By Steven Gimbel, Ph.D., Gettysburg College
When psychologists began learning about the human brain through technologies like MRI and PET scans, they realized the processes were not as simple as they expected. People were not the autonomous individuals that they expected and much of what they thought about humans was challenged. Could they prove that humans were autonomous individuals?
When scientists discovered and later observed atoms, they realized atoms were not distinctly functioning, and they depended on each other. The same thing happened when psychologists used modern imaging technologies to observe brain processes. They soon found out people were not the autonomous individuals they used to think. Genes and environment were the other two big players.
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Genes in Brain Development
Everything starts with the development of the brain in the human fetus. Genetics guides the process here—25,000 of a human’s genes are active in the creation of the central nervous system. Cells begin to develop into what they need to be to form an organ, and in the case of the brain, hundreds of types of cells are needed, for example, neurons.
Neuronal cells form complex webs to send particular signals and are glued together by glial cells. The gaps in the neural structure are called synapses, which complete the structure for neurons to transmit or inhibit chemical-electrical signals. Does this process happen the same way in every fetus?
This is a transcript from the video series Redefining Reality: The Intellectual Implications of Modern Science. Watch it now, on Wondrium.
The Role of the Environment
The environment plays a crucial role in every tiny step of human life. In the case of a fetus’s brain development, the chemical environment of the mother’s body significantly affects it. The reason is that the brain has an inflationary stage very similar to the universe in the Big Bang theory. In the rapid expansion stage, it will get the structure of the last moment before expansion.
In the second month, a thin tube of fluid is developed lined with progenitor cells, which will later become the brain. The progenitor cells somehow explode into dividing at the super-fast pace of a quarter-million times per minute to create the brain. The final brain structure will have about 100 billion neurons and at least a trillion glial cells that will remain the same number until the end of the person’s life. The brain is the only organ that cannot rejuvenate or fix itself by cell division by creating new raw materials.
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The Functioning of the Brain
The way the brain cells are created affects the functioning of the brain throughout the person’s life. For example, exposure to radiation can cause serious problems in brain cells, and alcohol in the mother’s blood can create cognitive and self-control issues for the child later.
Unlike what most people believe, genes do not determine everything. The environmental factors are undeniably important in the fetus’s brain development and the rest of the child’s life. The chemicals around the fetus at the time of development can be as important as the genes in determining who they will be in the future.
Interactions with the Environment
After birth, the effect of the environment gets even more significant as the individual begins interacting with it. The brain is an extremely dynamic structure and is significantly affected by a person’s experiences and surroundings. In fact, humans are elements of the environment and cannot be independent of it.
The role of genetics in a child’s development is also greatly affected by the environment. If certain environmental triggers do not start a development that the genes have prepared, the child will not develop that skill or ability. For example, if a healthy child with a working brain and eyes is raised in darkness, the parts of the brain responsible for sight will not be stimulated and, therefore, will never develop.
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The Connection Between the Brain and the Environment
When adults talk to babies, almost all of them change their pitch from low to high. Why? Because it is important in brain development! A monotonous speech can cause deficiencies in the child’s brain development.
PET scans of adult brains show that the brain is inextricably interconnected with its surroundings and runs parallel processes all the time. There are also some fully automatic processes like distinguishing one’s name in a crowded room. The brain wants the person to know why their name is being said and if it is a good or a bad sign.
Another example is how people tend to see faces in everything—the front of a car looks like a face with two big eyes (the headlights) and a big smile (the grill). There are psychological reflexes formed by pre-cognitive processes.
Thus, humans are not at all autonomous individuals independent of their environment. They are part of it.
Common Questions About Autonomous Individuals
An autonomous individual is one who can decide and act completely independent of their environment. Despite what most people believe, this is not the case of humans.
The power of will might make people think they are autonomous individuals, but when the role of the environment and genes is studied, one can see how dependent an individual is on those elements.
There are 25,000 genes in the central nervous system of an individual. They are a part of determining how un-autonomous an individual is, by showing how much they depend on the genes.
No, humans are not autonomous individuals from the genes and from the environment. Every genetically determined period of growth needs exposure to certain sorts of stimulation to begin development.