Our specific version developed by Dumoulin, requires no cortical surface reconstruction and yields a volume of interest analysis directly. Slide with three vectors, based on rate of change: polar angle, eccentricity and aMRI.  VOI involves collapsing the voxels in each visual area, of each subject, and averaging across subjects.
Unfolded/inflated
Medial posterior
Parietal, temporal, occipital
Actual surface for each SS as marked