Practice makes perfect: Switching between languages pays off

Bilingual toddlers who obtain more practice in language switching are better at certain types of problem solving

It's estimated that half of the world's population speaks two or more languages. But are there hidden benefits to being bilingual? Research from Concordia reveals a new perk visible in the problem-solving skills of toddlers.

The results of a study recently published by the Journal of Experimental Child Psychology show that bilingual children are better than monolinguals at a certain type of mental control, and that those children with more practice switching between languages have even greater skills.

Bilingual speakers can thank the sometimes-arduous practice of switching from one language to another for this skill. "This switching becomes more frequent as children grow older and as their vocabulary size increases," says Diane Poulin-Dubois, a professor in Concordia's Department of Psychology and the study's senior author.

"Therefore, the superior performance on these conflict tasks appears to be due to bilinguals' strengthened cognitive flexibility and selective attention abilities as they have increased experience in switching across languages in expressive vocabulary."

Poulin-Dubois and Cristina Crivello, a graduate student with Concordia's Centre for Research in Human Development (CRDH), led a group of researchers* in a longitudinal investigation, which compared bilingual toddlers to their monolingual peers, tracking the tots as they gained greater vocabularies in each of their two languages.

For the study, the researchers assessed the vocabularies of 39 bilingual children and 43 monolinguals when they were aged 24 months, and then again at 31 months. During the second assessment, the researchers also had the young participants perform a battery of tasks to test their cognitive flexibility and memory skills.

"For the most part, there was no difference between the bilingual and monolingual toddlers," says Poulin-Dubois, who is also a member of CRDH. "But that changed dramatically when it came to the conflict inhibition test, and the differences were especially apparent in the bilingual toddlers whose vocabulary had increased most."

In this case, conflict inhibition refers to the mental process of overriding a well learned rule that you would normally pay attention to.

To assess toddlers' abilities in this domain, Crivello, who undertook the research as part of her master's thesis and is the first author of the study, administered two tests:

1. Reverse categorization -- participants were told to put a set of little blocks into a little bucket and big blocks into a big bucket. Then the instructions were switched -- big blocks in the little bucket and little blocks in the big bucket.

2. Shape conflict -- participants were shown pictures of different sized fruit and asked to name them. Then a new series of images was shown, with a small fruit embedded inside a large one. Toddlers were asked to point to the little fruit.

It wasn't surprising to the researchers that the bilingual children performed significantly better on the conflict inhibition tasks than did their monolingual counterparts.

"Language switching underlies the bilingual advantage on conflict tasks," says Crivello. "In conflict inhibition, the child has to ignore certain information -- the size of a block relative to a bucket, or the fact that one fruit is inside another. That mirrors the experience of having to switch between languages, using a second language even though the word from a first language might be more easily accessible."

The unique feature of the study was the finding that the more language switching toddlers engaged in, the more it benefitted them. Within the bilingual group of toddlers, those who had amassed a greater number of "doublets" -- pairs of words in each language, such as dog/chien -- performed even better on the conflict inhibition tasks. "By the end of the third year of life, the average bilingual child uses two words for most concepts in his or her vocabulary, so young bilingual children gradually acquire more experience in switching between languages," says Poulin-Dubois.
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Reference:

Science Daily. 2016. “Practice makes perfect: Switching between languages pays off”. Science Daily. Posted: February 3, 2016. Available online: http://www.sciencedaily.com/releases/2016/02/160203110936.htm

Study shows how bilinguals switch between languages

Individuals who learn two languages at an early age seem to switch back and forth between separate "sound systems" for each language, according to new research conducted at the University of Arizona.

The research, to be published in a forthcoming issue of Psychological Science, a journal of the Association for Psychological Science, addresses enduring questions in bilingual studies about how bilingual speakers hear and process sound in two different languages.

"A lot of research has shown that bilinguals are pretty good at accommodating speech variation across languages, but there's been a debate as to how," said lead author Kalim Gonzales, a psychology doctoral student at the University of Arizona. "There are two views: One is that bilinguals have different processing modes for their two languages — they have a mode for processing speech in one language and then a mode for processing speech in the other language. Another view is that bilinguals just adjust to speech variation by recalibrating to the unique acoustic properties of each language."

