Figure 2

Vector plots of PBS for two axial (a and b) and two sagittal (c, d) slices. Length of vectors have been scaled for visualisation purposes: their magnitude is represented by the underlying contour plots. As reference, dashed coloured lines represent the position of the other slices. In particular, slice a was positioned at the level of the anterior and posterior horns of the lateral ventricles, whereas slice c was positioned at the level of the falx cerebri.