Musings on the Human Brain

The human brain is one of the most complex biological structures that has evolved in any animal. It is who we are, both individually and in concert with other human brains, and it has changed pretty much all life on Earth. Our brain tells us what to do and when to do it. It tells us when to sleep and when to wake, when to eat, and when to drink. When to love and when to hate. When to stay and when to go. It is our brain that responds to life and directs us through the trials and tribulations of the biological stages of infancy, growth, puberty, adulthood, reproduction, life, age, and even death. Sometimes this works well, and the tribe survives. And sometimes it doesn’t, and when that happens, tribes become history. The human brain is not the largest brain in the animal kingdom, that belongs to the sperm whale at about 20 pounds, the human brain is about 3 pounds, and the elephant brain weighs in at about 10 pounds. But comparative brain size is important only to humans, what is important to all animals is not the size of their brains but how well their brains function with the task of keeping them alive and reproductively active within their ecological niche during their natural life span. Over the last 50 years, especially the last 20 years we have learned a great deal about the evolution and development of all brains, but especially the human brain. The genetic research into brain formation and function has exploded our understanding of what the brain does and how it functions. Our knowledge of how we think and what we think has expanded exponentially and the science of who we are and how we function has greatly increased. Our understanding of what our brains do and why we can do what we do are remaking human understanding of who we are and why we do what we do is rapidly growing.

The human brain is composed of two halves or hemispheres that each contain three sections, the cerebrum, cerebellum, and brainstem. Each of these hemispheres is made up of four lobes, each with specific functions. These are the Frontal lobe (decision, movement, sense of smell, speech, and sense of self), the Temporal lobe (short-term memory, speech, music, rhythm, senses), the Parietal lobe (spatial relationships, pain, touch, and language, understanding speech), and the Occipital lobe (vision). There are many other sections and biological tasks of the human brain, the prefrontal cortex, the pituitary gland, amygdala, brain stem, hippocampus, cerebellum, and hypothalamus, all with purpose for the entire life of the human animal. This relatively small conglomeration of fatty electrical nervous tissue on the top of our head determines who we are and what we can do; and directs us through all the growth and cacophony of a human life. It works to direct this third chimpanzee through the success and pitfalls of humanity’s struggle to survive despite our efforts to destroy each other and also maintain a livable planet.

The human brain evolved over millions of years and is probably the most operationally complex of animal brains. ?The mature human brain is composed of about 100 billion neurons with 100 trillion connections, and it takes some time for the brain to fully develop. The human brain does not exist until the human embryo is about a month old. It begins to form at the end of the neural tube, which is the precursor of the brain and the spinal cord that develops early in embryonic formation at the base of the skull. The brain is at the forefront of human embryo formation, a very complex biological creation. Only in the last 30 years or so through new scientific tools we have we really begun to research and examine how the human brain developed the structures and programs to support human intelligence and the intellect needed to create civilization.

The human brain is something like the engine in a truck. Nothing happens unless the engine is in operation. When the engine is turned off the truck does not function. However, a charged battery keeps the truck “alive” and when the driver turns the truck on again, it “wakes up” and is ready to go. But when the battery loses its charge, then the truck is “dead”. The human animal is similar to the truck in that as long as the brain is awake it is alive and active. It may sleep and consciousness then turns off but the brain still has an active intellect that has no directives from the sleeping brain. But it can wander and create a subconscious world in dreams. The mental direction is turned on again when the brain wakes up. When the sleeping truck gets turned on again it can be driven along the highway as long as it has fuel. When the brain wakes up and becomes conscious again it can once again sense reality and provide direction. When the human brain sleeps, it does not sense reality. But through sleep, it can dream and create its own reality, and that is real to the brain until it wakes up and once again begins its tasks of sensing and observing reality and analyzing what it observes within the scope of understanding that its human owner has created and stored in memory.

