Brain, what brain?

A Trekkie would remember this line from the third season episode: Spock's Brain. Alien women, who use a pain device to control men rule an advanced society in a buried city on a distant planet. They suffer a major problem when their computer environmental control unit fails. The ruler removes Spock's brain--his body is kept alive--to run their environmental systems. In this episode, McCoy is called upon to restore Spock's brain to his body after using 'The Teacher' brain enhancement device that the women used to take his brain. This idea is completely ridiculous but it makes for an interesting story.

The study of the brain is called neuroscience because it deals with neurons, which are the main cells of the brain. Everything your body does to maintain life is brain controlled, but understanding the brain is a very difficult task. Neuroscientists can describe the various sections of the brain and what they do but no one really understands how the human brain works to give us consciousness. Actually, this subject would require an entire book if not many books.

The human brain is the central organ of the nervous system, which is responsible for how we as a living organism react to our environment. It is also the seat of conscious thought and the initiator of muscular action both willful and autonomous. The main thing to remember about the human brain is that it evolved over a long period of time and has the elements of evolution contained in its structured design. In other words, the human brain contains the primitive brain structures of the species we humans evolved from.

The human brain is very complicated, and the part that's the most complicated is the neocortex (cerebral cortex). This is the part that one sees when viewing a human brain. The neocortex looks like a bumpy folded mess of gray matter convoluted with groves (sulci) and ridges (gyri). The brain is divided into two hemispheres, the left and right. It has four major lobes, the frontal, parietal, occipital, and the temporal. The thing to remember about this is that the frontal lobe is where we put conscious thought into action because the neurons (the brain cells) in this part of the brain have their axons (output cables) running down the spinal cord. The occipital lobe is where sight is processed. The parietal lobe receives the sensory inputs from the skin such as pain, temperature and touch sensations. The temporal lobe processes auditory inputs.

The cortex part of the brain sits on top of the more primitive sections of the human brain. Directly below the cortex is the thalamus. This part of the brain is like a control mechanism. It handles all of the circadian rhythmus and things like temperature control. The thalamus also acts like a command center for the cortex. As you can see, the brain is divided into sections that have specific functions. It's not all one unit but rather several units tied together.

As you know, the human brain is the epitome of evolution and represents not only an increased complexity but also volume over the more primitive Hominids. As the first Hominids came on the scene with brains about 600 cubic centimeters, the volume increased to roughly 1500 cubic centimeters in Homo habilis. For some reason brain volume has decreased to 1350 cubic centimeters. What does that mean? Are we getting dumber? Apparently, our brain is as large as necessary and further increases are not going to be easy.

One thing is for sure: doing a head transplant would be an almost impossible trick. The wiring that goes down the spinal cord is extremely complicated. Medical science is a long way from doing anything as crazy as this; although, I think they've tried it in Russia.

Thanks for reading.