Hi, FDR correction for multiple comparisons gives you different p-values for the left and right hemispheres. It seems really weird to report in a paper: a) that you've corrected for the right and left hemispheres separately and b) that the p-value that gave rise to a corrected probability of .05 was different for each. How do people deal with this issue? Take the most stringent p-value and use it for both hemispheres? Just report that FDR adjusted the p- value to .05?
Also, correcting for right and left hemispheres separately assumes that they are independent observations. Unless you're studying callosotomy patients (and maybe even if you are) this doesn't seem justified. Are we supposed to be adjusting p-values accordingly?
Thanks, Dara
Dara S. Manoach, Ph.D. Psychiatric Neuroimaging Massachusetts General Hospital Charlestown Navy Yard 149 13th Street, Room 2608 Charlestown, MA 02129 email: dara@nmr.mgh.harvard.edu phone: 617-724-6148 fax: 617-726-4078