transformation was performed to return the single trial data to the voltage domain, minus the artifacts. The artifact criteria were: 1) > +/− 90 μV change in one time point; 2) amplitude range within an epoch exceeding 200 μV; and 3) horizontal EOG deviations exceeding calibration values for 1 degree of visual angle. Participants’ data were not included in the data set if they had less than 200 epochs following artifact removal. The number of epochs retained per subject was (mean +/− standard deviation) 276 +/− 27 for HC and 271 +/− 21 for SZ. Only non-target trials were analyzed. Average ERPs were computed from the single-trial epochs for the LVF and RVF stimulus trials and transformed into CSD waveforms (Perrin et al., 1989) using the CSD Toolbox version 1.0 (Kayser and Tenke, 2006) (http://psychophysiology.cpmc.columbia.edu/Software/CSDtoolbox). Each participant’s CSD waveforms were filtered from 1–15 Hz and baseline-corrected with a −100 to 0 ms baseline. The filter was of finite impulse response type, zero phase shift, with a 200 ms width, and passband weights determined in the frequency domain (Cook and Miller, 1992). The filter was applied to the waveforms beginning at −200 ms so that the first filtered point was −100
