activity by the experimental manipulations (e.g., Nunez and Westdorp, 1994). This indeterminancy is not resolved by using an average reference, which has the additional caveat of being different for different EEG montages and, due to practical limits of sampling from the ventral side of the brain, is biased toward the montage center or pole, which is typically the vertex (e.g., Dien, 1998; Junghöfer et al., 1999).
