Institutt for biomedisin

BBB Seminar: Christian Sorg


Affective disorders and the default mode and salience network 

Christian Sorg
Department of Psychiatry, Neuroradiology and Nuclear Medicine, Munich Technical University, Germany

Affective disorders such as Major Depression or Somatoform Pain Disorder are characterized by impaired affect, affect regulation, and affect learning. Affects control the interaction between self- and world-related processes. When I am hungry, my attitude towards a sandwich is very different from that when I am not hungry. Self-related processes depend critically on activity in the default mode and salience network (DMN, SN). DMN and SN are intrinsic functional connectivity networks of the brain characterized by synchronous activity, which is consistent across different task and rest states. DMN activity decreases during world-oriented behavior and increases during self-related processes. SN activity does not depend on the type of world-oriented behavior but on the degree of personal salience. Since affective deficits of affective disorders are associated with impaired self-related processes, changes of DMN and SN activity might contribute to affective disorders. This is the leading hypothesis of the talk. Functional magnetic resonance imaging (fMRI) is the central method to test it. First, some basics about the fMRI signal, task activation networks, and intrinsic functional connectivity networks will be reported. After that, the focus will be on characteristics of the DMN and SN. The main part of the talk will focus on functional and structural changes of the DMN and SN in Somatoform Pain Disorder, Major Depression, and Borderline Personality Disorder. Finally, a brief report will be given on neural correlates of effects of affect regulation on affect learning and their potential relationship to the DMN and SN.

Host: Arvid Lundervold , Department of Biomedicine