The Human Brain: Biology, Biography, and the Making of Self
The Human Brain and the Making of Self
The Brain-Body Connection
What is the relationship between the brain and the body? The brain’s significance is evident in the concept of brain death. While organs like the heart, lungs, or liver can be transplanted, brain death signifies the end of a person. Brain activity, measured by an electroencephalogram (EEG), indicates the level of cellular activity in the brain, specifically the neurons and their synapses.
Brain Regions and Functions
The brainstem includes the medulla oblongata (responsible for vegetative functions) and the midbrain (controls functions like iris operation). The cerebellum controls fine motor movements. The hypothalamus regulates hunger, while the amygdala governs emotions. The cerebral cortex, divided into two hemispheres, plays a crucial role in higher-level functions. The left hemisphere is often associated with language and analytical thinking, while the right hemisphere is linked to creativity. Each hemisphere is further divided into four lobes: frontal, parietal, temporal, and occipital.
Brain Development and Pruning
Charles Darwin’s theory of evolution highlights the role of chance in the development of life. The human brain undergoes significant changes during development, including neuronal pruning. In early childhood, we lose up to 60% of our neuronal connections. This process, called myelination, protects axons and streamlines brain function. Myelination is not solely biological but also influenced by biographical and cultural factors.
Critical Periods and Social Development
Harry Harlow’s research on monkeys demonstrated the importance of social interaction during critical periods of development. Monkeys isolated during these periods exhibited neurotic behaviors and failed to develop social skills. Konrad Lorenz’s concept of imprinting further emphasizes the importance of early social bonds. These findings highlight the role of both biology and biography in shaping the brain and personality.
The Human as a Social Animal
Aristotle’s assertion that “man is a political animal” underscores the inherent social nature of humans. Cases of feral children, like Amala and Kamala, demonstrate the devastating effects of social isolation on human development. Victor of Aveyron, a feral child discovered in 1800, further illustrates the importance of social interaction in acquiring human characteristics. Itard’s attempts to educate Victor highlighted the role of society in shaping human behavior.
The Importance of Early Childhood Experiences
The cases of Romanian orphans and Anna, the deaf-mute girl studied by Helen Keller, demonstrate the impact of early childhood experiences on development. These cases underscore the human’s vulnerability and the importance of early intervention and social support.
The Role of Society
Humans are inherently social beings. We need society not just for survival but also for our development as individuals. Family plays a crucial role in procreation and raising children. While the traditional family structure has evolved, the need for parental figures to complement a child’s education remains essential.
The Brain and Personality
The brain plays a crucial role in shaping our personality. Brain injuries or accidents can significantly alter personality traits, as exemplified by the case of Phineas Gage. Conditions like prosopagnosia (difficulty recognizing faces), Wernicke’s aphasia (language impairment), and neglect (lack of awareness of one side of the body) further illustrate the link between brain function and personality.
Brain Plasticity and Free Will
The human brain exhibits remarkable plasticity, meaning it is capable of learning and adapting throughout life. A large portion of the human brain is not predetermined, allowing for new experiences and learning. This capacity for change is essential for free will.
The Human Habitat and Excentricity
Unlike animals, whose habitats are fixed, humans can adapt to and modify their environment. Heidegger’s concept of “respectivity” describes how humans create networks of relationships and meaning. Humans interact with the world not just through instinct but also through culture and technology.
Environmentalism and the Human-Nature Relationship
The environmentalist movement emphasizes the importance of balance between humans and nature. Humans, unlike animals, can pose a threat to nature due to their capacity for conscious action. However, humans also have the ability to protect and preserve the natural world.
Bipedalism and the Quest for Knowledge
Human bipedalism, walking upright on two legs, has played a crucial role in our evolution. Freeing our hands allowed us to manipulate objects, develop tools, and ultimately control our environment. Bipedalism also allows for a wider field of vision, contributing to our quest for knowledge.
Conclusion
The human brain is a product of both biology and biography. Our social interactions, cultural experiences, and capacity for learning shape who we become. We are inherently social beings, dependent on others for our survival and development. Our ability to adapt to and transform our environment, coupled with our quest for knowledge, makes us unique among animals.