Hi, yes this sounds good and I would also orthogonalise EV1 wrt 2.
Cheers
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Stephen M. Smith, Professor of Biomedical Engineering
Associate Director, Oxford University FMRIB Centre
FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
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On 27 Mar 2008, at 11:02, Egbert Hartstra <[log in to unmask]>
wrote:
> Dear fellow FSL users,
>
> I want to test which areas show a linear increase or linear decrease
> in activation in my task over a series of 16 trials. To this end I
> have modeled the bold response in EV1 as showing an increase in
> activation of one step on each trial (so for trial one I set the
> value in the third column in my EV file to 1, for trial two to 2,
> trial three to 3 and so on). I am not sure whether I should also
> model a constant for the same condition (that is, add EV2 with
> ‘1’ in my third column for all occurrences).
>
> Any advice will be greatly appreciated.
>
> With kind regards,
>
> Egbert Hartstra
>
> Phd student-Ghent University
>
> <egbert_hartstra.vcf>
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