Understanding how deaf children and adults learn sign language
Professor Chloë Marshall
00:00:02 Female voiceover
You're listening to an IOE Podcast, from the UCL Institute of Education. Powered by UCL Minds.
00:00:22 Male voiceover
This is Research for the Real World. Conversations with researchers about the paths they've taken to to shape our everyday lives.
00:00:44 Dr Sam Sims
This is Research for the Real World. I'm Sam Sims. I'm a lecturer at the UCL Institute of Education.
And on today's episode, I'm talking to Chloë Marshall, professor of Psychology, Language and Education in the Department of Psychology and Human Development at the Institute. Chloë researches language and literacy development, cognitive skills underpinning these processes and developmental disorders related to language and literacy. She also teaches on a wide range of Masters courses and modules at the IOE. Chloë is the director of the Acquiring Language and Literacy in Challenging Circumstances Lab. Otherwise known as ALLICC.
And sits on the management committee of the Centre for Educational Neuroscience. She's also the editor in chief of the journal First Language.
We're going to talk to Chloe today about how children learn to speak and read why some children struggle with that and what we can do to help them. Chloë, welcome to the podcast.
00:01:43 Professor Chloë Marshall
Thank you very much Sam. It's lovely to be with you today.
00:01:47 Dr Sam Sims
Chloë, as I understand it, you began your career as a Montessori nursery school teacher. I mean, like most people, I've never attended a Montessori school.
What is a Montessori school? What was your time like working there?
00:02:00 Professor Chloë Marshall
Well, Montessori education is probably less unique now than it was when it first started over 100 years ago, and there are two main features of Montessori education, so Montessori education as well known for firstly for the types of learning materials that children use and the second obvious feature of Montessori education, is the way in which children engage with those learning materials. So is very much self-directed, individualistic learning where children have long periods of time to work on things that they are interested in, in a very self-directed way. Now a lot of those principles have entered mainstream education, but 100 or more years ago it was a very unique way of teaching and a way of teaching that really makes the most of children's self-motivation and their desire to learn.
00:02:49 Dr Sam Sims
And as I understand it, your move into academia was motivated by your kind of experiences working in Montessori schools. So tell us, you know, why did you decide to move from teaching 3 year olds in the nursery to, you know, 23 year olds and above in the University?
00:03:07 Professor Chloë Marshall
Well, I haven't really planned it that way, it was just how it worked out, so I was a Montessori teacher for six years, and during that time I taught children between the ages of two and six, and I became fascinated in their language development. They would start with me in nursery at the age of two. Not saying very much by the time I sent them off to big school, the majority were chatterboxes and I wanted to know how that process worked and I also wanted to understand a little bit about those few children in my class who just didn't seem to be making as much progress in terms of language development. And sometimes there was a very obvious reason for the fact they weren't making as much progress. So I taught children, for example, who had autism, children who maybe just arrived in the country, and so were taking a little bit longer to learn English. There are some children I just couldn't put my finger on what it was that was causing difficulty with language learning, and I came to UCL in fact, to do a Masters in Linguistics with the hope of better understanding how it is children learn language and what I could do as a teacher to support them.
And basically I never left. I never went back into the classroom. I discovered linguistics at UCL, stayed on to do a PhD, stayed on to do a postdoc. And here I am.
00:04:17 Dr Sam Sims
Tell us more about your PhD. What did you learn?
00:04:19 Professor Chloë Marshall
Well, I was working with Professor Heather van der Lely, who is an expert in children with developmental language disorders, and I was looking at one particular difficulty that children with language disorders have and that's with past tense formation. And so is often the case with a PhD, you take a tiny area of research and you look at it in a lot of depth. So I was interested in the grammatical problems that children with language disorders had.
And from there I went on to do a post doc looking at the similarities between children who have dyslexia and children who have language impairment and thinking about dyslexia. Although we know of dyslexia is a difficulty learning to read and learning to spell thinking about some of the linguistic underpinnings of dyslexia.
00:05:02 Dr Sam Sims
Interesting, and as I understand it, you've got a lot of research on deafness and sign language. So how did you come to be interested in these topics?
00:05:10 Professor Chloë Marshall
Well, I think if you study languages you're interested in language in all its different forms, and sign languages are fascinating because they're obviously presented in a different modality to spoken and written languages.
