Rik,
I also thought that SSSt removed artifacts from the data time step by
time step (using a specific interval, e.g., a 4s window).
How could this information be summarized in a single projection matrix?
Max
Rik Henson wrote:
> Burkhard -
>
> I thought so too, but another colleague thought this was not the case.
> So if the Neuromag experts don't give the definite answer, we could
> have a vote?
>
> ;-)
> Rik
>
> Burkhard Maess wrote:
>> Hi Rik,
>>
>> this is an interesting question - but I think the temporal projection
>> does not modify the spatially organized leadfield. SSSt takes out the
>> part of the data which correllates highly between both expansions,
>> but you can not describe it by a certain spatial pattern as in the
>> case of the SSP.
>>
>> Cheers,
>> Burkhard
>>
>>
>> Rik Henson wrote:
>>> Dear Neuromeg -
>>>
>>> Could you let me know how I can correct my leadfields for prior
>>> SSSt? In other words, I have a leadfield matrix, L, of n sensors x p
>>> sources, and would like to extract some form of projection matrix
>>> from Maxfilter that I can apply to L in order to remove those
>>> components of the sensor data that have been removed by SSSt.
>>>
>>> Many thanks
>>> Rik
>>>
>>
>
--
Max Garagnani, PhD
MRC - Cognition and Brain Sciences Unit
15 Chaucer Rd., Cambridge - CB2 7EF
U.K.
http://www.mrc-cbu.cam.ac.uk/people/max.garagnani/
Tel. +44 1223 355294 (ext. 290)
Fax: +44 1223 359062
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