Sorry, maybe a little misleading in my previous email. I did include
the subject terms in the model.
So the actually contrasts are: [zeros(subject number) 1 0 0],
[zeros(subject number) 0 1 0],
and [zeros(subject number) 0 0 1] each for A1>A2, B1>B2, and C1>C2.
Thanks,
Sheng
2010/12/2 MCLAREN, Donald <[log in to unmask]>:
> You need to include subject terms in each contrast as subject should be a
> factor in your model.
>
> Best Regards, Donald McLaren
> =================
> D.G. McLaren, Ph.D.
> Postdoctoral Research Fellow, GRECC, Bedford VA
> Research Fellow, Department of Neurology, Massachusetts General Hospital and
> Harvard Medical School
> Office: (773) 406-2464
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> On Thu, Dec 2, 2010 at 12:24 PM, sheng zhang <[log in to unmask]> wrote:
>>
>> Dear all,
>>
>> Does someone know how to apply a second level conjunction analysis
>> across subjects?
>>
>> From previous emails, one way seems to use flexible factorial
>> analysis. Let's say I have con_A.img, con_B.img, and con_C.img each
>> for A1>A2, B1>B2, and C1>C2 under subject level. So the idea is to
>> build a flexible factorial model with subjects and 3 conditions each
>> for con_A, con_B, and con_C. And then set contrast [1 0 0], [0 1 0],
>> and [0 0 1] to get activation each for A1>A2, B1>B2, and C1>C2, and
>> finally select all three contrasts to do conjunction of A1>A2 and
>> B1>B2 and C1>C2.
>>
>> But, spm do not allow to set a contrast as [1 0 0] or [0 1 0] or [0 0
>> 1] for this flexible factorial model, which might because there is no
>> "baseline". So, how should I do to get the second level conjunction of
>> A1>A2 and B1>B2 and C1>C2?
>>
>> Thanks,
>> --
>> Sheng Zhang
>
>
--
Sheng Zhang
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