Health

The Miracle of the Human Brain

Obaidur Rahman

Of all the mysterious aspects of the known Universe, the sophistication and the puzzling nature of the human-brain indisputably ranks no.1. It is said that the complexity of human-brain parallels to that of the grand design of the cosmos itself! If mankind has indeed come a long way, then our brains certainly have endured a lot more and much of the ancient wonders of nature that left this wonderful planet so many millions of years ago. As an effort to describe the mindset of the brain, the late astronomer Carl Sagan in his bestselling book “Cosmos”, penned down quite a few lines in honour of this magnificent organ that weighs approximately 1.4 kg, single handedly responsible for every thought, action, memory, emotion and experience which also contains a mind-boggling one hundred billion nerve cells, equivalent to the number of stars in our very own galaxy. But before that, few words in regard to the brain nerve cells are in order. The brain nerve cells or neurons are basically microscopic electrochemical switching elements sizing a few hundredths of a millimetre across an electrically excitable cell that processes and transmits information by an electrical and chemical signaling process. And this specialised, impulse-conducting cell is central to the proper functioning of the body's nervous system, and thus the sound survival of the entire human body.

Our brain, which took over a million years to develop, evolved from inside out. The oldest part of our brain, the brainstem, conducts our most basic biological functions like breathing, the tempo of heart rate along with other physiological systems that are independent of conscious brain functions. And on the ceiling of this ancient most part of the brain lies the R-Complex, a primitive system, common in other reptiles that sternly dictates our sense of aggression, ritualistic behavior, territoriality and communal hierarchy. It is this very part that was developed hundreds of millions years ago in our ancient reptilian ancestors. This part of the brain is responsible for the constant reminder that, despite our fancy TV programmes, cache of designer attires and scholastic marvels, we were, are and will always be one of the fierce competitors of the creature kingdoms. Neighbouring this animalistic part, resides the limbic system or commonly referred to as the mammalian brain which took tens of millions of years to evolve in our pre-historic ancestors who were at that point in time still mammals and not yet our ancestral primates. We owe our sense of mood, concerns and emotions to this particular part of the brain. Right adjacent to this care centre, we have the cerebral cortex, which took millions of years to evolve into the brain system of our ancestral primates and it is the realm of consciousness, memory, awareness of all kinds, thoughts, intuition, analysis and judgment, languages and much more. It is the “gray matter” of the brain (due to its grayish appearance) that commands the two third mass of the entire human-brain and is solely responsible for making human beings the most dominant of all species on the planet Earth. Out of the calling of this cerebral cortex, mankind embarks upon his historic cosmic voyages to foresee the future, study fossils to eavesdrop into the past and ponder over the contemporary sphere of space and time in such a pensive state that it often leads to great products, like Einstein's Theory of Relativity, Led Zeppelin's “Stairway to Heaven” and Satyajit Ray's silver screen stellar “Pather Panchali”. To be simple and precise, we make sense as human beings because of the presence of the cerebral cortex in our brain.

The complexity of the nature of human brains took a lot of time to be properly understood and experts say, so far we've realised only the tip of the iceberg as far as the mechanism and the elite power of human brain is concerned. In the 4th century B.C. Aristotle thought brain was a secondary organ and acted as cooling agent for the heart, which according to his opinion, was the centre of human intellect. Needless to say human beings have come a long way since that (or have we really?). In layman's terms, we understand that our brain is made up of 75 percent water, utilises 20 percent of the total oxygen of the human body and contains about 100,000 miles of blood vessels and as there are no pain receptors in the brain, the human-brain itself cannot feel any pain. The brain requires that 20 percent oxygen for the maintenance of cell-health and to energise electrical impulses that neurons employ to communicate with one another and also 6.750 ml of blood is pumped through our brain every minute, which is 15-20 percent of the blood flow from the heart. While awake and in a full-functioning state, our brain generates about 10 to 23 watts of electricity, enough energy to power a light bulb, hence the popular projection in cartoons, the appearance of bulb when the character suddenly gets an idea. Contrary to the popular urban legend, human-beings do not use only 10 percent of their brain or less which is nothing but a common misconception as experts believe that despite numerous unsettled mysteries of brain, every part of the brain has a purpose.

Also, the subject matter of whether the human brain is smarter than a computer has also been a great topic of discussion. The answer is, at least so far, definitely the nature of the brain is much more sophisticated than that of computers. Here is why. It is understood that, the brain has a processing capacity of 0.1 quadrillion instructions per second and one of the fastest super computers in the world, called Roadrunner is capable of handling 1.026 quadrillion calculations per second. However, it must also be realised that the computational power of the human brain is difficult to ascertain, as the human brain is not easily paralleled to the binary number processing of computers. While the human brain is calculating a math problem, it is also subconsciously processing data from millions of nerve cells that handle the visual input of the given information as well as the data of the surrounding area, the aural input from both ears, and the sensory input of millions of cells throughout the body. Not only that, the brain is also regulating the heartbeat, monitoring oxygen levels, hunger and thirst requirements, breathing patterns and hundreds of other essential factors of the body. Thus, it is simultaneously doing the analysis, absorbing data from the surrounding settings and keeping the body functional, all at the same time!

It is now commonly known about the two hemispheres of human brain that, the right side, which is responsible for creative insights, intuitions, sensitivity and pattern recognition, controls the left side of the body whereas the left side of the brain which organises the rational, analytical and critical thinking processes, controls the right side of the human body. Not bad for an organ which generates an average of 70,000 thoughts daily in each human being. Experts believe that the total information content of the human brain, if expressed in bits, will probably be comparable to the total number of connections among the neurons, which is about 100 trillion bits. Studies have found that if this information is penned down, it is believed that the data will fill up some 20 million volumes of books. This means that in each of us has an equivalent of 20 million book's worth of information stored in our brains! And precisely here lies the splendour of all questions-- what do we do with this information? How do we apply this knowledge for the betterment of all? Given the history of mankind that is embedded with battles and wars, it seems we are yet to master the true power of our most crucial organ. Blessed with something that is as complex, yet as grand as the Universe itself, perhaps, it could certainly do much better with just a little guidance from our good old hearts after all.