In the 1930s, Dr. Wilder Penfield was conducting a very bizarre operation at the Montreal Neurological Institute[8]. Dr. Penfield “pioneered the incorporation of neurophysiological principles in the practice ofneurosurgery.[2][9] Dr. Penfield was interested in determining a solution to solve the epileptic seizure problems that his patients were having. He used an electrode to stimulate different regions of the brain’s cortex, and would ask his still conscious patient what he or she felt. This process led to the publication of his book, The Cerebral Cortex of Man, in 2007[8]. The “mapping” of the sensations his patients felt led Dr. Penfield to chart out the sensations that were triggered by stimulating different cortical regions[10]. Mrs. H. P. Cantlie was the artist Dr. Penfield hired to illustrate his findings. The result was the conception of the first sensory Homunculus.
Homunculus: Diagram showing position of regions of the human cortex corresponding to the respective afferent/efferent nerve region of the body. Blue: sensory cortex. Red: motor cortex.
The Homonculus is a visual representation of the intensity of sensations derived from different parts of the body. Dr. Wilder Penfield and his colleague Herbert Jasper developed the technique of using an electrode to stimulate different parts of the brain to determine which parts were the cause of the epilepsy. This part could then be surgically removed or altered in order to regain optimal brain performance. While performing these tests, they discovered that the functional maps of thesensorimotor and motor cortices were similar in all patients. Because of their novelty at the time, these Homonculi were hailed as the “E=mc² of Neuroscience