Dear SPM experts,
I have a question concerning the spatial normalization in SPM (5 and 8),
specifically the writing option to preserve the concentration or the
total amount.
From the SPM-help I understand that "preserve amount" means a
modulation of the image, ie. if the brain is shrinked the signal
increases there. However, I was wondering why or in which circumstances
I would choose the option NOT to modulate ("preserve concentration"),
especially because this is the default option. I guess that most VBM
studies use modulation, but what about fMRI and PET images?
Thank you in advance for your help,
Andreas.
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Andreas Hahn, MSc.
Functional Neuroimaging Group - PET & fMRI
Department of Psychiatry and Psychotherapy
Medical University of Vienna, Austria
Phone: +43 1 40400 3825
Email: [log in to unmask]
Web: http://www.meduniwien.ac.at/neuroimaging/
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