9.5 Neurolinguistics and Second Language Learning
Check Yourself
Video Script
As we’ve been talking about mental grammar, we’ve concentrated almost entirely on the mental grammar of your native language — the language you learned to speak in childhood, in your home. Linguists refer to your native language, your first language, as your L1. But many people in the world speak more than one language, and many of those people learned a second or third language in a different way from their L1. Any language that you learned after childhood, whether you learned it in school, using software, by travelling or immigrating somewhere, is called an L2 (even if it’s really your third or fourth language).
Learning an L2 is different from learning an L1 for a couple of different reasons. One is that, obviously, the language learner is not a child, so their cognitive processes might be different from those of a child. L1 learning happens by being immersed in a language environment, and most of the learning is unconscious, without overt teaching. L2 learning often happens with a lot of conscious effort: studying and memorizing and practicing.
But of course, the biggest difference between L1 learning and L2 learning is that when you start learning an L2, you already know at least one other language. The mental grammar of your L1 can influence the mental grammar that you’re developing for your L2: this is called transfer. Transfer can be helpful in L2 learning or it can pose a challenge. If your L1 includes a structure that’s similar to a structure in the L2, then you might experience positive transfer, which facilitates learning the L2: you can transfer what you know from L1 and apply it to the L2. But if the structures that you’re learning in L2 are different from those in your L1, then you might experience negative transfer: the knowledge from your L1 could make it more difficult to learn the new structures in the L2. And of course, you might experience both positive and negative transfer from your L1 to different parts of the grammar of your L2.
One theory of second language acquisition predicts that we would observe differences between native speakers and beginner L2 learners, but as the L2 learners become more proficient, their mental processes should become more and more native-like — that is the mental grammar of a fluent L2 speaker should look very similar to the mental grammar of an L1 speaker of that language. We can use the tools of psycholinguistics and neuroscience to learn about the mental grammars of L2 learners. Let’s take a look at some of the evidence.
Several studies have compared N400 effects in L1 and L2 speakers of a language. Remember that the N400 is an electrophysiological response that our brains show when a word is semantically unexpected in a given context. The brains of native speakers of English show a negative voltage about 400 milliseconds after a semantically unexpected word (socks), compared to an expected word. But what do the bra