phantom limbs

In the Meditations, Descartes used the phantom limb as an illustration of the deception to which the inner senses are prone. 

The eminent Philadelphia physician Silas Weir Mitchell first coined the phrase "phantom limb" after the Civil War. In those preantibiotic days, gangrene was a common result of injuries, and surgeons sawed infected limbs off thousands of wounded soldiers. After amputation of movable, functional extremities, the phantom limb seems to be experienced in close to 100 per cent of cases. Oliver Sachs describes them as "fossil images" but explains them as the persistence of pathological excitation to the peripheral nerves, especially if there is formation of a neuroma in the stump. (see A Leg to Stand On, p.194,n.) (V. S. Ramachandran has convincingly shown that the locus of the phantom limb is in the brain, not near the hand or leg. 

Oliver Sachs points out that amputees can use the phantom image for propelling a prosthesis, a point which Elizabeth Grosz develops in the claim that "It is only through controlled use of the phantom that the artificial limb can (gradually) take the place of the lost limb. (Grosz, Volatile Bodies, p. 71) The phantom limb is a concept no theorist should deny herself. If Freud claimed that the female psyche was marked by the imaginary loss of a penis, the very thought of the phantom limb provides a " tool" for a recovery of what was "always already" missing for feminist theory. 

When given a psychological interpretation, the phantom limb can be seen as a libidinal memorial to the lost limb (see body image) and a kind of mourning for a pre-Oedipal (i.e. precastrated) body. There is refusal to accept the loss of a limb. It is erroneous localization

Is there an evolutionary advantage to holding this false belief? 

see anosognosia 
(see also perspective

The continued stimulus of severed limbs is described in "The Painful Reality of Phantom Limbs" , Scientific American, April 1992. Most phantom limbs are the source of protracted and excruciating pain

addit. readings: Henry Head, Paul Schilder (1931,1953, 1978) Sacks (1981), and Luria (1973) Merleau-Ponty, Kurt Goldstein, The Organism, V.S Ramachandran, Phantoms in the Brain.