Where does consciousness occur in the brain

Question to the brain

answer from Prof. Dr. Martin Lotze, Professor of Functional Imaging at the Institute for Diagnostic Radiology and Neuroradiology at the University of Greifswald.

To answer this question, the theory of so-called somatic markers, developed by Antonio Damasio, helps us. Somatic markers can also be called body signals that we become aware of and thus help us to make decisions by indicating a tendency in a certain direction. For example, the good feeling that a praise triggers after a good deed, as opposed to the bad feeling that a reprimand after a bad deed leads to. Both sensations are based on body signals that we become aware of even when we think about the respective actions and thus influence future decisions.

According to Damasio, body awareness is located in the lower parietal lobe. In the right hemisphere in particular, there are areas that process spatial information from the body. How are we aligned in space? How do our extremities relate to the body axis? How are our hands in relation to objects in our environment? If damage occurs in these regions, what is known as neglect can occur. Then, for example, the left half of the face or body can be perceived more poorly.

Furthermore, there is constant self-monitoring, which can be located in the island and is more of an emotional nature. This self-observation happens internally on the one hand, with regard to one's own state of mind, and on the other hand with regard to multimodal stimuli that come from outside.

We are currently investigating patients with damage in the island region in a research project supported by the DFG. There are exciting findings here, for example with regard to the arousal dimension of emotional processing. This means that some of these patients no longer experience the creeps that are usually caused by music. Others no longer feel a "kick" from noxae, i.e. after harmful stimuli such as nicotine. In addition, more errors in emotional recognition are observed with such complex basic emotions as disgusting faces, the multimodal external stimuli mentioned above.

The island is therefore a kind of internal monitor that is significantly involved in the perception of changes in the body and gives the brain a goosebump feeling. Or not when it is damaged. Which then also has the effect that these body changes can no longer be recognized in others.

Recorded by Dr. Jochen Müller