Generate surrogate data error

Hi @Francois,

For data exploration, I have computed tPAC for an ROI for a small number of subjects and trials and I am facing a few issues.
The tPAC maps are computed for every vertex in the scout, I understand the reasons for doing this but when I add all the tPAC maps to process 1 to compute average I get a mean tPAC map for every subject, rather than one representative (mean) tPAC map across all the trials/subjects. How do I average them across subjects?

I have followed the following process -
tPAC maps (Full) in process 1 -> frequency -> time-resolved PAC -> Basic analysis of tPAC maps -> Mean (Over sources, use phase in averaging).

The second issue I have is with extracting comodulogram from tPAC maps.
When I run the process with the following parameters, I get an error (see below).
Method: All sources/channels together
Files: Extract one comodulogram from all files (interpolate the comodulogram selected)

** Error: [process_pac_comod] Frequency > Time-resolved Phase-Amplitude Coupling > Extracting comodulogram from tPAC maps
** Line 405: Index exceeds the number of array elements (0).
**
** Call stack:
** >process_pac_comod.m>Compute at 405
** >process_pac_comod.m>Run at 204
** >process_pac_comod.m at 39
** >bst_process.m>Run at 229
** >bst_process.m at 36
** >panel_process1.m>RunProcess at 151
** >panel_process1.m at 26
** >gui_brainstorm.m>CreateWindow/ProcessRun_Callback at 788
** >bst_call.m at 28
** >gui_brainstorm.m>@(h,ev)bst_call(@ProcessRun_Callback) at 312
**
**

And lastly, the surrogate tPAC - block resampling - version 3.4 is option is greyed out completely. How do I use this option?

Is there something that I am doing incorrectly here?
Thanks