Dear Patrick
You should really ask these questions to the AFNI mailing list :-)
Best
Torben
Den 02/08/2010 kl. 22.06 skrev Patrick Pruitt:
> Hi all,
>
> I'm interested in running AlphaSim to calculate minimum cluster sizes
> for ROIs within my SPM analyses to reach a corrected significance
> level of p < .05. For example, I have the results of a group analysis
> and would like to have cluster thresholds for my regions of interest
> (dPFC, amygdala). A few questions for those who use AlphaSim:
>
> When calculating FWHM (using 3dFWHMx):
> - What is the dataset (i.e. -input or -dset)? That is, what does it
> represent and how do I get it from my SPM results?
> - If I'm interested in minimum cluster size for a particular ROI,
> should I calculate FWHM specifically for that ROI, or whole-brain?
> - Should the mask be anatomically-based (i.e. binary) or
> functionally-based (with significance values for each voxel)? Again,
> how would I get this in SPM?
> - Is 3dcopy an ok way to convert the dataset/mask from Analyze to AFNI format?
> - Do I need any parameters other than -dset and -mask?
>
> When running AlphaSim:
> - Can/should the same ROI mask that was used for calculating FWHM be
> used to threshold the AlphaSim analysis?
> - Given that when using a mask AlphaSim takes the dimensions and voxel
> sizes from the mask, is any consideration given to the native space
> dimensions/voxel sizes?
>
> I have AFNI up and running; I just want to make sure I'm using the
> proper inputs.
>
> Thanks!
> Patrick
|