Essentially you just want to scale the PE maps, since these are already the
measure of effect size at each voxel in the brain. If you compute the max
- min height of the individual regressor and multiply the PE image by that
number, you'll transform the PE image into a % signal change image. If you
want % signal change copes, then simply add/subtract the transformed PE
files according to your contrasts and you'll get % signal change copes.
Joseph T. Devlin, Ph. D.
FMRIB Centre, Dept. of Clinical Neurology
University of Oxford
John Radcliffe Hospital
Headley Way, Headington
Oxford OX3 9DU
Phone: 01865 222 494
Email: [log in to unmask]