Neural network connectivity in patients with schizophrenia who have persistent verbal auditory hallucinations

• Applicant: Professor Dr. Robert Christian Wolf, since 8/2017
• Subject Area: Biological Psychiatry ; Clinical Psychiatry, Psychotherapy, Child and Adolescent Psychiatry
• Term: from 2013 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 238961523

Auditory verbal hallucinations, defined as a sensory experience in the absence of a corresponding external stimulus are a core symptom of schizophrenia and related spectrum-disorders. The cognitive processes and the neural mechanisms underlying auditory verbal hallucinations are not fully elucidated. By means of functional magnetic resonance imaging, this study aims to investigate the functional neuroanatomy of auditory verbal hallucinations and to establish relationships between neural function, cognition and symptom dimensions. The study will test the following hypotheses: 1. abnormal resting-state fluctuations of ongoing neural system activity generate auditory verbal phenomena, and these processes are specific to symptom occurrence and not to the diagnosis of schizophrenia . 2. Symptom-related changes of resting-state function can be used to infer cognitive processes underlying auditory verbal hallucinations. This prediction relies on the assumption of symptom/system interference, i.e. on the assumption that symptom-bound neural resources will interfere with specific neural systems which subserve distinct cognitive processes. This interaction can be explicitly tested using multivariate statistical techniques for functional magnetic resonance imaging data taking into account the combined resting-state and paradigm-based protocol. 3. Assessing symptom/system interference allows characterizing behavioral consequences of symptom occurrence. 4. Assessing resting-state function and symptom/system interference in a hallucinating patient population allows characterizing neural correlates of distinct symptom dimensions, such as spatial awareness, symptom intensity and symptom control. By means of functional magnetic resonance imaging, functional connectivity of multiple neural systems associated with verbal auditory hallucination will be investigated in a selected population of patients with schizophrenia (n=25) who have persistent and treatment-refractory symptoms. A healthy control group (n=25) and a cohort of non-hallucinating patients with schizophrenia will serve as comparison groups. System mapping will be performed in the absence of experimentally controlled stimulation, i.e. under resting-state conditions, as well as under experimentally induced brain activation. Based on previous project-specific work of the applicant and study-specific hypotheses two activation paradigms tapping into a basic attentional (so-called alertness) and verbal working memory function will be employed. Apart from mapping multiple neural networks implied in symptom generation this study will use neuropsychological testing and detailed psychometric symptom characterization to establish relationships between cognition, distinct symptom dimensions and neural dysfunction. Thus, the study aims to bridge phenomenology and systems neuroscience in order to comprehensively elucidate the neural pathophysiology of verbal auditory hallucinations.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Professor Dr. Philipp Thomann, from 10/2014 until 8/2017