Dear SPM mailing list,
we have conducted a study comparing 2 rare patients against 16 controls.
We have the same contrast (lets call it C) in all 18 subjects at the
first level. At the second level I performed a 2-sample t-test
(voxelwise) with 2 subjects in group 1 and 16 subjects in group 2. One
of the reviewers states:
Regarding the 2 sample t-test. I wonder if SPM2 is able to compare 2
subjects versus 16. I believe this is not the case and that one must
use a different methodology to make this comparison.
I would like to see a citation to a study that uses a similar approach
that might alleviate this concern.
Is anyone aware of other studies using a similar approach, or a comment
from the makers of SPM regarding this issue?
ck
--
* *
*Prof Christian Keysers, PhD
*Scientific director neuroimaging center
Professor for the neural basis of empathy
http://www.bcn-nic.nl/index_research_empathy.html
University Medical Center Groningen, University of Groningen
A. Deusinglaan 2, 9713AW Groningen, The Netherlands
Phone: +31 50 3638794, Fax: +31 50 3638875
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