...
The output of randomise are statistic, p value, and corrected p value files, for each contrast. The contrasts to which statistics files correspond are indicated by numbers, e.g., *_tstat1 (or _fstat1), *_tstat2, *_tstat3, and so on. For a two-group design matrix, you will typically have four contrasts; these are listed in the *.con text file created when you create the design matrix with the Glm GUI. Below is an example:
...
[user@localhost temp]$ /usr/local/fsl/bin/first3Dview L_Hipp_vertexMNI_2sample_mask.nii.gz L_Hipp_vertexMNI_2sample_rand_tfceclustere_pcorrp_tstat1fstat1.nii.gz
Note: FSLView uses radiological convention, so left on right as in the above example.
...