Hi Jeanette,
On 9 May 2007, at 00:42, Jeanette Mumford wrote:
> Hello,
>
> I have a couple of questions about using featquery to calculate
> comparable copes and varcopes over an ROI.
>
> If I have an event related design with two tasks the EVS for these
> tasks could
> have very different ppheights, so if I had a cope for each of these
> tasks the featquery results for calculating % change of the 2 copes
> over an ROI would not be comparable unless I rescaled, correct?
Right - but this is easy to fix - just turn off the "convert to %"
button in Featquery!
> Is it
> easiest just to use avwmaths to undo the original ppheight scaling and
> apply the new scale (probably based on the min/max range of an
> isolated event)? For a group analysis is featquery averaging the
> ppheights over subjects? I'm assuming I could find the averaged
> ppheight in the featquery log somewhere.
>
> Second, when featquery is applied to varcopes does it use the ppheight
> at all or would I have to rescale that as well to make it comparable
> to the corresponding averaged cope?
Probably same answer is relevant here :)
Cheers.
>
> Thanks in advance,
> Jeanette
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Stephen M. Smith, Professor of Biomedical Engineering
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