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The ability of humans to learn and retain knowledge is an incredible power source and also a dominant characteristic of the human species. The intricate abilities of the mind allow for humans to learn skills and to have the power to control and dominate the world they live in by means of learned behavior. The two cerebral hemispheres of the left and right specialize in motor and sensory skills which specialize the socialy established beliefs and behaviors unique to humans. In writing The Social Brain Michael Gazzaniga proclaims an understanding of the principle of both the right and left brain hemispheres by examining split brain patients. Gazzaniga believes in cognitive dissidence and studies the modularity of the brain structure. The modularity is the independent functional traits that contribute to the skills and tools of language and writing. The contribution of individual modules is evident in the perception of a human belief system and the evolution of the sophisticated civilized life of a human being. The two cerebral sides of the brain operate with their own selective areas of domination, but depend on eachother for reference, information, and influence which yields continuation of human evolution of increasing brain activities.
Michael Gazzaniga writes chronologically as he studies the aspects of a split brain and the distinct behavior that humans have developed unique cognitive styles and the brain modules allow them for infer and differentiate . Gazzaniga believes that the “free will” of humans allows the species to choose and control their environment. The progress of his studies of the split brain, is by isolating the separate hemispheres to see if one influences the other. The interests of his studies of the effect of the sensory abilities of both the right and left hemisphere takes him around the world. The course of the book covers the studies of a lifetime from an inquiring student about the possibilities of a full functioning split brain, to an established professor with a belief in a cognitive theory. Gazzaniga introduces the structure of the brain and a foundation of the function and place in the evolution of the present human being. Through documented
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experiments, Gazzangia attempts to isolate the left hemisphere of the brain to examine the power of the modules and the importance of the capability of humans to infer and comprehend a variety of information.
Gazzangia uses trial and error experiments of stimuli and response to test his hypothesis of the split brain. A brain can only be changed at an early age by altering physical properties of the brain drastically changed. A split brain is defined by the physical separation of the two cerebral hemispheres that may translate into drastic differences both social and psychologically. The split brain procedure “consisted in cutting the two main bundles of nerve fibers... the corpus callosum and the anterior commissure” (Geschwind, 181). Modules that reside in the right and left hemisphere are a complex neural system that have a particular function, that can be endlessly modified and respond to environmental affects. The genetic control of the brain determines in advance the properties and abilities of the brain. Gazzangia wished to study the way a brain organizes the information into the separate left and right hemispheres. By observing modules, he saw how certain traits of a human took action in the evolutionary scheme.
Brain characteristics unique to humans are a distinctive trait of the individualism and powerful knowledge of the evolution of modern man, homo sapiens sapiens. A key brain structure is the corpus callosum a necessary part of human evolution and communication skills as information needs a structure to help transfer the information between the two hemispheres of the right brain and the left. The corpus callosum transfers the information so that the human being has greater knowledge and is able to communicate with others. The structure of teh anterior commissure isolates the two different brain hemispheres and breaks the union the corpus collosum had created. This behavior is observed under a split brain surgery when the hemispheres become isolated. Studies preformed isolating the learning process to only one hemisphere of the brain showed the relation of dependence to the other brain. When split brain surgery is preformed
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it leaves the patient emotional, psychological, stable and general behavior is left un harmed unknown to the patient.
The neocortex contains the separations of the two brain’s hemisphere amounting for half the entire volume of the brain. The structure is composed of two key elements: one controls the motor senses while the other part controls the sensory abilities of the human being. The two key areas dominate human behavior and belief in each the left and right hemisphere. The sensory cortex includes the function and controls the perception of the five senses. It includes the olfactory, visual, auditory, systems and is located on the left hemisphere of the brain (Zhilman, 47). The sensory motor functions of human beings is control primarily by the right hemisphere of the brain. The evolution of the sensory motor strips is associated with the skills and manipulation of the five sense by modifications in behavior, and the creation and use of tools.
The comprehension and origination of the brain crosses over from observance to the translation of the meaning of the object observed by the opposite side of the brain. The left visual field is perceived and comprehended by the right visual cortex crossing over dominant the other side of the body. Just as the right visual field is transmitted and translated to the left visual cortex. The cross over of the transference of information can often get confused, and information can be lost. The right visual field correlates for the behavior occurring of the dominancy of being right handed which is controlled by the sensory modules of the left hemisphere.
