Dear SPM experts,
I've got the same problem/question as the one that was posted here
yesterday:
The two different Dartel analysis pipelines yield different results. I
have attached a picture with the comparison of the con-images of one
subject (but there are also big differences on the group level). They
obviously differ in size and shape to a certain extent.
Which of the 2 methods would be "better" or more correct and what is the
reason for the different results? Could i have done something wrong with
the order of the preprocessing steps or statistical analysis? Should the
smoothing be before only afterwards, in both cases?
Thanks in advance
Robert Lech
Am 20.12.2011 11:29, schrieb Michel Dojat:
> Dear All,
>
> For group analysis, two possible pipelines can be used when using
> Dartel for registration:
>
> 1) individual statistical analysis in individual referentials for all
> subjects.
> Then, applying Dartel deformation fields to the individual contrasts
> to be in the common referential (Dartel template) and then RFX analysis.
> In this case, the smoothing is performed in the individual referential
> before individual analysis.
>
> 2) application of individual Dartel deformation fields to individual
> functional images. Then individual statistical analysis in the common
> referential.
> and then RFX analysis. Here the smoothing is performed after
> deformation field application (and before individual statistical
> analysis).
>
> The results obtained are different.
> What is the best way to proceed and for which reasons ?
>
> Thank for your answer
>
> Michel
>
--
Dipl.Psych. Robert Lech
Institute of Cognitive Neuroscience
Department of Neuropsychology
Ruhr-University Bochum
GAFO 05/611
Universitätsstraße 150
44801 Bochum, Germany
Phone: +49(0)234-3223175
Email: [log in to unmask]
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