Is EEG is better left alone?

A recent article (Delorme, A., 2023, EEG is better left alone. Scientific Reports , 13 , 2372. ) proposed a metric to determine the benefit of applying pre-processing methods to EEG data. Using that metric, it concluded that most pre-processing methods do not improve data quality. The question is revisited in this short paper, using a sample of the same data as used by that paper. It is argued that the metric is of limited applicability, and that in some situations pre-processing might be critical to make good use of the data. Note: This paper was submitted to Scientific Reports as a commentary to the paper cited and rejected without review. ### Competing Interest Statement The authors have declared no competing interest.