We are analyzing data from a bloc design fMRI study (2 condtitions A,B and
baseline C). We had 13 subjects. We showed the stimuli as [C A B C A B C A
B] for 7 subjects and [C B A C B A C B A] for the other 6 subjects.
Contrasts at the first level analysis were computed as follows:
Con_0003.img was computed as A-C for both subject specification [-1 1 0]
for 7 subjects and [-1 0 1] for the other 6 subjects.
Con_0004.img was computed as B-C for both subject specification [-1 0 1]
for 7 subjects and [-1 1 0] for the other 6 subjects.
Con_0005.img was computed as A-B for both subject specification [ 0 1 -1]
for 7 subjects and [0 –1 1] for the other 6 subjects.
We are interested in the contrasts: (A-C)>(B-C)
So we do the contrasts at the second level analysis as follows:
1. We select 13 Con_0003.img files of all the subjects and then 13
Con_0004.img files for all the subjects.
2. We specify the "group? " input as 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2
2 2 2 2 2 2 2 2 2 2
Our question is to compute the (A-C)>(B-C) what should we contrast specify?
Is it [ 1 –1 0] ?
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