And as a master's student at UCL, I was introduced to sign languages through my lectures and wanted to learn more about them and at the time that I was doing my PhD at UCL I was very fortunate to meet Professor Gary Morgan, who at that stage had a grant with collaborators to set up the deafness, cognition and language research centre at UCL. So I was able to join that group and start researching language development in deaf children and particularly focusing on sign language development, and actually trying to investigate whether deaf children who are learning sign language can have a developmental language disorder in their sign. That was something that therapists and teachers of the deaf were telling us was possible, but it had never been looked at before, so that was a very exciting time in the mid 2000s when DCAL, the Deafness, Cognition and Language Research Centre was set up and I was able to bring some of my expertise and looking at developmental language disorders to thinking about language development in deaf children.
00:06:21 Dr Sam Sims
Fascinating and just for listeners. What do we mean when we use this phrase, developmental language disorder?
00:06:28 Professor Chloë Marshall
Well, there are many different ways in which language developments can go awry. So I mentioned earlier for example, children with autism. There are some developmental syndrome, such as Down Syndrome, where language development can be affected. Developmental language disorder was commonly known for a while as specific language impairment.
The idea being that this was the difficulty that was specific to language development, rather than affecting other areas of cognition rather than affecting more general intellectual ability and children with developmental language disorder have difficulty with grammar. They also have difficulty learning vocabulary. They have difficulty both with the understanding of language and the production of language. This can affect their written languages as well. And it's often known as a hidden disorder because teachers aren't particularly aware of it. Parents may not be aware of it. Estimates are that maybe two children in a class of 30 will have developmental language disorder, but it might not be identified. These are often children who may be sitting in class, maybe not necessarily participating, not necessarily understanding the language that's being used in class.
00:07:38 Dr Sam Sims
Wow, so one or two in 30. So you know most teachers can expect to have a pupil with a problem like this in, you know at least some of their classes. So this is sort of relevant to everyone?
00:07:49 Professor Chloë Marshall
00:07:50 Dr Sam Sims
And you mentioned that it used to be called a specific language impairment. Why have we moved away from that language, is that not how it's seen anymore?
00:07:58 Professor Chloë Marshall
Well, there's always been an argument over how specific it is, and this gets back to our understanding of the cognitive underpinnings of language, how language is processed in the brain, whether language is a separate module that can be affected developmentally, so that it only affects our own language itself, or whether language is part of sort of broader cognitive processes, in which case the specificity of a language disorder has been debated.
And now the move is towards using the term developmental language disorder because that doesn't make any claims about the specificity of the disorder. But for many children it's language, which is the critical difficulty.
00:08:41 Dr Sam Sims
And so I guess the specificity or potential specificity of this means that perhaps this would be particularly hard to spot a developmental delay among deaf children. Is that right? Are there extra challenges in sort of diagnosing this there?
00:08:57 Professor Chloë Marshall
That's exactly the point. Yeah, it's exactly the point. So I mean listeners may not know this, but the majority of deaf children are born to hearing parents. Hearing parents who are not expecting a deaf child. Hearing parents who know nothing about deafness, who've never seen deaf role models who don't know about the vibrant deaf community who don't know about in our country, British Sign Language.
And so many deaf children will grow up with a language delay even if they have a cochlear implant or hearing aids, that assistive technology doesn't cure their deafness. It doesn't restore their hearing to normal levels, and so most deaf children, unless they are lucky enough to be born to deaf parents who are using a sign language at home, most deaf children are going to have delayed access to an accessible language because they won't be able to access spoken language clearly enough, and many of them may not encounter sign language until they go to school. So most deaf children. as I've said, unless they're born to deaf parents who sign with them, most deaf children are going to have a language delay.
And then the question is, can we identify developmental language disorder on top of that delay? Because it's very difficult to tease apart in those cases, a language delay from a language disorder. We think that we did that in our study and there's a group of researchers in the States looking at American Sign Language who also have been able to identify cases of developmental language disorder in American Sign Language. We've known from therapists and teachers of the deaf for a while that these children exist.
00:10:39 Dr Sam Sims
I'm so fascinated by this. So how have researchers gone about sort of distinguishing between deaf children who are, you know, are disadvantaged with language acquisition because you know most people are speaking a kind of oral spoken language around them which they don't have access to or have reduced access to versus deaf children who also have some sort of developmental language problem.
