Wasn't class the first time we kind of done something like this. And it's very cool. It came about largely from this discussion forum topic, where we were talking about handedness. And we had this idea of maybe. Well, I don't know as much as I'd like to know but I know people who know things and luckily one of my well fellow graduate students, we went to graduate school together Professor Daniel Voiay who's now at University of New Brunswick. He agreed to have a chat with us about handedness and basically lateralization more generally. So, I kind of went through your side dish, or your discussion forum and pulled out a few questions. And I want to just ask Dan and see what he thinks. So I've got the questions listed over here. I don't want to cut off Dan's face though. I mean. [LAUGH] >> That's okay. You won't lose anything. >> No, no, no, no. There we go. [LAUGH] That'll work. All right. So, let me just kind of go through these and the first one is yeah, we know there's this weird thing where right handed people seem to have strongly lateralized brains, but why? Is there any reason why lateralization is seen as any kind of benefit? What do we know about that? >> Okay, well, there's two questions in there, okay? The idea that there'd be a benefit to lateralization, essentially sharing functions. For the brain map you develop resources in specific areas of the brain to specific functions and that allows it do a more efficient job. But also there is a point of communication in the corpus callosum where they actually share the information and they can synchronize. I could go on forever about this. There's actually an old book that has been published recently about the master and his emissary. The book's about the topic that the raw experience might be a little messed up now adays. We're giving more role to the left than we should because of the way the world has evolved. But in reality, the masters are right, in this area. That mouthpiece is left. So they're working together, and they both have a job. So the right would be more looking at the big picture, and the left would be more passing the message and Doing the more close things. It makes us a more complete person. >> Well that's kind of interesting. So if we think of left handed people then being less lateralized is the implication then that they are at a disadvantage somehow because they're not mos efficiently using their brain? >> Well whether left handed people are actually left lateralized toward the page I know there's been a meta analysis that was published. Recently where I think they found a link that just maybe people are right handed people. I do my own research. I always do an analysis, I used to on right handers. Because together to To keep handedness a constant in our design. And lately I've included both left and right-handers, and I'm doing an analysis with and without the left-handers and it changes nothing. So, again, I'm starting more and more to look like maybe they're not that different. But it might be the task that I use. If you use your, well I don't more precise the word, but if you use your more radical task, like sodium amibarbital testing. >> A sodium >> To inject anesthetic >> In the. And you put one part of the brain to sleep, that's where you see the differences. That's where you see clearly there's about 80% of left-handers that would lose language for an injection to the left artery, and 95% of right-handers. So that's where you see the big difference. So it's probably true. Okay, I probably haven't answered the question. Why? There's more than one factor. Do you have many hours to talk about this? >> [LAUGH] >> I would expect that, for starters, One of the explanation we might talk about, if you left handed there's already been some evidence showing that your attention would be biased to the left side anyways. So when information's presented to the left, you will then do it first, compared to the information presented to the right and then, dominant might actually buy us information where it's processed. For example, okay, so just the way that the visual system and the auditory system are organized, and you did enough research on attention to know about attention and what lecture you on, now you can tell a lot about that in your class. To your insure your own time. But really it would be an intentional event for start [CROSSTALK] >> That's a cool point to say that's not just to say whether your hand is dominant, but actually the way you Perceive the world and experience the world, is also a function of this. So, I think that's very cool. >> Of course, yes, yes. But it might be also, I've just talked at this point about it'd be a top-down effect of attention. But then, it'd bring back bottom of the pack. Because you pick up that information that's presented on one side or the other. And then it scan like some kind of shoe box and it feeds itself automatically. >> Yeah. >> So that's one thing okay. Maybe left handers are less lateralized. But when we look at the behavior of the brain that might work like that. When you look and I talk about the sodium phenobarbitol test. >> Yeah. >> And that would be, well we don't have attention here, it's all neurological. And you can start looking at connections for example, left-handers, it seems that you have