density of source space

✉️ Mailing List Archive (read-only)
1

Hello MNE users,

Is there an upper limit to the density of a surface-based source space? I
tried to use '--ico 6' but end up with the following error (below). Any
comments are appreciated!

Thanks and best regards,
Pavan

Mapping lh canonical_spm -> ico (6) ...[done]
Source space vertex moved from 122918 to 122919 because of double occupation.
Source space vertex moved from 115207 to 115208 because of double occupation.
Source space vertex moved from 126414 to 126427 because of double occupation.
Source space vertex moved from 127512 to 128573 because of double occupation.
Source space vertex moved from 122931 to 122932 because of double occupation.
Source space vertex moved from 67868 to 67881 because of double occupation.
Source space vertex moved from 120280 to 121558 because of double occupation.
Source space vertex moved from 111346 to 111345 because of double occupation.
Source space vertex moved from 127458 to 127465 because of double occupation.
Source space vertex moved from 130733 to 130732 because of double occupation.
Source space vertex moved from 122893 to 122912 because of double occupation.
Source space vertex moved from 124127 to 125309 because of double occupation.
Source space vertex moved from 125309 to 125310 because of double occupation.
Source space vertex moved from 122914 to 122915 because of double occupation.
vertex 122915 is in the map multiple times.
Cannot continue
Source space creation failed
Temporary files removed.

2

Hi Pavan,

This is due to a safety check that MNE runs on the ico surfaces. You
can go all the way to 1mm spacing in the --spacing option (that is the
smallest spacing of FreeSurfer surfaces); however, with --ico you need
to pass that check. In my experience, I cannot get --ico to work
higher than 5 reliably. For much of my work I therefore use --spacing
1

HTH
D