> In the current LME model, effect of this Lable is significant: -gltLabel 6 after_before_in_anode_now -gltCode 6 'CiJi : 1*anode QainHou : 1*after -1*before Contrast3 : 1*now' \. That is to say, in the "anode" "now" condition, there was a significant difference between "after" and "before" conditions. Therefore, I tried to extract the data in the "anode" "now" condition for "after" and "before" condition separately, then data were fed into a paired t-test.
The proper way to do this is to add two more specifications:
-gltCode ... 'CiJi : 1*anode QainHou : 1*after Contrast3 : 1*now' \
-gltCode .. 'CiJi : 1*anode QainHou : 1*before Contrast3 : 1*now' \
Then combining with the original one -gltCode 6 'CiJi : 1*anode QainHou : 1*after -1*before Contrast3 : 1*now', you should be able to sort out the details. Similarly for the other contrasts in your 3dLME script.
> I guess one reason for 'not significant in the t-test, but significant in the LME' is that: in the LME, the model was modelling many effects, including interactions and main effects of 'CiJi', 'QainHou', 'Contrast3', and main effects of age, education. In contrast, in the t-test, these effects were not modelled. Is that correct?
You have other explanatory variables plus more factor levels in the LME model. In contrast, your paired t-test does not take those variables into consideration. These are two different models.
Gang
