Proceedings of the Annual Meeting of the Cognitive Science Society

This paper illustrates the use of connectionist models to explore the relationship between biological variables and cognitive deficits. The models show how empirical observations about biological and psychological deficits can be catpured within the same framework to account for specific aspects of behavior. W e present simulation models of three attentional and linguistic tasks in which schizophrenics show performance deficits. At the cognitive level, the models suggest that a disturbance in the processing of context can account for schizophrenic patterns of performance in both attention and language-related tasks. At the same time, the models incorporate a mechanism for processing context that can be identified with the function of the prefrontal cortex, and a parameter that corresponds to the effects of dopamine in the prefrontal cortex. A disturbance in this parameter is sufficient to account for schizophrenic patterns of performance in the three cognitive tasks simulated. Thus, the models offer an explanatory mechanism linking performance deficits to a disturbance in the processing of context which, in turn, is attributed to a reduction of dopaminergic activity in prefrontal cortex.