Interoceptive Integration in the Primate Insular Cortex
HC Evrard
Abstract
The functional organization of the primate insula is shaped by interoceptive afferents encoding ongoing homeostatic bodily states. A differential posterior, middle, and anterior integration of these afferents with somatomotor, environmental, autonomic, and hedonic activities has been proposed to culminate in an ultimate representation of subjective feelings in the anterior insula in humans. Recent examinations of the insula in macaque monkeys indicate that such integration could occur within a consistent postero-anterior and dorso-ventral latticework pattern. The disproportionate expansion of the anterior insula in humans could have been accompanied by an enrichment of high-order homeostatic representations associated with motoric and autonomic efferent output and with the descriptively less distinct but arousing sensations underlying subjective feelings.