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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Dear Lin,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>It could have multiple causes. Under the
assumption that the location of the sources is not different in pre and post,
only the power, the common filters can lead to better results, because you use
more data to construct the filters. Especially when you have a strong beta
decrease in post compared to pre (almost no power in post, much power in pre)
using the data in pre in the filters, can help to get better localization in
post. It all depends to a large degree on your data. To decide which result you
can trust, you could compare the results on source level, with the sensor
level.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I hope this helps,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Ingrid<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> FieldTrip
discussion list [mailto:FIELDTRIP@NIC.SURFNET.NL] <b><span style='font-weight:
bold'>On Behalf Of </span></b>??<br>
<b><span style='font-weight:bold'>Sent:</span></b> Monday, February 16, 2009
11:30 AM<br>
<b><span style='font-weight:bold'>To:</span></b> FIELDTRIP@NIC.SURFNET.NL<br>
<b><span style='font-weight:bold'>Subject:</span></b> [FIELDTRIP] common filter
in source analysis</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Dear all,<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>I'm trying to use beamforming to calculate the sources of beta
activities to the tutorial's data. I got very different results by using common
filter to pre and post (according to the event) conditions comparing
with the un-common filtered method.<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Do you have any idea why this happens? Thank you very much!<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Best,<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Lin<o:p></o:p></span></font></p>
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<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>----------------------------------<o:p></o:p></span></font></p>
<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>The aim
of this list is to facilitate the discussion between users of the FieldTrip
toolbox, to share experiences and to discuss new ideas for MEG and EEG
analysis.<o:p></o:p></span></font></p>
<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>http://listserv.surfnet.nl/archives/fieldtrip.html<o:p></o:p></span></font></p>
<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>http://www.ru.nl/fcdonders/fieldtrip/<o:p></o:p></span></font></p>
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<p>The aim of this list is to facilitate the discussion between users of the FieldTrip toolbox, to share experiences and to discuss new ideas for MEG and EEG analysis.</p>
<p> http://listserv.surfnet.nl/archives/fieldtrip.html</p>
<p> http://www.ru.nl/fcdonders/fieldtrip/</p>