fmri｜SPM contrast manager

整理一下遇到的基础问题

问题1：batch建立的contrast manager 和 results建的contrast是一样的么？

是的，一样的
建立contrast的两种方法，一种点点点，一种通过batch。

1 通常的点点点：点击results，选择估计好的SPM.mat，出现下图，这种也是contrast manager（小窗标题），好处在于分析时，条件设置直观。

2 Batch editor：点击fmri menu - Batch - SPM - Stats - Contrast manager

batch的好处是可以保存成脚本，被试多的情况可以通过代码跑1st level。

但是输入Weights matrix时需要注意输入，可以在第一种点点点里验证一下输入的matrix是否是自己需要的。比如第一种方法里的F contrast在batch里需要输入的是:
[1 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1]
而result小窗输入的是：
1
0 0 0 0 0 0 0 1
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

问题2：虽然两种方法都生成smpF_001.nii，但是batch方法不生成2ed level需要的con_文件，生成的是ess_，二者性质相同么？

解：
…
he various images created by SPM can be summarized as follows (thanks to Tom Johnstone!):

beta_***.img: these are created during the estimation stage - i.e. the fitting of the model. There is one beta image per column of the design matrix. These are the parameter estimates of course, with the first ones corresponding to the variables of interest, the last one corresponding to the constant in the model.
con_***.img: these are created when calculating t-contrasts and correspond to weighted sums of the beta weights. The numbering of the contrast images corresponds to the number of the contrast created in the contrast manager
SPM{t} is computed by dividing the contrast image (con_***.img) by its standard error (a multiple of the square root of ResMS.img). The SPM{t} is saved as spmT_***.img.
ess_***.img: these are images of the extra sum of squares for the corresponding F-contrasts, corresponding to the con_*** images from a t-test.
参考链接：http://brainimaging.waisman.wisc.edu/~oakes/spm/spm_random_effects.html

batch 程序

results 窗口

也就是为什么生成的是ess，是因为F contrast，contrast manager 和 results点点点生成内容是一致的。如果contrast为t-test，则生成con***.nii 文件。【= = 】