Wernicke discovered that damage to the ____ cortex produced language impairment.

If you have studied portions of the brain in psychology, you may have come across the term "Broca's area." The mind behind this vital area of the brain comes from Paul Broca. Who is he? Why is he essential to psychology?

• What are some brief biographical facts about Paul Broca?
• How did Paul Broca contribute to psychology?
• What did Pierre Paul Broca discover?
• What are Paul Broca's enlightening experiments?
• What is an example of dysfunction in Broca's area of the brain?

Paul Broca – Biography

Before Paul Broca became known for his major discovery of the function of a specific area of the brain, what was his life like? Who was he?

Paul Broca's Biography – Education and Work

Broca was an incredibly intelligent and tenacious student. At the age of 17, Broca entered medical school in Paris and quickly graduated at the age of 20. Shortly after, Broca became a professor at the University of Paris and taught surgical pathology.

When he was 24, Broca had already been awarded medals and important positions in his field. These scientific awards were due to his research on cancer pathology, the treatment of aneurysms, infant mortality, and the study of cartilage and bones. These areas were not Broca's main interest, however. Broca was most interested in the anatomy of the brain and how it functions.

Broca was a neuroanatomist who made contributions to the study of the limbic system and rhinencephalon. His research on the localization of speech in the brain paved the way for new research into the lateralization of brain functions.

Neuroanatomy is the scientific study of the parts (anatomy) of neurons (brain cells).Rhinencepholan is the area of the brain involved in smelling (the olfactory system).

Broca wrote extensively on Darwinism, which became known as transformism in France. He also founded the École des Hautes Études, one of France's most elite establishments for education and research in neuroscience and chemistry. Also started in France by Broca is the Société d'Anthropologie de Paris (founded in 1859). It was a society for scientists to share their ideas and theories. The society Broca founded is the oldest anthropological society in existence.1

Paul Broca's Biography – Notable Research

Paul Broca's research is extensive, but here is a brief list of his accomplishments:

Anatomy Research

Broca contributed significantly to the comparative anatomy of primates. He was interested in the possible relationships between the brain's anatomical features and intelligence.

Anthropology Research

Physical anthropology was another area of interest and expertise for Broca. In addition to founding an anthropology society, he founded the Revue d'Anthropologie in 1872, and the School of Anthropology in Paris in 1876.

In his anthropology research, Broca helped advance the science of cranial anthropometry. He developed new tools to measure the cranium (the outside of the skull) and named these instruments craniometers. Broca theorized that there was a correlation between the size of someone's face and skull and their level of intelligence.

Anthropometry is the study of physical measures of a person's size, form, and functional capacities. Craniology is the study of the shape and size of the skulls of different human races.

Of course, the most notable discovery for Paul Broca was deep inside the brain. One important experiment led Broca to create a wave of changes in the field of psychology.

Paul Broca – Contribution to Psychology

When an entire area of the brain is named after you, it is safe to assume it was a large contribution to science! So what was Paul Broca’s contribution to psychology?

Broca studied anthropology extensively and wanted to study different-sized craniums (skulls). He created new techniques to map and measure the structures and forms of skulls and brains. His curiosity grew, and he wanted to understand more than just wherethese areas are found. He wanted to know what each area did. In his research, he was able to map an important area of the brain that is responsible for our speech. This area was later named Broca's area of the brain.

Paul Broca – Experiment

In 1861, Broca announced that he had made an extraordinary discovery! Broca said that he could identify the area of the brain that was in charge of speech. Within the left frontal region of the brain, Broca named this the "convolution of Broca."Why was this so important? It was the first time someone could anatomically (within the body's structure) pinpoint an area of the brain and tell you what it did.

Broca’s area is known as the area of the brain that contains neurons involved in producing speech.

Broca's Patient Tan

Broca wanted to understand how important speech function was to this area of the brain. In 1861, Broca performed an autopsy on a patient who had lost the ability to speak. Broca nicknamed this patient Tan. Interestingly, even though Tan was not able to speak, he was able to understand language, and his vocal cords were undamaged. Why was he unable to speak?

Broca studied the areas of Tan's brain through autopsy and found deterioration in Broca’s area of the brain. More specifically, there was damage to the frontal lobe of Tan's left cerebral hemisphere. Broca determined that Tan had a lesion or cut caused by syphilis in the left portion of his cerebral hemisphere. That lesion covered the area of the brain responsible for speech production and caused Tan's strange symptoms.

Tan was not the patient's real name. When trying to respond to doctors, the only word that the patient seemed to be able to say was "tan." Therefore, Broca nicknamed this important patient Tan.

The Discoveries of Pierre Paul Broca

What did this damage mean for Tan and his symptoms? This destructed area of his left frontal lobe led to his inability to speak. A loss of speech due to damage in this area of the brain became known as Broca aphasia.

Discoveries of Pierre Paul Broca – Connections to the Wernicke Area

Broca's discovery of this brain area is not the only important area associated with speech. Karl Wernicke also discovered an important area of the brain responsible for understanding speech. Wernicke's research focused on an area in the posterior (back) superior temporal lobe of the brain that connects to Broca's area through a neural pathway.

Wernicke's area is mainly involved in the comprehension or understanding of speech. This area of the brain is most associated with language processing (written or spoken forms of language).2 These two areas of the brain work harmoniously together in understanding speech (Wernicke's area) and using speech (Broca's area).

Broca's Area – Example

What if Broca's area is damaged? How will that change a person's functioning? Let's discuss an example of a person with symptoms of Broca's aphasia and what they may be experiencing.

A patient comes into a medical office with some severe and strange symptoms. The patient cannot speak in complete sentences, and the speech is very broken. The patient can understand what is being asked or said to them; however, they are having great difficulty responding. When trying to respond, the sentences are reduced to simple phrases or even just singular words such as "yes," "no," or "need help." Trying to answer questions easily frustrates the patient. Even stranger still, the patient's right arm and leg feel weak (due to damage to the frontal lobe).

Brain scans of this patient show lesions in the area of the left frontal region of the brain. These lesions are severe and seem to have been there for a short period of time. All of these serious symptoms point to a diagnosis of Broca aphasia, meaning that there is damage to Broca's area of the brain.

What if there is damage to both Broca's area and Wernicke's area of the brain? This will result in a diagnosis of global aphasia, and its effects are even more severe. Those diagnosed with global aphasia experience difficulty both using and understanding speech. They can only understand a few words and phrases. They also struggle with reading and writing as well as simply repeating words spoken to them.

Paul Broca - Key takeaways

• Broca's research on the localization of speech in the brain paved the way for new research into the lateralization of brain functions.
• Broca’s area is known as the area of our brain that contains neurons involved in our speech function.
• Broca determined that Tan had a lesion or cut caused by syphilis in the left portion of his cerebral hemisphere that was the cause of Tan's strange symptoms.
• A loss of speech due to damage in this area of the brain became known asBroca aphasia.
• Damage to both Broca's area and Wernicke's area of the brain will result in a diagnosis of global aphasia.

References

1. Muni, Gitau, Turker, Crouch, F. M. F. B. (2018). Pierre Paul Broca. History of Psychology. Retrieved June 21, 2022, from https://history-of-psychology.readthedocs.io/en/latest/broca.html
2. Speech & Language. (2022). Memory and Aging Center. Retrieved June 21, 2022, from https://memory.ucsf.edu/symptoms/speech-language

What is Broca's area and Wernicke's area?

Which of the following is an example of Wernicke's aphasia?

Which of the following defines Wernicke's area?

What kind of difficulty did Wernicke identify among his patients?