Nowadays the majority of the world's population is bilingual/multilingual, mainly due to English as lingua-franca and international policies on foreign language education. In the past year many researchers have been investigating the cognitive aspects of foreign language learning and bilingualism, and here are some of their discoveries.
Learning a foreign language is known to be an efficient (and fun) way to train your brain. Even just a one-week crash-course can boost your cognitive abilities (such as attention span) and if you want to maintain and enhance them -- keep on learning regularly! But while some people seem to have a talent for learning foreign languages, others struggle for years to reach fluency. It turns out that there are indeed some innate neural aspects which support language learning, which can be seen in resting-state connectivity: strong connections between the left anterior insula/frontal operculum and the left superior temporal gyrus enhance speaking proficiency, while strong connectivity between the visual word form area and a different area of the left superior temporal gyrus in the left temporal lobe enhance reading comprehension. Moreover, variations of the COMT gene can alter the white matter as a result of language learning. If you're not among the lucky ones with a "polyglot brain", you could try neurosensory auditory stimulation to reset your ears back to the "critical period" of language learning. Learning a new language is worth it not only for international communication, but also for training your brain's elasticity and its ability to process information in the long term. If you're curious to see what actually happens in the brain when learning a language, researchers have managed for the first time to capture images of linguistic information being integrated into the same brain areas for the native language.
If learning a foreign language seems challenging, think about juggling two (or more) languages in everyday conversations. Early bilinguals, who learn two languages in parallel from birth on, are able to learn the rules of each language faster than monolinguals. The effects of early bilingualism on the brain can be observed early on: 11 month-olds present brain activity associated with executive functioning, and it turns out they are more open to learning new language sounds. Babies' executive function also seems to be improved by the age of 3 due to early bilingualism. The cognitive advantages of bilinguals are a hot topic and this year many studies have contributed to its research. It has been confirmed that bilinguals can control better competing cognitive tasks and show better attention span and ability to focus. Language switching in conversations seems to come easily for bilinguals, and an explanation is consistency in using one word from one languge for a specific noun, which allows them to avoid the cognitive costs of language switching. Even speaking two dialects seems to confer the same cognitive advantages as those observed in bilinguals of different languages. New insights into the neural underpinnings of bilingualism show that speakers use different neural networks for reading transparent languages (pronounced as they are written) and opaque languages (pronounced different than written).
Research in this field is advancing at a fast pace and here I have mentioned only a fraction of the studies published this year on the topic. Stay tuned for future discoveries!