On Thu, Jul 23, 2009 at 11:10 PM, Heather Collins<[log in to unmask]> wrote:
> Thanks, Liam!
>
> One question I want to address is "Where is the mean activation for all 4 of these
> conditions together?"
>
> For example, let's say the 4 conditions are all different types of face stimuli. I
> want to know where, on average, faces are activating.
>
> Would I then do the [1 1 1 1] contrast?
This will give the correct Z-statistic for the mean. But the contrast
image (COPE) will be the sum of activation. For the mean cope it
should be [0.25 0.25 0.25 0.25].
-Tom
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