Hi Eugene,
No demeaning?
Hope all is well.
Cheers-
Andreas
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Von: FSL - FMRIB's Software Library [[log in to unmask]] im Auftrag von Eugene Duff [[log in to unmask]]
Gesendet: Dienstag, 28. September 2010 10:44
An: [log in to unmask]
Betreff: Re: [FSL] paired t-test with behavioural correlates
Hi Patrick -
Yes, that's reasonable way to model a covariate in this design.
Regards,
Eugene
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On 28 September 2010 00:34, Patrick Thompson <[log in to unmask]<mailto:[log in to unmask]>> wrote:
Hi All,
I have a question on statistics. I have scanned (perfusion scan) multiple subjects with each subject scanned twice (before treatment-after treatment). I am interested in looking for a difference between two scan session and any correlation with behavioural changes. I know, I need to conduct a paired t-test. However, I am just wondering on how to include other behavioural measures including average reaction time etc in the paired t-test model.
For example, if I have two subjects scanned under two conditions A and B, is this the right design matrix with RT as a covariate of interest.
A>B S1 S2 RT
1 1 0 0.3
-1 1 0 0.1
1 0 1 0.5
-1 0 1 0.2
contrast A>B 1 0 0 0
contrast B>A -1 0 0 0
RT>0 0 0 0 1
RT<0 0 0 0 -1
Can I include other covariates (that are not correlated) in this model ?
Regards,
Pat
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