Integrating EEG/MEG and fMRI: Activity Correlation Between Frontal and Temporal Lobe Structures in Schizophrenic Patients, Their Siblings and Unrelated Normal Volunteers

It is the aim of this study to investigate the functional activation and coupling between brain regions in normals, patients with schizophrenia and unaffected family members. We will perform electrophysiological recordings (MEG, EEG) during cognitive activation (Continuous Performance Task, Sternberg paradigm, working memory). We will focus on the investigation of oscillatory brain activity as this is considered to be crucial for information processing related to neuronal integration. The measurements will be closely adapted to equivalent fMRI-measurements presented as an independent protocol (00-M-0085). The combination of both methods will help to improve activity source localization (MEG/EEG) and correlation of this activity between different parts of the brain. In addition, local activity patterns (fMRI) can be better characterized in the time domain (tonic versus phasic BOLD-activation). We will address whether cognitive activation goes along with an increase or decrease of correlation between regional brain areas. In this context, we will investigate whether this correlated activation pattern is different in schizophrenics and unaffected siblings when compared with normals. The study is integrated with the schizophrenia-sibling study (95-M-0150). Siblings of schizophrenic patients are investigated in order to achieve a better understanding of the genetic determination of schizophrenia-related pathophysiology.