%0 Journal Article %J Psychological Review %D 1992 %T Stimulus configuration, classical conditioning, and hippocampal function. %A Schmajuk, Nestor A. %A DiCarlo, James J. %K Animals %K Association Learning %K Brain Mapping %K Cerebellum %K Cerebral Cortex %K Classical %K Computer Simulation %K Conditioning %K Hippocampus %K Humans %K Models %K Neural Pathways %K Neurological %X

Hippocampal participation in classical conditioning is described in terms of a multilayer network that portrays stimulus configuration. The network (a) describes behavior in real time, (b) incorporates a layer of "hidden" units positioned between input and output units, (c) includes inputs that are connected to the output directly as well as indirectly through the hidden-unit layer, and (d) uses a biologically plausible backpropagation procedure to train the hidden-unit layer. Nodes and connections in the neural network are mapped onto regional cerebellar, cortical, and hippocampal circuits, and the effect of lesions of different brain regions is formally studied. Computer simulations of the following classical conditioning paradigms are presented: acquisition of delay and trace conditioning, extinction, acquisition-extinction series of delay conditioning, blocking, over-shadowing, discrimination acquisition, discrimination reversal, feature-positive discrimination, conditioned inhibition, negative patterning, positive patterning, and generalization. The model correctly describes the effect of hippocampal and cortical lesions in many of these paradigms, as well as neural activity in hippocampus and medial septum during classical conditioning. Some of these results might be extended to the description of anterograde amnesia in human patients.

 

%B Psychological Review %V 99 %P 268 - 305 %8 04/1992 %G eng %U http://doi.apa.org/getdoi.cfm?doi=10.1037/0033-295X.99.2.268 %N 2 %! Psychological Review %R 10.1037/0033-295X.99.2.268 %0 Journal Article %J Behavioral Neuroscience %D 1991 %T A neural network approach to hippocampal function in classical conditioning. %A Schmajuk, Nestor A. %A DiCarlo, James J. %K Animals %K Cerebellum %K Classical %K Computer Simulation %K Conditioning %K Extinction %K Eyelid %K Hippocampus %K Models %K Nerve Net %K Neurological %K Neurons %K Psychological %K Rabbits %K Reaction Time %X

Hippocampal participation in classical conditioning in terms of S. Grossberg's (1975) attentional theory is described. According to the theory, pairing of a conditioned stimulus/stimuli (CS) with an unconditioned stimulus/stimuli (UCS) causes both an association of the sensory representation of the CS with the UCS (conditioned reinforcement learning) and an association of the sensory representation of the CS with the drive representation of the UCS (incentive motivation learning). Sensory representations compete for a limited-capacity short-term memory (STM). The STM regulation hypothesis, which proposes that the hippocampus controls incentive motivation, self-excitation, and competition among sensory representations thereby regulating the contents of a limited capacity STM, is introduced. Under the STM regulation hypothesis, nodes and connections in Grossberg's neural network are mapped onto regional hippocampal-cerebellar circuits. The resulting neural model provides (a) a framework for understanding the dynamics of information processing and storage in the hippocampus and cerebellum during classical conditioning of the rabbit's nictitating membrane, (b) principles for understanding the effect of different hippocampal manipulations on classical conditioning, and (c) novel and testable predictions. 

 

%B Behavioral Neuroscience %V 105 %P 82 - 110 %8 01/1991 %G eng %U http://doi.apa.org/getdoi.cfm?doi=10.1037/0735-7044.105.1.82 %N 1 %! Behavioral Neuroscience %R 10.1037/0735-7044.105.1.82