Effect of orientation and letter selection at N1 level. LEFT. Back view of topographical distribution of difference voltage (μV) obtained by subtracting grand-average ERPs to standard from ERPs to rotated words, at N1 peak. RIGHT. Topographical distribution of difference voltage obtained by subtracting grand-average ERPs to non-targets from ERPs to targets. A left-sided lateralization of the letter selection effect is evident, presumably linked to orthographic analysis.