Hi,
I am not sure if any of these papers can help you:
NeuroImage 15 (2002) 870-8
NeuroImage 22 (2004) 1203-13
NeuroImage 33 (2006) 599-608
J of Biopharmaceutical Statistics 13(4) (2003) 675-89
In any case, if there is a good reason for selecting some specific areas
and by doing a small volume correction or a mask the activation in these
area survive an FWE correction I would probably say that, and I would
clarify in the paper (maybe in the discussion) that even though FWE is
more powerful, it is nonetheless a less sensitive correction, so even
though the data corrected with FDR might be interpreted more as
"suggestions" than 100% sure activations, the fact that the results are
highly informative make your findings interesting, even if more work is
necessary to derive a more sure interpretation.
The other option is to increase the number of subjects in the study, I
suppose.
In any case, me too I find it disturbing, especially after reading so
many papers in wich it is only mentioned that the data "have been
corrected for multiple comparison", without mentioning at all with wich
correction.
And especially when in some cases the results are not even corrected for
multiple comparison.
Best,
Laura
-----Original Message-----
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]]
On Behalf Of Doug Burman
Sent: 08 October 2007 14:53
To: [log in to unmask]
Subject: [SPM] FDR correction
I have an article that has been reviewed where the only major complaint
was that the reviewer would not accept the results as valid because we
used a FDR correction (p=0.05) -- even though our cluster sizes were
fairly large, we also used an extent threshold of 25, and our Z-scores
were generally greater than 5.0. The editor is backing him up, and
refuses to publish our findings unless we satisfy him that our "result
is
not a chance finding".
Many of our primary findings would survive a FWE correction if we
applied
a mask. I find it disturbing, however, that a FDR correction is not
considered an acceptable method for multiple-comparisons correction by
this reviewer / editor, and some highly-informative brain / behavior
correlations in our study require this correction. Any suggestions on
articles and explanations on the validity of the FDR approach?
(I know this has been discussed on the list before, but I suspect the
listserv discussion will not in itself satisfy the editor.)
Doug Burman
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