What is the earliest thing you remember? How old were you? What was happening? Have you ever wondered about all the things from before that moment that you can’t remember? Or all the things since that moment that you have forgotten?
Maybe your family says that you used to refuse to eat yellow food, listened to the same song for six days in a row, or became terrified of your uncle for more than a year. If you can’t remember these things, could they still be affecting you as you grow up?
Scientists who study this question find that many of your very early experiences actually shape your brain – so even if you don’t remember something, your brain might.
Let’s think about the example of language.
Scientists wanted to know how early you would be able to tell babies from families that spoke different languages apart. How quickly do you think that they could see a difference between babies from families who spoke French and babies from families who spoke German? One month? Three months? One year?
What about from the moment they are born?
The scientists recorded crying babies who had been born to parents who spoke German or French. They grouped all of the cries from the German babies and all of the cries from the French babies to see if there was a pattern – and there was!
Look at the graphs of the cries from the babies below. Each cry is only about a second long, and you can see that the biggest part of the curve – or where the cry is the most intense – is different between the two groups. The German babies start out with a much more intense cry and get softer, and the French babies had their most intense sound at the end.
This happens because babies are already able to hear for about three months before they are born. They hear the voices of the people around them and can hear the shape of that language. They won’t be able to understand the words, but they can hear whether the sounds start off intense and become softer, or start softer and become more intense. This shape already starts to affect the way they create language – even in their earliest cries.
The sounds we hear start to affect us before we are even born – but how long do these effects last? What if we heard one language as a baby, but moved to a new place and never heard this language again? Even if we didn’t remember, would our brains remember?
Another group of scientists asked just that question. They studied a group of kids and teens who were born in China and then were adopted when they were six months to two years old by families who spoke French.
These kids and teens could not remember Chinese, but the scientists wanted to know if there was still evidence of these early encounters with this language in the brain.
Scientists already know that our brains have different regions for all of the things we need it to help us do – hear, see, smell, breathe, walk, read, recognize faces, and understand sounds. When you need to understand sounds, you usually use areas in the right half of your brain. When you are trying to understand language, you usually use two specialized areas in the left half of your brain.
In this study, the scientists scanned the brains of the kids and teens to see what areas they were using when they were listening to Chinese words or other sounds that were meant to sound like Chinese words. These kids and teens were from three groups:
1. Kids who had been born in China and adopted at a young age to Montreal, Canada and only learned French since
2. Kids who have always lived in Montreal, Canada, never learned Chinese, and have only learned French
3. Kids born in Montreal, Canada who originally learned Chinese, but then also added French as a second language while they were still young
When studying the brains of these three groups, the scientists saw a clear difference between the two groups who had learned Chinese and the group who had not.
All three groups could clearly tell the sounds apart - they knew the sounds did not match each other - but they used different parts of the brain to figure this out. The group who had never learned Chinese used the right half of the brain – the part used for processing sounds that are not language. Both of groups who had heard Chinese when they were very young actually used the special languages areas in the left half of their brains.
Even the kids and teens who had not heard Chinese in more than ten years used the language parts of the brain – their brains still recognized Chinese and treated it as a language!
Think about this the next time you see babies and toddlers. They already sound different than young kids from other countries – even the ones who can’t really talk yet. Also, when you talk to them – even though they won’t remember it – you are helping to shape the language parts of their brain in a way that will last a very long time. So don't be afraid to talk to them, and think about something interesting to say.
Brauer J (2014) The Brain and Language: How Our Brains Communicate. Front Young Minds. 2:14. doi: 10.3389/frym.2014.00014
Intagliata,C. (Senior Producer). (2014, November 21). Ghosts of Early Language May Linger in the Brain [Audio podcast]. Retrieved from http://www.sciencefriday.com/