All subjects are right-handed.
All images were spatially co-registered with a template image in Talairach space using a 12 parameter affine transformation. The spatially normalized images were segmented into grey and white matter compartments using a modified clustering algorithm, which incorporated a correction for image inhomogeneity. Prior to statistical analysis the segmented images were smoothed with an 8 mm FWHM isotropic Gaussian filter. All rights reserved.