Q & A with Dr Thomas Bak

Dr Thomas Bak at Bilingualism Matters

If you are interested in bilingualism, chances are you have heard about Dr Thomas Bak’s work, suggesting that speaking another language may delay symptoms in dementia , and slow brain ageing in healthy adults .

Last week, Dr Bak kindly agreed to answer your questions on twitter. We have reproduced the conversation in full here, including some longer answers that had to be squashed into shorter twitter format. If you’re short on time, why not look at the collection of tweets on storify .

Full transcript

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Ragged university, via twitter:
Are there significant health benefits long term to learning languages? I’m interested in dementia prevention activities

Thomas:
In terms of dementia, a large study from Hyderabad in India, published in 2013, suggests that bilinguals develop dementia 4-6 years later than monolinguals.

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Jackie, via twitter:
What does Dr Bak think is the causal connection with Alzheimer’s Disease please?

Thomas:
The effects aren’t only true for Alzheimers, in fact we found that effects are larger in frontotemporal dementia. At the moment our best guess is that it involves attention/executive functions (see reply to Seralynne, below).

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Seralynne, via email:
Can these effects be explained by differences in executive function?

Thomas:
Differences in executive function are currently the prevailing explanation, but other factors might play a role. In the Hyderabad study [where second language speakers showed a delay in the onset of dementia symptoms], the longest delay was observed in fronto-temporal demantia, which is usually characterised by executive dysfunction.

In the Lothian Birth Cohort study [where second language speakers showed better performance in cognitive tasks], the strongest effects were observed on tasks with high executive load. These findings support the idea that bilingualism has a particularly strong effect on executive functions.

The Lothian Birth Cohort study also went some way to show the direction of cause and effect, since we had records of people’s IQ aged 11. From these records, we know that it is not simply the case that having a higher IQ to begin with means you are more likely to learn a language and to show delays in brain ageing. It really seems to be something about learning a language that helps slow the signs of cognitive ageing.

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Fiona, via twitter:
Do you think the level a person speaks their 2nd language matters? Is it the learning activity creating the effect?

Thomas:
There are different effects at different stages of learning. Higher proficiency is better but you don’t need to be perfect.

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Chiara, via email:
Speaking 2nd language delays brain ageing: is this true only for early bilinguals, or do 2nd language learners benefit too?

Thomas:
Most research so far has been done on early bilinguals – i.e. people who grew up with two languages from a very early age. In our studies, we found similar effects in people who learnt a second language in adulthood, but it is true that we are only just starting to explore the effect of language learning in adults.

The Lothian Birth Cohort data, which we used in our recent 2014 paper about brain ageing is a great way of doing this. As I said to Fiona, you certainly don’t need to be perfectly fluent in order to reap the benefits, and it is never too late to start!

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Fionna, via email:
Does learning a language with a different alphabet have any bearing?
Judith McClure from the Scotland-China Education Network, via email:
Does it matter how similar the two languages are? Is there any particular benefit to learning a language like Chinese, which requires you to learn a different writing system?

Thomas:
At present there is very little research on written language and different alphabets. A lot of work still to be done! Madeleine (from Bilingualism Matters) and I have a few papers looking at the different languages studied in research into language loss following stroke, brain injury or dementia, and there is a massive bias towards Western European languages. So the short answer is, we don’t know – but we should be trying to find out!
Regarding similarity between languages, again, the short answer is that we don’t know. One of the questions that the major EU “AThEME” project will be looking at over the next five years is the effect of learning two similar languages (e.g. English and French) compared with two very different languages (e.g. English and Chinese). So keep your eyes peeled for updates!

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Age UK, via email:
Should we make foreign languages compulsory in secondary education?

Thomas:
There certainly do seem to be advantages in terms of brain health, as well as all the cultural and economic advantages (a lack of language skills costs the UK economy billions of pounds a year!). Personally, I would say that encouraging language learning at any stage of education is a good idea. The earlier you start, the easier it is to learn. That is one reason why the UK and Scottish government’s commitment to language learning in primary schools is so important.

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Vicky, via twitter:
Hi Dr Bak. What can people who don’t speak another language do? Would another skill like learning a musical instrument help?

Thomas:
The quick answer is yes, language learning is only one type of beneficial mental activity. There are many others, music being one. Work by Denise Park suggests that engaging in cognitively demanding, novel activities enhances cognitive function in older adults. In other words, any cognitively demanding activity can be beneficial and rewarding – learning a language is a good example, and so is learning the piano.

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Ian, via email:
Are dementia rates higher in bilingual countries like Switzerland?

Thomas:
Interesting question, but we need to keep a few things in mind.
The first is that our work looked at the onset of dementia symptoms, not the frequency of dementia. It’s a subtle difference. Rather than looking at how many people have dementia, we looked at people who we know have dementia, and asked at what age did they start to show symptoms? This is important because the longer you can delay the onset of symptoms, the better quality of life that individual is likely to have.

The second thing to keep in mind is that it is extremely difficult to compare different countries, because the number of official languages is not the only difference. There are also differences in lifestyle and healthcare which we would need to take into account.

Thirdly, we need to separate the individual from the country. For example, just because Switzerland has more than one official language, it does not follow that everyone living in Switzerland speaks all of those languages. Similarly, other countries may only have one official language, but there may be many citizens who speak multiple languages in that country.

In fact, according to recent figures by Wimo et al. (2010), Switzerland has one of the highest rates of dementia in Europe. Although these figures are only a best guess and should be treated with some caution. As we said above, it is extremely difficult to make any kind of meaningful comparison between countries.

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Ragged university, via twitter:
I know you specialize in studying the effects of speaking more than one language. What are the myths associated?

Thomas:
Good question! There are two opposing myths.

The first is that bilingualism is damaging, strongly believed for much of the 20th century. It was even believed that bilingual education causes schizophrenia!
The second is that bilingualism helps with everything – over the last ten years the pendulum has swung the other way and some people believe that bilingualism can prevent dementia completely and improve all cognitive functions.

The reality is that bilingualism seems to have beneficial effects on some cognitive functions, but there can also be cognitive costs associated with it. For example, bilinguals often need longer on lexical decision tasks (deciding if a word is real or not), possibly because they have a much larger combined vocabulary to screen through. In our view, the benefits by far outweigh the costs!

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Jackie, via twitter:
Does the language have to be verbal? Would learning to code – effectively computer language – work?

Thomas:
Hmm, that is hard to answer and as far as I know no research comparing effect of speaking second (human) language and computer coding, However, writing code does not have the same communicative and possibly attentional aspects (e.g., switching between vocabulary in English and Chinese), so I would guess the effects would not be as strong. However, it is true that any engaging, cognitively demanding task has been shown to be beneficial (see response to Vicky), so we certainly can’t rule it out!

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Speakita, via twitter:
What’s the best way to teach children a second language? Any advice about songs, books, games and activities?

Thomas:
The most important thing is motivation, so keep it fun. Playgroups can be a great resource – see the Bilingualism Matters local resources page

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Speakita, via twitter:
So would it be useless to plan some online activities? Like a parent-child online class?
Judith McClure, via email:
Does online learning give similar benefits, or is face to face communication key?

Thomas:
In my view online tasks can be a useful addition but they are unlikely to replace personal contact as the best way of learning a language. Although you don’t need to be perfectly fluent in a language to gain the cognitive benefits, these benefits do seem to increase as you get more proficient. And face to face communication is really important in order to increase your confidence in that respect. However, it is certainly worth doing online activities in order to learn certain vocabulary or grammatical structures in the first place. Just try and make sure you practice them on a real person eventually 🙂