The ability to speak other languages aside from one’s native language is a highly valued skill in society. The human brain has an amazing capacity to serve multiple languages at once and even discriminate between them in different contexts. However, is there any neurological benefit to acquiring a second language?
A study by Berken et al. set to determine the effects of early versus late second language acquisition on brain structural development and communication patterns. They studied 3 different groups of people which included simultaneous bilinguals who acquired both the French and English languages from birth, sequential bilinguals who acquired French at birth, then English after a delay period of at least 5 years, and English-speaking monolinguals. Multiple techniques were used, such as voxel-based morphometry to measure gray matter density, structural MRI, and functional magnetic resonance imaging (fMRI) to access resting-state functional connectivity and activation during a speaking/reading task.
Berken explains the idea of an optimal period in language development. If an individual learns two languages before the optimal period closes, then there is a higher capacity of the brain to easily adapt the neural circuitry to attend to two languages. Berken’s data proves that a simultaneous bilingual's brain is optimally organized and thus less neural effort is required for speech. Berken saw increased functional connectivity between language processing regions (both linguistic and non-linguistic) as well as structural growth in areas such as the left putamen, which is important for motor articulation. Even when a sequential bilingual can speak their second language to the same high proficiency as a simultaneous bilingual, this experience has a different effect on the brain, both functionally and structurally. This is because the neuroplasticity and ability to adapt the brain to the second language is limited, therefore brain organization has to compensate for this by increasing gray matter density and neural activation (quantified through the strength of its BOLD signal) in certain areas. For example, the brain of late learners had to enlargen its left and right premotor cortex in order to achieve the native accent of their second language: “...the later in life that the second language experience begins, the greater the activity required to manage the demand of overt reading and articulation” (Berken et al., 224). Also, the inferior frontal gyrus and fusiform gyrus were more activated. However, this was not seen in early learners because they did not have to recruit these areas as much during speech as a result of increased brain efficiency. The monolingual control group had to recruit a lot more areas to a greater extent because they had to rely on their English-reading machinery to try to articulate French words.
Another study by Gonzalez-Barrero and colleagues examined whether bilingualism can increase the cognitive flexibility of children with Autism Spectrum Disorder (ASD). There were 40 participants which included 20 children diagnosed with autism and 20 neurotypical children. Half were bilingual while the other half were monolingual. Through a computer-based task, they were told to sort a range of random objects by color. After some time had passed, they had to switch the sorting category to the shape of the object instead. The article states that “Children with ASD tend to find it harder to “switch gears” when changing tasks, as their cognitive flexibility is impaired…For instance, they tend to have a narrower focus, a desire to keep things unchanged, and inflexible daily routines” (Newman). Because of this impairment, autistic children did not perform as well on the task. However, the researchers observed that the bilingual children with ASD had an easier time switching between these tasks than the monolingual children with ASD. It is also important to note that the working memory of both groups was the same. Because having proficiency in two languages requires the person to transition from one language to the other fast and easily, it allowed bilingual children with ASD to use that same skill to switch between cognitive tasks. Although future studies and larger trials are still needed, the data suggests that acquiring a second language may be able to mitigate and improve the ability of autistic children to switch cognitive tasks.
Based on these two studies, one can infer that being bilingual has multiple neurological advantages, such as an improvement in the efficiency and flexibility of cognitive functions. In regards to children with ASD, bilingualism gave them a unique skill set that one cannot acquire through one language alone.
Works Cited
Berken, Jonathan A., et al. “Early Bilingualism, Language Attainment, and Brain Development.” Neuropsychologia, Pergamon, 1 Sept. 2016, https://www.sciencedirect.com/science/article/abs/pii/S0028393216303293?via%3Dihub.
Newman, Tim. “Children with Autism May Benefit from Being Bilingual.” Medical News Today, MediLexicon International, 23 Jan. 2018, https://www.medicalnewstoday.com/articles/320640#Studying-cognitive-flexibility.
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