By François Grosjean
Also worth noting, President Eric Barron recently wrote a piece on the Power of Language, highlighting the Center for Language Science. Ping Li runs the Brain, Language, and Computation Lab at Penn State, which is part of the CLS.
A short while back, Ping Li, professor of psychology and linguistics at Penn State, answered a first series of questions on the bilingual brain (see here). We can now continue the interview, and are grateful to him for the time he has devoted to our questions.
Could we go back to the bilingual experience and the impact it has on neuroplasticity, that is how it can lead to functional and physical changes in the brain?
Yes, another unique aspect of how the bilingual experience impacts the brain is related to the fact that bilingual speakers often have to change the language they are using and have to monitor this, not to mention intertwining their languages in the form of code-switches and borrowings. These processes, it has been suggested, result in positive brain changes in the frontal and subcortical brain regions (due to inhibition of the unwanted language(s)) and in the anterior cingulate cortex (due to monitoring).
Although the specific brain mechanisms underlying these processes are still being debated, it is safe to say, given the available evidence from recent neuroimaging studies, that learning a new language and becoming a bilingual is a good choice for neuroplasticity, particularly in light of the uncertainties associated with the question of which type of cognitive experience is better for the brain.
It should be noted also that the language learning experience impacts many areas in the brain, in both the left and the right hemispheres–as we previously alluded to regarding how complex language is–whereas other types of cognitive experience (like juggling, doing jigsaw puzzles, etc.) may be beneficial to limited brain regions, such as the occipital cortex for vision, the motor cortex for movement, and the hippocampus for memory.
So what can be concluded concerning the bilingual experience?
It helps to shape the brain, even if such brain changes may not be revolutionary when evaluated against the grand spectrum of the evolution of the human brain (see Part 1 of the interview here). Such changes come about precisely because of the frequency, intensity, and duration of the bilingual experience. Scientific studies have shown that the extent of brain change is positively correlated with the level of proficiency gained in a second language.
Generally speaking, for all cognitive experiences–learning and using a language being one of them–the more often you perform the task, the more you will see brain changes; and the longer you work on it, the stronger will be the effects. Indeed, there has been work showing that if one stops learning a language or performing a cognitive task, the gained brain changes, such as increases in gray matter volume, will return to pre-learning or pre-training levels. So, “use it or lose it” and “no pain no gain” are all true when it comes to the positive effects of neuroplasticity.
Since there are many types of bilinguals, do some bilinguals resemble monolinguals in neural structures and/or connections whilst others are very different? If so, what factors are behind this?
This is a hugely important issue at the core of psychology: how do we identify the factors underlying individual differences in the learning and representation of knowledge? This question is also related to my earlier point that we cannot categorically describe ‘the bilingual brain’ versus ‘the monolingual brain’: rather, there is a continuum from being monolingual to being bilingual.
As you yourself have pointed out elsewhere, bilinguals use their two languages to a different extent, in different contexts, for different purposes, and with different people (see here). Underlying these volatile experiences of bilingualism are the different behavioral and brain patterns, such as which area of the brain becomes activated and which areas are better connected with one another. The many different shades of the term ‘bilingualism’ also make it exceedingly difficult to find two bilinguals who are exactly the same in every aspect of their language history or behavior. We may also need better tools and methods to study individual differences in bilingual learning and representations.
To continue reading this interview, please click here to head over to Psychology Today.
Featured image: Rachel Garman, Penn State via Flickr