Visual impairments in schizophrenia

The obvious symptoms of schizophrenia are hallucinations, delusions, and cognitive dysfunctions. However, schizophrenia patients have many other abnormalities, including visual impairments. Visual paradigms are versatile tools of schizophrenia research because patients׳ deficits are often very pronounced. Amongst the variety of techniques, visual masking has been shown to be one of the most sensitive visual tests. We have shown that unaffected relatives show clear performance deficits compared to controls. Moreover, in patients, performance deficits are stable over the time course of 18 months (Chkonia et al., 2010b). Hence, masking is an endophenotype and accordingly we found genetic correlates related to a deficient nicotinic system in the patients (Bakanidze et al., 2013). We propose that visual dysfunctions are emanations of general dysfunctions dedicated to deficient neuromodulation and thus offer insights into the causes of the disease.