By Leanne Louie
Whether you still speak it or not, your first language dictates the way your brain processes languages learned later in life.
In a paper published in Nature Communications in early December, researchers at McGill and the Montreal Neurological Institute showed that children with different first languages had differing brain activation when performing a French language task. Of the three groups of children tested, one group had learned only French since birth. Another had known Chinese as their first language before adoption into French families, whereupon they learned only French and forgot their Chinese. The final group had Chinese as their first language, learning French as a second language around the same time as the adopted children, but retaining their Chinese. Using functional magnetic resonance imaging (fMRI), the researchers observed the brains of the children while they identified French pseudo-words, such as vapagne and chansette. Although all groups performed the task equally well, they had differing patterns of brain activation throughout it. The French speakers with no exposure to Chinese had activation in the brain areas normally associated with the processing of language-associated sounds (most prominently, the left inferior frontal gyrus and anterior insula). However, in the brains of the children who had learned Chinese as their first language, additional areas of the brain were activated (particularly the right middle frontal gyrus, left medial frontal cortex, and bilateral superior temporal gyrus), regardless of whether the first language was still spoken.
“These results suggest that exposure to a language early in life affects how the brain processes other languages that you learn later on, even if you stop using that early language,” explained Lara Pierce, a doctoral student at McGill and the first author on the paper. Scientists have long known that early childhood experiences such as being read to and hearing languages can shape long-term brain architecture. However, although early events can dictate neural development, the brain remains an adaptable and plastic organ, able to adjust to what it needs to learn later in life despite its underlying circuitry. Such is made obvious from the high proficiency of all of the children in French, each of the three groups performing the language task with great accuracy despite their different linguistic backgrounds. Thus, it’s clear that having a different first language doesn’t impede the ability to learn a second language— but early language experiences do influence the way the brain might learn and process future languages.
Such research contributes to a growing understanding of both neural development and neuroplasticity, demonstrating the influence that experience and environment have upon the brain. In the future, the scientists are interested in looking more in depth at the influence of early experiences on later language learning. One question of interest is how the results would differ if a first language more similar to French than Chinese, such as English, were to be tested. This would help to clarify how different elements of first languages might influence the learning of second languages. While it provides answers, this study also raises many new questions, paving new paths for future research on the brain.
To read the full article in Nature Communications: http://www.nature.com/ncomms/2015/151201/ncomms10073/full/ncomms10073.html