Reading babies' minds: UTM professor examines how infants learn language

For more than 20 years, UTM psychology professor Elizabeth Johnson has tried to answer many questions related to how babies and children acquire language: how do children begin learning the meaning of words? How do they cope with unfamiliar languages and voices? How do they learn language so quickly?

Now, she has the chance to delve deeper into the mysteries of language acquisition and essentially tap into the minds of infants as young as six months old.

Johnson, who is also the director of UTM’s Child Language and Speech Studies (CLASS) Lab, has recently received a Canadian Foundation for Innovation’s John R. Evans Leaders Fund grant for her new project, titled Baby Brain and Behaviour Lab (BaBBL): electrophysiological measures of infant speech and language development. The lab will help Johnson and her team better understand how children acquire language.

In her CLASS lab, which was first established in 2008, Johnson’s team focused on more traditional behavioural measures such as eye-tracking, looking time and motor responses.

But BaBBL, which will be an addition to her CLASS Lab, will be the first of its kind at UTM. At the lab, Johnson’s team will carry out event-related potential (ERP) studies to better understand how children acquire language. ERPs are an electrophysiological measure reflecting the brain’s activity in response to specific stimulus or events in the world. The researchers will use electroencephalogram (EEG) to measure infants’ neural response to speech sounds and words.

“It’s all really exciting because we haven’t been able to do ERP work in my lab, so it’s going to be a whole new lab component,” Johnson says, adding that the procedure is safe and well-established for use in infants. “With this new tool, we will have a more complete window into the initial workings of the human mind.”

As Johnson and her team study what’s happening in infants’ brains, they will also be able to physically observe the baby’s reactions and behaviours as their brains respond to that information.

“The ERP measure will allow us to actually see how the brain is responding to words when they hear them, so I will be able to look at how neural responses line up with behavioural responses that we observe,” Johnson explains.

Researchers will examine how infants’ brains respond to words through the ERP measurements. The babies will then return multiple times, at different ages, so researchers can monitor changes over the years.

“By analyzing changes in those responses over time, we can learn a lot about what children are picking up on in the world,” Johnson says. “And, we can look at how the way their brain responds to different words early on in development at six months of age, and how that might predict how well they’re speaking and how many words they’ll know when they’re a toddler, or when they’re older.”

She adds that researchers will also look at the ways caregivers interact with their children, and how this interaction might impact children's neural response to the words that they hear. For example, the research team will record and analyze interactions between caregivers and their children, examining how their different interaction styles might support children's language development.

Johnson’s Canada Research Chair grant will also allow her to study how children learn language in linguistically-diverse environments – which is a reality for many children in the GTA as they grow up in more diverse communities.

She says more children today are growing up in households that speak a language other than English at home, meaning they are learning more than one language or hearing different accents.

She adds that one eventual application of her work could be to predict reading and speech difficulties in children – especially in linguistically-diverse populations.

“Traditionally, infant research has been largely focused on children learning one language,” Johnson says. “But many – if not most – of the children in the world are learning more than one language, and being exposed to more than one language variety. If we want to understand how language acquisition and speech development works in the real world, we have to study how children learn language in linguistically-diverse environments.”