The limbic system remains the pre-eminent mechanism of emotion. Heimer and colleagues (Alheid and Heimer 1988; de Olmos and Heimer 1999; Heimer et al. 1991) proposed an anatomical framework that delineates limbic regions into functional—anatomical systems consisting of the basal forebrain, “extended amygdala”, and limbic lobe. In doing so, this revised conceptualization of the limbic system more appropriately address the complexity of the basal forebrain and extended amygdala as primary output channels for activities originating from the neocortex (Heimer 2003; Heimer and Van Hoesen 2006). An abbreviated schematic of this extended limbic network is provided in Fig. 2.