00:11:08 Professor Chloë Marshall
So I should clarify that we were looking for developmental language disorder in deaf children who signed, so I should just clarify that.
00:11:15 Dr Sam Sims
00:11:15 Professor Chloë Marshall
Actually we relied at the start of our project when we were identifying deaf children with developmental language disorder. We were relying very heavily on the expertise of teachers of the deaf. So teachers of the deaf who have taught many children over the years who know amongst that cohort of children who might be from hearing families and therefore suffering from delayed language input.
They still have an expectation of what typical language development would look like for those children, and so we relied very heavily. We surveyed services and schools for the deaf and we relied on that expertise from professionals, and then we thought about what are the markers of developmental language disorder in spoken languages, and we know that these children's I've said before have difficulty with vocabulary learning, have difficulty with grammar, so we thought about what that might look like in a sign language like BSL, and develop some language tasks, some sort of language assessments that we could use with these children. It's a very long process and we are far from having a complete understanding of what these children's language development might look like. That's partly because we know very little about deaf childrens' sign language development. Anyway, we don't have that wealth of evidence that we have for a majority spoken language like English.
00:12:30 Dr Sam Sims
And BSL, is that British Sign language, Chloë?
00:12:34 Professor Chloë Marshall
Sorry, yes, pressure sign language is BSL. Absolutely so different. Countries have different sign languages.
00:12:40 Dr Sam Sims
Right, right. I'm learning a lot here, thanks.
00:12:42 Dr Sam Sims
And so the assessments that you developed were they administered in British Sign Language. How did you go about doing that?
00:12:50 Professor Chloë Marshall
Exactly so we were looking at tasks in British Sign Language. So one of the tasks that's used in spoken language is a task called sentence repetition, and in a sentence repetition you would say a sentence like, 'the boy and the girl played in the park' and the child would repeat that. And the child with language difficulties will find that harder to repeat than an age match peer who has typical language development. So what we did was we created a sentence repetition task, but in British Sign Language - in BSL, so the deaf children watched a video of a deaf colleague signing BSL sentences and they had to repeat them. We had a control group of children whose language development we were not worried about and a group with children who we thought might have developmental language disorder in their sign and we compared them, and indeed our children, that we suspected had developmental language disorder, found these sentences harder to repeat, so they missed out signs, they muddled signs about, they inserted the wrong sign or they just refused to repeat the sentences altogether.
00:13:54 Dr Sam Sims
Right, so in a way your data from your assessments sort of corroborated the sort of expertise and the sort of survey data from the teachers that you surveyed?
00:14:07 Professor Chloë Marshall
Absolutely, we should never underestimate the knowledge that professionals bringing the expertise that we can tap into there, absolutely. That was one of the tasks. We had other tasks as well. Narrative tasks for example. So telling a story and narrative is something that we know children with spoken developmental language disorder find difficult and that turned out to be the same for deaf children with developmental language disorder too. They didn't have difficulties so much with the overarching construction of the story. The explanation of what was going on. It was more at the grammatical level and choosing vocabulary.
00:14:43 Professor Chloë Marshall
BSL is a language which is set out in space and you have to use space according to certain conventions and it was those conventions that they found a little bit more difficult than we would expect given their age.
00:14:55 Dr Sam Sims
And so you said, we're kind of at the, you know, we've made a lot of progress, but we're at the early stages here. I mean, what do we know about kind of how we can help deaf children with developmental disorders develop their language skills?
00:15:12 Professor Chloë Marshall
Well, I can't give a very good answer to that cause I'm not a speech and language therapist, but it raises the question as to whether what these children need is more sign language input or whether they need sign language input of a different kind. So if these children really do have a language learning disorder, maybe more of the same input is not what they need. Maybe they need a different type of input, an input which is carefully crafted to their needs.
00:15:40 Dr Sam Sims
How interesting, how interesting, and I think you've been involved in some work, Chloë, developing a sort of toolkit for teachers and other educators around deaf awareness. Can you tell us about that?
