Chapter 19 Dopamine, cognitive control, and schizophrenia: the gating model

This chapter presents a theory of cognitive control that is formalized as a connectionist computational model. The theory suggests explicit neural and psychological mechanisms that contribute to the normal cognitive control, and proposes a specific disturbance to these mechanisms, which may capture the particular impairments in cognitive control in schizophrenia. The chapter presents the cognitive control results from interactions between the dopamine (DA) neurotransmitter system and the prefrontal cortex (PFC). The chapter presents the information that is actively maintained in PFC, and thus serves as a source of top-down support for controlling behavior. The chapter explains that the DA projection to PFC serves a gating function, by regulating access of context representations into active memory. As such, DA plays an important control function, by enabling flexible updating of active memory in PFC, while retaining protection against interference. Moreover, in schizophrenia, the activity of the DA system is noisier, and that this increased variability leads to disturbances in both the updating and maintenance of context information within working memory.