How Second-Language Acquisition Shapes the Brain

By Aubrie, 9th Grade

Wanting to forget the fiasco of your world language final, you flinch as your teacher places the exam, now graded, face-down on your desk. You pray for at least a B, but it’s no use; stenciled in stark red letters is the letter C-. Why did you even take this course? What’s the point of learning a second language when you have Google Translate or ChatGPT at your fingertips?

Luckily, your struggle is justified by scientific research. Bilinguals constantly juggle between two languages. They extract from a vocabulary double the size of monolinguals. Since the average bilingual uses a smaller vocabulary than a monolingual in a given language, they are more likely to endure “tip-of-the-tongue” states and other mishaps with articulation.

However, learning a second language offers increased levels of brain enrichment like neuroplasticity. When you learn something new, repeated chemical activity prompts the neurons within your brain to form new connections (synapses). Synapses serve as units of memory and language function. By recording the electrical activity of synapses, neuroscientists can better visualize the clockwork behind language-related cognition. Via this technology, they deduced that second-language learners grammaticalize their second language; If a sentence has incorrect grammar (“the flower will grew” instead of “the flower will grow”), the brain responds to the discrepancy and transmits a half-second wave of electrical activity. However, the brain often draws from the first language; if the second language heavily differs in grammatical composition, the brain will release many of such electrical “alarms,” increasing the difficulty of acquisition and hence making the brain more plastic over time.

Bilinguals use a greater percentage of their brain for speaking, listening, and reading comprehension, thereby increasing its capacity designated for communication. Each language is structured around varying logical frameworks, conversational undertones, and phonetic syllables. Typically, when conversing in a less proficient language, the brain is more electrically active, and the speaker must exert more effort to configure words into sentences. Specifically, scans of second-language learner brains are characterized by higher gray matter content in the right hippocampus (responsible for long-term memory formation), mid-temporal lobes, parahippocampus (spatial processing, memory, and context), putamen (movement and learning), and insula (feelings).

Beyond communication, a study conducted by My V. H. Nguyen et al. reveals that fully bilingual children and current second-language learners outperform monolinguals in executive functioning tasks. Although the underlying mechanism is still unclear, scientists hypothesize that bilinguals inhibit irrelevant information in trying to juggle the two languages, which refines goal-directed behavior.

Second language acquisition not only forges person-to-person connections but also is an intellectual stimulant. The more languages you pick up, the more elastic and efficient your brain becomes, and the more likely you are capable of handling complex cognitive tasks. 

References:

https://pmc.ncbi.nlm.nih.gov/articles/PMC2600795/ 

https://pmc.ncbi.nlm.nih.gov/articles/PMC3786097/ 

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/98F73A0EFB7FCE82FC98F8A89C9BB802/S1866980823000467a.pdf/div-class-title-degree-of-bilingualism-and-executive-function-in-early-childhood-div.pdf