The Cingulate Gyrus

Introduction
The cingulate gyrus is a stretch of cortex directly dorsal to the corpus callosum and can be split into multiple areas: the anterior cingulate cortex (ACC), middle cingulate cortex, and posterior cingulate cortex (PCC). Each of these subsections has different structural characteristics and neuronal projections that characterize their individual cortical areas and functions (Stevens et al., 2011). The ACC has been functionally tied to several behaviors, including decision-making, socially driven interactions, and empathy related responses (Lavin et al., 2013). As part of the “limbic loop”, it has significant connections to emotional behavioral states. At the same time, the ACC relays information from the thalamus to the motor system, highlighting its role in executive function (Yen et al., 2008). The nature of these higher-order behaviors suggest that the connections of the ACC are a relatively recent evolutionary addition to the brain, and is important for processing and reconciliation of contradicting information in humans.

ACC Structural
The ACC lacks layer IV, which receives thalamic input, and has a developed layer V with the presence of Von Economo Neurons, along with other general pyramidal cells. These characteristics of the ACC make it structurally similar to the neocortex motor areas that lie next to it. These suggest that the ACC could be a more recent evolutionary development as a specialized development of the neocortex (Allman et al., 2006). The lack of thalamic input to the ACC may also suggest that basic sensory information is not fundamental to ACC processing and function; higher-level thinking and processing of information may be more important to the ACC, as opposed to simple understanding of the external