Two languages = two speech centres!
It doesn't matter to our brain when we learn a language. This is because it has different storage areas for different languages. Not all the languages we learn are stored together. Languages we learn as adults have their own storage area. That means the brain processes the new rules in a different place. They aren't stored with the native language. People who grow up bilingual, on the other hand, only use one region of the brain. Multiple studies have come to this conclusion. Neuroscientists examined various test subjects. These subjects spoke two languages fluently. One part of the test group, however, had grown up with both languages. The other part, in contrast, had learned the second language later in life. Researchers could measure brain activity during language tests. This way they could see which areas of the brain functioned during the tests. And they saw that the "late" learners had two speech centres! Researchers had already long suspected that this would be so. People with brain injuries show different symptoms. So, damage to the brain can also lead to speech problems. Those affected can't pronounce or understand words as well. But bilingual accident victims sometimes show unusual symptoms. Their speech problems don't always affect both languages. If only one area of the brain is injured, the other can still function. Then the patients speak one language better than the other. The two different languages are also re-learned at different speeds. This proves that both languages aren't stored in the same place. Since they weren't learned at the same time, they form two centres. It is still unknown how our brain manages multiple languages. But new findings could lead to new learning strategies.