UCL Deafness Cognition and Language Research Centre



Please click on each question to reveal the answer.

What is DCAL?

The Deafness Cognition and Language Research Centre (DCAL), is based at University College London, part of the Division of Psychology and Language Sciences. DCAL brings together leading Deaf and hearing researchers in the fields of sign linguistics, psychology, and neuroscience. DCAL was initially funded from 2006 until 2015 by the UK Economic and Social Research Council. DCAL is the largest research centre in this field in Europe.

The vast majority of research studies on language and cognition are based on languages which are spoken and heard. DCAL's research provides a unique perspective on language and cognition based on deaf people's communication.

What is the significance of spelling distinction made between someone who is 'deaf' and someone who is 'Deaf'?

The use of a lower case 'd' for 'deaf' refers to people with the physical condition of hearing loss; the use of a capital 'D' for 'Deaf' refers to those who identify themselves as part of a linguistic and cultural minority group whose first or preferred every day language is British Sign Language (BSL).

The Deaf community is united by shared experiences and history, but most importantly, by BSL. Many people in the Deaf community have Deaf parents, life partner, or children.

By contrast many people who are hard of hearing or who have become deaf in later life may not use BSL and may not identify with the culture of the Deaf community. It is estimated that 1 in 6 people in the UK - around 11 million- experience hearing loss[1].

Further reading:

Ladd, P. (2003). Understanding Deaf Culture. In Search of Deafhood, Toronto: Multilingual Matters.

Padden, Carol A. & Humphries, Tom L. (2005). Inside Deaf Culture, ISBN 978-0-674-01506-7.

Woll, Bencie, & Adam, Robert. (2012). Sign Language and the Politics of deafness. The Routledge Handbook of Multilingualism, 100-115.

[1] https://www.actiononhearingloss.org.uk/your-hearing/about-deafness-and-hearing-loss/statistics.aspx

Who uses BSL?

British Sign Language is the preferred language of tens of thousands of deaf people in the UK, for whom English may be a second or third language. The British Deaf Association (BDA) estimates that 87,000 Deaf people use BSL as their first language[1]. Others estimate more conservatively at 60,000. BSL is the fourth most widely used indigenous language in the UK. It is the most important sign language of the UK although other sign languages (for example Irish Sign Language) are also used.

Many people learn BSL as a second language every year for both personal interest and professional reasons. Some of those who learn BSL for professional reasons work with Deaf people in capacities such as sign language interpreters and teachers of the deaf.

BSL was recognised as an official British language by the UK government in March 2003 and it does not have any legal protection. This has meant that Deaf people do not have full access to information and services that hearing people take for granted, including education, health and employment.[2] In Scotland however, the Scottish Government recognized British Sign Language in 2015[3]

[1] https://www.bda.org.uk/bsl-statistics

[2] http://blogs.ucl.ac.uk/library-rnid/2013/11/13/official-recognition-of-british-sign-language-1987-2003/

[3] http://www.parliament.scot/parliamentarybusiness/Bills/82853.aspx

What is BSL and what are its origins?

British Sign Language (BSL) is a natural language with its own vocabulary and grammar, which has emerged from Deaf people's communication over centuries, and is not a representation of English on the hands.

While there have always been Deaf people in society, in the West the first written evidence of the existence of deaf individuals or groups communicating by gesture or signs can be found with the rise of the Mediterranean societies in the 5th century BC.

The first recorded description of signs in Britain is from the register of the marriage of Thomas Tillsye and Ursula Russell in 1575 (Sutton-Spence and Woll, 1999). Other early accounts include an entry in Pepys' diary of how Sir George Downing and his deaf servant conversed using signs about the Great Fire of London in 1666 (cited in Sutton-Spence and Woll 1999). The first school for deaf children was opened in 1760 in Edinburgh by Thomas Braidwood (Jackson, 2001), using both speech and signing (Kyle and Woll, 1985).

The name 'British Sign Language' was first published in 1975 in an article where it was argued that deaf children should have access to sign language in education.

With more than 60,000 using BSL as their first or preferred language and around 125,000 people in total able to converse in BSL in 21st century UK, BSL was finally recognised as a language by the Department of Works and Pensions on 18 March 2003. Moves are continuing, particularly in Scotland, to have this recognition enshrined in legislation. Because of Britain's colonial history, closely related languages can be found in Australia (Australian Sign Language or Auslan), New Zealand (NZ Sign Language), Malta (Maltese Sign Language) and in some parts of South Africa, India, and Canada (Maritime Sign Language).

In Britain, it is possible to obtain BSL language qualifications awarded by the Institute of BSL or Signature. Interpreting qualifications are also offered by colleges and universities in Britain and awarded by Signature, and as NVQs. 

Further reading:

Jackson, Peter. (2001). A Pictorial History of Deaf Britain. Winsford: Deafprint..

