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Emotion and Learning - A Computational Model of the Amygdala

Morén, Jan LU (2002) In Lund University Cognitive Studies 93.
Abstract (Swedish)
Popular Abstract in Swedish

Avhandlingen handlar om ett område i hjärnan som kallas amygdala. Detta området är ansvarigt för att lära sig vad man bör tycka om och vad man skall vara rädd för. I avhandlingen diskuteras hur det här området verkar fungera, och hur det arbetar tillsammans med andra områden för att göra sitt jobb. Dessa reaktioner är primitiva känslor; rädsla, lycka och så vidare. Avhandlingen tittar på data från djur (främst råttor) - den tar alltså inte upp vårt eget (mer komplexa) känslolov.



Dessutom presenteras en datormodell för några av dessa områden. Denna modell baseras dels på vad vi vet om anatomin, och dels på vad vi vet om inlärning. Inlärningen baseras på klassisk betingning.
Abstract
The amygdala is a small subcortical structure that has long been implicated in the conditioning of fear and other emotions. It is heavily interconnected to a number of both cortical and subcortical structures and is thus well placed to integrate sensory inputs from multiple areas to produce emotional reactions directly as well as influence learning and attention systems. Data suggests that the amygdala works in close cooperation with the orbitofrontal cortex; the amygdala learns emotional reactions to stimuli, while the orbitofrontal cortex learns to inhibit the reactions from the amygdala in a context-sensitive manner. The hippocampus is encoding the contextual representations that are used by the orbitofrontal cortex. Being responsible... (More)
The amygdala is a small subcortical structure that has long been implicated in the conditioning of fear and other emotions. It is heavily interconnected to a number of both cortical and subcortical structures and is thus well placed to integrate sensory inputs from multiple areas to produce emotional reactions directly as well as influence learning and attention systems. Data suggests that the amygdala works in close cooperation with the orbitofrontal cortex; the amygdala learns emotional reactions to stimuli, while the orbitofrontal cortex learns to inhibit the reactions from the amygdala in a context-sensitive manner. The hippocampus is encoding the contextual representations that are used by the orbitofrontal cortex. Being responsible for the conditioning of emotional reactions, the amygdala forms a part of a conceptual system integrating emotions, motivation and actions. The thesis briefly discusses this system, and also reviews the neurophysiological and neuroanatomical features of the amygdala, the orbitofrontal cortex and related areas.



As a learning system, data suggests the amygdala is working as a classical conditioning system. This system is used both to elicit autonomous reactions to emotional stimuli directly through the central amygdala, and as an evaluative part of an instrumental conditioning system through the basolateral amygdala. Through this mechanism, the structure is also involved in selective memory consolidation and in selective priming of stimuli in the sensory cortices. Classical and instrumental conditioning is discussed, and a number of computational models of classical conditioning are presented and compared.



The second half of the thesis presents a computational model of the amygdala and orbitofrontal cortex. The model has a very simple design for each component; much of the abilities of the model instead comes from the neuroanatomically guided interconnections between these components. The model is tested with only the amygdala and orbitofrontal cortex, and then extended with a simple hippocampal model able to generate contextual signals from an externally imposed attentional sequence. The model is compared to the previously tested conditioning models and its benefits and drawbacks - especially its current inability to handle time-dependent effects - are discussed. (Less)
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author
opponent
  • Prof Dayan, Peter, London College
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Applied and experimental psychology, Sociologi, Sociology, orbitofrontal cortex, learning, hippocampus, emotions, computational models, mygdala, classical conditioning, Tillämpad och experimentell psykologi, Philosophy, Filosofi
in
Lund University Cognitive Studies
volume
93
pages
160 pages
publisher
Lund University Cognitive Science
defense location
Room 104, Kungshuset, Lundagård
defense date
2002-09-26 10:00
ISSN
1101-8453
ISBN
91-628-5212-4
language
English
LU publication?
yes
id
bc56e86c-b604-4228-a531-e51a4f32f6fb (old id 20444)
date added to LUP
2007-05-28 08:59:07
date last changed
2016-09-19 08:44:54
@phdthesis{bc56e86c-b604-4228-a531-e51a4f32f6fb,
  abstract     = {The amygdala is a small subcortical structure that has long been implicated in the conditioning of fear and other emotions. It is heavily interconnected to a number of both cortical and subcortical structures and is thus well placed to integrate sensory inputs from multiple areas to produce emotional reactions directly as well as influence learning and attention systems. Data suggests that the amygdala works in close cooperation with the orbitofrontal cortex; the amygdala learns emotional reactions to stimuli, while the orbitofrontal cortex learns to inhibit the reactions from the amygdala in a context-sensitive manner. The hippocampus is encoding the contextual representations that are used by the orbitofrontal cortex. Being responsible for the conditioning of emotional reactions, the amygdala forms a part of a conceptual system integrating emotions, motivation and actions. The thesis briefly discusses this system, and also reviews the neurophysiological and neuroanatomical features of the amygdala, the orbitofrontal cortex and related areas.<br/><br>
<br/><br>
As a learning system, data suggests the amygdala is working as a classical conditioning system. This system is used both to elicit autonomous reactions to emotional stimuli directly through the central amygdala, and as an evaluative part of an instrumental conditioning system through the basolateral amygdala. Through this mechanism, the structure is also involved in selective memory consolidation and in selective priming of stimuli in the sensory cortices. Classical and instrumental conditioning is discussed, and a number of computational models of classical conditioning are presented and compared.<br/><br>
<br/><br>
The second half of the thesis presents a computational model of the amygdala and orbitofrontal cortex. The model has a very simple design for each component; much of the abilities of the model instead comes from the neuroanatomically guided interconnections between these components. The model is tested with only the amygdala and orbitofrontal cortex, and then extended with a simple hippocampal model able to generate contextual signals from an externally imposed attentional sequence. The model is compared to the previously tested conditioning models and its benefits and drawbacks - especially its current inability to handle time-dependent effects - are discussed.},
  author       = {Morén, Jan},
  isbn         = {91-628-5212-4},
  issn         = {1101-8453},
  keyword      = {Applied and experimental psychology,Sociologi,Sociology,orbitofrontal cortex,learning,hippocampus,emotions,computational models,mygdala,classical conditioning,Tillämpad och experimentell psykologi,Philosophy,Filosofi},
  language     = {eng},
  pages        = {160},
  publisher    = {Lund University Cognitive Science},
  school       = {Lund University},
  series       = {Lund University Cognitive Studies},
  title        = {Emotion and Learning - A Computational Model of the Amygdala},
  volume       = {93},
  year         = {2002},
}