Insula, a "mysterious" island in our brain -- minireview

Until the last decade of the past century, insula was one of the less frequently investigated cortical areas in the human brain. Due to the introduction and wide use of neuroimaging techniques in human brain, insula became the focus of attention. Recent studies confirmed former observations about the presence of the olfactory, taste and viscerosensory cortical centers in the insula, and provided very fine new information about the mechanism of actions and interactions of these activities. Furthermore, the functional significance of insula in social-emotional, cognitive and sensorimotor network, speech and language processes, as well as in interoceptive awareness have been determined. For performing of these activities, insula receives extensive neuronal input from the body and from various cortical areas. Through its opercular cortices and the anterior cingulate cortex, insula is connected to prefrontal, premotor, limbic and central autonomic areas. With our present knowledge, insula may serve as primary (unimodal) cortical area for olfactory, taste and viscerosensory information, and acts as a multimodal cortical association area in the emotional, cognitive, limbic and autonomic systems in the brain.