Within the left hemisphere there are distinctive areas dominated by the Limbic system which allow a human being to infer information and reflect upon it. In the Limbic region, the Broca’s area and Wernicke’s area are found unique only to homo sapiens. The Wernicke’s area is the key to language and speech, the source of comprehension . The evolution of this brain area acts as the important structure to increase communication and inference of human beings. The dominance of the left hemisphere increased rapidly due to these two specific regions. As the
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species evolved verbal ability was a dominant trait with control and specialization of skillls. With this advanced control of speech and the comprehensive ability of the homo sapiens to reflect and reason by cognitive ability. The greater use of this unique trait of sophisticated speech became a source in building stronger, more complex relationships with other individuals in the species.
The Limbic system uses the brain as an evolutionary tool to develop belief and behavior rooted in control of the emotions and senses. The importance for a species dependent on maternal care, nursing, and taking care of infants comes from the dominance of the Limbic system of the brain. The Limbic system includes brain areas already mentioned Broca’s and Wernicke’s. The key aspect of vocalization is traced to hominid behavior of maternal attention, and social unity of a separation call. The vocal element is key in building a community based on the understanding of language and speech. Vocalization has existed among primates for years, however it is the unique ability of a hominid to translate, understand and give specific meaning to vocals.
The evolution of the increased capabilities of the left brain is translated through dominant language behavior increased by social interaction between humans. There was a drastic change in the inherited social practice of living a small group or community. Communication between individuals increased and the behavior of the humans changed. Larger social groups began to form.
The importance of building community is easily understood by maternal care and the strength of the family.
The evolution of man shows clear brain differences between species as the complexities of the brain evolve to be more structurally advanced. The evolution of early man, beginning with homo erectus, displays different brain functions. The first major brain differences was in the vascularization of the the cranium of homo erectus. Since homo erectus walked upright the human
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needed more circulation of blood, The oxygen that followed to his brain allow the hominid to better manage as a new species in the environment. Emissary veins helped drain the blood from the bran cooling the brain due to access heat. (Bower) This brain blood drainage increased the circulation of blood in the homo erectus’ body. The social characteristic of homo erectus were also unique, as he realized the “environment could be controlled for personal improvement” (Gazzaniga, 149). This was evident in the new nomadic behavior of hunters and gathers as populations behavior become more nomadic
As a hominid continued to evolve the Neanderthal played an important role in the changes of brain activity and behavior. The Neanderthals dominant influence of the Wenicke’s and Broca areas of the brain allowed for the specialization of skill in tool making, shelter, and hunting ability. Neanderthals lived in larger groups thrived off competition and social relations evident in their self adornment with clothing and tools. Neanderthals “lived in caves and buried their dead, They took care of their own” (Lowenstein, 34). The Neanderthals is an unique evolutionary subject that exemplifies the power of the left hemisphere to dominate human behavior and decision. “Neanderthal learned to use water and began to navigate” ( Gazzaniga, 151) which made them a mobile society. The brains capacity from this point on began to radical develop at a quick rate. The human ability of use and understand language and speech made it easier to communicate, learn skill, and developed more specified tools such as sharps spear tips or cave shelters.
From early a hominid the importance of the dominant life cerebral brain is evident in our social behavior as we evolve we think and reflect on decision. The left hemisphere of the brain is not only distinct and unique to humans because of the special skills learned but the cognitive ability of the modules behind the behavior. “Beliefs emerges as a very specific feature of our species” (Gazzaniga, 141). Behaviors are changed and easily influenced by environmental
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pressures and biological affects upon the human species. Beliefs of that species are harder to change. Many social beliefs are learned and society reflects a system of beliefs or a code of conduct that makes it difficult for an individual to dismiss or reject such a belief. The ability of the left brain to reason, and infer and experience is the cognitive ability to form beliefs. The beliefs are held and preserved in evolution longer than human behaviors.
Human behavior is easily influenced and shaped by the environmental affects and social structures and institutions. Through this experience prejudices have developed against others passed on by simple difference, so that dominant traits will carry, and the behvior system goes unchanged. As the behavior of humans usually remains the same, beliefs change continuously. “Western civilization that personal consciousness is a product of a unified cognitive system and human action the product of a monolithic brain system” (Gazzaniga, 144). Gazzaniga refutes this belief and holds that a complex form of modularity control the right and left hemispheres that create individuality and differences in human preference. The beliefs of the early humans developed in to more complex societies and ultimately in to the present globalization of the world. These early societies were centered around early religion and beliefs about their existence. The foundation of psychological thought it cognitive thought which is unique to human perception. With different belief systems humans evolved expanded their Brains knowledge with a variety of information and important skills. This developed into the creation of institutions and the important features of modern society like school, religion, and government over the influence of individual lives.
