[SOUND] The idea that early learned languages might be more resistant to damage is also present in the neuro psychosocial literature. So Theodore Ribot considered by many the father of neuro psychology in France, developed this theory which he called the law of regression. So the idea was the following. Memories that are learned very early in life are organic. He called them organic memories. They were memories that were very natural, that were deeply routed in the brain, and memories that are developed later in life, were more conscious and effortful. And he looked at a number of things. For example, if he looked at patients who had dementia, they would naturally go through this progression of loss of their ability to speak. They started with things that were much more complex. Maybe things like grammar that started to fall off. Then over time they would drop off and they would start to lose the meaning of words. Then they would just be down to single words. And eventually they would go down to simply having gestures. And his idea was that they were progressing from the things that were more complex, more difficult, over to things that were more organic and earlier learned. The problem for Ribot was, how do I test this? How do I look at early versus late memories. And, it turns out there was a very large population of bilinguals and multilinguals who had brain damage of some sort. And he was able to actually look within the bilingual population to test his ideas. But his ideas originally were developed not with bilingualism in mind but actually with the way people developed in mind and what memories might be most resistant. And so Rebeau developed this idea that earlier learned things would be more resistant to damage than later learned things. One example that Ribot gives to support this is a story of a forester. So it's a forester who had grown up in Poland and had moved to Germany as an adult. And spoke German for his entire adult life. One day, because of a surgical procedure, he was under anesthesia, and he suddenly reverted to speaking Polish. And prayed in Polish. Spoke Polish for several hours under anesthesia. And his children were surprised because they assured the surgeon that this patient had never, ever used Polish in more than 30 years. And so this is an example that Ribot gives to provide support for his idea that under stress the earlier learned memories will surface. In this case, the earlier learned language will surface. Polish surfaced as a language that he used when he was under anesthesia. We can ask the question, then, about, you know, which is, more resistant to damage. The first language or the second language. Alright, is it, is it earlier learned or more familiar. In 1999, Franco Fabbro wrote a book called the Neurolinguistics of Bilingualism, in which he looked through many of the cases. And he actually went through and reviewed for a hundred years back at the time, all the cases he could look at that involved someone who spoke two languages and had some form of brain damage. And what he found was quite intriguing. So roughly about a third of patients recovered their first language more quickly. About a third of the patients recovered their second language more quickly and about a third of the patients recovered both languages in parallel. So it suggests that there's a very complex kind of interaction that occurs between the first and the second language. And that recovery is not a very clean process. It's quite, idiosyncratic. And it differs across people. We could also ask whether there might be some contribution to language loss or recovery that doesn't have to do with language. So let's take another patient, A.S., so this patient spoke Farsi as a native language. Went to study in, in Germany. During his time when he was doing his PHD dissertation in Germany, he also traveled to England to do research. So he was a Farsi native speaker, but he learned German and English as second and third languages. Now interestingly, what happened to him, he had a stroke when he was in his fifties. And what happened was that he had a period during which he could alternate between Farsi and German. For a certain number of days in a row, he could speak Farsi. Then later he could only speak German and he would alternate between these two languages for days at a time. So he would be stuck in German for some days and then stuck in Farsi for some days. Even if he encountered someone who was a German speaker he would speak to them in Farsi, when that's all he could speak. Eventually he recovered both languages and then only did then English come back. Now you might ask what have, why would this have something to do with a system outside of language? Well, to me it was very interesting at the time when I first encountered this case. I encountered it when I was an undergraduate a UC Berkeley. studying, taking a class in cognitive neuropsychology. And the reason it was so stunning to me, was that, I had experienced something like that at the age of 20. So, at the age of 20, I went to Brazil, for two years. And initially when I arrived, I noticed pretty quickly that I had trouble speaking in Spanish. So I grew up simultaneous. I spoke Spanish and English as a child. As a young child, all the way through my childhood. And at 20, when I learned Portuguese in Brazil, I felt that I had a very difficult time accessing my Spanish and also my English. I, I couldn't speak them as well and it was very surprising to me because I had spoken these two languages my entire life. Here I go and learn a third language and suddenly I'm having trouble accessing my two native languages. So when I read this case, it reminded me a lot of what I'd experienced and I began to ask the question, well why is that? Now, I recovered eventually, right? Spanish English came back, and I'm today lecturing to you in English. And Portuguese not in my mind. Many years later. And, and so the question was, well, how does that happen? And one of the ways that people have started to think about this. And was thought about a little but after Ribot and Petrie's which was the idea of control, or what's called maybe a language switch