00:15:54 Professor Chloë Marshall
Absolutely well, this is work that's led by my colleague, Dr Manjula Patrick at the Deafness, Cognition and Language Research Centre. We're developing a course. As I said earlier, many teachers will not come across a deaf child in their teaching will just come across one or two deaf children and therefore don't really feel well equipped as to how to support the deaf child and may be very unaware of the communication needs of the deaf child. Maybe unaware of the need, for example, of deaf children to speech read, so to be able to look at the lips and the jaw movements and use those to supplement the residual hearing that they may have and the hearing that they get through their amplification device. They may not be aware, for example, of the difficulties that deaf children have in following a multi-speaker conversation so deaf children will need to look at the face and during a conversation with several people need to reorient.
So what are we doing with this toolkit? It's going to be an online self-paced learning module that teachers and education professionals will be able to take, and it's going to be freely available. And it's going to be launched sometime in 2021. It's been a little bit delayed by COVID, but then so many things have and the idea is that while the majority of this module is actually presented in the words of deaf people themselves. So we have a lot of interviews with young deaf adults who have just left education and who are able to reflect.
00:17:58 Dr Sam Sims
That sounds fantastic and how can people find that Chloë? What should they Google or where can they go to access this resource?
00:18:05 Professor Chloë Marshall
Not available yet, I cannot tell you, but the Deafness, Cognition and Language Research Centre will host a link to it.
00:18:13 Dr Sam Sims
Got it, got it okay, watch this space. Okay, so you mentioned there Chloë about one of the videos featuring the parent of a deaf child. I think you've also researched how the parents of deaf children learn to sign. What have you found in your research there?
00:18:30 Professor Chloë Marshall
Ah well, let me go back a few steps so we know very little about how hearing adults learn a sign language.
And when hearing adults are learning a sign language, they're not just learning a new language, they're learning a language in a new modality.
So obviously when we speak, we move our hands around. We do co speech gesture, but the point was sign language is that the movements that these hands make are conventionalised.
And so those conventions need to be learned. So people who, hearing adults learning a sign language, learning not just a new language, but having to use their hands in a particular way and not just using their hands but using multiple articulators. So sign language is involved, the eyes and eye gaze, they involve the eyebrows. This information on the mouth, there is information through facial expression, through the turn of the torso, the way that shoulders are facing, for example.
So it's a very different type of language, and we know very, very little, even though many hearing parents of deaf children will want to learn to sign. And indeed many hearing adults will be interested in learning sign because it's a fun language to learn. Or they may want to train as a sign language interpreter or as a teacher of the deaf. But we know very little about how these people learn sign language and it's really important we understand this is really important, that we understand how learners learn so that we can teach them better.
Sign language is just as challenging to learn as spoken languages and so that means that the the language input, the sign language input that parents are providing to their deaf child might not be grammatical, might not be rich in terms of vocabulary, and so we need to teach people how to sign better, but at the moment we don't even know how they learn sign language. So the project that I'm running is at the very early stages of trying to understand how it is that hearing adults learn a sign language.
00:20:30 Dr Sam Sims
You mentioned there Chloë, the importance of gestures and expressions, and the information that the mouth carries, even for deaf people. I mean, at the moment a lot of us you know for public health reasons are covering our mouths with face masks in order to stop transmission of infection. What implications does that have for deaf people?
00:20:52 Professor Chloë Marshall
Well, it obviously has very strong implications because the sound is muffled and those visual cues are not there. But in fact there are implications more generally because pretty much all of us rely on being able to speech read in order to supplement that auditory stream, which as I say, will be muffled with a face mask.
00:21:12 Professor Chloë Marshall
We've been doing some work with young children. We started this project long before COVID, but we've been interested in the many cues that parents and caregivers use when they communicate with children. By cues, I mean things like parents using their hands to point at objects using their hands to manipulate objects when they're talking about them, using their hands to produce gestures which represent the object in some way, but also using their voices, so modulating their voices use certain words like onomatopoeic words. By that we mean animal noises, sound effects, words which sound like what they refer to. Parents have a whole toolkit of cues that they use in order to facilitate language learning and in order to facilitate communication. And we've been thinking about how it might be useful for caregivers and for parents in a time of face mask wearing to have these sort of big intonational contours to speed up or to slow down their speech to to think about how they can capitalise, how they can use these resources to effect effective communication and effective language learning. So yes, these cues are really really important, particularly at a time of mask wearing yes.
00:22:31 Dr Sam Sims
I mentioned at the start Chloë that you're involved in the Centre for Educational Neuroscience, and I know that some of your researchers looked at the relationship between language acquisition and executive function.
