Hello Brunno,
there certainly is a consensus that spatial smoothing, while decreasing
specificity, increases signal to noise. Usually, this is done on the raw
data (i.e., the fMRI images) before estimating the first level con maps.
However, you can also smooth the con maps before taking them to the
second level. Theoretically, these are linear operations so it should
not make a difference. In practice, it well might, which is likely due
to interpolation.
Cheers
Marko
Brunno M. Campos schrieb:
> Dear Experts,
>
> Quick question:
>
> Is there a consensus on smoothing the first level contrast maps before
> the second level analysis?
>
> Any reference?
>
> Thank you all!
>
> Brunno
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Prof. Dr. med. Marko Wilke
Facharzt für Kinder- und Jugendmedizin
Leiter, Experimentelle Pädiatrische Neurobildgebung
Universitäts-Kinderklinik
Abt. III (Neuropädiatrie)
Marko Wilke, MD, PhD
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Head, Experimental Pediatric Neuroimaging
University Children's Hospital
Dept. III (Pediatric Neurology)
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