All the truck needs to move along the highway is fuel, and a driver to start the engine and direct the path of the truck. The driver also supplies the purpose for the truck’s movement. All the brain needs to begin conscious life again after sleep is an active intellect to direct brain operation and purpose and provide analysis of reality to direct activity. The brain has to be in good working condition to be able to perform the tasks required for continued rational human existence. Many chemicals can interfere with the normal operation of the human brain. Some such as medically prescribed drugs can enhance normal brain function, some like alcohol interfere with normal function, and harmful drugs, injuries and diseases can greatly affect normal brain functions. The brain has a defense against harmful behaviors, drugs, and chemicals; the most powerful is recognition of the brain-destroying elements in modern life and strict control and avoidance of the use of anything that destroys intellect. The brain greatly appreciates the absence of external interference from humans that keep meddling with how it operates. ?

Unlike the mechanical structure of a truck, a brain, although it operates on a chemical/electrical basis is a biological organ and depends on biochemical interactions with many other organs to create normal animal behaviors that provide survival and allow evolutionary changes to maintain the existence of the species. Getting and keeping the brain in condition to meet the requirements for a day of human life is much more difficult than filling the gas tank or charging the battery of a truck. The major difference between a truck and a human brain is that the truck doesn’t know what it is or what it is doing, and if the human brain is working properly, it does.

The brain, the element of the nervous system that that gathers information, almost instantly analyzes a broad spectrum of this information both internal and external, and then goes through a process of determining what and how rapidly the mental and physical reaction to this information must be analyzed and then activated. Brain functions must be psychologically developed as the brain grows in early life and learns to store memory and apply functions. It “learns” how to analyze the content and meaning of the subjects that concern a human brain, quickly determines what additional information must be found in other areas of the brain, and governs the most effective response to the stimulus that initiated the mental activity. This could be the run or hide response to a predator, the attack or be still response of a predator seeking food, a chimpanzee standing at the edge of a creek determining whether or not to cross over the flow, a bird deciding where to build a nest, or perhaps a human doctor determining the correct amount of a stimulant to inject into an unconscious patient. The determined response to the stimulus may be rapid such as a basketball player deciding to either shoot for a basket or pass to another player. Also, the brain can determine that an action must be taken immediately without in any way considering the alternatives, such as slamming on the brakes of your car when another car runs a stop sign right in front of you. In that situation, the brain instantly determines that there is no time to evaluate any alternatives. Without analysis, it sends a signal to the muscles of the leg and foot to react, like, right now, don’t think about it, just DO IT, slam on the breaks and quickly!

The brain is an extremely important part of all animals. How this organ has evolved defines the existence and development of every animal species. How the brain operates and the behaviors it directs result in the survival or death of individuals of all species and this has determined how the animals of Earth developed over eons of evolution. The Animal Kingdom was created over the long, long history of the development of the primitive brain of the Chordates (with only a spinal cord) and then the also long history of the more advanced Craniates (with a vertebrate spine), hence the survival of the entire Animal Kingdom of the planet.

Every species of life on Earth has some characteristics that make that species different from all other species, past and present. Some closely related species have very similar structures and behaviors while other distantly related species have features where through evolution the demands of survival have made great changes to their structures and capabilities. The survival of a species within a changing environment depends on the development of changes in structures and behaviors that become unique and create a path to the survival of a new species. This process is very slow and often results in features of unique abilities, skills, and body structure. From a mouse to an elephant, from a deep-water fish to a whale, evolution can change what begins as minor characteristics into physical and mental structures that create very different animals. But in every case, there are remnants of ancient ancestors.

One of the most complex biological developments of evolution is the creation of the human brain. Other animals have evolved particular characteristics that enable survival in many different environments, i. e. polar bears, whales, and penguins, and even some that demand a degree of intelligence, like primates, predators, some birds, and other animals that can learn from experience. However, only Homo sapiens have developed using intelligence to create intellect, and through that biological trait, humans can knowingly modify the environments of Earth from the north and south poles, to deep caves, to desserts, to jungles, and even to oceanic depths, that allows survival of humans without depending on evolution to make the physical changes necessary for survival.

