If you lose a finger, the somatosensory cortex that received its input will begin to pick up signals from the neighboring fingers. this best illustrates the concept of neuroplasticity. The neurons rewire themselves to participate in the functioning of other nearby brain regions. Another consequence of this in the experience of the presence of a phantom limb or finger. The brain activates that region to signal the muscles of the absent limb and confuses itself in the absence of any feedback from it.
