Institutsforschungskolloquium des Psychologischen Instituts
Prof. Dr. Michael Herzog
(École Polytechnique Fédérale de Lausanne EPFL)
A Vision into Madness, Personality, and Gender
Vortrag in englischer Sprache
Mittwoch, 27. November 2013, 16:15 Uhr, Hörsaal 01-231, Psychologisches Institut, Binger Straße 14–16, 55122 Mainz
Schizophrenia is a heterogeneous disease, strongly influenced by genetic disposition. However, large scale genetic analysis has not identified any gene substantially contributing to the disease. On the other hand, medical diagnosis (e.g. DSM IV) is a reliable tool to diagnose schizophrenia, but is not well suited for research. For this reason, so called endophenotypes are of primary interest, linking phenomenology to genetic predisposition. We have developed an endophenotype based on visual masking. Observers discriminated the offset between two vertical bars (vernier acuity). Performance was only slightly deteriorated in patients relative to healthy controls. However, when the vernier was masked, large performance differences are found and the same holds true for the unaffected relatives of patients, pointing to genetic contributions. Interestingly, also healthy students with high scores on schizotypy (cognitive disorganization) show similar masking deficits. Using high density EEG, we found strongly diminished brain activity in patients and, to a lesser degree, in the high scoring schizotypy students, again, pointing to one crucial factor underlying schizophrenia, present in a substantial amount of the normal population. Based on our genetic analysis of the nicotinic system, I will put forward a theory of target enhancement dysfunctions, which potentially can explain how visual deficits relate to the characteristic symptoms of schizophrenia (and partly to personality). As a side effect, we found small, but reliable, differences in visual masking between male and female observers in patients, relatives, and controls.
Prof. Dr. Michael Herzog, Head of the Laboratory of Psychophysics LPSY, École Polytechnique Fédérale de Lausanne EPFL.