Abstract
Emotion is a general term for subjective feelings of individuals such as happiness, sadness, anger, and so on. Emotion is related fundamentally to preserve species and individuals. For example bad odor alerts animals not to eat while pleasant perfumes act like pheromones to lure the opposite sex. Emotion includes at least three principal components, (1) physiological changes such as autonomic responses, (2) changes expressed in behaviors like facial expressions, and (3) components recognizable and being expressed by words. Most researches in the past handled the above three elements as indexes of emotion. Recently thanks to progress in brain imaging techniques, we have 4^<th> overt element of emotion. Emotion is expressed on regional anatomical brain maps as activation or deactivations of distinct brain areas. P.MacLean explained our brain as a composition of three evolutionally distinct layers, the neocortex, reptilian, and limbic brain (Triune Brain in Emolusion, 1990). He explained the limbic system or intermediate brain between the neocortex and the reptilian brain is responsible for emotion. Activations in these regions create feeling of emotion. The limbic brain is evolutionally created to regulate the autonomic nervous system and primitive (reptilian) brain. In mammals it intervenes or relay signals between the neocortex and primitive brain. Sensory information is processed in the limbic brain and is transmitted to the neocortex with a tag of emotion. The tags help us to select necessary signals to be processed and stored. This session reviews recent progress in brain imaging related to emotion.
