Hi Steve,
Does the model look "right" when you are presented with the summary graphic?
I.e. do the responses appear with the correct gaps and offsets that
you specified in the model?
Cheers,
Jon.
In message <[log in to unmask]> FSL - FMRIB's Software
Library <[log in to unmask]> writes:
> Hi,
>
> Using FEAT, I have 3 EV's I want to model - Stimulus A (1 second duration)
> Stimulus B (1 second duration) and stimulus C (5 seconds duration)
>
> Stimuli A or B (randomised stimuli presentation, 20 stimuli each) is
> presented every 30 seconds beginning at timepoint zero i.e 0, 30 , 60.
>
> The third stimuli "C" is subject responses that I am not interested in but
> want to put in as a co-variate. "C" occurs every 30 seconds (40 in total)
> starting at 15 seconds: ie 15, 45, 75.
>
> When I put in these three conditions as EV's I get the rank deficiency
> message. However, when I code A and B as the same EV i.e simply one
> stimulus every 30 seconds for the duration of the experiment and still
> include "C" there isn't a problem. I don't understand why!? There are the
> same number of stimuli with the same ISI and duration, just coded together.
> Can someone explain?
>
> Many Thanks for your help,
>
> Steve.
>
--
Jonathan Brooks (Ph.D.) Research Assistant
PaIN Group, Department of Human Anatomy & Genetics
University of Oxford, South Parks Road, Oxford, OX1 3QX
tel: 01865 272156 fax: 01865 282675
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