History of the study of the human brain

In our days, the study of the brain is very advanced (although not as much as we would like, since the human brain still hides many questions). Indeed, more progress has been made in the study of the brain in the last 20 years than in all the previous millennia.

The history of the study of the brain is exciting.. How has this organ been considered by different times and cultures? From Prehistory to the present, passing through Ancient Egypt and the European Middle Ages, the brain has gone through different states of appreciation.

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History of research on the human brain

In this article we offer you a brief journey through the study of the human brain.

The brain in Prehistory: the beginning of trephinations

The brain and skull area were already important to men and women in the first millennia. The oldest manifestations of cranial surgery date back to no less than the 6th millennium BC. c.

Numerous human remains have been found with obvious signs of trephination

; Famous is the case of the 12 graves found in Rostov-on-Don, Russia, where at least 3 people showed holes in their skulls that had evidently been made with sharp instruments. But the practice was very common in other regions of the world that, in theory, were not connected culturally: we also find cases in Africa and South America, where the pre-Inca civilizations (III millennium BCE C.) practiced trephinations to alleviate migraine or epilepsy and, in addition, used coca or other vegetables to alleviate pain.

This raised the question: Were the trepanations part of a ritual, or were they performed for medical reasons? The first case would mean that, during Prehistory, the brain enjoyed capital importance in the religion of these first human communities. In any case, and despite the low survival rate, there have been cases in which the patient survived the operation for at least 4 years.

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In Egypt, the brain does not matter

Ancient Egyptian funeral rituals are rich and elaborate. In the first place, the organs of the deceased were extracted and deposited in the so-called canopic jars. The body was then dried with natron. The mummy was buried, after various rituals, with its canopic jars, since the organs had an outstanding postmortem function.

But was the brain also kept? The answer is no. Those responsible for the mummification extracted the brain from the corpse through the nostrils, using an iron hook, and then the organ was thrown away. This means, of course, that Egyptian religion did not attach any importance to the brain, nor did it have any important function in the afterlife.

However, despite not giving it any spiritual value, there is evidence that the ancient Egyptians knew about brain morphology and its relationship with certain injuries or diseases. So, in the call Edwin Smith papyrus (2nd millennium BC) C.), we find a detailed analysis where, for the first time, the importance of the central nervous system is highlighted, as well as the brain as the governing body's functions. The document is of capital importance, since it constitutes the first medical testimony based on an empirical and objective observation.

In fact, it is believed that, in Ancient Egypt, trephinations were performed to treat migraines, epilepsy and other ailments. And, again as during Prehistory, many of the patients survived. It may even be that, in some cases, their pain was relieved, since trephination could be relatively effective in relieving pressure on the brain or draining bruises.

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The classical era and the foundations of the study of the brain in the West

All Western medicine, until very recently, was based on the principles of the Greek physician Hippocrates (who, in turn, most likely drew on Egyptian lore). Knowledge was concentrated in Alexandria after the conquest of Egypt by Alexander the Great; the world-famous city library housed a multitude of books relating to human medicine and anatomy.

In fact, it was Herophilus of Chalcedon who established one of the currents that would later prevail in the Middle Ages. This Greek sage described the configuration of the cerebral cortex and its ventricles, in which he affirmed that the higher functions were found. Gregor Reich collects this theory many centuries later, in his work Margarita Philosophica.

Galen was another of the great names of classical medicine. His works contain quite a few errors (it is believed that because of the ban on dissecting human corpses, the doctor had to be content with animals). However, he established what would be another of the currents that would continue in force in medieval times: placed the mind, and therefore reasoning, in the brain tissue.

The Middle Ages, the brain and the "stone of madness"

Heir to classical wisdom, the medieval period collects, as we have already indicated, the main theories of Herophilus and Galen. In the Middle Ages it is believed that the higher functions (reasoning, emotions...) are found in the ventricles of the brain. Thus, madness or dementia is seen as the manifestation of a problem in these areas of the brain.

For the medieval human being, madness is caused by the formation of mineral strata that press on the brain or clog ventricles. For this reason, it is quite common at this time to find so-called "doctors" who offered to trepan "madmen" (quite an ambiguous term in the Middle Ages) and thus extract the "stone of madness". Famous is the painting of El Bosco, preserved in the Prado Museum, where the artist makes a caricature of such activity: a charlatan is extracting the stone from the head of a man, who allows himself to be deceived by the evil arts of liar. In Bosch's painting, a tulip appears instead of the stone, a clear reference to the deception of which man is being a victim, as well as to his own foolishness.

During the Middle Ages, madness is faced in contradictory ways. The "crazy" can be enlightened, a being who sees things that others do not see (and that is why tributes are dedicated to him such as the Fiesta of the Fools, an authentic exaltation of madness) or it may be a demoniac who must be expelled from the community.

In any case, the only solution is exorcism or the extraction of the stone that causes dementia.

Forbidden to dissect

The Middle Ages was not the only time when the dissection of corpses for anatomical study was prohibited. Already during the Greek and Roman times there were prejudices in this regard; We have already discussed how Galen had to experiment with animal corpses to draw conclusions from him.

Around the 13th century, dissections of human bodies began to become more frequent, although the shortage of corpses fuels the assault on the tombs, so the authorities decide to put back restrictions. Already in the fifteenth century we find a more or less common activity in terms of dissection of corpses: Leonardo da Vinci himself performed dissections to study human anatomy.

This advance in terms of direct exploration of the human body allowed the study of the brain to speed up and the first neurological studies began to proliferate.

the scientific revolution

In the 16th century, Andrés Vesalio published his De humani corpus fabrica, a capital work that represents a turning point in the study of human anatomy and, therefore, of the brain. This extensive work (no less than 10 volumes) laid the foundations of modern brain anatomy.

Based on his lectures at the University of Padua, this collection of Vesalius draws on cadaver dissections to present a detailed examination of various organs. Advances in printing made it possible to accompany the books with high-quality engravings that were a perfect illustration for explanations. This work emphasizes that the ventricles of the brain are the place where functions such as memory or emotions are based.

A little later, Nicolás Steno, a Danish doctor, affirmed that the brain is the most delicate part of the human body and, therefore, must be taken care of to avoid any dysfunction that culminates in craziness. For his part, Thomas Willis used the term neurology for the first time, joining the Greek word neuro (rope) with logos. Willis is considered the father of modern neurology; In his work Cerebri Anatome, this English doctor makes a very precise description of the internal morphology of the brain.

Already in the eighteenth century, Giambattista Morgagni associates diseases with anatomical injuries for the first time; for example, he claimed that the stroke was caused by lesions in the veins of the brain. Morgagni is the author of the first book of pathological anatomy.

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The 19th century, a time of progress?

The 19th century will mean an important advance in terms of the study of the brain. Santiago Ramon y Cajal published his work on the nervous system, where he stated that it is made up of independent cells connected to each other in specific places (neurons). His work earned him the Nobel Prize in Medicine in 1906 and laid the foundations of current neuroscience.

However, the supposed century of advances also had its dark spots. Darwin's theory of evolution gave rise to the appearance of racist theories that tried to "justify" the inferiority of races. In other words, the absurd theory spread that some human groups were more evolved than others. This idea reached its zenith in the 20th century, when the Nazi party tried to "prove" the supremacy of the Aryan race by measuring skulls, and other even more macabre experiments.

The study of the brain continues its course. We are getting closer to understanding this fascinating organ in its entirety, but there are still many doors to open.