By James Wadman
One of the most remarkable legacies of human evolution is the design of the cerebral cortex, or the outermost region of our mammalian brain responsible for complex perceptual function. Somewhere in the history of evolution, it became favorable for the brain to cease outward growth and begin to fold in on itself in the formation of notable grooves and bumps, responsible for increasing the surface area and capacity for function within a confined space. Think of the evolution of the brain like the growth of a marvelous tree. The tree’s roots, or the brain’s equivalent the hindbrain and attached spinal cord, play an integral role in survival but in an evolutionary race for development and adaptive advantage, survival is only half the battle. Then there is the trunk, the transportation center for nutrients, or the brain’s equivalent the midbrain. This is the site of sensory convergence from the body. The flowers at the tips of the branches, however, are what make us human. The human equivalent here would therefore be the forebrain, which is where our cerebral cortex is found. While the furthest reaches of the tree’s branches still rely on sunlight, carbon dioxide, and water just as the cerebral cortex feeds on the transduced signals of our five senses, human consciousness takes it one step further. Our brains do more than just absorb stimuli from the environment, we make sense of and reflect on sensation. This is the advantage bequeathed by a pivotal moment in evolutionary history, where the brain stopped growing and began to fold, just as a marvelous tree uses of its energy to grow higher and higher, but one day it stops growing and blossoms.
The best part is, in the scope of the conscious, neural networking, the subconscious, the molecular, and macroscopic, this is not even close to the whole story.