(0:02) So myself and Brittany want to give you (0:07) some overview about the interaction (0:11) between multilingualism and, I mean, (0:13) not just childhood multilingualism, but also (0:15) language learning and dementia from two points of view. (0:19) So can you see the next slide already? (0:20) Has it changed? (0:24) Yes, perfect, Thomas. (0:25) It's working now.

(0:26) So I mean, just to give you a quick overview of what (0:29) we want to speak about. (0:30) So first, I will speak about the impact (0:33) of multilingualism on dementia. (0:35) So the question here is, does speaking (0:37) more than one language influence dementia onset? (0:43) And then I'm turning the tables, looking (0:46) what happens if a multilingual develops dementia.

(0:50) And that's the moment where I give, so to say, (0:53) the voice and the slides, the screen to Brittany, (0:56) who will continue speaking about language learning dementia, (1:00) because we have already some experience together (1:02) with LingoFlamingo on that. (1:04) So the question is, can patients with dementia (1:06) still learn a new language? (1:08) And then we'll finish with a glimpse (1:11) into our current research on language changes (1:14) in later life and dementia. (1:18) OK, so let's start.

(1:19) I mean, we should remember that we (1:21) are living in a country which might not (1:25) have maybe the most positive attitude to language learning (1:30) in the whole universe. (1:32) So these are just some, I mean, you (1:35) might have seen some of those notices, (1:37) like children find foreign languages so stressful (1:41) they are being signed off by a GP. (1:44) And here, that learning French and German (1:47) can harm mental health.

(1:50) So this is, so to say, kind of the narrative. (1:53) And this on the left is just a tweet that I have seen today (1:57) that an adoption panel has forbidden a family in Wales (2:02) to send their child to a Welsh language school (2:04) because it can cause language disorder or learning (2:07) disability. (2:09) Now, these are views about children.

(2:12) But from what I heard from LingoFlamingo (2:15) is that they've heard very similar reservations (2:18) about the elderly and let alone patients. (2:23) So the kind of the main argument was always, (2:25) oh, it will get people confused. (2:28) And indeed, they can get so confused (2:33) when they listen to a different language (2:35) that they will get agitated and might need a sedation.

(2:39) So obviously, learning languages and hearing foreign languages (2:42) is a very, very dangerous stuff. (2:45) Now, to put it a little bit in the context, (2:48) world is and has been for the last probably 100,000 years (2:52) or so a very multilingual place. (2:55) And Homo sapiens is by nature a very multilingual species.

(2:59) If we look at the hunter-gatherer societies, which (3:02) still exist today, vast majority of them (3:05) is highly multilingual. (3:07) Three, four, five languages is normal (3:09) unless they live somewhere in the desert (3:11) on an isolated island where there's not much exchange (3:15) with other groups. (3:16) And in fact, in many groups, they have (3:18) the rule of linguistic exogamy, meaning (3:20) that people can only marry someone coming or speaking (3:23) a different language, which means that not only young, (3:26) but also adult and even older people (3:28) are exposed to new languages all their life long.

(3:32) So they not only grow up with different languages, (3:35) but they also learn languages across lifetime. (3:38) And here are just some pictures from Africa. (3:40) I remember giving a talk two years ago in Entebbe (3:44) in Uganda.

(3:45) And then the first question I got (3:47) was by Tom Tagore, who said, well, sir, but I come from Ghana. (3:51) And we all speak four to five languages. (3:53) Is it better when I speak six, seven, or eight? (3:56) So that is, so to say, basically the baseline in countries (3:58) like India, or like many countries in Africa, (4:02) or Papua New Guinea, and so on.

(4:04) And there is a good neural argument (4:07) why we don't get confused. (4:09) And a lot of this confusion argument (4:12) comes from a very outdated model of the brain, (4:16) where the idea was that the brain is something (4:19) like a chest of drawers. (4:21) Very strict, static competition for space.

(4:25) So basically, if you put socks in one place, (4:27) there is no place for T-shirts, and vice versa. (4:30) So if you put one language, (4:31) there is no place for another language. (4:32) And if you put too many languages, (4:34) there's no space for mathematics or any other things.

(4:38) So this view is completely outdated. (4:42) We see now brain much more as an added value machine (4:46) in which everything is highly interactive. (4:50) The problem with the old view was that you assume (4:53) that every single piece of information (4:54) is unconnected to the other.

(4:56) But in fact, basically everything we do (4:59) is connected to each other. (5:01) We have now terms like dynamic localisation, (5:04) neuroplasticity. (5:06) There is an emphasis on learning and adaptation (5:08) throughout the whole lifetime.

