Chapter Fourteen. Emotion, Reward, Aggression, and Stress

Transcription

1 Chapter Fourteen Emotion, Reward, Aggression, and Stress

2 EMOTIONS! Emotions generally include a Physical component, and a Subjective component or quality, and a Valence Emotions a product of Evolution? Adaptive advantages of emotions for ancestors Contribute to general arousal Manage approach and withdrawal behaviors Help us communicate nonverbally

3 Figure 14.1 Emotional Expression Helps Us Communicate

4 Expression & Recognition of Emotion How do we control facial expressions? Facial nerve (cranial nerve VII) & trigeminal nerve Upper 1/3 controlled differently than bottom 2/3 Pathways-motor cortex (voluntary expression) & subcortical system (spontaneous expression) Biological Influences on Emotional Expression? Universality of some emotions built into genes? Developmental progression of expression and recognition in humans (& nonhuman primates)

5 Figure 14.2 Innervation of the Facial Muscles

6 Figure 14.3 Voluntary and Spontaneous Expressions Are Managed by Different Areas of the Brain

7 Figure 14.4 Major Facial Expressions Are Easily Recognized Around the World

8 Figure 14.5 Infants Separation Protests Occur at the Same Times Regardless of Culture

9 Other Influences on Emotions? Environmental Influences on Emotions? Presence of others affects intensity of expression Culture influences how we are in public settings Individual differences in Emotion? Overall level of reactivity differs + the amygdala Can we spot a liar? We can watch for stuff like Slip ups like Uh, humm. Rigid on top, wiggly below Polygraph? Unreliable! 1/3 of innocent test guilty Functional MRIs MAY be used to detect changes in brain activation during lying.

10 Howz about some Theories of Emotion JAMES LANGE THEORY (late 1800s) Physical states are highly distinct, and we can label these as specific separate feelings Physical states PRECEED subjective feelings Support for this theory from the Facial Feedback Hypothesis Capilano Canyon Study throws a monkey wrench into the works

11 More Theories of Emotion CANNON-BARD Theory (1920s) Physical responses and subjective responses occur simultaneously and independently SCHACTER-SINGER Theory (mid 20th century) No specific physical responses- just general arousal Cognitive appraisal & labeling of subjective feelings CONTEMPORARY Theories of Emotion Responses may range from ambiguous to specific Somatic marker for emotional experience General arousal will delay emotional expression

12 Figure 14.9 Three Theories of Emotion

13 Biological Correlates of Emotion THE AUTONOMIC NERVOUS SYSTEM Fight or flight to what we perceive as a threat ANS produces different patterns of arousal during different emotional states THE AMYGDALA! Involved in identifying & processing both positive and negative emotions Also plays a role in emotional expression Has a dedicated Fear Circuit

14 Figure The Anatomy of the Amygdala

15 Biological Correlates of Emotion The CINGULATE CORTEX Processes feelings associated with physical and social pain, feelings of being socially excluded The CEREBRAL CORTEX Frontal lobe - Frontal lobotomies were supposed to decrease feelings of fear and anxiety Cerebral Hemispheres process emotions as well as directing emotional responses Left hemisphere more likely to process + emotions Right hemisphere more likely to process emotions

16 Figure Frontal Lobotomy

17 More Biological Correlates of Emotion Patterns of Activation and Emotion Widespread areas of the brain associated with each specific emotion Areas associated with different emotions overlap Single brain regions might participate in more than one emotional state

18 Pleasure and Reward Olds & Milner (1954) Electrical Self Stimulation The Mesolimbic System is busy, and let s not forget The Medial Forebrain Bundle Activity of the nucleus accumbens underlies many types of reward Dopamine is the primary neurotransmitter used Reward, Decision Making, and the Cortex Anterior Cingulate Cortex (ACC) handles costbenefit analysis Orbitofrontal Cortex manages delayed gratification

19 Figure Connections of the Medial Forebrain Bundle

20 Figure Dopamine Release in the Nucleus Accumbens Correlates with ESB

21 Aggression and Violence Genetics and Aggression Can be bred in animals Within-species aggression related to dominance BRAIN STRUCTURES and AGGRESSION Correlated with activity of the hypothalamus, amygdala and other subcortical structures & areas Sham Rage when we remove cerebral cortices Anterior Cingulate Cortex and Orbitofrontal Cortex inhibit aggressive behavior

22 Table 14.1 Homicide Rates in Selected Cities ( )

23 Figure The Orbitofrontal Cortex

24 Aggression and Violence Biochemistry and Aggression Alcohol use increases odds / provokes aggression TESTOSTERONE?!? Increasing reactivity to threatening stimuli Prenatal exposure affects BOTH sexes Adult levels not correlated with aggression Aggressive males affected by competitive and / or threatening environments SEROTONIN Low levels in amygdala associated with aggressive behavior as well as depression (violence to self?)

25 Figure Androgens Influence Biting Attacks in Mice

26 Figure Prenatal Testosterone Contributes to Aggression

27 Stress Hans Selye and The General Adaptation Syndrome (GAS) Alarm Stage sympathetic system arousal working exactly as it should Resistance Stage sympathetic system hangin in there, but running out of gas (punny?) Exhaustion Stage depleted immune system begins to leave us very vulnerable

28 Physical & Psychological Responses to Stress Sensory systems Amygdala fear response Hypothalamic-Pituitary-Adrenal Axis PVN of hypothalamus releases corticotrophin releasing hormone Anterior Pituitary releases ACTH Adrenal Glands release Cortisol Hippocampus acts to inhibit CRH release

29 Stress, The Immune System & Health During Sympathetic System arousal the Immune system is being suppressed / limited Lymphocytes directly suppressed by cortisol Heart Disease link? Type A Personality / Behavior Pattern? Neil s Theory? Decreased elimination of bad (LDL) cholesterol a result of ANS prolonged activation? Hard on one s liver too!