preparing to used fat_mvm_scripter

Hi all,
I’m a little unclear about a problem I’m having with I am also not sure whether it has been superseded by

In the former, I don’t get all of the ROIs (I get 3 ROI pairs, but I have 8 ROIs, so in theory, I’d have 28 pairs), but I don’t see any error messages. I did have to manually edit some of my *.grid files because they didn’t have ROI names (just numbers like 001), and maybe that’s part of the problem, but it seems unlikely.

The problem APPEARS to be related to cases where there are no tracts between region pairs, and in the study for which I’m analyzing data, not every subject has data for all pairs. Does the program require that for ROI pairs to be included, all subjects have to have tracts for the ROI pair? That is my guess.

When I use the latter, I get the message: ** ERROR: Wrong type of input here: need ‘lm2b.file_grid_netcc’

Any thoughts on how I can move ahead? At present, I’m using SPSS, and I’d rather not have to transform the files to be readable by that program
Best wishes,

Hi, Matt-

Sooo, I think the is still probably in beta mode, sorry about the confusion.

Re. you mention .grid files, so I assume we are talking about tractography outputs (from 3dTrackID). If you have 8 “target” ROIs input as your network to track, then you would indeed have 87/2 = 28 possible white matter connections between pairs of targets. In general, the brain is not wired with everything connected to everything, and so you would probably have <28 connections found, in practice.

Ummm, I’m curious about the namual editing of the *.grid files. That should not be necessary. If your “-netrois …” file input to 3dTrackID has labels, then those get passed along—that is a preferable way to go to avoid hiccups along the way (and the *.niml.tract files output will have those labels, too, for viewing in SUMA). Labels can be attached to a file with @MakeLabelTable, happy to discuss that separately. If you really have to put the labels into the *.grid files separately, we can discuss that—the format is pretty straightforward (but not preferred). Seeing the note about *.netcc strikes me as likely something being incorrect about how the labels have been entered.

What program for group analysis are you intending to run? 3dMVM? That was what was initially designed to help run things for, and that program’s assumptions didn’t allow for having missing data at a tract. So the program takes your set of *.grid files and purposefully extracts connections that exist across all subjects.

If you are aiming to run something like Gang’s newer Bayesian group analysis programs, then having missing connections can be handled. You should be able to use this option in then:

-u, --unionize_rois        :mainly for GRID files (shouldn't affect
                                  NETCC files)-- instead of making the ROI
                                  list by taking the *intersection* of all
                                  nonzero-regions in the matrix, make the
                                  list as the *union* of elements across the 
                                  group. In this case, there will likely be 
                                  some zeros in properties, where there were
                                  no tracts found, and the assumption would be
                                  that those zeros are meaningful quantities
                                  in your modeling (likely only for special 
                                  purposes).  Choose wisely!

… to get the union of connections or *.grid file matrix elements (not the intersection, as is default). Is that applicable for you?

The languishing is meant to be a more general and nicer-interfaced program for all of this. That should be finished soome day…


ps: to check your editing of the *.grid files, this is what the top of a “labelled” grid file output would look like, where the labels here are boring strings “001”, “002”, “003”, etc. Basically, having the number of labels match the number of ROIs is important, as is having the “# WITH_ROI_LABELS” string in Line 3:

# 8  # Number of network ROIs
# 9  # Number of grid matrices
        001 	        002 	        003 	        004 	        005 	        006 	        007 	         008
          1 	          2 	          3 	          4 	          5 	          6 	          7 	           8
# NT
       28138	           0	          19	           0	        1654	           6	           0	           0

… with the rest of the NT matrix provided in the next rows, etc.