Dear Dirk,
> I'm looking for a good method to assess laterality effects (e.g.
> right/left frontal cortex) with the data accessible in SPM99. Does a
> right/left comparison of z-values in a random effects group statistic
> allow inferences about laterality or have individual subjects z-values
> be entered in a statistical evaluation. And if that is so: how? Thanks
> for your comments
To implement a second-level analysis of laterality effects you can
simply flip the subject-specific contrast images across the midline and
use a paired t test in basic designs to look at the contrast x
hemisphere differences (c.f. interaction at the first level) by
entering the nonflipped and flipped images as two groups.
I hope this helps - Karl
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