better communication if you look at density cells in the corpus callosum and even the size of it. So where does it come from? That's another Story. But there's actually both functional or cognitive effects as well as neurological effects that might account for that difference. >> That's really cool. So left handers actually have a denser corpus callosum, the hemisphere's >> Well, I read that somewhere. Of course, next week there could be a paper published that'll say that it's totally wrong. >> [LAUGH] Yeah. Replication was important, yes, yes. >> [LAUGH] >> Okay, that's cool. So every time we talk about this, kind of sneaking to the third question here, every time we talk about this people will pull out stories and say, well, I'm neither really right or left-handed. I do this right-handed. I do that left-handed. I do and they're not claiming to be ambidextrous, they're not saying, I'm equally good with both. They tend to, instead say, depending on the context I seem to be either right or left handed. So, is this common and is there any link to lateralization? Given what we talked about right and left handed, I'm suspecting you'll say we don't know. I know, but- >> My favorite questionnaire is the [INAUDIBLE] put together. Supervisor, [INAUDIBLE] Any two items, and each item is a question. So, like which hand do you use to brush your teeth, which hand will you use to throw baseball. There's even kind of a weird question. Which hand will you use to, to throw a javelin, like we do that every day. But anyway my point is, and you have to think about it. We always ask people, think about doing the activity. My point here is that, okay, handedness is something, it's not like one or the other. [INAUDIBLE] And you can be completely left handed, you do everything with the left You could be completely right-handed. Do everything with the right hand. But most people are somewhere in the middle. In the studies that I conduct, I tend to give that questionnaire, and I don't find that many people with extreme scores. I find people that are like somewhat in the middle. Myself, I took that test a while back, but I still remember that I was very close to zero. Well, two words, left-handed. But I know I write with my left hand. So writing hand is often used a very good predictor of handedness because it's a very solid trolley with the overall score. But it's not the whole story. So the point here is that it's very typical for people to do one thing well with the left hand, another thing well with the right hand. Other things they can do well with both hands. And you play guitar. You don't have a choice, you have to adapt. So there are things, maybe not as well as you'd like, I know I'm the same. >> [LAUGH] >> But some activities you need both hands. You don't have a choice, and you have to become proficient. So it just tells us you can learn. >> Yeah. >> And I know, I know there's another question that you're going to ask me. [LAUGH] >> Well, yeah. >> But you were leaning on- >> Okay. So let's skip four because I'll come back to four and leave it to the end. But yeah. So we have these people that are born one-handed, and it was especially common I think, back many years ago when left-handers were viewed, I don't know [LAUGH] in some less than optimal way. And so if your parents or your teachers found that you were left-handed, they would try to turn you into a right-handed person. And there's a lot of people in the course who've had that sort of experience, and I think that they're wondering about does this relate to their brain in any way. If they were left but now they've become right, and is there any reason why they became left or right in the first place? So how does someone become a left or right-hander? >> I will start with that. >> Okay. >> And then we'll start with what happens if you're forced to do something. So as you might imagine, there's a few theories about how you become left and right-handed. But I'll tell you, the more commonly accepted one. There's one that it was hormonal, and it was supposedly during your station, but there was also genetic aspects. And the hormonal part's pretty well down, kaput. And it's been criticized to death, so I'll leave it alone. It's already sad enough as it is. The genetic view though is still alive, and it's going strong, and people are still working on it. And one of the contenders is that there might actually be two genes that determine hand preference, and that there be one that basically is the hand preference gene. But there's another one that's a chance gene, and it can switch either way. And then we don't quite understand how it switches, but so you can have cases, for example, I'm going to cheat when you send me the questions ahead of time, you mentioned that example. I like that example because identical twins, you expect they have the exact same genetic makeup. But you might have one that's left-handed and one that's right-handed. And that would just be that chance gene. But it's just a theory. There's support for it. If you look at patterns of handedness in families, they tend to fit, but handedness tends to run in families. I can think about it. My dad was left-handed. My sister was left-handed. My brother was right-handed. My mom is right-handed. Like- >> Yeah. >> We can look at it that way