We will determine the extent to which CNS responses to tactile and auditory stimuli habituate. Subjects will be presented with trains of stimuli, repeated 80 times. At the end of each of these blocks, a questionnaire will ascertain the subject s perception of these stimuli. CNS responses to the stimuli will be recorded using MEG and analyzed first for localization, and then for amplitude and frequency characteristics. Healthy volunteers will be included as a control group.