That worked -thanks!
You're answer raised another issue for me. I'm still trying to understand how thresholding is achieved in FEAT. Let me see if I understand...
For voxel-based thresholding, is each voxel treated independently?
Is the corrected p-value set by the user corrected according to GRF theory (eg., if I set the value to .05, the threshold is corresponds to a GRF corrected .05. In this case, is there any way of determining what the actual threshold is?
For cluster-based thresholding, are the voxels smoothed according to the FWHM set in the pre-stats tab of the FEAT GUI? Thus, for eg., if the FWHM is 5mm then the stats are run on clusters of 5 or more contiguous voxels?
What do the Z values and p values represent in cluster based thresholding, and are there any rules of thumb for determining what the appropriate values for these are?
Once again, many thanks for your assistance,
Alex
-----Original Message-----
From: Andreas Bartsch [mailto:[log in to unmask]]
Sent: Monday, December 20, 2004 8:01 PM
To: [log in to unmask]
Subject: [FSL] AW: [FSL] Timeseries in FSL view
Hi Alex,
ok - this one is easy:
Load the 4D-file (e.g., filtered_func_data) into FSLView. The selected file appears in the lower box on the left. Once you have loaded the stats image (e.g., thresh_zstat1) you need to select the 4D-file in the box again to view the time series. I assume you had the stats image selected (which is 3D), so you could not access the time series of the 4D file.
And yes - all clusters surviving the threshold are listed. But note that are always some stipulations involved in defining what is regarded as a cluster (which depend on the precise approach chosen). To define contiguous clusters, FEAT applies an initial Z-threshold you choose.
Best regards-
Andreas
-----Ursprüngliche Nachricht-----
Von: Alex Fornito [mailto:[log in to unmask]]
Gesendet: Mo 20.12.2004 03:39
An: [log in to unmask]
Cc:
Betreff: [FSL] Timeseries in FSL view
Hi,
I'm having trouble accessing timeseries data in FSL view.
I load the 4D image, and add the thresh_zstat image for the contrast of
interest. The stat image gets overlaid on the 4D image, but I am uable o
select "Timeseries" from the "View" menu. Am I missing something?
Also, as an aside, in the report.html page, do the cluster lists obtaine
by clicking on a contrast image represent an exhaustive list of all
clusters that syurvived thresholding?
Many thanks for your help,
Alex
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