Recently, The Varsity launched a novel project: a Chinese translation of the paper. This development speaks to the linguistic diversity of both the University of Toronto and Canada. Over 50 per cent of the world is bilingual, but are there scientifically proven benefits of being able to speak more than one language?
One implication of bilingualism is its influence on executive functions. Working memory is an example of an important executive function, as it controls important cognitive processes like conflict resolution, interference, and distraction. It can also predict the outcome of a child’s academic success. However, whether or not bilingualism can affect executive functioning has been a poignant area of debate.
A frequently cited 2013 study by Canadian and Spanish researchers investigated the differences of working memory between monolingual and bilingual children. Fifty-six five-year-old kindergarten students were tested with a Simon task paradigm, in which they had to press the button that corresponded to a stimulus on a computer monitor.
The results show that the reaction times of bilingual children did not slow even when there were incongruent trials, where the correct button was located opposite to the side where the stimulus appears on screen. Reaction times also did not slow when misleading cues were presented, which suggests an overall enhanced executive control in bilingual subjects.
Not all scientists have come to this conclusion. Angela de Bruin, a researcher from the University of Edinburgh, conducted similar tests to investigate whether bilingual individuals display enhanced executive function. She was not able to find support for this theory in her data.
According to de Bruin, only half of the work presented at conferences supported a bilingual advantage, while the other half refuted it. What many believe is a concrete asset may actually be a hypothesis that is neither globally recognized nor pervasive.
The apparent support for the existence of a bilingual advantage may be due to a disproportionate representation in scientific publications. de Bruin found that 68 per cent of published studies supported a connection between executive function and bilingualism, whereas only 29 per cent of studies supported the other side of the debate.
Another component of executive function affected by bilingualism is inhibitory control, which is the ability to regulate automatic attentional or behavioral responses and focus instead on the relevant stimuli. Bilingual individuals experience this when they suppress their native tongue in order to communicate in their second language.
Prior research on cognitive changes related to bilingualism has hypothesized that the management of two languages may actually be an exercise of executive control functions. It allows the brain to practice inhibitory control when speaking non-native languages, which can manifest as a bilingual advantage.
A Canadian study examined French- and English-speaking bilingual adults and hypothesized that bilingual individuals would outperform monolingual individuals with respect to interference suppression, but all showed similar response inhibition.
To measure interference suppression, the researchers used the Simon task, similar to the aforementioned 2013 study, and the Stroop task. The Stroop task measured the interference of reaction time and used three conditions: word reading, colour naming, and incongruent colour naming, when the colour ‘word’ does not match the colour of the letters.
Although both tasks measure interference suppression, the two tests showed contrasting results. With the Stroop task, monolingual anglophones and monolingual francophones both showed greater interference. However, this was not true for the Simon task. These inconsistent results were not able to provide clear evidence for a bilingual advantage.
Other studies are even more extreme and have shown that there is simply no connection between bilingualism and executive functions. Researchers from Duke University and Miami University found that early bilinguals — individuals who acquire a second language early in life — did not differ from monolinguals in performance on executive function tasks, but late bilinguals did and did worse. Their study further blurs the line between executive function and language acquisition.
Though knowing a second language can be useful for interacting with different cultures and travelling, the science behind a cognitive advantage of bilingualism is much less clear. Some researchers have suggested that it can enhance inhibition and working memory, but there are others who entirely refute that a connection between bilingualism and executive function even exists.
As further studies continue to explore the effects of language learning on the brain, the cognitive effects of a ‘bilingual advantage’ must be called into question.