Can you tell us more? Firstly, tell us what executive function is and what that research, what you've learned from that research.
00:22:52 Professor Chloë Marshall
Absolutely. So again, this is research that we've carried out with deaf children and hearing children and executive functions are those skills that you need in order to be able to plan and carry out a complex task. So executive functions enable you to see a task through.
Particularly important in a school context, so you would use your executive functions. For example, if you're needing to write an essay. If you're needing to work through a set of maths problems. If you're needing to carry out a science experiment so executive functions are absolutely critical at school, and we know that some children who are deaf might have lower executive functions than would be expected given their age, that's not the case for all deaf children by all means. So deaf children who are born to deaf parents who are learning to sign tend to have age appropriate executive functions, but those deaf children who have for whatever reason, a language delay tend to also have delayed executive function development and our research project was interested in looking at this relationship between language and executive functions. So some researchers have argued that it's language development which drives the development of these important executive function skills, and other people have argued that it's the reverse that its executive function development that drives language development. And if you don't have strong executive functions you're gonna have difficulty learning language, and of course there's also an argument for it being a bidirectional relationship.
And in order to answer this question, we looked at a large group of deaf children and a large group of hearing children, and we followed them over two years and we assess them at those two time points at two years apart, we assessed a lot of executive function skills. Importantly, we assess these skills through non verbal tasks, so these were all visual, spatial and non verbal tasks and we also had measures of their vocabulary at those two different time points and so looking longitudinally we could see that actually it was children's - we had vocabulary is a measure of language, so it was their vocabulary development which was driving their executive function development and that's really important when we're thinking about the language development of deaf children, that importance again of a really rich language learning environment for children, so that that will also boost those academically important executive function skills.
I mean, you may be aware that there's been a lot of research on trying to develop interventions for children's executive function skills. So for example, computer based games which will boost working memory for example, and the difficulty with those tasks is that they don't. They don't really, the benefits don't really seem to transfer across to other areas, and our findings are important because they suggested language that you've got to work on. If you work on deaf children's language, that will boost their executive functions.
00:25:43 Dr Sam Sims
Right, so this idea of transfer, if I understand this right, Chloë the idea is, you know we can sit down with this sort of computer game designed to train them on a task which is demanding for their executive functions. And generally we can, you know, we can show that they get better at the executive functions involved in that specific task or game. But then when we test whether it helps them kind of plan an essay or a different task, you know the benefits don't seem to sort of transfer over, right?
But you're saying that you know...
00:26:12 Professor Chloë Marshall
That's exactly right.
00:26:13 Dr Sam Sims
Rather than doing this kind of brain training stuff which doesn't seem to have kind of generalised benefits, we might be better off just focusing on language acquisition on the grounds that actually supports a more general or potentially supports more sort of general development in executive function.
00:26:49 Professor Chloë Marshall
I mean the other reason for working on language enrichment is that language is in itself incredibly important for academic success.
00:26:56 Dr Sam Sims
Right, in and of itself...
00:26:57 Professor Chloë Marshall
In and of it itself absolutely. You know, for literacy, learning for maths has a huge range of benefits. Social development, emotional regulation is absolutely central to everything in our lives.
00:27:09 Dr Sam Sims
Yeah, and I guess this is the point you are making about them having a sort of bidirectional relationship such that language helps improve executive function and then executive function might help you know, write a complicated essay when you're in secondary school or something like that, which is then reflected in your, in that essentially sort of language based skill of writing.
00:27:29 Professor Chloë Marshall
Absolutely, right. That's why we always need to think about language and cognition together, absolutely.
00:27:35 Dr Sam Sims
Chloë Marshall, I've learned so much from talking to you today. Thanks very much for coming on the podcast.
00:27:40 Professor Chloë Marshall
It was an absolute pleasure. Sam, thank you very much.
00:27:43 Dr Sam Sims
You can find more about Chloë's research by following her @ChloeRuMarshall on Twitter and you can find links to her research in the show notes. If you have questions or topics you'd like us to address in future interviews, also follow the links in the show notes and record your question there using either voice or text.
And as an added bonus, you can find the Research for the Real World playlist featuring tracks contributed by previous guests and producers. That's also in the links. Follow the links to Spotify. I'm Sam Sims, and this has been Research for the Real World. Goodbye.
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