Hi. Welcome back to our Office Hours. I'm here with the Dr. Arturo Hernandez to answer some of the questions that we found in forms. So let's just dive right in and get started. The first question has to do with a little bit of confusion from video 6.5. In that video you talk about how children have more difficulty switching, like they slow down when they have to switch. And then adults have a, they don't have as much of the difficulty in switching, so the switching costs decrease for adults. But then, you then say that the ability to switch between tasks becomes more difficult for adults even though it seems like it was kind of the opposite from what you said before. Would you be able to clarify that a little? >> Sure. I, I guess the confusion is I should have said older adults [CROSSTALK] and somehow that word didn't come out so, essentially what happens is the switching effect or the cost of having to switch between tasks is largest in younger children and then it, that slowdown gets smaller. So in other words, it starts to approach just doing one single task. It's never the same, it's always slower to do, to switch between tasks than do a single task, but that difference gets smaller. And then it stays pretty stable up until about 40 to 50, and then it grows again after 60, roughly. >> Mm-hm. >> So, you see basically something like this that gets smaller and then, it gets larger again. So. >> Okay. So, that's what you've meant by- >> Right. >> Older adults. >> Yeah. >> Actually have more difficult times. >> That's correct. >> Okay. >> The older adults have a more difficult time switching, which is interesting in light of the fact that older adults in our literature seems to be showing that older adult bilinguals seem to show an advantage relative to young adult sorry relative to monolinguals. And that advance seems to be bigger. The interesting thing about the data that we collected was that the older adults showed more of a slowdown relative to the young adult bilinguals. So even though switching is much harder for them, and that's also true in the, in the monolingual literature. Maybe one suggestion is that because it's so hard to switch for older adults in general if a bilingual has to do that, where they're speaking to one set of people and then they switch to speaking to another set of people that that's a sort of form of mental exercise. That's the, that's the suggestion from the literature. Because our, our effects were pretty gargantuan. And it's, you could see it and it's maybe a second, second and a half longer between the young adult and the older adult bilingual. Or I think it's something like 400 milliseconds when you look at just a single condition or a single language. So it's a really big effect and, and it's there also in children, although children of course are developing, so there is the added thing of having learning language, on top of the switching. But again yes, it should have been older adults. >> Okay, so we hope that that clarifies things- >> [LAUGH]. >> For you guys, it was a little confusing so hopefully that takes care of that. So the next question comes from a poster who was kind of disappointed that we didn't talk more about ASL and acquisition of a sign language as opposed to a spoken language. And they were wondering if there are differences in brain imaging of deaf children who were exposed to ASL early in life and those who were exposed later in life.

>> So we have, I mean, I guess I'll just start by saying that lots of people come up and ask me, you know, why don't we do a study with Vietnamese-English bilinguals. Or with you know you know Hebrew-English bilinguals. I mean I've gotten all sorts of questions along the, the way, and I always say if you can find someone who's a linguist, who knows about the language, and understands the culture, and understands the dynamics of that population in that particular situation, then I'm happy to do a study.

But I really feel, actually having grown up bilingual myself and sort of having a sensitivity to the differences and the sort of particulars of each population, that I don't feel that confident exploring a population which I don't understand that well. Now I ca, of course, that doesn't mean I will do, never do anything that I don't understand that well. But the point is, if I'm going to do that, then I want someone who really, really understands that population. So if I were going to study Chinese-English bilinguals, I would ask my colleague Ping Lee to please collaborate with me because he understands the population. He's Chinese, he has a daughter who's Chinese-American so, he will understand the dynamics across both countries and some of the factors that might play a role in the study that I don't have the sensitivity to, in the same way. I can ask lots of questions, but I just don't have that experience and that and that expertise on top of the fact that Ping Lee is a chi, is a linguist by training, so you can't get any better than that. So that's the type of person I would seek out. In terms of sign language work, if I were to do work in that domain, and we do have one published study where we have found some differences, not in the of the brain, but in terms of attentional control depending on whether bilinguals are, are early or later acquirers of a second language.