We may think we are an individual human and that our brain and it’s thinking belong to us as sapient individuals and that we are in control of what we think and what we believe to be the truth, and that we understand the everyday world and know our current place in this world; and to a great degree, this is true. And it is sort of true for some other animals that have complex brains and the beginnings of intellect, but not all of them, and none to the degree that human intellect provides. The evolution, structure, and function of the brain in many vertebrates and also some invertebrates are not totally unlike human brains. There are similarities in structure and function just as there are similarities in the structure and function of hearts, blood composition and function, food requirements, digestive systems, oxygen requirements, respiratory systems, nerves and nervous input and controls, reproduction, and more elements of life on Earth. That is to be expected because the origin of every species of life on Earth can be traced over deep time to an early origin of life on the fledgling planet Earth.

Humans have a well-developed Sense of Self. The Sense of Self is your brain creating who you are, telling you that you exist as an individual human, and functioning to guide you into developing a mental “picture” an assessment of who you are and how you fit into reality. This is known by the brain and expressed in language and feelings. “Feelings” are an emotionally based self-assessment of who you are and putting this into a description created through language as a developing maturity allows for detailed and comprehensive analysis. It is possible that as the human brain evolved and developed mentality and spoken language, the realization of life and the use of intellect worked with brain evolution to give the brain a functional understanding of human existence, basically the meaning of life, reproduction, and death. This is a condition that stimulated the questions of how and why intellect was formed.

Much of humanity found and still finds answers to these basic questions in religion. It seems that for many, certainly the majority of humans in both past and present, the basis of reality is not, “I think therefore I am”, as penned by René Descartes in his Discourse on Method (1637), no, the basis for their existence is belief in one or more of many supernatural stories that explain and define existence as the product of one or more supernatural deities. In one way or another religion considers reality and personal existence as the product of supernatural planning and subsequent creation that defines human life and death.

The belief is that we exist because God created humanity. With no other explanations for the human existence and intellect that lifts humanity above other species, religion stepped in to explain the unknown.

Religion does some good things for humanity. It provides a social core for the tribe, an understanding (if false) of everything that exists, and a mental and physical structure for civilized human interaction. Sometimes it is successful and sometimes it fails, but it’s authority and power always claim absolute truth.

Religion also does bad things for humanity. It creates a false structure for tribal culture, a false understanding of the biology and history of the Earth, and a false understanding of the structure and history of human life. And also the universal and constant presence of WAR. Religion demanding power and superiority can be a direct cause of war and strife within a society, but most often it is used externally of society to provide a rationale for a war of conquest. Religion can also create social structures and behaviors that with male physical superiority, favor different aspects of culture, sexuality, and ethnicity that extend to the extremes of social and cultural superiority, commercial human ownership, and competitive annihilation of other human tribes. All this is the result of the evolution of the human brain into a primate animal developing a consciousness that can generate and control intellect.

Religion explains the existence of, well, everything including human intellect, much differently than does science. It considers human existence, human consciousness, intelligence, and even human understanding of reality not as a product of evolution, but as a gift from a supernatural being that created all reality. Religion considers the most important aspect of humanity is that we recognize that a supernatural deity exists and that It, God, created all else that exists including humankind. And that God created humans as the only creatures with the intellect to know and understand that God created everything that exists, and then created humans (the supreme product of Its effort) and provided humans with intellect for the specific purpose of being able to learn that God exists and then fulfill their purpose of worshiping God. And then if humans were faithful to God’s wishes, they would live forever in a supernatural existence where lions would lie down with lambs. Of course, there are many religions, all with different compositions, understandings, rituals, and beliefs. But also there are many who eschew religious beliefs and expunge the supernatural for the incomplete but rapidly increasing understanding of existence that science produces.

