Several brain regions have emerged relatively recently as major contributors to the human psychological system. A good example is the cingulate cortex. As early as the 1930s, it was observed that cats become mute and akinetic after the occurrence of lesions of the cingulate cortex. However, it was not until the 1950s that the cingulate gyrus was examined more carefully. Together with the parahippocampal gyrus, which lies below it, the cingulate gyrus (Figure 12.1) forms a large arcuate convolution that surrounds the rostral brainstem and constitutes what Broca referred to as the grande lobe limbique (see Figure 13.1).

Anatomy and behavioral considerations

The cingulate cortex lies deep within the longitudinal cerebral fissure and spans the corpus callosum like a great arc (see Figure 12.1). It is separated from the frontal and parietal cortex above by the cingulate sulcus, within which much of the cingulate cortex lies. Two major subdivisions of the cingulate cortex and a connecting bundle can be identified:

• The anterior cingulate cortex (ACC) forms a large region around the genu of the corpus callosum. The majority of the ACC consists of BA 24 and lies just beneath the supplementary motor area. The smaller paragenu area of the ACC wraps around the front and underside of the genu of the corpus callosum and corresponds largely with BA 25 (see Figures 2.3 and 12.1). The terms infralimbic, subcallosal and anterior limbic have been applied to all or parts of the paragenu area located below the genu (IL and PG, Figure 12.1). […]