Hi Peter,
Yes I think for your purposes it would be the latter (zeros(1:11) 1).
As Iwo pointed out, the "adjust data" option removes the null space of your F-contrast, i.e. the zeros, from your timeseries. See lines 143-153 in spm_regions.
Hope that helps
Steve
On 27 Aug 2011, at 19:11, Peter Michalsky wrote:
> Hello Iwo,
>
> first let me thank you for your reply. You understood correctly that I want to regress out all nuissance factors while extracting a time-series from a VOI. However, I also want to regress out the task variance (first two regressors in the design matrix). Hence, I want to regress out all 11 regressors and only keep the mean time-series. Do I do that by ones(1:11) zeros(12) or by zeros(1:11) ones(12). If I understood you correctly the correct solution should be to define an F-contrast with all zeros except for the constant (zeros(1:11) 1). Maybe you could explain to me why the opposite (ones(1:11) 0), which I thought would be right is wrong. Thanks again for your help.
>
> Peter
____________________________________
Stephen M. Fleming PhD
Wellcome Trust Postdoctoral Fellow
http://web.me.com/stephen_fleming/web/Welcome.html
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