Emotion

1. Emotion • Emotions are not descriptions of external events, but purely internal responses to them. • Emotions assign values to external events, which: • Motivates action. • Organizes action.

2. Anatomy of Amygdala hippocampus amygdala

3. Kluver-Bucy Syndrome (Kluver & Bucy, 1937; Weiskrantz, 1956) • Following amygdala lesions, animals: • Lose their fear of previously threatening stimuli. • Attempt to copulate with members of another species. • Attempt to eat a variety of things that normal primates find unattractive such as feces and rocks.

4. The Role of the Amygdala • The amygdala is a key structure in: • The assignment of reward value to stimuli. • The conditioning of fear to novel stimuli. • The self-administration of rewarding brain stimulation. • Direct experimental electrical stimulation of the amygdala elicits behavioral and autonomic responses typical of emotional reactions. • Amygdala neurons also respond to complex socially relevant stimuli

5. The Emotional Network • The amygdala participates in 5 pathways in the emotional network: • Cortical pathway (e.g., receives output of visual construction stage). • Limbic pathway (to hippocampus). • Memory. • Direct thalamic pathway. • Basal Ganglia pathway. • Initiation of actions. • Direct hypothalamic pathway. • Hormonal and autonomic nervous system responses.

6. Emotion & Learning • Learning is a positive function of the strength of the emotional response, whether positive or negative, to the study materials. • Post-traumatic stress disorder (PTSD). Traumatic events are difficult to forget.