# pia surface outside of head after mne\_watershed and forward model

**URL:** <https://mne.discourse.group/t/pia-surface-outside-of-head-after-mne-watershed-and-forward-model/505>\
**Category:** Mailing List Archive (read-only)\
**Tags:** list-archive\
**Created:** [November 7, 2012, 11:26pm UTC](https://mne.discourse.group/t/pia-surface-outside-of-head-after-mne-watershed-and-forward-model/505 "2012-11-07T23:26:59Z")\
**Posts on this page:** 1\
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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [November 7, 2012, 11:26pm UTC](https://mne.discourse.group/t/pia-surface-outside-of-head-after-mne-watershed-and-forward-model/505/1 "2012-11-07T23:26:59Z")

</div>

Dear experts,

I have a problem with the mne\_wathershed\_bem procedure. I got the data  
out of freesurfer and the looked ok, did mne\_watershed\_bem, setup the  
forward model but while checking the inner\_skull.surf file I saw, that  
it is actually outside of my head (it has some strange bulges on the  
top of the head). Using mne\_watershed\_bem --atlas reduced the bulg a  
little bit, but it was still there and it is not depending on whether I  
set up an 1 or 3 layer BEM. Can you help me in this issue?

If you want I can provide you with some screenshots. If you need  
further information, please tell me.

Thanks,  
Tim