Hi,
We are experimenting with statistical methods for analyzing cortical thickness differences in a case/control study. After doing the cortical reconstructions and running mris_glm, we will have the significance (p-value) of the t-ratio of the contrast between case and control. What we want to do is first apply some spatial smoothing to the p-values, and use a false discovery rate controlling method on the resulting smoothed p-values to find an appropriate significance level.
We can run mris_glm, save the output in bfloat format, and load into Matlab using 'fread'; no problems.
What we are lacking is a description of the topology of the vertices, and the mapping from the vector of floats to this topology. I assume a triangulation implies a 6-connect structure. Correct? Assume the vertices are numbered 1:163842 (as in the output of mris_glm --sigt), which vertices are neighbors (what are the six neighbors of vertex 100) ?? Are distances between neighbors (nearly) constant, or do they vary???
Very much appreciative of your reply,
+glenn