# Adding back the original Pz reference channel before PyPREP: should I apply average reference first?

**URL:** <https://mne.discourse.group/t/adding-back-the-original-pz-reference-channel-before-pyprep-should-i-apply-average-reference-first/11957>\
**Category:** Support & Discussions\
**Tags:** preprocessing, eeg\
**Created:** [September 16, 2026, 12:40pm UTC](https://mne.discourse.group/t/adding-back-the-original-pz-reference-channel-before-pyprep-should-i-apply-average-reference-first/11957 "2026-09-16T12:40:47Z")\
**Posts on this page:** 1\
**Showing post:** 6

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**Author:** ![cbrnr](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/cbrnr/32/1409_2.png) [@cbrnr](https://mne.discourse.group/u/cbrnr)\
**Post date:** [October 7, 2026, 5:37am UTC](https://mne.discourse.group/t/adding-back-the-original-pz-reference-channel-before-pyprep-should-i-apply-average-reference-first/11957/6 "2026-10-07T05:37:28Z")

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I think PyPREP and ICALabel should catch most large artifacts, and smaller artifacts should normally not matter in such a large dataset (if one missed artifact changes the outcome, something’s wrong with the analysis anyway). If you really want to make sure you are not missing anything, I don’t think there’s an alternative to manually reviewing the data – at least that’s what I am still doing, and having automated artifact annotations as a starting point makes that process reasonably fast. If you want more automated tools, you could take a look at [autoreject — autoreject 0.5.1 documentation](https://autoreject.github.io/stable/index.html), but I doubt it will add anything substantial if you’re already using PyPREP/ICALabel, so I wouldn’t really recommend it.

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