and certainly encourage your students to think about it because that would kind of give them an idea. If there's no right-handers in their family and they are left-handers, they shouldn't think maybe the mailman was an addition. They shouldn't think that. You should think there's quite a chance factor, that chance gene that created that. But as you know, people are still working on the human genome, and maybe at some point, they will actually identify those genes. At this point as a contending theory, there's a genetic factor to start with. And you can go back, I mean, there's books written about how that evolved in the first place, and why is it that the population is about 90% right-handed and 10% left-handed. Even better, why is it that it's about 12% men are left-handed, and 8% of women are left-handed? These are things we still have to explain. We still have a lot of work to do, and that'll keep people like me in business. >> Yeah, cool. [LAUGH] Let me throw around, I got a new one that I just thought of while you're thinking about, that I know we've all heard. Which is the claim that left-handed people are also more creative, and it all implies that somehow their right side of their brain is a little more powerful. There's more of a master perhaps. >> Well, I have vested interest in saying that they're smarter and better looking and more creative because I am left-handed. It's a very interesting question, and I don't know that it's grounded in facts. I think that it makes sense because we think, well, supposedly they use their right hemisphere more, and supposedly the thinking is that their right hemisphere would be more creative and blah, blah, blah. But in reality, we know now that it's not that compartmentalized like that. We look at neuroimaging data, and we see, yes we find these effects, these laterality effects, but there's more to it than that. There's always a lateralized component, but we can't say while you're left handed, you use your right brain more, but we don't even have evidence for that. And then we don't even have evidence that creativity is the exclusive domain of the right hemisphere. So I think that's another one of those area that just might be a stereotype and- >> Maybe just notice the creative left-handed people and sort of highlight those a lot, the Jimi Hendrixs or the whatever and yeah. >> Yeah. And I think it's Leonardo Da Vinci, and like you can actually buy mugs, in San Francisco, there's the left-handed store, and you can buy mugs with name of famous people. >> Which brings up that funny thing. I think it is true that the life expectancy of left-handed people, sorry dad, is lower, right? That they tend to not survive as long? >> Yeah, about six months. >> Is it literally about six months? >> Yeah, it's about six months. Yeah, and there's a lot of explanations for that. Of course, as a left-hander, my favorite theory is that it's all over a mantle because we live in a world that's built for right-handers. And so I do activities, I'll use them on my circular saw, and my hand is closer to the blade than a right-hander's hand would be. And that would create a higher risk of accidents. So I might die. So I'm very careful around that kind of tools. >> I think we got sidetracked, and there's still one question I didn't answer, and that was, what happens to you if you're forced to change activity, and people do strange things, I know that. I had a teacher in high school that he could go to the blackboard and write his name with both hands, but one hand was writing the mirror image of the [INAUDIBLE] >> Whoa! >> And I think you mentioned to me that someone can write in a different language. I'm totally amazed by that. >> Yeah, by the way, I mentioned that to other people and whoever that student is. If you could send a little video of yourself doing that with each hand writing in a different language, I think a lot of people would love to just see that. I love it. >> Yeah, yeah. That would be really cool. >> Yeah. >> I think what happens with that, but first of all, it will change you, if you force like that to use a non-preferred hand. And we talked about intention earlier. It would effect, in part, if you had an intentional bias, maybe it would be less biased. But it also, we know there's a brain plasticity. And that would affect a bit, how connections happen. And it would be interesting to, for one, these people to give their brain to science. And that we could actually go look at their corpus collosum. Or even just a structural MRI on their brain. I wouldn't be surprised if there was a lot of connections. There would be more connections in people like that. But, we don't know. >> Yeah. >> I mean, I'm not going to tell you, start forcing your kids to write with both hands. Because on the other hand, other people, I've heard of other people that started stuttering as a result of that. And so it actually kind of confused them to some extent that it mixed the signals. So it can have beneficial effects, but it also can have detrimental effects. We don't understand the brain as well as we'd like. We're working, everybody's working on it. But that is really to me is one of those great areas that there would be a lot of research to be done. To go look at what people can do that and look inside their brain. And