[caret-users] importing thresholded functional data

wolf zinke zinke at brain.uni-bremen.de
Thu Feb 25 03:16:21 CST 2010


Hi,

I am sorry for this naive an likely many time answered question, but a 
first search did not bring up any clear statement to this issue.

I use caret to view functional data on inflated monkey brains. The data 
was analysed with FSL on data oriented according to a coordinate system 
based on eye and ear bars, but the caret files use the 
anterior,posterior commisure, hence I apply a transformation to my 
thresholded functional data (z-values) including a trilinear 
interpolation. This of course lead to subthreshold values surrounding 
the patches, and reduced, more smooth values within patches. In the step 
of mapping the volume data to the surface I again apply 
interpolation/averaging of the z-values.

I am wondering now, if this is an accepted procedure and that the 
interpolation of statistical maps is in general not seen as a serious 
problem. Though the statistics of the maps are reduced and smeared, I 
doubt that this introduces a serious misplacement of the activation 
foci. However, I don't fell well to present the range of z-values as 
'z-values' anymore, because of the interpolation.

I am happy for any pointers regarding such issues.

thanks,
wolf




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