Two persistent issues in ERP research are the dependency of surface potentials on a reference location (e.g., linked-mastoids, ear lobe, nose, average, sternum) and the definition and measurement of appropriate ERP components (e.g., specific time windows for peak or integral amplitudes), which crucially affect component interpretation (e.g., polarity, topography, generator) and statistical analysis (e.g., Kayser and Tenke, 2003, 2005; Nunez and Srinivasan, 2006). Although these issues are generally known and disseminated through textbooks (e.g., Nunez, 1981; Luck, 2005) and other seminal publications (e.g., Picton et al., 2000), the implications for applied electrophysiologic research have as of yet not been fully appreciated by the field at large. For example, the visual appearance of a limited set of surface potential waveforms may change dramatically if referenced to mastoid (ear lobe) or nose (e.g., see visual condition in Fig. 8 of Kayser et al., 2007, depicting the shift and polarity inversion of a nose-referenced N1/N2 complex from inferior-lateral sites to mid-centroparietal sites when using a linked-mastoids reference), which may also influence which electrode sites are selected for statistical analysis. A particular bias is
