Authors: Christine Wiebking and Georg Northoff
Interoceptive awareness is defined as the awareness of stimuli originating inside one’s own body such as the heartbeat. The emergence of new brain imaging techniques like functional magnetic resonance imaging (fMRI) or magnetic resonance spectroscopy (MRS) has increased our knowledge of neural substrates underlying interoceptive awareness. In particular, the bilateral brain structure of the insula has been identified as a key region involved in interoceptive processes in healthy populations. In line with prominent theories of human emotion, the insula has an important function in connecting interoceptive awareness with affective experience. This connection hinging on the insula between interoception and emotional processing is suggestive of an involvement of the insula in mood disorders such as major depressive disorder (MDD). Multilayered deficits in the insula cortex of depressed individuals such as abnormal function, biochemistry, and anatomy support this hypothesis.
The aim of the present article is to describe the importance of the insula for the interplay between interoception and emotional processing and how this might be figured into psychotherapeutic treatment of depressed patients. The article begins with a brief introduction about neuroanatomical settings of the insula. Afterwards, early behavioral studies to investigate interoceptive awareness are described, followed by a description of more recent imaging studies outlining neural mechanisms underlying interoceptive awareness and emotional processing in the insula. Throughout, the article addresses the question of why the investigation of individuals suffering from depression might provide novel insights into the neural underpinnings of interoceptive awareness and its link to abnormal behavior. Following the description of a selected study that combines functional results of interoception (fMRI) with biochemical (MRS) results, the article concludes with a perspective outlining the potential for using imaging techniques to enhance neural activity in the insula during interoceptive awareness, which potentially leads to faster recovery in depressed patients. This electronic document is a “live” template. The various components of your paper [title, text, heads, etc.] are already defined on the style sheet, as illustrated by the portions given in this document.
Keywords: interoceptive awareness, insula, major depression, emotional processing, functional magnetic resonance imaging