Hi,
there is no clear-cut answer as to when it is preferable to create your
own priors, other than "more is better". However, you may want to check
Figures 6, 7, and 8 in https://doi.org/10.3389/fncom.2017.00005 where we
did some simulations to explore this. Bottom line was that the quality
of the GM and WM templates increased by adding more subject well beyond
the several hundreds. Whether either approach changes your results
perceptibly, or importantly, will only be answered by trying both.
With regard to the other question, there is a clear-cut answer: you
should always use all your subjects to create your own template as you
will otherwise bias your data processing. The alternative, as you
mentioned, is using an external template to which none of your subjects
contributed.
Cheers
Marko
Ozkan schrieb:
> Dear SPMusers,
> I have 75HC and 100 disease data (for adults not children). I am confused with either i use DARTEL existing template from 555 HCs or create my own templates? Does it change the results importantly?
> Additionally, if I create Templates, should I create template by using all healty and disease data together and create one template for both of them or create one template for HCs (by using only HCs data as input) and another template for diseases(by using only disease data)?
> For existing template case, it is created by using only 555 healty controls and it is used both for healty controls and diseases.
> I would appreciate your help a lot.
> Thank you in advance
> Ozkan
>
--
____________________________________________________
Prof. Dr. med. Marko Wilke
Facharzt für Kinder- und Jugendmedizin
Leiter, Experimentelle Pädiatrische Neurobildgebung
Oberarzt der Abteilung Neuropädiatrie
Universitäts-Kinderklinik
Marko Wilke, MD, PhD
Pediatrician
Head, Experimental Pediatric Neuroimaging
Consultant in Pediatric Neurology
University Children's Hospital
Hoppe-Seyler-Str. 1
D - 72076 Tübingen, Germany
Tel. +49 7071 29-83416
Fax +49 7071 29-5473
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http://www.medizin.uni-tuebingen.de/kinder/epn/
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