Ryan,
> I am getting an error message when masking for area 39, which I have
> attached. I am using pickatlas 2.1 to create the mask. For this
subject I
> am masking for areas 21, 22, and 39. When I do FWE @ 0.05 I get the
error
> message (and when I do FWE @ 0.20); however, when I choose none @ 0.01
I
> do not get the error. For this subject,when I mask for area 39 alone,
the
> analysis works with FWE @ 0.05. But with other patients, I get a
similar
> error for 39 alone, but not when in conjunction with 21 and 22. Any
help
> in understanding why I am getting this message and how to fix it would
be
> appreciated.
I saw the error message you sent, and I suspect you got the message
because no voxel within your mask survived the FWE p<0.05 (or p<0.20)
threshold. Look at the first error in the series of errors you got (for
spm_Tcdf function). This error occurs when NaN is passed onto this
spm_Tcdf function, which probably means no T-value exists within your
mask, which probably means no voxel survived your threshold. One way to
check this is to threshold with p<0.01 uncorrected, and take a look at
the FWE p-values on your results. If no voxel has an FWE p-value of 0.05
or smaller, then that means no voxel survived the FWE p<0.05 threshold.
You get the same error message for some subjects but not the others,
probably because some subjects have some voxels surviving within the
mask while the other subjects don't.
Hope this helps!
-Satoru
Satoru Hayasaka PhD ----------
Assistant Professor, Public Health Sciences & Radiology
Wake Forest University School of Medicine
(ph) +1-336-716-8504 / (fax) +1-336-716-0798
(email) shayasak _at_ wfubmc _dot_ edu
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