Broca's Aphais

Paul Broca was a French physician, anthropologist, and an anatomist. He specialized in the study of speech. His major discovery was of “Broca Area”. Broca area is also called convolution of Broca. It is the left hemisphere of the brain that contains neurons and these neurons are involved in speech function. The Broca’s area lies in the third frontal convolution, just anterior to the face area. This area is connected to the other regions of the brain. This area involves in language comprehension that is associated with hand movements.

History tells us that the real motivation behind this research was a person named Louis Victor Leborgne who lost the ability to speak when he was 30 years old. He could only utter a single syllable word: Tan. After the accident, when he came to the hospital, he had a speech disorder. He could not speak properly for two to three months. Apart from his inability to speak, no other major trauma was observed. After the 10 years of the accident, Tan was admitted to the hospital again because many other health problems had started. There he met the first time the French physician “ Pierre Paul Broca.”

Broca’s major area of interest was speech. This case of Tan intrigued him. Broca decided to check the other faculties of the patient. It was a tricky business as Tan was right-handed, not only could he not speak but also could not write. Communication proved complex. However, he could gesture his left hand which at times become incomprehensible. Surprisingly, he was good at numbers. He knew precisely how long he had been at the hospital. His other faculties had degraded but in some ways, he remained sharp as ever. When it comes to “ Broca’s Area”, he remained hopeless. Broca termed this as, “deficit aphémie, or aphasia, the loss of articulated speech.”

Later findings include the biopsy of his brain after his death. It revealed a great lesson in the frontal area. After some months, Broca met another patient Lazare Lelong. Unlike Tan, he could speak five to six words such as, “yes, no, three, always and Lelo ( his attempt to say his name).”

After his death, his brain, too, was autopsied. Here Boca found that that there is a specific area in the brain, if it is affected, a person is unable to produce meaningful sounds and ultimately loses the ability to communicate.

Other researchers and neurologists also worked in this area. The German physician and medical writer Johann Gesner published a treatise on the topic, “Speech Amnesia”. Another neurologist named Carl Wernicke also worked on fluent aphasia. In 1824, French physician Jean-Baptise Bouillard took Gesner’s idea further and proposed a remarkable notion that brain may well be localized.

The method of research which Paul Broca adopted was Case Study. He studied almost 25 patients with the almost the same problem. He observed them and interviewed them too. The best case study was of Leborgne’s brain which presented an opportunity to test and refine Bouillard and Auburtin’s theories. Finally, in 1865, a full four years after the famous Tan’s brain autopsy that Broca was finally ready to assert that speech production was localized in a specific part of the left frontal lobe, the region that now bears his name. By that time, he had described the brains of 25 additional patients who had suffered from aphémie and had come to conclude that speech articulation was indeed controlled by the left frontal lobe, just as Bouillard and Auburtin had suspected. Brain function wasn’t entirely fixed, Broca wrote, “With time and therapy individuals could improve.”

In an analysis of findings, Broca noted that most aphasics would within week begin to regain some of their abilities or become better even with their loss if they were given the opportunity to practice. Broca raised a question that could it not be that the right hemisphere was taking some of the functions of left? In this question, Broca went a step beyond. He anticipated the current understanding of brain plasticity that is the ability of the brain to learn new ways of function.

In modern days, new findings show that Broca may have been, in many ways, marvelous but he was also not altogether correct. As early as 1906, Pierre Marie-Broca’s student- noted that Broca’s aphasia could be caused by much larger lesions that one identified by Broca himself. Later hypotheses show that even Leborgne’s original lesion, when scanned with modern MRI technology, was shown to extend beyond the areas originally identified by Broca. Boca was correct in the localization of speech production but not completely correct in the understanding of how large localization maybe.

Still, the extent of Broca’s contribution to psychology and neuroscience can’t be underestimated. His work set the stage for much of what we now term cognitive neuroscience and neuropsychology. Two major principles that now govern how we think about the brain—the localization and lateralization of function and the notion that an impairment in one area of cognition (i.e., language) as a result of brain damage does not necessarily signify a general impairment in intellect—are in large part a result of Broca’s pioneering work.