Dear Johann,
> In SPM 99, it seems to be percent change of signal, is this correct ? But what is 100 % then, is it the mean value of the voxel across all sessions after normalization for global changes (I used "scaling" to normalize) ?
> Could anyone explain, please ?
100% means the estimated global intracortical mean of an image. I
faintly remember that there were some emails on the list concerning this
issue, please try and search for
'% signal change' on http://www.jiscmail.ac.uk/cgi-bin/wa.exe?S1=spm
Stefan
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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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