Hi Doug,
For some reason, I no longer get an e-mail when you respond to my questions on the mailinglist, so until today I only saw the first response to this question (from Bruce).
Anyway, I get your point about smoothing and clusters but I guess showing a continuous cortical map with vertex values should be ok, right? The map itself is rather smooth and it's impossible to see the individual vertex in the figure, so we're basically saying "this region generally has about 0.8% reduction" (for instance).
Also, how much precision can I assume here? 0.004 mm^2 is not very much. These changes are apparently very consistent across subjects since most of the cortex shows significant change. But what if we find very consistent changes that are on the order of 0.000001 mm², which therefore become statistically significant? Is that beyond our level of precision here?
Thank you!
yours,
Lars M. Rimol, PhD Norwegian University of Science and Technology (NTNU) Trondheim, Norway