In the last years, the imbalance between excitatory and inhibitory neuronal activity has come to the fore as a possible molecular disease mechanism of schizophrenia . Pharmacological studies have suggested different fMRI and EEG markers of that molecular dysfunction (resting state connectivity changes, auditory mismatch and steady state deficits). However, previous research is inconclusive regarding their genetic basis, their reliability, inter-individual relationship as well as disease specificity. Therefore, in this study we aim at estimating the effect sizes, test-retest-reliability and clinical correlates of the respective markers in a comparative fashion in patients with schizophrenia, their relatives and healthy control subject. To assess their molecular validity, we will assess their relationship with glutamatergic and GABAergic genotypes and cellular disease models. The proof of such a relation would give the opportunity of detecting a glutamatergic and GABAergic imbalance throughout non-invasive imaging. Furthermore, it would help deepening our understanding of the molecular pathophysiology of mental disorders which will be essential for the development of more effective drugs.