A dynamical model of event-related FMRI signals in prefrontal cortex: predictions for schizophrenia

Two different models of the topographical and functional organization of the prefrontal cortex have been proposed: organization-by-stimulus-domain, and organization-by-process. The present work utilizes an integrate-and-fire network to model fMRI data on short term memory in order to understand data obtained in topologically different parts of the prefrontal cortex during working memory tasks. We explicitly model the mechanisms that underly working memory-related activity during the execution of delay tasks. It is shown that the effects of neuromodulation by dopamine of the synaptic processes utilized in the neurons in the model leads to experimental predictions of the effects of manipulations of dopamine on working memory.