The phantom limb phenomenon is based on the feeling that the amputated organ is still attached to the body. This sensation caused by the human brain is studied within behavioral neurology. The scientists explored that individuals with an amputation have the feeling that their limb is still attached. However, such sensation may also occur after the amputation of other organs such as eyes, breasts, or teeth.
According to Hegarty, “the syndrome occurs in at least 90% of amputees – in two-thirds of those it manifests as an insatiable itch in the missing limb, many feel extreme discomfort or even chronic pain” (2011). Analyzing this phenomenon, Dr. Ramachandran invented the mirror box that allows alleviating the pain that occurred due to a phantom limb. The representation of the body’s parts within the brain is different due to the specifics of human nature called the sensory and motor homunculus.
The phantom limb phenomenon occurs when people after amputation can vividly feel their limbs or other parts of the body. Thus, according to Banich, the symptom of phantom limb pain is common for many people who lost their limbs; however, the missing limb is still perceived as it is still present, and it can move (Banich, 2011, p. 19). The human brain does not reorganize after amputation and provides the same picture as before. Banich says that, in some cases, when people who lost their hands touch the face, they can feel the phantom hand (2011, p. 19).
Dr. Ramachandran supposed that one interesting gift might help to reduce the phantom limb pain. He created a mirror box with two mirrors in the middle that affected the presence of the missed limb. Putting a good limb into one side of the box, the patient can see its movements with the mirror-symmetric and, thereby, he can see two limbs as if the missed one was still there. As a good limb moves, the patient can get the visual feedback from missed one, and, as a result, one can feel the phantom limb and “unclench it from potentially painful position” (Hegarty, 2011).
During the experiment with a man who lost his arm, Dr. Ramachandran proved a theory of the mirror neuron, analyzing the brain activity of a group of people with amputation: “using a magnetic scanner he showed that neuron activity was indeed migrating from the hand area to the face” (Hegarty, 2011). According to Dr. Ramachandran, the sensation of the phantom limbs is caused by the brain’s changes during the mapping of the body called the somatosensory homunculus that can be two types, such as sensory and motor.
The larger parts of the brain control the body’s larger organs responsible for motor and signal functions. The researchers say that the human body builds the motor movements according to the proportion reflected in the brain needed for this action. According to this mapping, the hands and mouth would be proportionally bigger than they are, in fact (Banich, 2011, p. 18).
Therefore, the representation of the body’s parts within the brain is different due to the specifics of human nature called the sensory and motor homunculus. As a result of this phenomenon, the representation of the hands or mouth in the brain is larger than the representation of the other parts of the body, which are bigger.
Banich, M. (2011). Cognitive Neuroscience. 3rd ed. US: Wadsworth Publishing.
Hegarty, S. (2011). What phantom limbs and mirrors teach about the brain. Web.