Dear Bruce etal,
Let's say we have a list of Talairach coordinates from a database of fMRI results, in a text file. Can we create a tcl script to read those values and then find the nearest surface point for any subject to each xyz Talairach value? The tcl script should just return a list of vertex indices for each Talairach coordinate. Even better would be a small patch for each Talairach coordinate, based on growing from the nearest vertex found. Matlab has a function called dsearchn and Alex Wade sent me some useful c code for the same process, do you have something like that in the tcl commands? This tcl command below looks related, but it's not clear what it will do when the x y z values do not fall precisely on a vertex.
/select_talairach_point/ /*x y z*/
Takes the given talairach coordinate, writes it to the /edit.dat/ file, and then sets the cursor to that point. *x* *y* and *z* are floating point talairach values.
Best, Darren
freesurfer@nmr.mgh.harvard.edu