Hello,
We are using TBSS to look for voxel-wise correlations between FA and test
scores. Could you please answer the following questions for us?
1) Using the GLM tool, we specificy 1 covariate and provide values for each
of 10 subjects in the EV tab. Then in the contrast tab, we specify 2
contrasts (1 and -1)
2) The output is a t statistic image. We were exepcting an r statistic map.
Does FSL calculate the t from the r?
3) Will the "1" contrast yield positive correlations and the "-1" contrast
yield negative correlations?
4) The t statistic values are very, very large. We only get reasonbable maps
when we threshold at t>20. Do you know why this might be?
5) Is there a way to threshold the map based on p-values rather than t
statistics?
Thank you very much for your assistance.
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