Everyday scenes in bilingual cities can be simultaneously perplexing and fascinating when experienced for the first time. Imagine sitting in a café and eavesdropping on a casual conversation between two friends at a nearby table. They

• can both speak in a different language, and do so smoothly and naturally, 
• engage in code-switching where they transition from one to another language, and the flow of conversation is seamless, and
• express certain words in another language, even if speaking in English. For example, in Quebec, you ask for the nearest “deppaneur“ instead of asking for a “convenience store” (a term that may sound odd locally).

As you can see, these situations go beyond overhearing people speaking in a foreign language, not uncommon in big cities. The key difference is the degree of integration of the two languages in everyday life.

Being bilingual refers to the capacity if speaking two languages and is quite common worldwide. This fact may be surprising for those living in English-speaking countries, where bilingualism is less common.

While speaking more than one language has been associated with cognitive benefits, there are many open questions and unknown details about bilingual cognition.

One such question is whether there is shared representation of multiple languages. In other words, if you speak more than one language, are the cognitive processes that allow you to speak and understand them the same?

Mathieu Declerck, Yun Wen, Joshua Snell, Gabriela Meade, and Jonathan Grainger explored whether syntax comprehension depends on language-independent cognitive representations. The results appear in the recent paper “Unified syntax in the bilingual mind,” published in the Psychonomic Society’s journal Psychonomic Bulletin & Review.

The question is far from trivial, as established methodologies for studying the subject in language production, such as syntactic priming, have not provided conclusive evidence in contexts of language comprehension.

To address it, they proposed a new methodology by adapting the Rapid Parallel Visual Presentation (RPVP) paradigm to a bilingual context. In the RPVP, people are briefly shown words or sentences (less than 1-second), after which they disappear (similar to this). In single-language studies using this method, people are more accurate to identify words in grammatically correct sentences (e.g., “our fox can fly”) than ungrammatical ones (e.g., “our can fly fox”). 

This “sentence superiority effect” is attributed to its underlying syntactic representation: only the grammatical sentences allow constraining the expectations of which words are likely to appear in a given sentence position. For example, after “our” it is more likely to find a noun (“fox”) than a verb (“can”).

The authors presented similar grammatical/ungrammatical sentence pairs to French-English bilinguals, but mixing English and French words. For example: “ses feet sont big” (“his feet are big”) vs “sont feet ses big” (“are feet his big”). They reasoned that sentence superiority effects in this context could only happen if the cognitive representation of syntax is shared between languages.

As shown in the schematic below, in each trial, after waiting for 50 ms, a sentence appeared for 200 ms, and participants wrote the word from the sentence that was marked by a dot.

The results were in line with the shared syntax hypothesis. More words were correctly identified in grammatical sentences than ungrammatical ones, as shown in the figure below. Additional evidence in favor of the shared syntax hypothesis was that errors in the same part-of-speech category as the target word (e.g., reporting “dog” instead of “fox”) were more common for grammatical than ungrammatical sentences (right axis and lines in the figure below).

The similarities between this experiment’s results and those from studies using a single language suggest that the underlying processes are similar. This finding implies that the representation of syntax is unified, as indicated by the conversational code-switching observed in bilingual communities and by findings from neuroscience and meta-analytic studies. Moreover, the findings suggest that the way we represent languages in our minds is similar, regardless of which languages we speak.

And philosophically, if you may, this tells us something important about our similarities as humans. At our very core, people from different cultures and who speak different languages seem to have similar cognitive representations of something essential to humanity: language.

So, hey amigo! Shall we go learn une autre langue together? 

Psychonomic Society’s article focused on in this post: 

Declerck, M., Wen, Y., Snell, J. Meade, G., & Grainger, J. (2020). Unified syntax in the bilingual mind. Psychonomic Bulletin & Review, 27, 149–154 https://doi.org/10.3758/s13423-019-01666-x