Neurolinguistics

Neurolinguistics is the study of how the brain represents and computes language. Neurolinguistics is an interdisciplinary field, with elements of psychology, neuroscience, and linguistics all being an important part of the history and development of the field. Neurolinguists are people who study neurolinguistics. These scientists are interested in brain function and the implications of the way the brain works. Neurolinguists have to understand both neuroscience—the structure and function of the brain, and linguistics—the structure and human use of language. Neurolinguists use a variety of methods for studying the brain and its use of language, but the most important are imaging machines and machines that measure the electric signals in the brain. Scientists use data collected by the machines to develop ideas about how the human brain creates, processes, and responds to language. Humans have been interested in the brain and human thought for thousands of years, but the field of neurolinguistics only developed into its own field in the 1960s. The field developed thanks to new research about language acquisition in humans and new technology that allowed scientists to study the living brain without conducting surgery.

Background

The brain is part of the central nervous system (CNS) and is made up of two types of cells, neurons and glial cells. Neurons are most often responsible for sending and receiving information throughout the brain. Glial cells often mostly help support neurons, although scientists have learned that glial cells also play an important role in transmitting information. Neurolinguistics studies the parts of the brain and the pathways in the brain through which messages are sent. Language, like other information such as other sounds or images, is transmitted in the brain. Neurolinguists and other scientists are still answering many questions about where and how language travels in the brain. Humans use roughly seven thousand different languages, but scientists have found that the human brain deals with all language—no matter the language or the form of communication (e.g., through speech, through sign, through writing)—in a similar way. The job of a neurolinguist is to answer questions about how the brain processes and deals with language.

Overview

Humans have been interested in the brain and thinking for almost all of recorded history, although they still do not have a complete understanding about the brain and its functioning. Before modern medicine and technology, humans had very little information to develop theories about the brain and its use of language. One way humans learned more about the brain was through brain injury and disease. When people’s brains were injured or damaged by illness, scientists and doctors observed changes in patients’ behavior, thinking, and actions. These observations helped people better understand the roles that different parts of the brain play. In the nineteenth century, scientists learned details about areas of the brain that seemed to deal with language through such observations.

In 1861, a doctor named Paul Broca observed a patient who could no longer form words. The patient could say only the word “tan,” no matter how much he tried to communicate something else. The patient said the word with different expressions, but the word itself was always the same. As Broca observed the patient, over time, the patient’s physical condition worsened and eventually the patient died. Broca biopsied the man’s brain and found a lesion on the frontal lobe that was caused by disease. Broca also observed a second patient whose speech was greatly impaired. This patient could say only five words, though the words he could say, such as yes and no (in his own language), had meaning when he used them. When the man died, an autopsy showed that he too had damage to the frontal part of his brain. Based on his observations of these and other patients, Broca believed that language production was localized in that area. The area in question became known as Broca’s area, and doctors began associating it with language production. When this area of the brain is damaged or affected by disease, people can lose the ability to produce meaningful speech—even though they still understand language.

Over time, scientists learned that other areas of the brain could also cause problems with producing speech. For example, Wernicke’s area is another part of the brain that is important for language. It was named after scientist Carl Wernicke. When this part of the brain is injured some people’s speech is affected. They can produce words, but the words they say have no particular meaning and are unrelated to the ideas they are trying to convey. Broca’s area and Wernicke’s area are connected by a large bundle of nerves, as these parts of the brain communicate with each other often. Still, damage to one area causes a different disability than damage to the other.

Through further research, neurolinguistics and other scientists have found that, although some parts of the brain are highly specialized to perform certain functions, the brain can adapt and learn to perform functions in different parts. Even Broca himself noted that aphasia, or loss of speech, could improve with treatment, indicating that the brain could adapt to injuries by moving the functions of the damaged areas to other parts of the brain. Furthermore, some patients with aphasia can still sing because signing is processed in another part of the brain. Although no single part of the brain is specifically the section responsible for processing language, Broca’s area, Wernicke’s areas and other sections remain important sections for language processing.

The field of neurolinguistics evolved into its own separate field of study starting in the 1960s. At that time, new technology was making studying the human brain easier. Furthermore, ideas about learning and language acquisition were changing. For example, more linguists began to believe that language acquisition was an innate trait that humans had. With these changes, the field of neurolinguistics was able to change how people perceived of the human brain, language, and communication.

