Four representative left and right adjacent channels from iEEG recordings (LTD3–LTD6 and RTD3–RTD6) are shown in Fig. 3, where only 10 of 100 s are shown representatively. The reference signal (R2) in Fig. 3(A) was calculated based on the second method in [1] by using the entire time period (100 s) and all 16 iEEG channels (where we want to point out that the equivalence between Models (1) and (3) in [1] plays an important role in the R2 method and is usually true for real EEG data). In Fig. 3(A), the second eight channels (LTD3–LTD6 and RTD3–RTD6) are the corrected iEEG and were obtained by subtracting the calculated reference signal (R2) from the original referential iEEG. It is easy to see that each referential iEEG channel was contaminated by muscle artifacts that are removed in the corrected iEEG. This shows the following: 1) Muscle artifacts in the referential iEEG come from the reference signal in this case, and 2) the reference signal was mostly removed using the approach described in [1]. Four bipolar montage iEEGs (LTD3–LTD4, LTD5–LTD6, RTD3–RTD4, and
