GNU General Public License (GPL) Yes Medical University of South Carolina NITRC Pythagorean Displacement and Motion Regressors Yes This Matlab script uses the Pythagorean Theorem to calculate head motion and position, while preserving degrees of freedom. The motion parameters output by SPM (rp*.txt) estimate head position relative to the first volume in 3D translation and 3D rotation, which are often entered as a nuisance regressor during individual-level statistics. Regressing the total displacement and relative position can potentially explain more variance in voxel-level BOLD signals that is related to head movement during an fMRI experiment. 2013-2-28 5 - Production/Stable/Mature Pythagorean_Motion_version_20130220 Pythagorean Displacement and Motion Regressors Algorithm or Reusable Library, 5 - Production/Stable/Mature, MR, Developers, End Users, GNU General Public License (GPL), English,