Even if the declared research goal is the understanding of psychological functions and not the delineation of the underlying functional neuroanatomy, the fact that brain activation is responsible for the EEG phenomena used to study psychological functions and because the measured outcome can be reversed by changing the reference should be enough reason for concern. While there may be an optimal EEG reference for a given constellation of neuronal generators (e.g., Fig. 14C; cf. also Dien, 1998), the neuronal generators under study are typically not known in advance and consist of more than a single dipole. Thus, from a purely pragmatic perspective, the use of an ambiguous activation measure seems highly undesirable, and should be replaced with a non-ambiguous measure as long as this alternative will not introduce considerable costs offsetting these benefits.
