AN ANATOMICALLY CONSTRAINED NEURAL-NETWORK MODEL OF FEAR CONDITIONING

Conditioning of fear reactions to an auditory conditioned stimulus (CS ) paired with a footshock unconditioned stimulus (US) involves CS tran smission to the amygdala from the auditory thalamus, the auditory cort ex, or both. This article presents a simple neural network model of th is neural system. The model consists of modules of mutually inhibitory nonlinear units representing the different relevant anatomical struct ures of the thalamo-amygdala and thalamo-cortico-amygdala circuitry. F requency-specific changes produced by fear conditioning were studied a t the behavioral level (stimulus generalization) and the single-unit l evel (receptive fields). The findings mirror effects observed in condi tioning studies of animals. This computational model provides an initi al grounding for explorations of how emotional information and behavio r are related to anatomical and physiological observations.