Apologies, but I can not be sure that I have understood what you are after. But it sounds like you have so far included in your first level analyses 3 EVs - 2 of which model 2 different error events and 1 of which models correct response events - and you carry these ups to the group level. Now you are also interested in including at the group level a covariate that models the number of correct response and errors that each subject made. If so, then take a look at:

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Dr Mark Woolrich

EPSRC Advanced Research Fellow University Research Lecturer

Oxford University Centre for Functional MRI of the Brain (FMRIB),

John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK.

Tel: (+44)1865-222782 Homepage: http://www.fmrib.ox.ac.uk/~woolrich

On 12 Jul 2007, at 03:47, Julius Fridriksson wrote:

Hi - I have a group of 11 subjects who were scanned using an event
related stimulus presentation. Including correct responses, the
participants also made five different error types during the task. I am
mainly interested in brain activity associated with correct responses as
well as two different types of these errors. I already used a tripled
t-test for this analysis. However, I would also like to be able to
include participants' number of correct responses and errors as a factor
of interest. That is, what are the areas the best predict a given error
type (or correct answer)? I am not sure how I would set this up in my
higher level analysis. Any suggestions would be greatly appreciated.
Thanks - Julius