There is no a priori assurance that a scalp-recorded EP/ERP component structure will be mirrored by local intracranial CSD components or the LFPs from which they are derived. This caveat is particularly relevant to prominent late components, such as the auditory N1, which have their own literature based on the summation (volume integral) of generators with overlapping time courses and anatomical localizations (Fishman et al., 2001a; Godey et al., 2001; Liegeois-Chauvel et al., 1994). An appropriate interpretation of the corresponding CSD profiles necessarily requires an appraisal of the scale of the measurement as well. For example, if the purpose of a study is only to identify generators of globally-recorded field potentials (e.g., the scalp-recorded EP/ERP), highly localized patterns of neuronal activity (e.g., processes limited to the scale of a single cortical column) that are largely cancelled (i.e., closed) may be of minimal interest, due to their negligible contributions to the distant field. Conversely, these same patterns may be of considerable interest to an understanding of local neuronal processing. Because of these divergent needs, CSD estimates based on spatial high- and
