The Neurobiology of Emotions: Exploring the Innermost Parts of the Brain

1. COGNITIVE SCIENCE 17 Neurobiology Of Emotions Part 2 Jaime A. Pineda, Ph.D.

2. The main purpose of the innermost part of the brain is survival To Get at Emotion, Go Deep... Amygdala is deep within the most elemental parts of the brain.

3. Cognition and Emotion The brains shortcut for emotions

4. Brain Structures That Mediate Emotion Hypothalamus Limbic System limbic cortex amygdala Brainstem

5. Hypothalamus (Under the thalamus) What is it? A deep brain structure made up of a number of nuclei Where is it? Base of the fore brain Behind the optic chiasm Forms part of the walls of the 3rd ventricle Contiguous with infundibular stalk to pituitary

7. Hypothalamus What does it do? Integration of emotional response Forebrain, brain stem, spinal cord Sexual response Endocrine responses neurosecretory oxytocin, vasopressin

8. Hypothalamus How do we know that it integrates emotions and behaviors? Ablation studies Stimulation studies Primary Emotions: Fear and Anger

9. Ablation Studies Cats Remove cerebral hemispheres: rage Remove hemispheres and hypothalamus: no rage

10. Stimulation Studies on Cats Lateral hypothalamic stimulation: rage, attack Other areas: defensive, fear

11. Hypothalamus: Routes of information Input from: cortex (relatively unprocessed) Output to Reticular Formation

12. Brainstem: Reticular Formation Brainstem web 100+ cell groups Controls sleep-wake rhythm Arousal Attention

13. Reticular Formation Receives hypothalamic and cortical output separate descending projections that run parallel to volitional motor system Output to somatic and autonomic effector systems cardiac, respiratory, bowels, bladder Coordinates brain-body response

14. Limbic System Higher Cortical Processes (Secondary Emotions) Why do humans feel embarrassed with flatulence and dogs dont?

15. Limbic System Link between higher cortical activity and the lower systems that control emotional behavior Limbic Lobe Deep lying structures amygdala hippocampus mamillary bodies

16. Limbic Lobe What is it? Cingulate gyrus Parahippocampal gyrus Where is it? Encircles the upper brain stem around corpus callosum

17. Limbic System What does it do? Integrates information from cortical association areas How do we know this? Kluver - Bucy Syndrome

18. Kluver - Bucy Syndrome Removal of temporal lobe in animals Pre-op aggressive, raging Post-op docile, orally fixated, increased sexual and compulsive behaviors

19. Kluver- Bucy Syndrome in Humans Severe temporal lobe damage tumors, surgery, trauma Visual Agnosia Apathy/ placidity Hyperorality Disturbance in sexual function (hypersexuality) Dementia, aphasia, amnesia

20. Additional Structures in Limbic System Hippocampus learning/ retrieval of memory Circuit of Papez

21. Circuit of Papez First localization of Emotion (Overemphasized role of hippocampus) (Left out the amygdala)

22. Amygdala What is it? Nuclear mass Where is it? Buried in the white matter of the temporal lobe, in front of the hippocampus

23. Amygdala Almond

24. Amygdala: What Does It Do? Connects to: olfactory bulb and cortex brainstem and hypothalamus cortical sensory association areas Emotional Association Area

26. Amygdala and Learned Emotions Learned fear: rats and classical conditioning Conditioned emotional response Abolish fear response cut central nucleus from amygdala OR infuse NMDA antagonist into amygdala during learning