The complexity of the human brain, a few handfuls of fatty tissue, is still beyond complete comprehension of itself, but we are making strides in understanding what the brain is and how it works. Traveling down this path is amazing and provides great insight into who we were, who we are, and who we may become. It would also take several doctorate degrees, many years of study, and much more intellect than the average human possesses. For example… if you look for it the internet can tell you that ZEB2 is a human gene that codes for proteins. What it does is delay a change in the shape of early brain cells in the forebrain of humans. And what that does is to change the shape of the human brain resulting in a much larger forebrain in humans than that of apes. And that is part of the reason that human intellect is much greater than that of apes. Of course, it is far more complex than that, but it is a tiny insight into the explosion of information and understanding of animal and human brain structure and function that is now possible to research and understand. And understanding something often leads to modification and change.

The concept and actuality of reality is understood and experienced by the human brain. Our brain does not create reality, it observes and analyzes reality, and it also has the capability of using reality to modify that that does exist into a more useful reality. Some other animals can also achieve some changing of reality such as building nests, digging holes, and creating dams but this is instinctive and not the product of analysis and intellect. In fact, reality is not contested or even imagined by animal species besides humans. It just is, and they have no intellect that knows that existence, well, exists. As humans, animals have evolved highly specialized structures and ways to evaluate and detect elements of their world. There are the five basic senses, touch, sight, hearing, smell, and taste, and humans have them but nature has far exceeded the natural sensing capability of humans. ?

There are many ways animals have developed to use the elements of their environment, such as ultrasound to sense their environment when typical senses are not sufficient, and a sense of gravity when sight and sound are limited. Low-frequency sound to travel long distances in aquatic environments, detection of small prey animals through electroreception, echolocation, infrared radiation, polarized vision, an extremely acute sense of smell, sensitivity of hair (trichobothria), magnetism, and extreme vision are all senses developed by various animals to make survival of the species possible. Humans, through intellect, can create sensitivities that far exceed these senses and much more through the application of science to develop ways to explore reality in ways only the human brain can understand. ?

Humans can also understand life, and the beginnings and endings of life. The reality of existence is forever in the healthy human brain, but even so, various evaluations by some humans past and present, question and analyze the existence of reality. They mentally create a world where reality is very different from the reality that human intellect observes and experiences. That world includes things like a flat Earth and living human brains used to create artificial worlds, mostly fiction but some with an aspect of actuality and belief. I don’t understand the various forms of human thought that can so completely reinvent reality.

Life and the evolution of life are complicated. And the organ we term the brain is a complex and major part of the survival of the human species. The human brain, with the intellect to direct purpose and store memory, often needs to analyze a particular situation, provide answers, and direct actions to resolve problems and difficult situations. So how does a brain analyze the elements of a problem? First, it has to have information on the nature of the problem. That helps to direct the intellect that the human mind can use to find and identify critical information. Without the finely honed mental capability to detect and analyze surrounding environments, such as is a predator or an herbivore hiding behind that tree? Human beings could not have developed the environmental knowledge needed for survival without the ability to save and process information about the existence and relationships of life and structures that compose the environment and support existence.

The basic requirements for a fully functional human brain are maturity, experience, memory, and analysis of current reality to fuel the required mental activity. The human brain and its intellect are in control of every movement, every plan, every consideration, every turn of the wrench, every tap on the keyboard, and every action required to complete the tasks, some simple and automatic, some complex but familiar, and some so complex and creative that they may be created and required for individual survival in a hazardous time. For a human brain to be capable of a task like this, there are two basic requirements, the first would be the education to supply memory with the knowledge required to perform the tasks, and the second would be the mental capability to analyze the environment and provide the correct information essential to the successful completion of the impending tasks. Only a human brain could be capable of such complex tasks and not all human brains can accomplish them. ?

Humanity is now in a great race to use science to expand human knowledge in all areas, and hopefully, to reset the elements in human brains and civilizations that employ war to resolve problems of overpopulation, and industrial pollutants. If we could do this, which would require a “reset” of human concepts of the meaning of existence, then we could create a future with a balanced, peaceful, and science-based civilization. One can only hope.

Darn, I wish I had another life to live.

?

Martin Moe