And and also how proficient they are in their second language. We did find some attentional differences there and that was done by a student of mine Poorna Kushalnagar who is a deaf and who is deaf and also an ASL English bilingual. So she understood the population, she understood, she had a very beautiful task that she set up as her, part of her dissertation and that got published and in that case I was happy to go along with that work. But if I were to do this work, I would, I would ask Rachel Mayberry. She's at U.C. San Diego. She's done lots of work. Looking at the issues of AoA age-of-acquisition, proficiency in ASL English bilinguals. It's very, very well done work work that's very well done, very well controlled and they do find some differences. So the, the reason is partly because I felt that was just a little too far out, outside of my area of expertise. >> Hm. >> And there's lots of issues that come up because sign language is a visual spatial language but at the same time it is language. And so, these sort of intricacies when I go to talks and I, you know Karen Emery is another person who does a lot of work, David also, I know, I know them quite well. As colleagues and having seen their talks it's clear there's a lot of complexity to that issue. And its complexity for which it would be difficult for me to bridge that and feel confident in my results. And most scientists want to feel at least some confidence that what they're measuring is exactly what they intended to measure at the beginning and not something else. >> Hm. Mm-hm. So, just kind of, maybe a very quick follow-up. is, do you know of any studies that show

a difference between spoken language versus sign language? >> Yeah, sure. I mean, you can look up Karen Emery and David Karina, and also Rachel Mayberry, and they will, there are quite a few studies. David Karina's a UC, UC, UC Davis is California Davis. Karen Emery is at San Diego State University. Rachel Mabry, Mayberry is at UC San Diego. University of California, San Diego. And all three of them show pretty clear differences between brain the way that the sign language is instantiated in the brain versus spoken language. On the other hand, there are also many similarities, at least from my understanding, language is language. They're trying to, even though it may be a spatial signal, it's still trying to communicate what language communicates in a very tight, time window. There's some interesting differences too. So sign language, they can sign and speak at the same time. >> Mm-hm. >> So for example, the interference effect, this, advantage that appears in what, what are called unimodel bilinguals doesn't appear in bimodal bilinguals, because they can sign and speak, so there's less interference, in that sense. >> Mm-hm. >> So there's some interesting differences with spoken bilingualism. but, yeah, there's, there, there are, there are studies that have shown both these differences and similarities between spoken and sign language. >> All right. Well, I hope that that kind of helps clear things up as to why we don't discuss it so much and in this course and give the poster some feature readings to look into, all right? So the last question that we have today this has to do with a little bit of confusion, confusion about what control actually means. Is this something we have learned, is this something that just kind of develops naturally? What is control? >> That's a really good question. >> [LAUGH]. >> And, and we could, it, it, gets more complicated if we go from control to working memory or to executive functions. So these are labels that are given to things basically which involve you. And we can start maybe with the simplest version of control, so does, does it, does it, so what was that question was does it de, it develops. I'm going to talk about that, but. That there was another quest, sub question. >> Just what is control, what does it mean how do we learn it? >> And do we have to train it, was that the other question? >> How do we learn it? >> How do we learn it. Okay. Simple. All right, so, if we think about sort of the simplest form of control you could think about object permanence. And I did talk about this again in the course, but the idea Pagge had that you know at certain ages infants will, will search for something even though it's hidden, right? And so we could think of a form of control as being able to think about something that we can't see, which would he would describe as representation, it's something in the mind that's not in the world. And in order to do that requires control because it it requires for us to attend

to something that we can imagine, but we can't actually see. Visualization, if you will. And so that's a very early form of control. It does develop on it's own. It develops a, I mean, you can train it, in the sense that now they have Lumosity or things like this where you can do these brain training games, but, really, the best form of brain training is just to be in the world, right? So, to interact, to navigate through the world, to interact with adults. We could think of symbolic representation as an extension of that. Now suddenly we have a word. A bee, right? Which doesn't really have anything to do wit the bee that flies around.

