Another major function of the anterior cingulate cortex: the representation of requirements.

The anterior cingulate cortex (ACC) is a ubiquitously active brain region, doubtless reflecting a multiplicity of functions. Improved knowledge of such functions should progress understanding of disorders with established ACC involvement, including depression, apathy, and addiction. This theoretical paper proposes a hypothesis concerning an original and important ACC function, namely that the ACC operates as part of distributed networks to which it contributes the representation of requirements. Such requirements are further suggested to proactively coordinate and organize processing in effector regions to achieve consummation, thereby implementing an optimal strategy. The ACC (predominantly Brodmann's areas 24 and 32) is activated during states characterized by active requirements such as homeostatic perturbations, pain, desire, addiction, and cognition, and this is evidenced by systematic reviews of neuroimaging studies, and by neuropsychological findings. Further, ACC activity commences early in processing, and proactively influences processing in effector regions, further supporting the hypothesis. Thus, this hypothesis accounts for some ACC findings that are otherwise unexplained, and proposes novel testable predictions offering new insights into ACC functional organization.