Greetings all,

I apologize in advance for what may (or may not) be a basic question. I want to map values from a continuous variable (non-integer) to each vertex on a surface so that I can visualize these values on the surface (or an inflated brain), but I can't figure out how to do this.

I've projected the pial surface of fsaverage5 to native space within a volunteer, then exported the xyz coordinates of each vertex (10242 * 2, lh & rh) for that volunteer to an .asc file using mris_convert. These xyz coordinates (and the vertex #) and a 3D summary volume (NIfTI) for a BOLD scan in native space for the subject were read into MATLAB, and I've used a separate toolbox in Matlab to generate weights from the BOLD data that map to each vertex (a continuous variable, one weight per vertex per subject), and these weights can be written to a text file in the following format for each hemisphere:

x1 y1  z1 weight1

x2 y2 z2 weight2

...

x10242 y10242 z10242 weight10242

or 

vertex1 weight1

vertex2 weight2

...

vertex10242 weight10242

or another format if that would be helpful.

How can I map these weights back to a surface and visualize it? Please advise. I began to think this fell into the realm of annotation, but it seems that annotations are categorial rather than continuous. Thank you so much for your time.

Best,

Fred