look at, I mean, you could even look at their personality for all I know, and find differences. So this one, I probably can't give a really satisfactory answer. I think it will affect how you deal with the world, your processing, your cognitive abilities, but I don't know which way and I don't know how. >> I find it kind of interesting in a way because, I mean, you can look at the task as asking somebody to use the other hand. But you can also look at it as forcing them to inhibit a natural tendency, and to consciously control something that would normally be unconscious. And of course, I love all this conscious unconscious stuff. >> Of course. >> [LAUGH] Yeah. But I also like the idea that, I wonder if there might be benefits. For example, we will talk about the famous marshmallow experiment at some point. I don't think I've unveiled it on them yet, but the idea of asking children to avoid eating a marshmallow for a period of time. And if they succeed, then you give them an extra marshmallow. But it requires will power. And there's been a lot of evidence that suggests that the kids that have the stronger willpower are ultimately more successful in life. So I kind of wonder whether it could be a potential for training your willpower and training you to consciously control things. And that could potentially have benefits that go well beyond handedness, maybe. >> I would agree with that. It's a possibility that, like I mentioned, that there could be beneficial effects, but it might not work for everybody. Now we get in the realm of individual differences, and this is my realm. And there's a lot of points to study. >> Yeah. >> And as we used to see at Waterloo, that's an empirical question. >> Yes, [LAUGH] all right. >> Go ask the right question and go look for answers. >> I think we've covered a lot of great ground. I just have this one other question that always has bothered me because I've never had a good answer. And I don't know if there is a good answer, but the general fact that the brain seems to have this contralateral organization. Especially in terms of sensory and motor functioning, where the left side of the brain is controlling the right side of the body and vice versa. Why is that, what's the story on that? >> I think again, that's kind of resource sharing. I think that's the best way that, all I can say is that chances are that's the way it evolved to start with. And then when it split. Humans are one of the few species that have that lateralization of functions. >> Okay, even you consider there's been a lot of research done on hand preference in mice, and there's no such thing. Mice will reach with whatever hand is closer. With humans, you could put a thing on the desk. And give me that pen. And we'd use our preferred hand, even if it's on the other side of our body. >> Hm. >> Just because that's our preferred hand. So- >> I think I've heard that before. I think it was the only other species was a parrot. And I think parrots, which are weird in many ways, including our language abilities, which may be linked. But I think they show a hand preference, maybe. >> They show a hand preference, and they actually, parrots will, when they sleep, they leave one eye open, at all times. So, they keep an eye on things, you, their brains sleeping. And I do have a parrot so. >> Do you? [LAUGH] >> So, I keep watching him sleep, and I often invite my nose, a number of times. So, but anyway. And apparently, I don't remember the exact pattern now. But it's essentially when they look at an object. If it's a threat, they assess the threat factor. They will use one eye. And if it's something. If it's food or a sexual object, they will use the other eye. So the brain is lateralized. And now because they also have collateralize connections in that way. So [INAUDIBLE]. I don't do research on animals, so that's a little fuzzy in my mind. But I know that they are laturalized, in that they handle things differently.- >> They will also sometimes show mental disorders too. It's difficult I think to have a parrot as a pet, because things like going away on vacation can be very traumatic to a parrot. And change in- >> It can be traumatic to the owners [LAUGH]. >> We take our bird everywhere we go. >> [LAUGH] >> Really. >> So, anyway, that's enough for this forum. >> [LAUGH] That's good. >> I was saying, I think that there's a functionary and certainly resource sharing advantages throughout that collaborative organization. And it keeps things straight. And also, if it was all centralized in one place, if you have a brain injury, you lose everything. And so this way there's kind of a more or less duplication of the information. Because there's some control that is bilateral, but it's not a very good. >> Yeah. >> Yeah, like in the cerebellum. But even then, recent research suggests that even the cerebellum has some lateralized connections, so we have to follow that story. >> Cool. Well, Dan, I really appreciate the time, and it's been a lot of fun. Man, I think I want to do this more. [LAUGH] >> Thanks for asking me. And I was looking at their questions. I think your students are very smart. >> I think they are too. Yeah, they're a great group. Well, thank you, Daniel. Have a great day. Have a great weekend. >> Okay, bye bye. >> Cheers, man. [LAUGH]
