[citation][nom]bogcotton[/nom]It's very likely that they could, however, you can only control parts of you're body your brain is familiar with. This guy will be imagining he's moving his hand which no longer exists. I can't see us being able to move extra limbs independently.[/citation]
If you start young enough, while the mind is still forming synapses you could conceivably engineer multiple limbs or even other forms of sensory abilities... as long as your brain is still under construction, it's pretty darn adaptable.