Brainy Bilingual Babies

Credit: PBS/Otherwords/Spotzen

Maria Arredondo first learned English when she moved from Argentina to the U.S. at the age of 12. Now, as head of the Child Learning and Development Studies Lab at UT Austin, the assistant professor of human development and family sciences wants to understand how growing up in a bilingual environment affects a child’s learning.

Questions she’s exploring include: How do children learn multiple languages? And how does developing the underlying skills needed to learn them transfer over into other kinds of learning? There’s a hotly debated hypothesis that bilingual children are better at higher cognitive functions that are critical for learning – such as memory, inhibitory control and attention – compared to monolingual children. Arredondo designed a series of experiments that test these cognitive abilities in infants. During the session, babies wear a stretchy cap that holds small sensors that emit and reflect infrared light. This technique is called functional near-infrared spectroscopy (fNIRS) and it safely maps brain activity in real time. 

“It’s possible a code-switching environment is making biliguals more attentive”

In a pair of studies that focused on the development of attention abilities, babies from bilingual households who often heard their parents switch between both of their languages (i.e., code-switching) experienced a greater increase in brain activity. Specifically, babies showed an increase in brain activity within the left frontal region of the brain. This is an area associated with hearing and speaking language, but the task was assessing non-linguistic attention skills in the infants under one year old. Bilingual babies also improved more rapidly than monolinguals.

Arredondo’s findings provide more evidence that code-switching between languages in the home may sharpen bilinguals’ attention and boost learning.

“Bilinguals’ brains and ability in attention are adapting to their environment and improving over time,” Arredondo said. “It’s possible that a code-switching environment is making bilinguals more attentive to their environment during learning.”