John D. West wrote:
> I am currently running a multiple regression in SPM5 to find the a
> correlation between my image data and another value and have also
> included 2 covariates of no interest. Once I get the results I can
> extract the 1st eigenvariate for a cluster by using the VOI tool,
> but this (as far as I can tell) caluculates the 1st eigenvariate of
> the data not adjusted for the 2 covariates. Therefore, if I use
> the matlab corrcoef function I get an r and p value that is not
> representitive of the SPM results. Can anyone tell me how I can
> get the adjusted eigenvariate or suggest another way of getting the
> Pearson correlation coefficient for the 1st eigenvariate for a
> particular cluster?
Hi John,
I'm not sure how to get the adjusted eigenvariate, but can you use
Matlab's partialcorr instead of corrcoef? I think if you pass in your
two nuisance covariates as the Z matrix then you should get the
partial (Pearson's) correlation coefficient.
Hope that helps,
Ged.
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