QUESTION

I have read your research paper "Voxel-wise meta-analysis of grey matter changes in obsessive-compulsive disorder",it's reported that"required abnormalities to be detected both in the slope and in one of the extremes of the regressor" in the meta-regression. Now if i found right ACC in the 0 and 1m0 map. Do the Z value of right ACC in the two maps need to be both posivite or negative (Z>0 or Z<0) if i want to report ACC as a regression result? Thank you for your help! forward to hear from you.

ANSWER

The Z does not need to be both positive or negative. Indeed, the following combinations might be expected in e.g. fMRI:
- Positive _0 and negative _1m0, meaning that the activation or hyperactivation is only or mostly found at _0.
- Negative _0 and positive _1m0, again meaning that the deactivation or hypoactivation is only or mostly found at _0.
- Positive _1m0 and _1, meaning that the activation or hyperactivation is only or mostly found at _1.
- Negative _1m0 and _1, meaning that the deactivation or hypoactivation is only or mostly found at _1.
- Positive _0 and negative _1m0 and _1, meaning that there's activation or hyperactivation at _0 and deactivation or hypoactivation at _1.
- Negative _0 and positive _1m0 and _1, meaning that there's deactivation or hypoactivation at _0 and activation or hyperactivation at _1.