Dear Luca,
> here a couple of general questions regarding interpretation of SPM results:
>
> Is it allowed to compare the t-values in a single t-map?
> And between maps from different contrasts?
>
> To which extent should, in a single t-map, different t-values in different
> regions be interpreted?
> We may certainly say that different voxels showed different significance
> levels. But may we conclude that to those voxel with higher t a
> corresponding higher activation is associated? I do not think so...
You're right. A t-value is an expression that tells you something about
evidence with respect to an underlying activation, not the strength or
amplitude of the signal itself. You would then use some corrected
p-value to make your inference.
Stefan
--
Stefan Kiebel
Functional Imaging Laboratory
Wellcome Dept. of Cognitive Neurology
12 Queen Square
WC1N 3BG London, UK
Tel.: +44-(0)20-7833-7478
FAX : -7813-1420
email: [log in to unmask]
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