Hello world,
This past week has been extremely interesting, yet exciting, to say the least. After a TERRIBLE delay at JFK airport, I finally made it to Paris (about 6 hours behind schedule…). Once settled into my room, I met up with my friend, Sasha, to grab a quick dinner. We decided to go to a small restaurant close to where we live, as our long day of traveling left us extremely tired. When we sat down at the restaurant, the waiter walked over and said, “Bonjour, comment puis-je vous aider?” This caught me extremely off guard, as this was the first time I engaged in a conversation with a true francophone.
Sasha (left) and me (right) at dinner
Sasha and me at the Eiffel Tower
Let me rewind a little bit. I have studied French since 6th grade, and although it may not be my primary concentration in college, it plays a huge role in my academic career. However, this was my first time in a French speaking country, so I have not had much experience with French conversation, aside from with my fellow French-speaking peers and professors. So, when the waiter confronted me and asked a question in French, I was rightfully so caught off guard.
(Anyway, returning to the restaurant…) Sasha, being from Montreal and growing up speaking French with her family, swiftly answered the waiter. After a few seconds of gathering myself and adjusting my vocabulary, I too answered him (in French, of course). This event made wonder what physiological differences, if any, occurred in my brain when switching between English and French vocabulary. Were different areas of my brain active for French words versus English words and vice versa? This question sparked my interest, so, upon returning to my room I searched for an answer.
Before I try and explain the studies I found, let me give you a quick and easy lesson concerning neuroscience and language. Broca’s area, a region of the frontal part of the brain, is linked to the production of speech, while Wernicke’s area, a region of the temporal part of the brain (slightly above where your ears are), is linked to the comprehension aspects of speech. In order to engage in a coherent conversation with another individual, one must use both of these areas, as the language one hears must be understood
(via We
rnicke’s area) and the language one speaks must be intelligible (via Broca’s area). So, when looking for an answer to my original question about language, I immediately thought that this must be the sole system affected, but boy was I wrong.
After some quick searching, I stumbled upon an article by Correia et al., 2014, concerning brain activation in bilingual individuals. The researchers in this study subjected bilingual participants, fluent in English and Dutch, to a series of experimentations in which the participants were placed inside an fMRI and told to listen to a series of words. The words consisted of the names of specific animal species, and the language spoken varied between English and Dutch. The fMRI constructed images of the participant’s brains, highlighting the regions most active during this process. By examining and comparing the fMRI images created by solely Dutch words, solely English words, and a combination of the two, Correia et al. isolated several regions of the brain active for both languages. The main region of activity they observed was the anterior temporal lobe (ATL). This cortical region is associated with semantic memory, that is, memory of physical objects, people, information, and (most important to this study) words (Bonner and Price, 2013). This finding is significant as it provides evidence that semantic knowledge is processed in a language-independent form in the brains of bilingual listeners (Correia et al., 2014). Essentially, this means that as the participants listened the either English or Dutch words, their ATLs become equivalently active for each. So, when I was in the restaurant with Sasha, although I may have been caught off guard by the waiter speaking French, similar regions of my brain became active compared to if the waiter spoke English to me.
A figure from Correia et al. (2014) depicting the language-independent regions of the brain, one of which being the anterior temporal lobe (ATL)
Another interesting study I found was conducted by Mohades et al. in 2012. In this study, the researchers assessed the brain circuitry associated with language in children aged 8-11 years old. They compared this circuitry in children raised monolingual to those raised bilingual. Through this, the researchers discovered significantly different white matter density in specific brain regions involved with spoken language and comprehension of language. Certain areas of bilingual’s brains contained different densities of white matter in comparison to the brain’s of monolinguals (Mohades et al., 2012). This means that the circuitry of the brain involved with language differs depending on one’s language capabilities. So, in relation to my brain and Sasha’s brain, we have different densities of white matter in specific regions of our brains, since Sasha was raised bilingual (woah).
The type of fMRI imaging used by Mohades et al. (2011) to measure white matter integrity (density).
I found both of these articles very interesting because they offer different findings regarding brain activation in bilinguals. In my NBB classes I learn about many regions of the brain discussed in these studies, yet I never knew the role they played in bilingual individuals. With this newfound knowledge, I am interested in doing further research to discover more differences in brain activation associated with language.
~ Ethan Siegel
References
Bonner M, Price A (2013) Where is the anterior temporal lobe and what does it do? The Journal of Neuroscience. 33(10): 4213-4215
Correia J, Formisano E, Valente G, Hausfeld L, Jansma B, Bonte M (2014) Brain-based translation: fMRI decoding of spoken words in bilinguals reveals language-independent semantic representations in anterior temporal lobe. The Journal of Neuroscience. 34(1):332–338
Mohades S, Struys E, Van Schuerbeek P, Mondt K, Van de Craen P, Luypaert R (2011) DTI reveals structural differences in white matter tracts between bilingual and monolingual children. SciVerse ScienceDirect. 1435: 72-80