Hello,
            Is the mask binary? If not you may want to binarise to see if that changes anything.

Hope this helps
Matthew

> Dear all,
>
> to follow up on the issue, the log file doesn't mention any error. The program simply doesn't move on when it reaches 'Starting PCA' with no error information. There is no problem when there's no masking involved.
>
> I tried a few different things, but unfortunately the same thing kept happening. I used a different installation of FSL on another machine, but the results were the same. I also tried to do the masking myself and inputted already masked images without implementing the mask command in melodic, but the result was also the same.
>
> The mask is that of a component already outputted by the analysis on the same data. I am trying to find subcomponents of a specific component. It is of course non-contiguous, so I don't know if this has anything to do with it.
>
> The command that I implement is the following:
>
> melodic -i [name of input files separated by commas] -o Group_ICA -a concat --tr=2 --Ostats --report --mmthresh=5 .
>
> I would really appreciate your help on this issue. Or if there's any other possible way to get subcomponents of a component.
>
> Best regards,
>
> George