Jie:
if you look at the batch script for fmri analysis click on multiple
conditions and scroll down the help text. Here is the summary
1) If you enter each condition by hand then the time and parametric
modulators are entered for each condition under the Condition subtree. (fmri
model spec-> data & design -> subject/session -> Conditions -> condition).
2) If you use the multiple conditions facility then the mat file will always
contain 3 variables (cell arrays) to specify the conditions (names, onsets
and durations). So as an example let's say you have 2 conditions, 5 events
per condition (onsets in seconds)
names{1} = 'rest';
names{2} = 'visual stimulus';
onsets{1} = [0 12 38 49 55];
onsets{2} = [9 18 25 34 42];
durations{1} = [0 0 0 0 0]; (or you can have just a single 0)
durations{2} = [0 0 0 0 0];
Let's say you want to model a quadratic time effect on the second condition
then include the cell array tmod
tmod{1} = []; (could also put in a 0 meaning no time modulation)
tmod{2} = 2;
If you wanted a parametric effect include a variable called pmod.
This is a structure array of cell arrays.
Let's say you want a linear (first order) parametric effect on the second
condition
pmod(2).name{1} = 'visstim-param';
pmod(2).param{1} = [1 1 2 3 5]; (this must be the same length as #onsets in
that condition)
pmod(2).poly{1} = 1; (i.e., first order).
If you wanted 2 parametric modulators on the second condition you include
the second one as follows
pmod(2).name{2} = 'another-modulator';
pmod(2).param{2} = [48 52 8 -43 -55];
pmod(2).poly{2} = 1;
and so on. Note that for the time modulator it is the cell index that
relates to the condition, while for the parametric modulator it is the
structure index that relates to the condition while the cell index relates
to the number of parametric modulators for that condition.
hth,
darren
> -----Original Message-----
> From: Jie Zhuang [mailto:[log in to unmask]]
> Sent: Friday, November 23, 2007 4:21 AM
> To: [log in to unmask]
> Subject: batch of multiple modulators per condition
>
> Dear Darren,
>
> According to Jan's email to the SPM mailing list, the problem
> of the batch of multiple modulators per condition has been
> solved by you.
> However, I still could not find the help text or other
> related information. Could you be kind to give me some tips?
> Thank you very much!
>
> Cheers,
> Jie
>
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