[FieldTrip] ft_sourceinterpolate

[RICHARDS, JOHN]

We are trying to use ft_sourceinterpolate.

1--We have a tetra source model, do source analysis with eLORETA, ERP data, etc.  The source model is based on a tetrahedral mesh on gm rather than a hex mesh.

2--We have a 1mm hex mesh on gm

3--The goal is to interpolate the "sparse" tetra mesh with the functional data, onto the 1 mm hex mesh, in order to create MRI volumes with the activation.

4--The ft_sourceinterpolate(cfg,sourcewithtetrameash,hex1mmmesh) does not work.  It does not result in the same no of "inside" voxels as the 1mm hex mesh

e.g., like 25K voxels in the tetra, 855K in the 1 mm grid, but only 15K voxels in the interpout.inside(:).

Alternatively
1--using a 3 mm hex mesh, source analysis, the source model is based on a 3 mm hex mesh on gm.
2--1mm hex
3--same goal
4--ft_sourceinterpolate(cfg,sourcewith3mmhexmesh,hex1mmmesh) works.  It has 855K voxels in the interpout.inside(:).  It also correctly saves to the gm of the MRI volume.


Any ideas on this?
We have tried int32(pos) on both tetra3mm ahd hex1mm; used only overlapping  tetra3mm and hex1mm voxels; etc

John


***********************************************
John E. Richards
Carolina Distinguished Professor
Department of Psychology
University of South Carolina
Columbia, SC  29208
Dept Phone: 803 777 2079
Fax: 803 777 9558
Email: richards-john at sc.edu
https://jerlab.sc.edu
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