(5:10) And I will tell you what I mean lifetime, (5:12) I mean up to 85 at least. (5:15) And from this point of view, (5:17) I think the new models of brain are very much in favour (5:22) or kind of can integrate multilinguals much easier. (5:26) Now, just, I mean, because we are speaking about elderly, (5:28) so just one slide about children, (5:30) because it gives me a chance to show some pictures (5:32) of my wonderful daughter.

(5:34) So what has been found in children (5:36) is that exposure to different languages (5:39) leads to better what we call metalinguistic knowledge, (5:43) so people understand more about language, children, (5:45) but also better theory of mind perspective (5:48) taking social cognition. (5:50) Brittany will come to it later (5:52) that in fact the social aspect of language learning (5:55) is a very important one also in later life (5:58) or maybe particularly in later life. (6:00) And then simultaneous activation of different languages (6:03) leads to a better cognitive ability (6:07) switching attentional (6:09) so-called executive control mechanisms.

(6:12) It has its price, (6:13) so you get a couple of milliseconds slower (6:16) in so-called lexical decision tasks (6:18) because when you see a picture, for instance, (6:20) you have to say, is it this or that, (6:22) you have to screen two or three languages instead of one. (6:25) But generally in children, (6:27) this is relatively well established. (6:28) What about older people? (6:30) Well, I would say this is a paper (6:32) which really changed the landscape.

(6:35) 2007 by Ellen Biawistock (6:38) in the middle with her colleagues, (6:39) Fergus Craig and Maurice Friedman from Toronto. (6:42) They look at 230 dementia patients, (6:45) roughly half of them bilingual. (6:46) It was in Toronto (6:47) and in this area of Toronto, Baycrest, North Toronto, (6:50) this is absolutely usual.

(6:52) It's not very unusual. (6:54) And they found that bilinguals develop dementia (6:57) about four years later. (6:59) Now four years is a huge amount of time.

(7:01) It's much more than any drugs can offer at the moment. (7:06) And although it might look surprising, (7:09) it is related to other research (7:11) being done before and after. (7:14) Biawistock 2004, so the same group, (7:16) showed also better cognitive performance (7:19) early who spoke more than one language.

(7:22) And there were some studies, for instance, (7:24) from Israel showing also a better performance (7:26) the more languages people spoke. (7:29) So the idea is here that languages (7:32) offer a kind of cognitive reserve. (7:34) They offer, because they produce, (7:37) so to say, extra connections in the brain, (7:40) the brain is still affected by dementia.

(7:44) So the important thing is, (7:45) it's not that it prevents, you don't get dementia. (7:47) That's not the case, (7:48) but the brain is better equipped (7:53) to cope with cognitive problems caused by dementia. (7:57) Now, the main criticism against this study was (8:01) that a lot of bilinguals were in fact (8:04) coming from immigrant backgrounds.

(8:07) So they were either first or second degree immigrants. (8:10) So the question arose, well, (8:12) maybe there is something special (8:13) about immigrants that selects them. (8:15) So together with Suvarna Alladi, (8:18) whom you see on this picture, (8:19) I decided to do a study in Hyderabad in India, (8:22) which is a good place because bilingualism (8:24) has been common there for at least 500 years, (8:27) probably longer, and it's not a socialist migration.

(8:30) So people have been there, (8:32) been bilingual for generations and generations in a row. (8:35) You have excellent clinical services, (8:37) there's multilingual tests and stuff. (8:40) And what we found in the study, 648 patients, (8:44) again, 60% bilingual, (8:46) which is roughly the percentage in the village, (8:49) I mean, in the city.

(8:51) And we found also four years delay, (8:54) very similar to Białystok study in Toronto. (8:58) More interesting than that, (9:00) because in India you have a lot of people (9:02) who are illiterate, never went to school, (9:05) cannot read and write, but speak more than one language. (9:07) And in this group, the difference was six years.

(9:10) So that means it's not about (9:12) bilinguals going to better schools. (9:14) People who don't go to school at all (9:17) have even stronger effect. (9:19) And we found similar things also (9:21) on age of onset of mild cognitive impairment.

(9:25) So here again, education gave people (9:28) additional 6.3 years, sorry, 3.6 years, (9:32) bilingualism, 7.4 years. (9:34) So the effect of bilinguals was more than twice (9:36) as big as that of education. (9:39) And by the way, not only dementia, (9:41) we found similar things in stroke patients.

