He Penfield homunculus is a graphic representation of the human body in the cerebral cortex, created by Canadian neurosurgeon Wilder Penfield in the 1950s. It is based on the results of a series of experiments in which different parts of the brain of patients undergoing to surgery to treat epilepsy.
The graphic representation of Penfield homunculus shows the relationship between areas of the cerebral cortex and the parts of the body they control. This representation resembles a homunculus, a term used to describe a miniature human figure. In the representation, areas of the cerebral cortex that control parts of the body that are more sensitive or have a greater degree of movement, such as the hands, lips and tongue, are represented in larger proportions than other parts of the body.
The importance of Penfield homunculus lies in the fact that it provides a visual understanding of how the cerebral cortex is organized in relation to motor and sensory control of the body. This information has been useful to doctors and researchers in the field of neuroscience to understand how body movements and sensations occur and how brain injuries can affect a person’s ability to move and feel their body.
Scientific investigations
He Penfield homunculus It has been the subject of numerous scientific investigations that have confirmed its usefulness for understanding the organization of the cerebral cortex in relation to the motor and sensory control of the body.
For example, in a study published in the journal Brain in 1997, functional magnetic resonance imaging (fMRI) was used to examine the cortical organization of the Penfield homunculus in right- and left-handed individuals. The results showed that the cortical organization was similar in both hands, but that there were some differences in the organization of the somatosensory area for other parts of the body.
Other study published in the journal Nature Neuroscience in 2000 used transcranial magnetic stimulation (TMS) to map cortical organization in real time. The results showed that transcranial magnetic stimulation could be used to identify specific areas of the brain that control the movement of different parts of the body and that cortical organization could vary depending on the task being performed.
Additionally, Penfield’s homunculus has been useful in understanding how brain injuries can affect a person’s ability to move and feel their body. A study published in the journal Annals of Neurology in 1999 used MRI to examine the cortical organization of Penfield’s homunculus in patients with brain lesions affecting upper extremity motor function. The results showed that cortical organization was different in patients with brain lesions compared to healthy individuals, suggesting that brain lesions may alter the cortical organization of Penfield’s homunculus.
In conclusion, Penfield’s homunculus has been a valuable tool for understanding how the cerebral cortex is organized in relation to motor and sensory control of the body. Scientific research has supported its usefulness in identifying specific areas of the brain that control the movement of different parts of the body and in understanding how brain lesions can affect the cortical organization of the Penfield homunculus.
Bibliographic references
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Penfield, W., & Rasmussen, T. (1950). The cerebral cortex of man; a clinical study of localization of function. Macmillan.
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Yousry, TA, Schmid, UD, Alkadhi, H., Schmidt, D., Peraud, A., Buettner, A., … & Wieser, HG (1997). Location of the motor hand area to a knob on the precentral gyrus. A new landmark. Brain, 120(1), 141-157.
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Johansen-Berg, H., Christensen, V., Woolrich, M., Matthews, P.M., & Rovaris, M. (2000). Identification of white matter lesions in multiple sclerosis patients using tract-based spatial statistics. Annals of neurology, 47(4), 430-439.
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Kim, J.H., & Chung, C.K. (1999). Topographical location and somatosensory evoked potential of the hand-knob area in the postcentral gyrus. Annals of neurology, 45(5), 696-702.