Of course, coarse spatial resolution is the main disadvantage of electrophysiology methods. Yet, higher cognitive functions are subserved by highly dynamic, rapidly forming and dissipating distributed functional networks involving dynamic interaction among distant brain regions. This raises the question of whether we really need a very fine spatial resolution in order to localize processes that may inherently lack a strict anatomical localization, as suggested by both electrophysiology and fMRI data (e.g. substantial variability of regional BOLD “activation” across subjects in the same task and variability within subject across sessions or even within a single session). Finally, the neural substrates of well-established ERP components are being increasingly clarified by studies integrating ERP and fMRI data (see e.g.Debener et al., 2005; Ford et al., 2004), which provides neuroanatomical validation for ERP phenotypes.
