Ium to strong effect on psychopathological scales, the correlations did not reach the level of statistical significance (PANSS general score; r = 20.698, p = 0.08; other scales r = 20.31?.44, p.0.1). The LDAEP using DSA was significantly associated with the group membership in both hemispheres (right: Wald = 10.094, df = 1, p = 0.001; left: Wald = 7.791, df = 1, p = 0.005). Patients with schizophrenia showed a significantly higher LDAEP than the control group (Table 2, Figure S2). Results were adjusted for age and nicotine use. The magnitude of the group effect on LDAEP on both hemispheres was remarkably large, as indicated through the standardized mean difference Cohen’s d = 1.04 (left) and d = 1.20 (right) (benchmarks are as follows: d = 0.3 depicts a small effect, d = 0.5 a medium effect and d = 0.8 a large effect). No significant differences in the LDAEP between the groups were found using Title Loaded From File single electrode estimation at Cz (Wald = 0.057, df = 1, p = 0.811). No significant differences between left and right LDAEP were found, neither among the whole sample (Z = 21.283, p = 0.200), nor among schizophrenic patients (Z = 21.153, p = 0.249) or the control group (Z = 20.524, p = 0.600). Moreover, we observed a significant positive relationship between the SANS subscales “affective flattening” (beta = 0.207, p = 0.000), “Title Loaded From File anhedonia” (beta = 0.155, p = 0.016) and “attentional impairment” (beta = 0.189, p = 0.015) and the LDAEP in the right hemisphere in patients. 18204824 SANS composite score (the sum of scores for all items), which reflects severity of negative symptoms, was also positively correlated with the right LDAEP (beta = 0.153, p = 0.035) (Table 3). Depressive symptoms (BRMS and CDSS G scale) (beta = 20.372, p = 0.000; beta = 20.305, p = 0.000) as well as PANSS general score (beta = 20.159, p = 0.026) were associated with the left LDAEP. Patients with higher scores on these Table 1. Demographic and clinical data of the sample.Statistical AnalysisComparison of age and smoking status in patients and controls was conducted with a t-test for independent samples and crosstabulation with x2 test, respectively. To test the association between LDAEP values and the group factor (control group vs. schizophrenic patients) we conducted a series of generalized linear models (GLM) [59]. GLM was chosen because it allows for variables that are not normally distributed in comparison to familiar used methods as ANOVA or linear regression analysis. LDAEP of the left and right hemisphere and from Cz-estimation were entered as the dependent variables. The covariates age and nicotine use were tested separately in bivariate analyses against LDAEP using DSA. Distribution and link-function of the LDAEP variables were chosen according to their graph and the goodness of model fit indices. For this purpose we compared the Akaike’s information criterion (AIC) and the Bayesian information criterion (BIC) for the different distributions and link-functions. The best fit to the data was finally obtained with a gamma distribution (right skewed distribution) and log link-function. In all GLM a robust estimator was used to reduce the effects of outliers and influential observations. Group effects on LDAEP were displayed with mean differences, whereas associations between continuous measures and LDAEP were depicted with unstandardized regression coefficients (B). In order to provide comparability among predictors all continuous covariates were standardized using the z-tra.Ium to strong effect on psychopathological scales, the correlations did not reach the level of statistical significance (PANSS general score; r = 20.698, p = 0.08; other scales r = 20.31?.44, p.0.1). The LDAEP using DSA was significantly associated with the group membership in both hemispheres (right: Wald = 10.094, df = 1, p = 0.001; left: Wald = 7.791, df = 1, p = 0.005). Patients with schizophrenia showed a significantly higher LDAEP than the control group (Table 2, Figure S2). Results were adjusted for age and nicotine use. The magnitude of the group effect on LDAEP on both hemispheres was remarkably large, as indicated through the standardized mean difference Cohen’s d = 1.04 (left) and d = 1.20 (right) (benchmarks are as follows: d = 0.3 depicts a small effect, d = 0.5 a medium effect and d = 0.8 a large effect). No significant differences in the LDAEP between the groups were found using single electrode estimation at Cz (Wald = 0.057, df = 1, p = 0.811). No significant differences between left and right LDAEP were found, neither among the whole sample (Z = 21.283, p = 0.200), nor among schizophrenic patients (Z = 21.153, p = 0.249) or the control group (Z = 20.524, p = 0.600). Moreover, we observed a significant positive relationship between the SANS subscales “affective flattening” (beta = 0.207, p = 0.000), “anhedonia” (beta = 0.155, p = 0.016) and “attentional impairment” (beta = 0.189, p = 0.015) and the LDAEP in the right hemisphere in patients. 18204824 SANS composite score (the sum of scores for all items), which reflects severity of negative symptoms, was also positively correlated with the right LDAEP (beta = 0.153, p = 0.035) (Table 3). Depressive symptoms (BRMS and CDSS G scale) (beta = 20.372, p = 0.000; beta = 20.305, p = 0.000) as well as PANSS general score (beta = 20.159, p = 0.026) were associated with the left LDAEP. Patients with higher scores on these Table 1. Demographic and clinical data of the sample.Statistical AnalysisComparison of age and smoking status in patients and controls was conducted with a t-test for independent samples and crosstabulation with x2 test, respectively. To test the association between LDAEP values and the group factor (control group vs. schizophrenic patients) we conducted a series of generalized linear models (GLM) [59]. GLM was chosen because it allows for variables that are not normally distributed in comparison to familiar used methods as ANOVA or linear regression analysis. LDAEP of the left and right hemisphere and from Cz-estimation were entered as the dependent variables. The covariates age and nicotine use were tested separately in bivariate analyses against LDAEP using DSA. Distribution and link-function of the LDAEP variables were chosen according to their graph and the goodness of model fit indices. For this purpose we compared the Akaike’s information criterion (AIC) and the Bayesian information criterion (BIC) for the different distributions and link-functions. The best fit to the data was finally obtained with a gamma distribution (right skewed distribution) and log link-function. In all GLM a robust estimator was used to reduce the effects of outliers and influential observations. Group effects on LDAEP were displayed with mean differences, whereas associations between continuous measures and LDAEP were depicted with unstandardized regression coefficients (B). In order to provide comparability among predictors all continuous covariates were standardized using the z-tra.