Author/Authors :
Weisbrod, Matthias Research Group Neurocognition - Department of General Psychiatry - Centre for Psychosocial Medicine - Heidelberg University - Heidelberg, Germany , Sharma, Anuradha Research Group Neurocognition - Department of General Psychiatry - Centre for Psychosocial Medicine - Heidelberg University - Heidelberg, Germany , Sauer, Heinrich Department of Psychiatry - University of Jena - Jena, Germany , Hill, Holger Institute of Sports and Sports Science - Karlsruhe Institute of Technology - Karlsruhe, Germany , Kaufmann, Claudia Department of General Internal Medicine and Psychosomatics - University of Heidelberg - Heidelberg, Germany , Bender, Stephan Department of Child and Adolescent Psychiatry - University Hospital Cologne - Cologne, Germany
Abstract :
Activation of semantic networks is indexed by the N400 effect. We used a twin study design to investigate whetherN400 effect abnormalities reflect genetic/trait liability or are related to psychopathological processes in schizophrenia.Methods.We employed robust linear regression to compare N400 and behavioral priming effects across 36 monozygotic twin pairs (6pairs concordant for schizophrenia/schizoaffective disorder, 11 discordant pairs, and 19 healthy control pairs) performing a lexicaldecision task. Moreover, we examined the correlation between Brief Psychiatric Rating Scale (BPRS) score and the N400 effect andthe influence of medication status on this effect.Results. Regression yielded a significant main effect of group on the N400 effectonly in the direct priming condition (𝑝=0.003). Indirect condition and behavioral priming effect showed no significant effectof group. Planned contrasts with the control group as a reference group revealed that affected concordant twins had significantlyreduced N400 effect compared to controls, and discordant affected twins had a statistical trend for reduced N400 effect comparedto controls. The unaffected twins did not differ significantly from the controls. There was a trend for correlation between reducedN400 effect and higher BPRS scores, and the N400 effect did not differ significantly between medicated and unmedicated patients.Conclusions. Reduced N400 effect may reflect disease-specific processes in schizophrenia implicating frontotemporal brain networkin schizophrenia pathology.
