We have proposed two possible mechanisms that contribute to differences in measured theta power between scalp and intracranial EEG. Of the two, we believe the first to be the most prominent. Though referencing schemes likely contribute to observed theta effects, there are notable counterexamples: [46], for example, used an intracranial average reference to find decreases in theta power during successful memory encoding and retrieval. A full list of the referencing scheme for each study reviewed here can be found in the Supplement (Supplemental Table 1).