(9:44) So this is a study of stroke patients. (9:46) And again, what we find here is that (9:49) you find that normal cognition was preserved (9:52) after a year, after a stroke in 40%, (9:56) over 40% of bilinguals, but less than 20% of monolinguals. (10:00) So from this point of view, I mean, (10:02) there is a whole group of half a dozen studies (10:06) showing all pointing in the same direction.

(10:10) And we have from Edinburgh an interesting study (10:13) showing also a better cognitive performance (10:15) in dementia, in healthy ageing. (10:18) So these are people who are in the 70s, 80s, (10:21) not demented, but in this case, (10:23) we know how they performed when they were children, (10:26) because in Scotland, all kids born in 1936 (10:31) and therefore 11-year-old in 47 (10:34) were tested for the cognitive performance at school. (10:39) So thousands of those people roughly were found (10:42) in the both loss and birth cohort in, (10:44) and then we can ask whether people learn (10:49) another language thereafter.

(10:51) So this is important because it addresses the question (10:53) of the kind of, which is very, very often asked, (10:57) well, we call it in science reverse causality (11:00) or in colloquial speech, (11:03) it is about the egg and chicken question. (11:07) So basically, is it that speaking languages (11:11) makes you better in cognitively (11:13) or is it that people who are cognitively better (11:15) are more likely to learn languages? (11:17) Here, we could show that people perform better (11:20) in comparison to their childhood performance (11:23) if they learn another language. (11:24) So it means that there is definitely an effect (11:27) of language learning beyond that, (11:29) that it makes you more likely to learn a language.

(11:33) And here, I mean, I promised you something about 85. (11:36) So this is a study, I mean, (11:37) we have now two studies from there. (11:39) This beautiful place is Salmer Ostad, (11:41) the Gallic College on the Isle of Skye.

(11:43) And one of my first master and PhD students (11:46) went there and was testing people over several years (11:49) doing a one-week intensive course of Gallic, just one week. (11:54) And we had people from 18 in the first study till 78, (11:59) in the second study till 85. (12:01) So the oldest person in the group was 85-year-old.

(12:05) And all of them, after one week, (12:07) improved in their cognitive functions. (12:09) So that means that this improvement (12:11) is not something which is reserved for the young. (12:13) You can find in any age, (12:15) and I would say the older you get, the more important it is, (12:18) because the more likely you are to have lower functions (12:22) and therefore, so to say, need this improvement.

(12:25) And the last slide before I move to, (12:28) so to say, we move to Brittany. (12:30) So what happens now with ageing and dementia? (12:34) So one thing, I mean, this is again, (12:36) this is outer hebrides, so we are also in West Scotland, (12:39) but now even further out to the West, into the Atlantic. (12:43) I mean, here's the Isle of Harris.

(12:45) And we're looking at people who are now over 65. (12:48) So all of them were bilingual when they were growing up (12:50) because the usual home and community language (12:53) would have been Gallic, (12:54) but in English, it was forbidden to speak Gallic. (12:58) You had to speak English.

(13:00) So at school and work, we were speaking always English. (13:05) But after retirement, some of them went back to use, (13:12) in fact, much more Gallic (13:13) because then they can choose what they speak, (13:15) where the other became (13:15) almost secondary monolingual English speakers. (13:20) And the interesting point was (13:22) that their kind of cognitive performance (13:24) in those who were non-active bilinguals (13:28) was somewhere between monolinguals and active bilinguals.

(13:30) So that is important. (13:31) It means if people know more than one language, (13:34) it's not just good to know it, it's good to practise it. (13:37) Because if you don't practise it, (13:38) at some point the effects are going to be.

(13:41) And that leads me to a topic (13:44) which Brittany will be speaking in more detail, (13:47) which I think we found very, very relevant (13:49) and very interesting. (13:51) After many talks, I get asked by people, (13:54) well, you know what? (13:55) My granny used to speak English with me (13:59) and now she's speaking only Punjabi (14:01) or only Gallic and so on. (14:03) And in fact, last year I was approached (14:05) by an artist playwright who wrote a play, (14:09) autobiographic play based on the real story of his mother (14:12) who developing dementia is a Gallic speaker (14:15) who married a monolingual English speaker, (14:18) practically lost her English and was speaking Gallic only.

(14:22) And the question is, is it an isolated case (14:26) or do people generally go back to their first language (14:31) when they develop dementia? (14:33) And that is a question about which we will hear (14:36) a little bit more now from Brittany.

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