Tom Holroyd holroydt at MAIL.NIH.GOV
Thu Aug 11 23:26:41 CEST 2005

Sanja Kovacevic wrote:
> I have a set of questions related to meginterpolate: Can CTF274.lay be used
> for ploting the planar data?

I don't know the answer to your question, but I would like to note
that CTF274.lay is based on the NIMH system which has one dead SQUID,
namely MRF43.  You might want to generate a CTF275.lay with that
channel replaced.  The meginterpolate code can actually "fix" dead
channels anyway...

> Should I use a default single sphere model for
> each subject or a single sphere model particular for a subject for
> realignment? Should "nominal" sensor locations be used as a template for
> each subject, or do you recommend taking an average across subjects for the
> template?

Oh, as long as I'm here:

Personally I wouldn't bother averaging across subjects, because even
"aligned", averaging subjects together in sensor space is nearly
meaningless.  (Though an interesting project, by analogy to Talairach
or MNI space, is to "warp" the sensor space data into a common space,
based on "anatomical" landmarks such as the peaks of the AEF and/or
SEF.  I still wouldn't do that, though.)

Dr. Tom Holroyd
"A man of genius makes no mistakes. His errors are volitional and
are the portals of discovery." -- James Joyce

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