# Average referencing eeg data

**URL:** <https://mne.discourse.group/t/average-referencing-eeg-data/3136>\
**Category:** Support & Discussions\
**Tags:** eeg\
**Created:** [May 13, 2021, 7:03pm UTC](https://mne.discourse.group/t/average-referencing-eeg-data/3136 "2021-05-13T19:03:06Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![apoorva6262](https://avatars.discourse-cdn.com/v4/letter/a/c6cbf5/32.png) [@apoorva6262](https://mne.discourse.group/u/apoorva6262)\
**Post date:** [May 13, 2021, 7:03pm UTC](https://mne.discourse.group/t/average-referencing-eeg-data/3136/1 "2021-05-13T19:03:06Z")

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Hi,

With my eeg dataset, I marked a few channels as “bad channels” after loading it and then performed average referencing. I just wanted to check if average referencing accounts for the bad channels and excludes them when referencing.

````python
raw=mne.io.read_raw_eeglab(filename) 

--- output----Channels marked as bad: ['F4', 'CP4', 'FC2']

raw = raw.set_eeg_reference("average")```
````

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<div class="post-metadata">

**Author:** ![drammock](https://yyz2.discourse-cdn.com/free1/user_avatar/mne.discourse.group/drammock/32/4_2.png) [@drammock](https://mne.discourse.group/u/drammock)\
**Post date:** [May 13, 2021, 9:03pm UTC](https://mne.discourse.group/t/average-referencing-eeg-data/3136/2 "2021-05-13T21:03:43Z")

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Bad channels are ignored when setting EEG reference. Quoting [the EEG referencing tutorial](https://mne.tools/stable/auto_tutorials/preprocessing/55_setting_eeg_reference.html#setting-or-changing-the-reference-channel):

> Notice also that `EEG 053` (which is marked as “bad” in `raw.info['bads']` ) is not affected by the re-referencing.