Hi Fatima.
We just did this ourselves in SPM5 where it is very easy to do. The
full factorial design in that program lets you do exactly what you just
described. You can specify two factors where in one of which the levels
are independent and one in which they are not.
Unfortunately, I am not sure how you can do this in SPM2.
-John
-----Original Message-----
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]]
On Behalf Of FATIMA HUSAIN
Sent: Tuesday, May 01, 2007 2:29 PM
To: [log in to unmask]
Subject: [SPM] Mixed ANOVA in SPM2
I am trying to do a within-subject (task1, task2) and between-subjects
(patients, controls) ANOVA in SPM2. Because of the mixed design, none of
the standard options in SPM2 basic models work. The problem is that you
need non-sphericity correction for the within-subject factor and not for
the between-subject one. The number of patients is also fewer than
controls.
Has anyone had success doing mixed ANOVAs in SPM2?
I see on the archives several work-arounds were posted. Has anyone
published results using any of these alternative methods?
I tried using Rik Henson's batch script for mixed ANOVA design (posted
in
2005, same errors with Thilo Kellermann's script) but ran into errors,
pasted below.
Any help is most appreciated!
Fatima Husain
p.s. Thanks to everyone for the helpful book suggestions.
--------------------------------------------------------------
>> batch_mixed_anova
SPM2: spm_spm (v2.66) 12:36:28 - 01/05/2007
========================================================================
Initialising parameters : ...done
...initialised
Plane 69/69 , block 3/3 : ...done
Temporal non-sphericity (over voxels) : ...REML estimation
ReML Iteration : 1
...2.281850e+02
SPM2: spm_spm (v2.66) 12:36:37 - 01/05/2007
========================================================================
Initialising parameters : ...computing
s =
(1,1) 3.3174
(2,2) 3.3174
(3,3) 3.3174
(4,4) 3.3174
(5,5) 3.3174
(6,6) 3.3174
(7,7) 3.3174
(8,8) 3.3174
(9,9) 2.6825
(10,10) 2.6825
(11,11) 2.6825
(12,12) 2.6825
(13,13) 2.6825
(14,14) 2.6825
(15,15) 2.6825
(16,16) 2.6825
??? Index exceeds matrix dimensions.
Error in ==> spdiags at 114
a((len(k)+1):len(k+1),:) = [i i+d(k) B(i+(m>=n)*d(k),k)];
Error in ==> spm_spm at 421
s = spdiags(1./sqrt(diag(s)),0,nScan,nScan);
Error in ==> spm_spm at 830
SPM = spm_spm(SPM);
Error in ==> batch_mixed_anova at 158
SPM = spm_spm(SPM);
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