The ability of a human to continually increase their knowledge is their unique ability to reason and control their own lives and environment. the two distinctive hemispheres of the brain still control a human’s physical and psychological perception of them selves in society. As an individual in the species I experience the dominate control of my brain over my senses.
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Recently a man stopped me as I was writing and commented on my ability to write left handed. He explained that most left handed people are hooked left handers that turn their hand to the right imitating how a right handed person compose. He said I wrote unequally and did not coform to the ‘right’ way to write. I took this as a compliment, but began questioning my habit of writing. The more I thought of being a “true left handed dominant writer” I thought maybe this correlates with the power and strength of my right brain hemisphere. According to Geschwind, “ Left- handed people also make better progress than right-handers” (189). I think being left handed allows for the continued important role of the Left hemisphere, but the influence in the conceptional thought is largely influenced by the right hemisphere's artistic influence.
Since I learned to write I have been very curious to why I am left handed. The dominate trait in my family is a long history of right-handed people, I didn’t see from where I had evolved. For much of my life in various situations I felt at a disadvantage to the dominant norm of right-handed people. Everything in modern society is designed with the over riding assumption that humans are naturally right handed. The reality is that the right-handedness is dominant in the population of human. However the choice of left or right hand does not mean that individual has a greater dominant left brain or large spatial dominance. What could be inferred is that the right hemisphere’s ability to infer information is more greatly receive in those people who demonstrate left handiness.
As I researched this paper I found two opposing beliefs of the dominant choice of a particular hand. According to professor Zhilman, “All human groups studied are mostly right-handed, by a ratio of a least three to one, whereas chimpanzees and other primate groups have equal numbers of right and left handers.” I found this evidence interesting and can understand how the dominance of the right developed along with the specialization of the left hemisphere, creating a greater communication. The Left hemisphere is dominant source of vocalization and
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communication and I understand how this is observed also in critical use of and development of tool use. I was therefore confuse by the information gathered by Geschwind who claims, “left-handed individuals are equally common. In human population no more than 9 percent are left-handed” (194). I believe more in the results found by Zihlman, because of the evolutionary evidence in the dominant role of the Left hemisphere and it’s sensory abilities.
I read this book in search of more information about the control of the right hemisphere of the brain and the submissive trait of being left handed. I found little information, and I am still unclear as to why the traits present in the right hemisphere do not become more dominant in an evolutionary sense. I think often about they way I process information and relative characteristic of my brains activity as I preform my daily task. Personally I feel as though my life in my beliefs, and the behaviors I act out are usually controlled by some aspect of the right hemisphere. I consider myself more artistic yet I also see the left hemisphere playing a key role in the fine tuning and detailed activities in the work I preform. I am definitely more educated about my own brain activity after reading this book. I feel as the knowledge of how I collect information and knowledge from my environment and is explained by the intricate systems of the human brain.
The Social brain operates as a collective cognitive system that relying on both the individual modules of the right and left hemispheres. This cognitive theory of brain activity is present in a human’s conscious and unconscious neurological level of modules. The two hemisphere's of the brain creates a dual system of action, behavior and belief which is displayed by a human emotional response. The subjective reflection of these behaviors and the change of belief is the key to future human evolution. The evolution of the human brain is related to the social atmosphere and environment where the individual learns daily.
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Bower, Bruce. The Great Brain Drain. Science News, Vol. 138, Oct. 13th, 1990
Gazzaniga, Michael. The Social Brian: Discovering the Networks of the Mind.New York: Basic Books Inc., 1985
Geschwind, Norman. Specializations of the Human Brain. Science America, pages 180-194, 1979
Lowenstein, Jerold M. The Other People: First Neanderhal Tells All. California Wild, 2000,
Maclean, Paul D. Brain Evolution and the Family: The Newness of mammals in the Oldness of Reptiles. Bethesda: National institute of mental Health, Anthro Quest, No. 24, winter pages 3-6, 1985
Perlman, David. A Passion for the Quirks of the Brain. San Francisco Chronicle, July 14th, 1996
Zihlman, Adrienne L. The Human Evolution Coloring Book. Oakville: Coloring Concepts Inc., 1982
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