Figure 3c. Figure 3 (continued). (b) Plot of normalized SEM histograms for all voxel signal intensities over time. In experiment 2, the control subject was asked to move to simulate an uncooperative patient; results were plotted with the registration algorithm for the correspondence of closest gradient voxels applied to the data. Note the spread of the histograms for the second experiment as compared with that for the first and third experiments. (c) Graph displays the degree of rotation detected and corrected with the registration algorithm for the correspondence of closest gradient voxels for each experiment.