Monday, October 1, 2007

Even DaVinci Got It Wrong

Referencing DaVinci is an ideal way to initiate any presentation on Scientific Visualization. In seminar it has happened three times so far. In the second instance, Dr. Judith Hirsch began her discussion with a DaVinci illustration featuring a lateral, side-to-side cross section of the brain. This illustration is remarkable in many ways, because it gives us one of the first accurate depictions of the shape and volume of the brain's cavities. Posted here is a similar illustration, but featuring an up and down cross section of the brain's volume. Leonardo's accuracy in determining this volume is the result of using a wax-injection method. In fact, Leonardo is credited as being the first individual to use a wax injection method to make castings to determine the shape and volume of the various organs of the body. But, while Leonardo is correct in determining the volume of the brain, he was wrong in illustrating what existed in the brain's cavity. In this DaVinci illustration, the brain is depicted as having 3 small cavities listed O, M, and N. These cavities reflect the prevailing notion, at the time, that the brain consisted of three cavities (or ventricles), which held imagination, reason, and memory. This theory was postulated by Galem of Pergamum (AD 131-201), who based his work off of Hippocrates, and was part of the ancient belief that the solid parts of the brain were worthless. Furthermore, this belief stated that the three small cavities, held within the solid brain matter, sent fluid (i.e. imagination fluid, reason fluid, memory) through the nerves to control the muscles and organs. This exemplifies, how even the greatest of minds, can propagate misinformation through an incorrect scientific rendering.

The research above was taken from Micheal O' Shea's book, The Brain, A Very Short Introduction.


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