[SOUND] At this point you might say well, that's logical. We spoke a language for about a year, you didn't ever hear it again. It's not your home language, it's not a language that's common in your environment, and of course you would lose it. And that brings up some, questions from people who consider it. But let's consider a more extreme case of that. In what I think is one of the most interesting studies that's been published in the neuroimaging literature, Cristoph Pallier and his colleagues, looked at a group of Koreans who had been adopted, by French families. These were adults, when they arrived into the lab, Pallier felt that they sounded just like French speakers. He could not notice anything different about them relative to the monolingual French speakers that were in his lab, or those he encountered on a daily basis. But these adults, these adoptees, had actually lived in Korea up until age eight, in one extreme example, and as early as age four in the other example. So the range was four to eight. These were only six individuals. Christoph explained to me that, of course, it's very difficult to find these adoptees, to bring them in from different regions in France. So, six subjects was actually quite a bit considering how difficult it was to get access and also convince these subjects to come in for testing. So, they range from four to eight. As far as anyone could tell, they sounded just like French speakers. And then he put them in the scanner and asked them to listen to Korean, French and then backward speech. What he found was that in fact when you looked at their brains, and he looked at the brain activity the Korean adoptees looked almost indistinguishable from French monolinguals. So, they looked very, very similar. There were some slight differences in the brain activity across the two groups, but again they were very slight. Interestingly, when listening to Korean, there were also no differences between the two groups. Suggesting that listening to Korean sentences somehow did not elicit some long stored memory, but rather it really sounded like foreign speech. So the question was left and I think a lot of people have wondered well, but isn't there anything that they remember about that language? Don't they have some memory? So in a follow-up study of [FOREIGN] tested these subjects and asked, what would happen if we played a sound from Korean that doesn't exist within French and ask them to listen to this sound, to see if they have better recognition? And in fact they did find some very subtle abilities in these Korean adoptees to recognize sounds that exist within Korean that French speakers don't hear any more because they're not exposed to them. So there does seem to be a residual ability to hear and listen to sounds from their native language, that don't exist in French, and we've seen that before in other studies. But the interesting aspect of this study is that for the most part, there was almost no, trace of the native language, even in the person who had acquired French at eight basically the second language had overwritten the first language, and to me this is one of the most profoundly interesting and kind of nerve racking findings, right? That some child who's eight years old, could move to another country, be immersed completely in that other language, and essentially lose their native language, right? Something they had 'til they were age eight. And, it allows us to think, I think, a little more deeply about what memory really means.
