Effect of RETROICOR and RVHRCOR on brain and spinal cord activation is qualified from simultaneously acquired fMRI motor task data. tSNR and activation volume at subject-level are examined using (1) no physiological noise correction, (2) RETROICOR only, (3) RETROICOR and RVHRCOR. Although RETROICOR and RVHRCOR improve tSNR in both brain and spinal cord while removing false activation in brain, these corrections can remove true activation in spinal cord. Examination with and without physiological correction is the only known way to determine whether subject-level activation were removed by noise correction. In general, an increase in activation volume after physiological noise correction is a good indicator of little correlation between physiology and task.