Clusterplot not highlighting clusters & average layout file

[Ingrid Nieuwenhuis]

Dear Manish,

You give a bit too few information to be able to figure out what could be
the problem with clusterplot. After calling clusterplot, clusterplot gives
information on which clusters it finds. Does the function find any clusters?
Does the .mask field of the structure that comes out of freqstatistics
contain any ones? Is everything else plotted normally? Do you get any errors
or warnings?

I'm not familiar with BESA layout files, but assuming that all layout files
are similar over subjects, I think it is fine to just use an individual
subject's layout file.

Hope this helps,
Best Ingrid


>   ---Original Message-----
> From: FieldTrip discussion list [mailto:FIELDTRIP at NIC.SURFNET.NL] On
> Behalf Of Manish Saggar
> Sent: Tuesday, May 12, 2009 10:17 AM
> To: FIELDTRIP at NIC.SURFNET.NL
> Subject: [FIELDTRIP] Clusterplot not highlighting clusters & average
> layout file
>
> All,
>
> I have a question regarding clusterplot function. I am doing a
> within-subject analysis.
> The experimental design that I have is as follows, there are three
> conditions C1, C2 and C3. Each condition is of 1 min duration (e.g.
> rest with eyes open for 1 min).
>
> Now I am comparing grandaverage of freq representation of a set of
> subjects for C2 with C1 etc. FreqStatistics is running just fine
> creating significant (<0.025 alpha, for 2-tailed test) clusters
> (positive). Now the problem is that when I try to plot the location of
> this cluster using clusterplot it doesn't show any highlighted
> channels. Any ideas why that is happening?
>
> Another question is that since I am using grandaverages of freq
> representation, what should I use for layout file (using BESA sfp file
> here). I have individual subject layout files. Currently I am just
> giving any file from one of the subjects. Since, I noticed that
> FreqStatistics finds a common minimum set of channels and then apply
> statistics on it. So do I need to average layout files for the subject
> group or is there any other way?
>
> Any help is much appreciated.
>
> Regards,
> Manish
>
> ----------------------------------
> 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. See also
> http://listserv.surfnet.nl/archives/fieldtrip.html and
> http://www.ru.nl/neuroimaging/fieldtrip.

----------------------------------
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. See also http://listserv.surfnet.nl/archives/fieldtrip.html and http://www.ru.nl/neuroimaging/fieldtrip.