Exploring function in the hallucinating brain

For many patients with schizophrenia 'hearing voices’ is frightening and severely disruptive symptom of their illness. Recent analysis techniques now offer the possibility to study the complex brain as a communicating network, and in this way develop more realistic models on the origin of hallucinations, which is desperately needed in our search for targeted interventions for hallucinations. In this thesis we present an integrated network model in which we show how the same mathematical principles can be used to explain psychotic symptoms on different levels of human functioning (from nerve cells to brain areas to social networks). In this way we put an end to a fixation on one or several causes of schizophrenia, and we embrace a multi-factorial or (eco)systems approach to this disorder. Derived from data-driven analysis of fMRI data from patients with schizophrenia, we comprehensively describe the neural circuit involved in hallucinations. Specifically, our findings show that miscommunications between two functional networks are central in the occurrence of hallucinations, i.e. linguistic content from the right-sided area of Broca is assigned false salience in the insula. This mechanical insight directly informs us where we can effectively intervene into the hallucination network .