Tactile Phantom Illusion
Follow the directions below to experience a striking "phantom limb" (or, perhaps we should say, phantom pencil) illusion.
Gently pull your upper lip in one direction, and your lower lip in the opposite direction.
Now insert a pencil centrally between your twisted lips...
You'll experience a "tactile illusion" in which it seems that two pencils are jutting out between your lips.
Could this phenomenon be related to the "ghost limb" sensation felt after surgical limb removal?