EDIT: It is also interesting to note that his EEG observations tend to confirm that each type has a "toe-hold" (as he puts it) into one's opposite type. An ISFP will occasionally show patterns emulating those of an ENTJ or INTJ, but will never have the "Christmas tree pattern" of an Ne type. He says that this appears to be the case across all of the types. Note that this would appear to be a demonstration that the tertiary function is not in the opposite attitude as the secondary, as some Jung theorists have asserted. I.e., a competing theory was that ISFP = Fi-Se-Ne-Te, not Fi-Se-Ni-Te. Nardi is observing Ni, not Ne, in the EEGs.