This blog post explores why humanity has regarded the brain as the most mysterious organ and has continuously explored it across the ages.
Ever since the first beings worthy of being called ‘human’ appeared on Earth, humanity has carefully observed and studied their own bodies. In an era when the body was one’s entire possession and the sole driving force for obtaining food, clothing, and shelter, this curiosity was entirely natural. What began as a tool for survival, the exploration of humanity, has been passed down as a spiritual legacy from generation to generation. Sometimes as an object of intellectual inquiry, sometimes as a means to kill more easily in war, the study of the human body has continued into the modern era, driven by diverse purposes and desires.
Among a body so full of questions it could be called a collection of riddles, what is the most mysterious? I am confident that many would answer ‘the brain’ to this question. The brain is an organ that does not readily reveal its secrets, and neuroscience is regarded as the cutting edge of modern natural science, holding unpredictable and boundless potential for application. This article briefly examines the history of neuroscience from prehistoric times to the present.
The earliest recorded research on the nervous system dates back to ancient Egypt. Records indicate that patients suffering from severe headaches or mental disorders underwent trepanation. To put it politely, it was trepanation; to be frank, it was simply cutting open the head with a crude knife and then stitching it back up whenever someone had a headache or seemed a bit off. The notion that the brain governs mental activity only became established as conventional wisdom in late Greece. Prior to Hippocrates, it was commonly believed that the heart governed consciousness. The notion that the brain regulated body temperature and that nasal discharge resulted from the brain overflowing due to overload was widespread throughout society, including Aristotle. However, through the era of the legendary Greek physicians Hippocrates and Galen, the idea that the brain governed consciousness solidified into common knowledge. Galen, who treated gladiators in Roman times, even recorded that gladiators lost their mental faculties when they sustained persistent brain damage.
After antiquity, research on the brain began to stagnate in Europe. In medieval Western Europe, praising the divine and harboring no questions about nature was considered a virtue. During this period, the baton of research was taken up by the Eastern Islamic world. Scholars like Abu al-Qasim (known as Abulcasis), Al-Zahrawi, Avensojar, and Averroes documented medical questions, but their research was lost when medieval Islamic states collapsed. Research on the brain began anew in Western Europe during the Renaissance. Descartes, who asserted that the brain governs all animal movement, and Vesalius, who conducted brain research through human dissection—then considered taboo—were leading figures.
As the era transitioned into the modern period, brain research began advancing rapidly, starting with Galvani’s experiments on bioelectricity. This experiment, which proved that electrical currents could be generated in frog legs, was a crucial first step suggesting that the nervous system was a mechanical system using electrical signals to transmit commands. Later, Richard Caton proved that electrical currents could be generated in the brain. This, combined with the mechanical understanding of the brain and advances in microscopy, finally ushered in modern brain research.
The first major achievement, made possible by precise dissection and advances in microscope resolution, was the discovery of the neuron. While common knowledge today, neurons were only discovered in the early 20th century. Before that, they were perceived as peculiar entities, deviating from the common understanding that organs were tissues formed by clusters of cells. However, when Italy’s Camillo Golgi developed the silver staining method, which enabled the observation of neurons, it was confirmed that the brain is also an organ composed of clusters of these cells. Subsequently, research into the functions of each brain region and the principles of brain operation flourished. Among the most representative examples are the ‘Broca’s area’ and ‘Wernicke’s area’ in the cerebral cortex. French physician Paul Broca proposed that specific regions of the cerebral cortex govern specific functions, a theory later proven by the fact that damage to these areas impaired language ability. Together with Carl Wernicke, who developed theories on language production and comprehension, they left their names on the brain. Both areas govern language, but their functions differ. Broca’s area is responsible for the function of speaking, while Wernicke’s area handles the function of interpreting language. Consequently, a person with damage only to Broca’s area can understand others’ speech perfectly but produces incomprehensible gibberish, while a person with damage only to Wernicke’s area interprets others’ speech strangely and responds accordingly. Thanks to advances in electrophysiology, bioinformatics, and molecular biology, neuroscientists have significantly advanced research into the brain’s mechanical operations, including studies of synapses—the gaps between neurons—and the electrical potentials involved in signal transmission.
Despite these major advances, much of the brain remains shrouded in mystery, with countless fascinating topics awaiting exploration. Examples include attempts to create biological parallel computers that could replace serial computers by applying the brain’s structure, research on brain implants, and cryotherapy for the brain. Currently, research into the brain’s mental activities is not confined to specific academic disciplines, and researchers need not necessarily be biologists or physiologists. Rather, the research topics are so vast that it is difficult to pinpoint exactly what constitutes the subject of study. However, this is by no means a negative situation. It is, in fact, a positive one. In the 21st century, an era of applied and convergent sciences, the synergy created by experts from diverse fields collaborating is expected to continuously inject vitality into the brain science community. One might even entertain the expectation that exploring brain science, the very frontier of modern intellect, could be a way to foresee humanity’s future.
