Dear John, We have some TMS stimulation sites which we'd like to report in Talairach coordinates. For each subject, we have a T1 structural scan and know the coordinates (in that image space) of the stimulation site. After normalising the structurals into standard space, I wondered how to convert the original image coordinates using the info in the _sn3d.mat file? I apologize if this question had been asked (and answered) before but I couldn't find the email in the archives. Thanks much. Joe Joseph Devlin, Ph. D. Department of Experimental Psychology South Parks Road Oxford University Oxford OX1 3UD, U.K. Phone: 01865 271 309 Email: [log in to unmask]