First of all, thanks for all matlab scripts you made, which are really helpful.
I'm using y_GRF_Threshold.m to do a FSL-style cluster-extent thresholding in matlab. As far as I know, y_GRF_Threshold.m is a matlab version of "easythresh" in fsl. One interesting thing about the function was it has an option for one/two-tailed thresholding, because I've never heard about one/two-tailed approach in cluster-extent thresholding. If the option is turned on, the function is using cluster-defining threshold (i.e., voxel-wise height p value) divided by 2. Also it's using a half of corrected p value. Then, it calculates cluster extent size < the corrected p value.
Is this process same as easythresh is doing? That is, easythresh has the two-tailed option as well? The two-tailed and one-tailed could produce big differences in results, I think... However, actually, I cannot understand the reason of dividing a cluster-level p value by two. This is because, as far as I understand, we are using the distribution of maximum cluster size in one direction (i.e., whether the cluster extent size is "bigger" (not smaller) than p = .05 or not given the primary (cluster-defining) p value). So I'm curious to hear about your understanding of this. Any comments would be really appreciated!