Endophenotypes of schizophrenia: electrophysiological correlates of schizotypy

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 (VBM) deficits, behaviourally, electrophysiologically and genetically. We found strongly reduced global field power (GFP) amplitudes to masked stimuli in schizophrenic patients (Plomp et al., 2013) and in 22q11 patients (Coop. Rihs & Eliez, ongoing). Here, we show that also healthy students with high scores of cognitive disorganization show masking deficits and reduced GFP but at a lesser extent as patients (Cappe et al., 2012; Favrod et al., in prep.; Coop. Draganski, Mohr, ongoing). Nicotinic cholinergic dysfunction has been proposed to be a key mechanism in schizophrenia (Bakanidze et al., 2013). Smoking can be seen as a compensatory mechanism to counteract these dysfunctions. Based on this hypothesis, we investigated the effect of nicotine on VBM in students with high scores of schizotypy (Shaqiri et al., in revision). However, we did not find any effect of nicotine on VBM performance.