Proceedings of the Annual Meeting of the Cognitive Science Society

Sutton-Barto (SB) model of learning is based on a neuron-like adaptive element. The model has computational features suitable for describins a variety of classical conditioning phenomena, including blocking, conditioned inhibition, and higher-order conditioning. However, it presently does not describe within-trial phenomena related to conditioned response (CR) topography. W e here describe in detail an extension of the SB element, referred to as the Sutton-Barto-Desmond (SBD) model, which is capable of simulating topography of the conditioned nictitating membrane response (NMR) of the rabbit. The SBD model places certain constraints on the SB modePs parameters and makes some additonal assumptions about the form of inputs to the element. The model describes (1) the gradually increasing amplitude of the C R within a trial with the peak amplitude at the temporal locus of the US, (2) the decrease in C R onset latency over training, and (3) appropriate interstimulus interval (ISI) functions, with optimal learning occurring with an ISI of .25 seconds. In addition, the model lends itself to descriptions of neuronal firing related to the CR. W e believe the S B D model may have implications for neurobiological studies of learning and memory.