Final answer:
The sensation of nonexistent fingers when the face is stroked illustrates the consequence of C. brain plasticity, which is the brain's ability to reorganize and rewire itself after an event like limb amputation.
Step-by-step explanation:
Understanding Phantom Limb Sensations
A person who feels sensations on nonexistent fingers when his face is stroked is experiencing the consequences of brain plasticity. This phenomenon occurs due to the reorganization of the somatosensory cortex following limb amputation. The somatosensory cortex is responsible for processing sensory information from different parts of the body, and normally, the fingers occupy a much larger area than the toes in this brain region. After an amputation, the brain's neuroplasticity allows it to rewire and use the now-unused neural pathways, originally associated with the amputated limb, for other sensory inputs such as those from the face. This case is a clear representation of how adaptable the brain is and how it can reorganize itself to adjust to new circumstances, demonstrating the capacity of the brain to undergo functional changes.
The answer to the question is therefore C) brain plasticity, which is the brain's ability to modify its connections or rewire itself. This occurs not only after serious injuries like limb amputation but also as a result of learning and experience. The case of phantom limb sensations is relevant to understanding the impactful role of neuroplasticity in sensory and motor functions.