Acquisition of EEG data by bipolar, unipolar and average reference methods: a theoretical comparison.

When an EEG recording is to be taken in a conventional manner, the choice of method depends to a large extent on the nature of the electroencephalographic problem and on the personal preference of the investigator. However, when EEG data are to be stored in an electrical form for subsequent analysis, the bipolar method of derivation would appear to have some practical advantages over both the unipolar and average reference methods. For a given array of n electrodes and (n−1) channels of amplification, the same basic information can be obtained by the use of any of the methods discussed.