Before proceeding further with a discussion of executive function, we should note there are different models of cognitive networks of the PFC. Prominent are variations of modular concepts where cognitive representations are essentially ascribed to different neural connections and anatomical locations (e.g., localization of working memory to the dorsolateral PFC) (Norman and Shallice, 1986). In contrast is the model of large-scale cortical networks first suggested by Bressler and expanded upon by Fuster (Bressler, 1995; Fuster, 2008). In this model, while cognitive networks may have foci, to one degree or another, in specific subregions of the PFC, they are widely distributed and bind together neuronal assemblies from widespread regions of the cortex during information processing. Importantly, a network can subserve different cognitive needs (e.g., memories), and different neurons or groups of neurons can participate in, or belong to, different networks depending upon the particular ongoing cognitive demands. The formation of these networks is presumably dependent upon attractor dynamics of cell assemblies that encode specific actions or memories.
