3.7 billion people are either bilingual or multilingual. Yet, scientists are just beginning to understand the neuroscience of learning a language. This article aims to be a comprehensive overview of neurolinguistics or the study of how the brain handles language.
The article will first delve into how the scientific understanding of how language has evolved over time, benefits of learning a language, and how language is processed at different ages. Finally, the article will discuss how identifying disturbances in linguistic ability can be used to recognize larger neurological disorders including Schizophrenia and Dementia.
HISTORY OF NEUROLINGUISTICS
The ability to communicate is invaluable to the development of species. Not only does it help one express opinion, but, it builds friendships, culture, and identity. Unlike many other species, humans can memorize thousands of words. By adulthood, the average human’s knows anywhere between 20,000 to 50,000 words. source. Efforts to understand how humans are able to comprehend a vast amount of expressions date back to as far as 150 years ago. source It was not until the development of advanced neuroimaging devices the Magnetic Resonance Imaging (MRI), Functional Magnetic Resonance Imaging (fMRI), and Diffusion Tensor Imaging (DTI) that scientists were able to understand how the brain learns languages. Source.
BENEFITS OF BILINGUALISM
The understanding of bilingualism has changed throughout time. In past decades, bilingual infants were thought to have difficulty differentiating between two languages resulting in delayed speech development. source In recent years, new evidence has dispelled this theory due to the discovery of denser gray matter in the left hemisphere of the bilingual brain. Source Gray matter is responsible for speech, hearing, feeling, seeing, memory, and control of muscles. Individuals who learn a second language before five, or are extremely proficient in their language, have the densest gray matter of all. Source. This finding demonstrates that language learning in early stages of life significantly strengthens the brain.
Bilinguals individuals are better at executive functioning than their monolingual counterparts. This could be because bilinguals are constantly forced to switch between two languages at once. Source. The ability to switch between two languages also had proven to improve memory, planning, and motor control. Source.
Figure 1: Areas of the brain used for executive function, strengthened by bilingualism Source
AGE OF ACQUISITION
Does that mean that individuals who learned a language after the age of five have harder time learning language? No and yes. Children possess more linguistic self confidence than adults. Having linguistic self confidence makes an individual more likely to be motivated in their language learning journey. Source. This may contribute to why children can more easily learn a language, since there are less expectations of the level at which they can communicate. From a neurological perspective, older learners are more likely to use different areas of the brain for separate communicative tasks. For example, they might use the Wernicke’s area to discover the meaning of words but the Broca’s area for grammar and syntax. Meanwhile, their younger bilingual counterparts use overlapping areas of the brain when utilizing their second language. Source. Using overlapping brain areas to execute different tasks, means younger individuals can more easily strengthen their brain and language abilities. This could be a contributing factor to why younger individuals can more easily learn language. Yet, this seems to oversimplification of the understanding of language acquisition. It is also important to consider amount of exposure to the language and motivation. Source. All these factors contribute to how easily one can acquire a language. Clearly, the more motivated one is and more exposure an individual gets to a language, the more likely they are to succeed.
The cognitive and neurological benefits of being bilingual apply no matter what age one learns a language. Language learning in adulthood even has additional benefits including warding off neurodegenerative disorders. Source. A common finding is that older adults who regularly engage in brain-stimulating activities including reading newspapers, going to visit museums, or learning a new language may delay or reduce the occurrence of cognitive decline. Source. A 47% decrease in risk of developing dementia was found in adults over 75 years old who completed crossword puzzles four days a week versus only one day per week. Source. This could be due to increased brain plasticity or the brain’s ability to change and form new connections with brain cells. Source. Alzheimer’s disease causes negative changes to brain plasticity at the brain synapses or the areas where neurons communicate with one and other. Therefore, if individuals at risk of Alzheimer’s engage in brain-stimulating activities, they can compensate for the loss of brain plasticity by developing a strong and “plastic” brain. Source.
While progress has been made towards understanding how language is interpreted in the brain, more needs to be done. The methods currently employed to diagnose and treat brain injuries including stroke, tumors, and concussions need to be updated. This can be done through donations to brain banks, specifically among people with neurological disorders. The same could be argued for the research of neurolinguistics, donating to brain banks is crucial to answering many of the remaining questions.
Language mastery is not a simple task. Languages are complex: full of strict rules, unique characters, and sounds. As a result, acquiring a language takes an immense amount of time, dedication, and motivation. In the end, though, the challenge is worth it. Language offers a whole new understanding of culture, literature, food, and people. It is truly never too late to learn a language.
The header image was sourced here: https://www.thoughtco.com/what-are-neurolinguistics-1691342. All other sources are placed beside the sentence in which the idea was derived from in a linked text.