And suddenly we have to attach this sound bit to a visual representation, and that requires control. It requires us to now map, make this mapping, right? And so that, in some ways we have to stop thinking about the sound of this word and attach it to a thing in the world. >> Mm-hm. >> So again another extension of control. Not just worry about bee. Just saying bee, which is part of what an, an infant does is to say the, you know, make the sounds. But eventually it's to sort of, okay now I've got these sounds. Now I've gotta attach them to a thing. And of course, we could say okay, bee, and then I show you a little picture of the bee, or we could say now, give me a word that sounds like bee and now I say key, right? So now I've attended to the sound of the word and come up with another word that sounds like it, or I have attended to the meaning of the word and come up with a visual of that. >> Mm-hm. >> And that requires again, you going from one thing to another thing. To sort of selectively accessing some part of the signal that comes in. So, we could argue that control is present in pretty much everything that we do. It's just how much control it requires. And some things, of course, have become quite automatic and fast will require less control, but control is present pretty much in everything. And, and there is a, I think the easiest way for me to make sense of it is to think about what the brain does. If we think about the parietal lobe, roughly about here.

More on the right for humans because we have language that's kind of invaded our whole left hemisphere. And so our left parietal lobe actually takes on some language functions much more than our right parietal lobe, and so our left parietal lobe actually doesn't do as much visual-spacial stuff as it would if we didn't have language. >> Mm-hm. >> But more on the right, if we think about what the parietal lobe does, it does basically it, you know, figure out what's in space and kind of attend to location.

If we think about the frontal lobe then that becomes more like a sensory motor kind of integration type of thing whereas the parietal seems to be more a spatial kind of thing. A little bit more sensory.

So we can think about these as different forms of control, maybe as

less intense form of control that's posterior and then a more intense form of control that's pri, that's frontal, which would be involved in things like trying to switch between texting, driving and changing the radio station. That would require more like frontal, and parietal might be something like, for an adult, of course, this varies. Children may use frontal lobes for things that are simple for adults. But for an adult if you just had to attend to where a car is, and you have to change lanes, that might be more parietal. >> Mm-hm. >> Having to switch between texting [LAUGH] Switching a station and driving and attending to where all these cars are, that would be more frontal. >> Mm-hm. >> And so I think an easier way for me to think about it is, are we creeping into the frontal lobe, in which case it's more complex types of control? Or are we back in the parietal lobe, which, where it is less complex types of control. That, that's the way I think of it. >> Mm-hm. And like, we've mentioned before in the first question, this kind of develops into adulthood, and then you see kind of a, a decrease in this ability. >> Right. And some people have, in the intelligence literature have talked about the difference between fluid intelligence and, and crystallized intelligence, knowledge that you have. One example that is, vocabulary. So, for example do older adults, they actually show an increase in vocabulary across their lifetime. So child, children have a smaller vocabularies in general. Adults have larger vocabularies in general and older adults have the largest vocabulary in general. But if we look at these sort of fast types of tasks that involve what we might say is attentional control. Playing a video game, for example you would see that the peak would be somewhere in early adulthood and then gradual drop off across time. Or if we look at speed, just I presented a dot and I asked a person to just press the button when they see a dot the fastest responses will be somewhere or in early adulthood. And then a gradual drop off in speed. Just in that reaction to that dot. So yeah, there's this set, this general sort of drop off, you know, increase and drop off in these forms of what they call crystallized intelligence speeded types of tasks. Sorry, in fluid intelligence, speeded types of tasks, crystalized intelligence show this gradual increase. >> Hm. All right, well, that is all the time we have for today, so thank you guys for watching and thank you for taking these questions and we will be here next week to answer some questions about chapter 7.

Office Hours 6

The Bilingual Brain

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