Ryan,
OK, it was a bit perplexing, but I tried to come up with a possible
explanation. As far as I can gather from your previous e-mails, you have
two subjects which gave you the aforementioned error message. So, here
is what I think is happening.
For Subject A:
-FWE p<0.05 fails for BA 21, 22, & 39
-None p<0.01 works
-FWE p<0.05 works for BA 39 only
For this subject, the FWE correction is still too stringent to detect
activations in BA 21, 22, & 39. But if you narrow down the mask to BA 39
only, then the FWE correction is no longer so stringent, and you are
able to detect activations at FWE p<0.05.
For Subject B:
-FWE p<0.05 fails for BA 39 only
-FWE p<0.05 works for BA 21, 22, & 39
For this subject, strong activations are mainly in BA 21 & 22. There may
be some activations in BA 39, but not strong enough to be detected by
FWE p<0.05 threshold. However, if you extend your mask to include BA 21
& 22 in addition to BA 39, then the strong activations in BA 21 & 22 are
detected at FWE p<0.05 threshold.
I saw the SPM results you sent to the list earlier, but wasn't sure
which subject the results came from. It seemed to me that the mask
included BA 21, 22, & 39. The coordinates of the four significant peaks
(voxel-level FWE p<0.05) are located in BA 21 & 22, according to
PickAtlas's Talairach demon function. So I guess the results came from
Subject B?
-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
|