Brain research became more advanced as imaging technology allowed to doctors to see parts of the brain without having to perform surgery. In the 1970s, the computed axial tomography (CAT) scan helped doctors see inside the brain. This technology was important because it allowed doctors and scientists to scan the soft tissue of the brain, which helped them understand and identify brain injury, disease, and blood flow in the brain. The 1990s brought even more advancements with the improvement of functional magnetic resonance imaging (fMRI), which allowed scientists to have more detailed pictures of the soft tissue of the brain, and electroencephalography (EEG), which allowed scientists to measure the electric impulses that travel through the brain.

Scientists have also learned a great deal about human language development and acquisition through research. Before the mid-twentieth century, many psychologists believed that language was entirely a learned trait. Over time, however, scientists came to the conclusion that language is most likely an innate trait. Nevertheless, children learn the language or languages they encounter regularly. Children whose parents use only sign language will also begin using sign language rather than speech as infants. Children who are not exposed to particular languages will not have the ability to create certain sounds and tones of languages they do not learn. Nevertheless, many psychologists and neurolinguists accept the theory of universal grammar, which states that humans are born with the ability to acquire and use language. The theory also states that all language has certain parts (e.g., nouns and verbs) that humans are predisposed to understand. Although scientists are still studying and debating how humans acquire language, many neurolinguists believe that some of the acquisition is innate and some is taught. Modeling through artificial intelligence (AI) also helped scientists better understand language development and acquisition.

In addition to learning more about acquisition, neuroliguists’ research has taught humans more about brainwaves and brain function when the brain is exposed to language. Through modern technology, scientists have also been able to study brainwaves when humans are exposed to language. Scientists believe that human brains typically have similar responses to when they first hear speech. Because speech and brain processes happen so quickly, the initial change in brainwaves happens in the matter of only a few millionths of a second after the brain perceives speech. The same type of brainwave reaction occurs whether a person is awake or sleeping, indicating that humans have some awareness of language happening around them even when they are sleeping. Similarly, human brainwaves are similar when they encounter similar types of communication situations, such as a sentence with incorrect syntax. Neurolinguists believe that studying brainwaves will help them better understand the parts of the brain that deal with speech and the brain’s methods of dealing with language.

Bibliography

Ahlsen, Elisabeth. Introduction to Neurolinguistics. John Benjamins Publishing Company. 2006.

Alduais, Ahmed, et al. "Neurolinguistics: A Scientometric Review." Cogent Arts and Humanities, vol. 10, no. 1, 9 Apr. 2023, doi.org/10.1080/23311983.2023.2197341. Accessed 25 Nov. 2024.

Benítez-Burraco, Antonio. “Rhythms in the Brain: Exciting Times for Neurolinguistics.” Psychology Today, 29 Aug. 2018. https://www.psychologytoday.com/us/blog/the-biolinguistic-turn/201808/rhythms-in-the-brain-exciting-times-neurolinguistics. Accessed 9 Jan. 2019.

Cowie, Fiona. “Innateness and Language.” Stanford Encyclopedia of Philosophy, 2008. https://plato.stanford.edu/entries/innateness-language/. Accessed 9 Jan. 2019.

França, Aniela Improta. “Introduction to Neurolinguistics.” Federal University of Rio de Janeiro, 2004. http://www.ucd.ie/artspgs/langimp/RelatorioEvelin2004.pdf. Accessed 9 Jan. 2019.

Ingram, John C. L. Neurolinguistics: An Introduction to Spoken Language Processing and Its Disorders. Cambridge University Press, 2007.

Konnikova, Maria. “The Man Who Couldn't Speak and How He Revolutionized Psychology.” Scientific American, 8 Feb. 2013. https://blogs.scientificamerican.com/literally-psyched/the-man-who-couldnt-speakand-how-he-revolutionized-psychology/. Accessed 9 Jan. 2019.

Menn, Lise. “Neurolinguistics.” Linguistic Society of America. https://www.linguisticsociety.org/resource/neurolinguistics. Accessed 9 Jan. 2019.

Shin, David. “What Is fMRI?” UC San Diego, Department of Radiology. http://fmri.ucsd.edu/Research/whatisfmri.html. Accessed 9 Jan. 2019.