiface.

Therefore:The side of the poser's face that expresses greater emotional intensity is projected to the perceiver's hemisphere less adept at emotion processing.

Fact 4Emotional expressions are recognized more efficiently in the right hemiface, indicating that the right hemiface expresses emotions more accurately

Fact 5Evoked anger is uniquely expressed more intensely and accurately on the side of the face that projects to the viewer's right hemisphere, dominant in emotion recognition.

Chimeric Faces

EEG Evidence of LateralizationEEG = Electroencephalogram Electrodes placed on scalp, record brain activitySubjects see funny or gruesome movie, facial expression and EEG are recorded.Funny Smiling, happyEXPRESSIONHEMI ACTIVATEDLeft SideGruesome Nose wrinkle, disgustRight SideMOVIE

Muscle Contraction and Mood StatesSs 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 R-Side activity RightLeftHemi Hemi sadnesspositive, assertive

Hemispheric Activation and Social Judgment: TAT StudyTAT = 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 interpretationsMore positive interpretations

Why are emotions lateralized?What kind of emotions leads to approach, positive or negative?PositiveWith which hand to we approach things, Left or Right?Right (dominant)Which hemi controls these kinds of emotions, right or left?Left Which hemi controls Right hand, Left or Right?LeftConclusion: Emotions help guide approach/avoidance

Emotional Lives of Stroke PatientsStroke to Left Hemisphere ?DepressionStroke to Right Hemisphere ?ManiaChronically depressed people show less Left Frontal Activation

Neurological Development and the Limbic SystemR-Hemi has closer connections to limbic system than L-Hemi.R-Hemi develops earlier in infancy than L-HemiEmotions appear in babies before languageEmotionally expressive babies start talking laterWhen babies start to talk, dont show emotion13 mostalk, no emotion 19 mostalk + emotionWhat does this say about separate systems?

Are Affective Styles Genetic? Davidsons, Kagan et al. 1993Subs: 2.5 year olds (N = 386) tested with moms present.Start (T): Hang out with momT + 10:Talking robot appearsT+ 13: Robot leaves to take a napT+ 20: Stranger with fun toys Want to play?T + 23: Stranger leavesThree types of children identified:1. Inhibited: hover near mom, quiet, avoid robot, stranger2. Un-inhibited: Less time w mom, engage in activities3. In-betweeners: Between inhibs and un-inhibs

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

Amygdala and Emotions: Key Points1. Input connectionsVisual centers, auditory centers2. Output connectionshypothalamus3. Activation leads to self stimulation behavior, a range of emotions4. Assigns emotional significance to events* Conditioning occurs without cortex, just amygdala* Directs attention to important events* Sets up species specific action systems5. Does amygdala support appraisal or separate systems?

Otto Loewi and Discovery of Neuro ChemicalsOTTO LOEWI AND DISCOVERY OF NEURO-CHEMICALSStim vagus nerve, slows Heart 1 2. Extract fluid fromHeart 1 bath3. Apply H1 fluid to H2. H2 slows

Neurochemicals1. Neurotransmitters: Fast, nerve-to-nerve2. Hormones: Slower, longer-lasting. Endocrine-based3. Neuromoderators: Endorphins (bodys opiate)

Relevance to emotions * Different emotional systems employ different neuro-chemical messengers* Different chemicals lead to different emotional states

l-Dopa 1. Precursor to dopamine, a neurotransmitter2. Acts on striatummotor activity3. Re-awakens sleeping sickness patientsRevived emotions: joy, excitement, also extreme mood swings, powerful passions.

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

Rats Maternal Behavior: Example of an Emotional SystemFemale becomes pregnantPregnancy hormones: prolactin, estradiol, less progesteroneBirth hormone: oxytocinHormones 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 odorMaternal behaviors: Nursing, cleaning, protection.

Neurogastroenterology: Gut BrainFeatures 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

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)

What does K-B Syndrome say about emotions and judgment?

*This creates a situation in which the side of the poser's face that expresses greater emotional intensity is projected to the perceiver's hemisphere less adept at emotion processing.It compensates for a perceiver's bias by communicating greater intensity to the hemisphere that could miss subtler signals *Evoked anger is uniquely expressed more intensely and accurately on the side of the face that projects to the viewer's right hemisphere, dominant in emotion recognition. Emotions are expressed more intensely in the left hemiface (LHF). Because most facial muscles, particularly in the lower part, are innervated by the contralateral hemisphere, this finding has been interpreted as support for the hypothesis of right hemispheric dominance for emotion processingAsymmetries in facial displays of emotions have implications for both expression and perception of emotions. In a face-to-face situation, the poser's LHF, which displays the higher intensity, falls into the perceiver's right visual field, which projects to the perceiver's left hemisphere. Considering right hemispheric overall dominance in emotion processing, and a perceiver bias to judge the left hemifaces as more similar to the whole face (Wolff, 1943; Gilbert and Bakan, 1973), this creates a situation in which the side of the poser's face that expresses greater emotional intensity is projected to the perceiver's hemisphere less adept at emotion processing. This byproduct of neuronal wiring in the human visual system may have an evolutionary advantage in that it compensates for a perceiver's bias by communicating greater intensity to the hemisphere that could miss subtler signals (Sackeim et al., 1978). Such hypotheses could be tested by examining hemiface asymmetries not only in intensity but also in the accuracy of conveying the emotions and by comparing posed to evoked expressions. These effects have not been examined.

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