How Does the Brain Juggle More Than One Language?

We all use language in our everyday lives. For most of us, speaking can seem very easy. But in reality, many things are happening in our minds to get the words out. Imagine that you are shown an object, such as an apple, and asked to name it. It probably will not take you much longer than a second to produce the word apple. Within that second, you think of the concepts related to that object, such as “fruit” or “juicy”, but several words, like apple, peach, or mango are both “fruit” and “juicy”. Next, you select the correct word among these possibilities. Every once in a while, people’s tongues can slip and they may select the incorrect word, but people usually choose the right word. Once you select the correct word, and before saying it aloud, you string together the individual sounds making up the word apple. This is the basic process of how we choose our words when we speak.

But what might change if you know more than one language? You might think that being bilingual does not change much; if you are speaking in English, you only think of words in English. However, researchers have discovered that, in a bilingual mind, both of a person’s languages are active at the same time, rather than “turning on” the language they are using and “turning off” the other one. This phenomenon is called parallel activation [1].

So, in the mind of a person who knows both Spanish and English, both apple and manzana will be active when they are shown an apple (Figure 1). You might think that bilingual people would accidentally switch up their languages all the time, but it turns out that they are actually really good at managing their languages in their minds. To effectively juggle more than one language, bilingual people use something called inhibitory control to inhibit, or ignore, the language they are not using [2]. Think of using the brakes on your bicycle to slow down as you are going downhill. This can be thought of as similar to inhibitory control. This “slowing down” can make choosing the right word easier.

Which Words can be Tricky for Bilingual People?

Imagine that you know both Spanish and English. You are shown a chocolate bar and asked to name it. In this case, the correct word in both English and Spanish is chocolate, even though it is not pronounced exactly the same. This is an example of a cognate word. Cognate words are words that look and sound very similar across languages and share the same meaning. Since the words are so similar across both languages, it is easier for you to name a chocolate bar than to name an object for which the two words look and sound different (e.g., apple and manzana) [3]. (We refer to words that share the same meaning but are very dissimilar in form across languages as non-cognates.) There are many examples of cognates shared between languages. A few include the German–French pair Tasse–tasse meaning “cup”, the French–Spanish pair pays–país meaning “country”, and the Catalan–Spanish pair gat–gato meaning “cat”.

There are so many cognate words between English and Spanish that you might expect most Spanish words to be similar to English. Unfortunately, some words turn out to be tricky. Imagine you are shown a plum and asked to name it in Spanish. Among the words that you think about will be the word for plum in Spanish: ciruela. But you will also think of the English name, plum. Because plum sounds and looks a lot like pluma, meaning “feather” in Spanish, you may accidently say “pluma”. These tricky words, called false cognates, look and sound very similar to each other but have different meanings in the two languages [4]. Imagine the confusion if you meant to say that you ate a plum in Spanish, but instead your Spanish-speaking friend hears that you ate a feather! Other examples of false cognates include the French word librairie meaning “bookstore” not “library”; the Spanish word embarazada meaning “pregnant” not “embarrassed”; and the Dutch word eekhoorn meaning “squirrel” not “acorn”.

False cognates are the most challenging words for bilingual people to process because of their shared form but different meanings across languages; non-cognates (e.g., apple/manzana) are easier to process because they differ in form; and cognates (e.g., chocolate/chocolate) are the easiest to process because of their shared form and meaning. Most word pairs across languages fall into the non-cognate category.

How Does Bilingualism Influence the Way People Use Language?

We already defined a bilingual person as someone who knows two languages. However, no two bilingual people are ever the same. They can vary in the languages they speak, how well they speak and understand each language, how old they were when they learned each language, how they learned each language, and in many other ways. We conducted a study in which we investigated how Spanish–English bilingual people named objects while considering how skilled they were in one language relative to the other, which we call language dominance [5]. For example, a Spanish–English bilingual person who is more skilled in speaking English than Spanish is more English-dominant, while someone who is more skilled in Spanish than English is less English-dominant and more Spanish-dominant.

Because two bilingual people can be so different from one another, one challenge in bilingualism research is figuring out how to best describe bilingual people. In our study, we considered how much Spanish–English bilingual people encounter each language in their daily lives; how skilled they say they are in speaking, reading, and understanding in each language; and how skilled they are based on how well they can name pictures of objects in each language. Combined, these three items tell us how much stronger or more dominant a bilingual person is in one language compared to the other (Figure 2).

We then asked our group of bilingual people to complete a task in which they were asked to name pictures of objects in Spanish while ignoring the words that were written on top of the pictures (Figure 3). The object in the picture and the distractor word could be related in one of three ways. That word could be: (1) a false cognate of the English translation of the object, (2) a word unrelated in both form and meaning, or (3) simply the Spanish name of the picture, which we refer to as an identity relationship. We measured whether bilingual people named the object correctly and how quickly they could name it depending on the type of word on top of it.

As expected, we found that our Spanish–English bilingual people experienced crosslinguistic interference. They made more mistakes and were slower at naming an object when there was a false cognate written over it than when an unrelated word was written over it. In other words, they did get tricked! They also benefitted from identity facilitation. They made fewer mistakes and were quicker at naming an object when the word written over it was its name compared to an unrelated word. We also found that how Spanish- or English-dominant a person was influenced how well they named an object: the more English-dominant, the fewer mistakes they made when the name of the picture was written over it compared to when an unrelated word was written over it. Remember that the participants had to name the pictures in Spanish. Therefore, we think that the people who did not know Spanish as well used the object name to help them name pictures more than people who were really good in Spanish used those names.

Our results show that tricky words are indeed hard to avoid falling for. In addition, how well people can speak each of their languages influences how fast they name pictures. In summary, this article explained a bit about how bilingual people’s languages interact in their minds and how different bilingual experiences can influence how people use language. However, there is still much more we can learn about how the different faces of bilingualism influence language.

Glossary

Bilingual: ↑ Describes a person who knows and uses two languages.

Parallel Activation: ↑ The idea that all a bilingual person’s languages are active, or “on”, at the same time.

Inhibitory Control: ↑ In the context of bilingual language production, this is the process by which people suppress the language they do not intend to use.

Cognates: ↑ Words that look and sound very similar across two languages and share the same meaning, e.g., Spanish chocolate and English chocolate.

Non-cognates: ↑ Words that share the same meaning but that look and sound very different across languages.

False Cognates: ↑ Words that look and sound very similar across two languages but have different meanings; e.g., Spanish pluma (feather) and English plum.

Crosslinguistic Interference: ↑ When knowledge of one language affects a person’s use of another. In this study, this is seen by participants performing worse in the false cognate compared to the unrelated condition.

Identity Facilitation: ↑ In this study, refers to how participants benefit from seeing the name of picture written on top.

Conflict of Interest

The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgments

This work was supported by an NIH training grant T32 DC007361-17 to AGM, an American Speech-Language Hearing Foundation New Century Scholars Award and a National Science Foundation CAREER award #2143805 to SKR, and an Institute on Deafness and Other Communication Disorders Award #F31DC019272 to JRA. The content is solely the responsibility of the authors and does not necessarily represent the views of the National Science Foundation. We thank members of the Laboratory for the Brain Dynamics of Language (PI Ries) and the Bilingualism and Cognition Laboratory (PI Blumenfeld), as well as our research participants, for their contributions to this work.

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