This is a very interesting TEDx Talk about the “benefits of a bilingual brain” by Mia Nacamulli. – I only would like to point out that grown ups usually learn a new language in a very “conventional” way, which is rule-based (i.e. using books, learning grammar first), what leads to using one side of the brain only, like it is mentioned in this film/talk.
When adults learn a new language in the same spontaneous, memory based way like children, the brain activity is similar to the one of children who acquire a new language by involving both hemispheres. The approach is then less “rational” and more “emotional”. Language ability is measured in two parts: the active part – speaking and writing – and the passive part – listening and reading.
A balanced bilingual has a nearly equal ability in both (or all) the languages, whereas most bilinguals use their languages in “various proportions, and depending on their situation, and how they acquired each language they can be classified into three general types”*:
They learn the two languages, two linguistic codes, simultaneously in the same context where they are used concurrently, so that there is a fused representation of the languages in the brain. – This is the case when a child is brought up by bilingual parents, or parents with two different linguistic backgrounds.
The person learns the languages in separate environments, and “works with two sets of concepts”, and words of the two languages are kept separate with each word having its own specific meaning.
The person attained her bilingualism later in life. As a result, she often uses her primary language to subordinate the second language (cfr. Two Types of Bilingualism).
We can not see and sometimes not hear the difference between the kind of bilinguals. Thanks to recent studies in neuroscience and bilingualism we can tell more about how bilingualism affects the brain.
Language involves both functions, the analytical/logical one and the emotional/social one. Lateralization though, evolves gradually with age, which has lead to the critical period hypothesis: children seem to learn easier because of the plasticity of their developing brains, which makes them use both hemispheres in language acquisition.
Whereas in most adults language is lateralized in one hemisphere.” (slightly modified text from the talk by Ute) By learning a language early in life, which involves both hemispheres, children tend to grasp social and emotional contexts easier than adults who learn languages in the more conventional way, and using only one side of the brain.
Adults tend to have a more rational approach to the new learned language in adulthood,
My personal addition to the insights shared in this talk and video are that one can acquire a language also later in life in the same way children do. The approach is different and “more natural”. Of course, adults will try to connect all the new data with data they already know, i.e. the language structure of the other languages they already know, but an approach that doesn’t focus primarily on grammar and rules is proving not only more time efficient – because more engaging – but also more effective concerning the emotional understanding of the new language.
What concerns the visible increase of brain density in bilinguals and multilinguals is a fact and one of the most quoted advantages of speaking multiple languages. The “involvement of the dorsolateral prefrontal cortex which plays a role in executive function, problem solving, switching between tasks and focussing while filtering out relevant information”, makes the brain of multilinguals more healthy and actively engaged. No matter when one learns another language: it’s never too late!
On a side note: What is said about alzheimer and dementia in this film is not only related to bilingualism. The same beneficial effect can be observed in people who engage their brain actively on a regular basis.
* in linguistics we also use terms like simultaneous, additive, consecutive (or sequential), balanced, passive, early, late, replacive and subtractive bilinguals, depending on the aspect we’re focusing on.