Hi,
I have a couple of questions:
1)
In the Oxford Functional MRI book p 258 there is a formula for the F-statistic. This
makes sense; however, I'm unclear what the distribution is. That is, what are the
numerator and denominator degrees of freedom (it depends on both the number of
contrast vectors, and length of beta vector, true?)
subquestion: does flirt include just constant and first order beta values (no 2nd order
or higher level terms? is this set somewhere?)
2)
In the FEAT GUI under the Post-stats tab there is a field "Z threshold" and a field
"Cluster P threshold"
is "Z threshold" for individual voxels? (it doesn't make sense to be for cluster if there
is a separate, unlinked, field for clusters, that is, "Cluster P threshold")
thanks,
George
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