Hi,
I would treat this as a 3-level design, with a separate second level
FE analysis for each subject, doing within-subject, cross-session
(cross-condition) contrasts. The third level ME would then be cross-
subject group-mean averages of the contrasts achieved at second-level.
The second-level model would be simple: 5 'timepoints' in the data,
one EV per condition, (each containing a single 1 and 4 zeros) and
then yes, contrasts such as the linear one you suggested.
Cheers.
On 19 Feb 2009, at 15:55, Vishwadeep Ahluwalia wrote:
> Hi ,
> The same 12 subjects were scanned on 5 different days using a 5
> different
> Block paradigms.
> The block paradigms differed in the ISI and stimulus duration of
> stimuli
> within the On-block.
> How do i setup a design to contrast the 5 conditions? i also want to
> check
> for linear trend across the 5 conditions. Would the contrast be 2
> 1 0 -1 2
> for a linear decrease? how should i set up the model? Thanks
> -Vish
>
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Stephen M. Smith, Professor of Biomedical Engineering
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