Bilingualism is known to have many positive effects on cognitive development. However, the exact reasons why speaking a second language enhances cognition are still not perfectly known. Adding to the debate, a team of Canadian researchers recently investigated the benefits of bilingual environments in babies as young as 6-month old--long before the acquisition of language. To adapt to a greater diversity of stimuli, they reasoned, infants from bilingual homes could have to develop their capacity for attention beyond the level normally needed at that age. And this could shed light on the origins of the “bilingual advantage” as controlling and allocating attention is the basis of all subsequent cognitive processes.
To test this hypothesis, the team conducted a study during which it tracked the eye movements of 20 infants exposed to a series of pictures appearing on a screen. After a number of trials, the apparition of one of two different images in the centre of the screen predicted the subsequent apparition of a third image either on the right or on the left. Regardless of their coming from a monolingual or bilingual environment, all of the babies involved in this first phase of the experiment proved able to learn this simple rule and correctly anticipated on which side of the screen a smiling red star would appear.
In a second phase, however, things suddenly changed: the prediction was now reversed and the location of the star associated with the opposite image. This time, babies from bilingual homes were the only ones able to update their expectations and adapt to the new rule.
This finding supports the idea that infants raised in bilingual environments develop greater attentional control, and this even before they start acquiring language.
As explained by the authors: “The experience of attending to a complex environment in which infants simultaneously process and contrast two languages may account for why infants raised in bilingual environments have greater attentional control than those raised in monolingual environments.”
Furthermore, this early advantage could be the origin of the cognitive differences known as the “bilibgual advantage” that appear later in life, especially in terms of executive functions.
Reference: Comishen, Bialystok and Adler, “The Impact of Bilingual Environments on Selective Attention in Infancy”, Developmental Science.