[Mne_analysis] using inverse matrix from MNE

[Erik B Beall]

I've been given a more thorough understanding of MEG by John Mosher
and Rey Ramirez, who both patiently explained how the inverse solution
works in MEG and that I was asking crazy things.  Now that I know
better, I can ask slightly less crazy things next time that aren't
simple wastes of time (I certainly won't be doing the things I'd asked
for - they don't make any sense!).  Thanks,
erik

On Wed, May 19, 2010 at 9:23 PM, Erik B Beall <ebeall at gmail.com> wrote:
> Thanks Daniel.  We looked at the motion between runs, and it was
> minimal, although maybe we should try MaxMove anyway.  However, I
> don't see where this is an option in MNE, am I missing something?  MNE
> computes the inverse solution on the fly, and I dumped it to file, but
> I dont' know how to load it in other than using the matlab toolbox.
> The reason we want to do this is to look at the stability of the
> solution from one scan to the next.  So we could use the empty room
> noise covariance matrix, a resting state scan noise covar matrix,
> either of the two visual scans, or the average of the two visual
> scans, right?  For our first try, we wanted to just keep it simple and
> take the inverse operator for scan1 to scan 2 and see how similar the
> solution was.  Does that make sense?
> erik
>
> On Wed, May 19, 2010 at 8:45 PM, Daniel G. Wakeman <dgwakeman at gmail.com> wrote:
>> In this case, I believe you can use the inversion from the first run on the
>> second.
>> Simply, open the second run's average with the first runs inverse operator
>> ** in mne_analyze. This should work.
>>
>> **You should be aware of possible mislocalizations introduced doing this,
>> because the person's head will not be in exactly the same position. I would
>> recommend at least comparing the head positions between the two runs. If you
>> have maxfilter available, I would probably use this to transform the head
>> position.
>>
>> D
>>
>>
>> On 20 May 2010, at 01:02, Erik B Beall wrote:
>>
>>> yes, sorry, same subject, scans acquired in adjacent scans of same
>>> session.
>>> Erik
>>>
>>> On Wed, May 19, 2010 at 7:55 PM, Daniel G. Wakeman <dgwakeman at gmail.com>
>>> wrote:
>>>>
>>>> Hi Erik,
>>>>
>>>> Are these from the same participants & same recording session?
>>>>
>>>> D
>>>> On 20 May 2010, at 00:49, Erik B Beall wrote:
>>>>
>>>>> I have a question about using the inverse matrix computed using MEG
>>>>> data in MNE from a visual evoked experiment.  I have two scans, both
>>>>> visual evoked experiments, and I want to take the inverse matrix (and
>>>>> associated noise covariance matrix) computed during scan 1 and apply
>>>>> it to scan 2.  I don't think there is a way to do this using the
>>>>> compiled MNE, but I have been trying to use the matlab toolbox code to
>>>>> read in the matrices (forward solution, inverse matrix and noise
>>>>> covariance matrix) I've dumped from MNE run on scan 1.
>>>>>
>>>>> My question is, is there a way to apply the solution for scan 1 to
>>>>> scan 2's dataset?  Can I do this using the matlab toolbox or is there
>>>>> a way to do this using MNE itself?  Does anyone know of specific
>>>>> matlab commands from the MNE toolbox that
>>>>> would allow us to do this?  I had thought mne_read_inverse_operator.m
>>>>> was the right command to read it
>>>>> in, but I don't know how to use the matrix once read in.  Is there a
>>>>> toolbox command for
>>>>> applying it to the other dataset?  Thanks,
>>>>> Erik Beall
>>>>>
>>>>> _______________________________________________
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>>>>> Mne_analysis at nmr.mgh.harvard.edu
>>>>> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/mne_analysis
>>>>>
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>>>>
>>>
>>>
>>>
>>> --
>>> Erik Beall
>>> Cleveland Clinic
>>> U-15-Mellen Center
>>> Cleveland OH, 44195-0001
>>> 216-445-6110
>>>
>>> ebeall at gmail.com
>>
>>
>
>
>
> --
> Erik Beall
> Cleveland Clinic
> U-15-Mellen Center
> Cleveland OH, 44195-0001
> 216-445-6110
>
> ebeall at gmail.com
>



-- 
Erik Beall
Cleveland Clinic
U-15-Mellen Center
Cleveland OH, 44195-0001
216-445-6110

ebeall at gmail.com