Gonzales's research supports the first view — that bilinguals who learn two languages early in life learn two separate processing modes, or "sound systems."

The study looked at 32 Spanish-English early bilinguals, who had learned their second language before age 8. Participants were presented with a series of pseudo-words beginning with a 'pa' or a 'ba' sound and asked to identify which of the two sounds they heard.

While 'pa' and 'ba' sounds exist in both English and Spanish, how those sounds are produced and perceived in the two languages varies subtly. In the case of 'ba,' for example, English speakers typically begin to vibrate their vocal chords the moment they open their lips, while Spanish speakers begin vocal chord vibration slightly before they open their lips and produce 'pa' in a manner similar to English 'ba.' As a result of those subtle differences, English-only speakers might, in some cases, confuse the 'ba' and 'pa' sounds they hear in Spanish, explains co-author Andrew Lotto, associate professor of speech, language and hearing sciences at the University of Arizona.

"When most people think about differences between languages, they think they use different words and they have different grammars, but at their base languages use different sounds," Lotto said.

"One of the reasons it sounds different when you hear someone speaking a different language is because the actual sounds they use are different; they have a sound code that's specific to that language," he said. "One of the reasons someone might sound like they have an accent if they learn Spanish first is because their 'pa' is like an English 'ba,' so when they say a word with 'pa,' it will sound like a 'ba' to an English monolingual."

For the study, the bilingual participants were divided into two groups. One group was told they would be hearing rare words in Spanish, while the other was told they would be hearing rare words in English.

Both groups heard audio recordings of variations of the same two words — bafri and pafri — which are not real words in either language.

Participants were then asked to identify whether the words they heard began with a 'ba' or a 'pa' sound. Each group heard the same series of words, but for the group told they were hearing Spanish, the ends of the words were pronounced slightly differently, with the 'r' getting a Spanish pronunciation.

The findings: Participants perceived 'ba' and 'pa' sounds differently depending on whether they were told they were hearing Spanish words, with the Spanish pronunciation of 'r,' or whether they were told they were hearing English words, with the English pronunciation of 'r.'

"What this showed is that when you put people in English mode, they actually would act like English speakers, and then if you put them in Spanish mode, they would switch to acting like Spanish speakers," Lotto said. "These bilinguals, hearing the exact same 'ba's and 'pa's would label them differently depending on the context."

When the study was repeated with 32 English monolinguals, participants did not show the same shift in perception; they labeled 'ba' and 'pa' sounds the same way regardless of which language they were told they were hearing. It was that lack of an effect for monolinguals that provided the strongest evidence for two sound systems in bilinguals.

"Up until this point we haven't had a good answer to whether bilinguals actually learn two different codes — so a 'ba-pa' English code and a 'ba-pa' Spanish code — or whether they learn something that's sort of in the middle," Lotto said. "This is one of the first clear demonstrations that bilinguals really do have two different sounds systems and that they can switch between one language and the other and then use that sound system."

This is true primarily for those who learn two languages very young, Lotto said.

"If you learn a second language later in life, you usually have a dominant language and then you try to use that sounds system for the other language, which is why you end up having an accent," he said.

Research on bilingualism has increased in recent years as the global climate has become more intermixed, Lotto noted. These new findings challenge the idea that bilinguals always have one dominant language.

"This raises the possibility that bilinguals can perceive speech like a native speaker in both languages," said Gonzales, whose own son is growing up learning English and Chinese simultaneously.

"The predominant view of late has been that bilinguals will never be able to perceive a second language beyond what a late learner is capable of, or someone who learns a second language late in life. So even if you learn two languages simultaneously from birth, you're always going to perceive one of them like a late learner," Gonzales said. "Our findings cast doubt on that prominent view in the bilingual literature."
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References:

EurekAlert. 2013. “Study shows how bilinguals switch between languages”. EurekAlert. Posted: May 20, 2013. Available online: http://www.eurekalert.org/pub_releases/2013-05/afps-ssh052013.php