Ramachandran's The Perception Of Phantom Limbs

In today’s scientific world, research studies are in constant process leading to new discoveries. Every scientific discovery is rooted off a simple foundation that is then elaborated through years of research by various professionals. Therefore, it is important to understand where a specific finding originated from and how it evolved over the years – acknowledging the story behind the story. In such manner, highlighting one of the well known neuroscience research is the study on the reorganization of an adult brain. This topic has been monitored for several centuries by various scientists. In particular, a neuroscientist named Vilayanur Subramanian Ramachandran is known for his breakthrough contribution on the study of the adult brain and its

capability of reorganization.
In order to find the details of his work and get a better understanding on the topic, Web of Science search engine was used. As Web of Science carries numerous scientific works, the use of filter option helped simplify the search. Once the author’s Last name and First name was entered, I used key words such as “adult brain” and “reorganization” to restrict the search to the specifics of Ramachandran’s work. I filtered the results to only peer-reviewed journal articles as a key paper should consist of a detailed description of the work with specific research methodologies. The abstract gave a gist of what the article consists of and the key words such as “Massive cortical reorganization” helped in identifying the relevance of the paper. I also looked at the number of times the work was cited as it portrays the effectiveness and popularity of the paper.
The key paper that I found relevant to this topic is “The Perception of phantom limbs” by V.S Ramachandran in partnership with William Hirstien published in the journal Brain (1998).

Ramachandran’s work on the reorganization of the brain is mainly focused on the theory of the interdependency between the mind and the body(Ramachandran, 1998). He focused on this particular aspect through the study of phantom limbs- painful conditions in the limb after an amputation. With the help of previous findings such as the use of MEG, Ramachandran states that the adult brain consists of organized somatosensory maps that is affiliated with the senses and stores the memories into place. (Ramachandran, 1993). Therefore, when an individual’s arm or leg is amputated, the memories and the functionalities of the body part still remains in place. In scientific terms, the sensory map of the body is known to exist in the somatosensory cortex where the reorganization takes place. (Ramachandran, 1998). Through his detailed research on the phantom limbs, Ramachandran introduced the notion of “learned paralysis” where once the body part is amputated the brain learns that the body part is not functional anymore (Ramachandran, 1998). Ramachandran argued that if the brain is capable of learning such notion, then there must be a way for it to unlearn and reorganize. He justified this specific theory through his mirror box experiment where the patient’s normal hand is reflected where the amputee hand is

creating an illusion and indirectly convincing the patient that the deformed arm is functional again. (Ramachandran, 1998)
Ramachandran’s publication of “The Perception of Phantom Limbs” is heavily based on a combination of various works that has been cited. This shows that this topic has been under research for several years. Specifically, Ramachandran used the presence of the somatosensory system for his learned paralysis theory where he mentions that the sensory mapping takes place in the somatosensory cortex (Ramachandran, 1998). This specific finding is rooted from Wall and Wolstencroft in 1977 in one of their works “The presence of ineffective synapses”. The article focused on three specific regions of the sensory system noticing the opening of connecting pathways in adult brains. (Wall & Wolstencroft, 1977). Additionally, Ramachandran has elaborated furthermore on Wall’s work on plasticity. Ramachandran’s work in 1993 focuses on the use of MEG and its correlation of plasticity in the adult brain which is a further build up on the previous work conducted by Wall. Ramachandran’s work focuses on the use of microelectrodes and how the MEG shows the visual perspective of somatotrophic reorganization in the adult brain (Ramachandran, 1993). Following this, in 1994, along with the others Ramachandran published his work on the cortical somatosensory topography. This work further expands the research on cortical topography and non-invasive detection of plasticity (Yang et al., 1994) All of the supporting publications that I found were derived off the key paper used which was later published in 1998. Through reading Ramachandran’s article on Phantom limbs, I noticed that his findings were heavily based of the 3 publications listed. Therefore, it is evident that this topic of the reorganization of the adult brain has been a continued research.