Hello all,
I am attempting to export source-space data as a nifti file. The LCMV computation was done in volume space, using a 4x4x4mm grid. The data is then projected to a source grid. I noticed that whenever I perform the volume export function, the data is interpolated down to 1x1x1mm.
My question here is: is it possible to export my volume source-space data without performing any interpolation? In other words, can I export the data as it appears in the source grid, with the same spatial resolution?
Any advice here would be appreciated.
can I export the data as it appears in the source grid, with the same spatial resolution?
No, you can't. The grid of source space is defined as an arbitrary cloud of points, aligned in SCS space, corresponding to the GridLoc field of your head model.
Exporting the source maps as a .nii file produces a volume that matches the properties of the T1 MRI volume imported in the subject anatomy.
These are two different way of representing information, there has to be some form of interpolation between the two: the grid must be interpolated onto the volume (= the voxels).
In most cases, a resolution of 1x1x1mm is not necessary to represent the spatial resolution of the estimated source maps. In the export process, you can increase to 4 the "Volume downsample factor" to create a volume with a 4x4x4mm voxel size.