Endophenotypes are of crucial interest for schizophrenia research linking genetic abnormalities to pathology. During the last NCCR period, we have characterized one endophenotype, based on visual backward masking deficits, behaviourally and genetically (poster #1). We used high density EEG to determine the electrophysiological correlates of these deficits. We found strongly reduced global field power (GFP) amplitudes to masked stimuli in schizophrenic patients (Plomp et al., 2013), in 22q11 patients (Cooperation: Rihs & Eliez, ongoing) and, interestingly, also in healthy students with high scores of cognitive disorganization but at a lesser extent (Cappe et al., 2012; Cappe et al., in preparation; Cooperation: Draganski, Mohr, ongoing). In addition, resting state EEG of patients showed clear abnormalities (Cooperation: Michel, ongoing). Visual backward masking seems to be a very sensitive endophenotype for the schizophrenic spectrum. Our results link schizophrenia to dysfunctions of stabilization of fragile information (Herzog et al., 2013).