Central Park: The Callosum Commissure of East and West

By: Talia Bassali  |  April 3, 2017


As a lover of New York City and an admirer of the human brain, it is only natural that I draw parallels between the two, right? As I learn more about both my favorite city (more accurately, the borough of Manhattan) and the most fascinating organ of the body, I see an increasing number of similarities in their structure and characteristics.

It all started when I learned about brain lateralization and the corpus callosum. The two sides of the brain—the right and left hemispheres—each play unique and complementary roles in brain function. They each have different “personalities” and carry out different types of cognitive activities in order to maximize efficiency in the brain. For example, the left hemisphere is responsible for language, logic, and math. The right brain is strong in visual and spatial perception, music, and creativity. Of course, one side without the other is not conducive to the overall purpose of the brain, contrary to the pop-psychology myth that people can be either right-brain or left-brain dominant. It is the collaboration of both hemispheres that allows for the magical and perfectly composed execution of the brain’s tasks which are responsible for virtually every element of our lives.

How do the right and left hemisphere communicate? The structure called the corpus callosum (“tough body” in Latin) brings these two seemingly separate systems together in harmonious synthesis. The corpus callosum, also called the “callosum commissure,” is a thick band of 200-250 million neural fibers located in the middle of the brain. It is responsible for consistent communication between the two hemispheres, and is the largest bundle of white matter (myelinated axons) in the brain. Neural messages are transmitted through the corpus callosum quickly, accurately and continuously, for a constant transport of information and activity.

By virtue of its central location and multitude of thin axons bridging together the right and left hemispheres, the corpus callosum resembles Central Park, the iconic urban park connecting the East and West sides of upper Manhattan. This 843 acre bundle of trees, playgrounds, and ponds is the wonderful collaboration center of East Side and West Side. While otherwise divided in self-perceived superiority, the two sides k have no choice but to come together in enjoyment of this monumental man-made park. The 25,000 trees act as the “green matter,” quickly transmitting electrochemical messages (or bicycles, squirrels and strollers) through the park from one side to the other.

It is remarkable to note that the corpus callosum only divides the cerebral cortex, located in the forebrain. The midbrain and hindbrain are not separated by the corpus callosum; rather they are their own, unified parts of the brain with distinct structures inside of them, such as the cerebellum and medulla. In a similar fashion, midtown and downtown Manhattan have no particular park dividing them, though there are many neighborhoods within the rest of the city—Murray Hill or SoHo, for example. When it comes to uptown Manhattan, however, we ask, “East or west of the park?” 

When traveling through the park, superficial identity regarding “East-sider” or “West-sider” (or anywhere else for that matter) is simply not of concern. Central Park is a colossal green melting pot of Snobby Old Money East-siders, Friendly Down to Earth West-siders (admittedly, I am biased towards the West Side), and just about every type of person from around New York City, the U.S., and the world. The greatest city in the world would not be what it is without all of its individual components and their colorful union in the park. Whether you are riding in a horse and carriage, visiting the zoo or enjoying a concert and picnic on the Great Lawn, time spent in Central Park is full of rich and diverse moments of communication between both “sides” of the city, and all hemispheres of the earth—East and West, Northern and Southern. Not any less magical and complex a symphony than the callosum commissure.