² Color Opacity lets you select the opacity of colored voxels (those
that are above the threshold)
åOpacity of overlaid voxels is different from the opacity
it would have from the underlay dataset at
that location
åUsually want this to be high (0.5 or above)
åTow special values on this menu:
Ø Underlay means that the colored voxelÕs opacity will be determined by the opacity that it would have from the
underlay image
Ø ShowThru means that colored voxels show through underlay voxels (the Ôglass brainÕ effect), no matter how opaque the
underlay is
¥Takes
some practice to become accustomed to this type of image
¥But
can be a very useful way to see lots of activation at once: