Neuroscience of Emotion

Affective neuroscience as described in Purves 5e, Chapter 29.

Transcript

1. Neuroscience of Emotion Morteza Ansarinia Institute for Cognitive Science Studies December 2016
2. Outline ✦ Theories of Emotion ✦ Anatomy of Medial Temporal Lobe ✦ Limbic System ✦ Cortical Lateralization 2
3. Characteristics of Emotion ✦ An emotion is a state associated with stimuli that are rewarding or punishing. These stimuli often have inherent survival value. ✦ Emotions are transient in nature (unlike a mood, which is where an emotional state becomes extended over time), although the emotional status of stimuli is stored in long-term memory. ✦ An emotional stimulus directs attention to itself, to enable more detailed evaluation or to prompt a response. ✦ Emotions have a hedonic value, that is, they are subjectively liked or disliked. ✦ Emotions have a particular “feeling state” in terms of an internal bodily response (e.g. sweating, heart rate, hormone secretion). ✦ Emotions elicit particular external motor outcomes in the face and body, which include emotional expressions.
4. Emotion James-Lange Theory of Emotion 4 ✦ Emotion is the product of changes in body state 1. Emotion-provoking stimuli activate somatic and visceral sensory receptors. 2. Peripheral autonomic and skeleto-muscular activities are engaged. 3. Peripheral responses are detected. 4. Emotion elicited by peripheral feedback. ✦ “We are afraid because we tremble”.
5. Emotion James-Lange Theory of Emotion 5
6. Emotion as Associative Learning 6 ✦ Emotions are produced by the
 association of sensory stimuli
 (interoceptive and exteroceptive
 secondary reinforcers) with
 primary reinforcers (rewards
 and punishers). ✦ Attach a new meaning to neutral
 stimulus using LTP.
7. Limbic Forebrain Papez Circuit ✦ Papez: specific brain circuits are devoted to emotional experience and expression, guided by two hypotheses: - Hypothalamus influences the expression of emotion. - Emotions reach consciousness and that higher cognitive
 functions affect emotional behavior. Hypothalamus Posterior Hypothalamus Mammillary Bodies Anterior Nucleus of Thalamus Cingulate Gyrus Hippocampus Subiculum Fornix
8. Limbic Forebrain Broca 8 ✦ Broca: part of the cerebral cortex that forms a rim around the corpus callosum and diencephalon on the medial face of the hemispheres (limbic lobe). ✦ Cingulate gyrus above the corpus callosum. ✦ Parahippocampal gyrus in the medial temporal lobe. ✦ Olfactory bulbs as principal input to the limbic lobe.
9. The Limbic Lobe Old/Modern Conception 9
10. 10 ✦ Bard: the subjective experience of emotion might depend on an intact cerebral cortex, but the expression of coordinated emotional behaviors does not necessarily entail cortical processes. ✦ Hess: electrical stimulation of discrete sites in hypothalamus of cats could also lead to rage response. ✦ The basic circuits of organized behaviors accompanied by emotion are in the diencephalon and the brainstem structures connected to it. ✦ Hypothalamus ⟶ Reticular Formation ⟶ Brainstem and Spinal Cord ⟶ Widespread Visceral and Somatic Motors Responses. Hypothalamus & Emotion Early Works on Cats
11. 11 Hypothalamus & Emotion Early Works on Cats
12. Anatomy of Medial Temporal Lobe Amygdala and Hippocampus 12
13. 13 ✦ Olfactory divison: special sensory (smell and flavor). ✦ Parahippocampal division: explicits processing (episodic memory, spatial mapping). ✦ Amygdala/Orbitofrontal division: implicit processing (visceral motor control, emotional experience and expression, appetitive drive, and social behavior). Limbic Forebrain Functional Division
14. Amygdala Anatomy 14
15. Parallel Pathways 15
16. Parallel Pathways :-) 16
18. Patient S.M. 18
19. Trustworthiness and Amygdala 19
20. Patient S.M. 20
21. Subjective Feeling 21
22. Subjective Feeling 22
23. Subjective Feeling 23
24. 24 ✦ RH is especially important for the expression and comprehension of the affective aspects of speech. Aprosody (or Aprosodia) refers to the loss of emotional expression and speech patterns. ✦ LH is more importantly involved with what can be thought of as positive emotions (versus RH which involved with negative emotions). ✦ RH is superior in detecting emotional nuances in speech. ✦ Facial emotions are more readily and accurately identified (or expressed) from the information in the LH. Cortical Lateralization
25. Cortical Lateralization Asymmetrical Smile 25
26. Addiction 26
27. Addiction 27
28. Thank You :-)