Johnston, Trevor, & Schembri, Adam. (2007). Australian Sign Language (Auslan): An introduction to sign language linguistics. Cambridge: Cambridge University Press.

Kyle, Jim, & Woll, Bencie. (1985). Sign Language: the study of deaf people and their language. Cambridge: Cambridge University Press.

Sutton-Spence, Rachel, & Woll, Bencie. (1999). The linguistics of British Sign Language : an introduction. Cambridge, UK New York: Cambridge University Press.

How did BSL evolve?

The history of British Sign Language (BSL) is not well-documented because it is an unwritten language. Written records that we have of BSL in the past are usually in English, and often written by non-signers.

We do know that Deaf people were signing as early as the 16th century, and we can assume that wherever Deaf people met before then, they would have signed together.

Most researchers think, though, that BSL as we know it today began in the 18th century with the growth of towns in Britain and the opening of the first schools for deaf children, so that large numbers of Deaf people were close enough to form their own communities.

When more schools for deaf children were opened in the 19th century, BSL became an established language. Although schools were independent, there was considerable communication between the schools, and teachers often moved between them. However, there was no central training in BSL, and travel was difficult, so a wide range of regional dialects developed. Despite this, Deaf people have always travelled long distances around Britain to attend Deaf events, and this has helped to create and maintain a single language in the country.

You can read more on BSL History

Further reading:

Jackson, Peter. (2001). A Pictorial History of Deaf Britain. Winsford: Deafprint..

Kyle, Jim, & Woll, Bencie. (1985). Sign Language: the study of deaf people and their language. Cambridge: Cambridge University Press.

Sutton-Spence, Rachel, & Woll, Bencie. (1999). The linguistics of British Sign Language : an introduction. Cambridge, UK New York: Cambridge University Press.

Is sign language the same the world over?

No. There are sign language families just as there are spoken language families. In the European Union for example, 23 official spoken languages and 31 sign languages have been documented (Wheatley and Pabsch 2010). The boundaries between spoken languages and those between sign languages are not always the same.

The website The Ethnologue[1] - an encyclopedic reference work cataloguing all of the world's 6,909 known living languages - lists just 136 'Deaf sign languages', although there are more known but undocumented sign languages.

The BSL family includes BSL, Australian Sign Language and NZ Sign Language. These sign languages are similar enough for people who know any one of them to be able to understand Deaf people who use one of the others.

On the other hand, American Sign Language and Irish Sign Language belong to the LSF (langue des signes française) family, which is unrelated to BSL, and BSL and LSF are not mutually intelligible. Often American Sign Language is used for international communication in some academic settings (possibly due to the influence of Gallaudet University in the USA, the only liberal arts university in the world for deaf students).

However, as the international Deaf community is a highly mobile community, there is also a contact variety of sign called International Sign. This is not a standardised international language but is a form of communication which draws on the sign vocabulary and grammar of the people involved in the contact and the context of each situation.

Because of the visual nature of sign languages, it is often possible for two Deaf people from different sign language backgrounds to have a simple conversation using gestures and signs, even though sign languages around the world are not all the same - it has been said rthat it is easier for Deaf people from different language backgrounds to communicate than it is for hearing people. The strategies for communication differ from situation to situation, depending on who is communicating with whom, and what the topic is. At international conferences and events people sometimes interpret the proceedings into International Sign but this does not have the same depth of meaning and detail as interpreting into a sign language.

Fenlon, Jordan, & Wilkinson, Erin. (2015). Sign Languages in the World. In Adam Schembri & Ceil Lucas (Eds.), Sociolinguistics and Deaf Communities (pp. 5-28). Cambridge: Cambridge University Press.

Quinto-Pozos, David, & Adam, Robert. (2015). Bilingualism and Language Contact. In Ceil Lucas & Adam Schembri (Eds.), The Sociolinguistics of Sign Languages. Cambridge: Cambridge University Press.

Wheatley, Mark, & Pabsch, Annika. (2010). Sign Language Legislation in the European Union. Brussels, Belgium: European Union of the Deaf.

[1] http://www.ethnologue.com/18/subgroups/deaf-sign-language-0

Did spoken language evolve from sign language?

Some writers have suggested that the earliest human language was sign language. Evidence they put forward in support includes "iconicity" in sign languages as opposed to spoken languages. That is to say, in brief, that there is a similarity between the form of a sign and its meaning. There is also the observation that new sign languages can be created in ways that spoken languages cannot.


However the differences between sign and spoken languages in modern humans cannot be used as evidence for evolution of human language, since all modern humans have "language-ready" brains, and there are no "ancestral" sign languages older than spoken languages. More relevant for the evolution of language is the observation that all human communication is multi-modal. That is to say speakers typically use vocal and manual/bodily gestures when speaking, and signers always use facial and body gestures when signing.


Emmorey, Karen. (2005). Sign languages are problematic for a gestural origins theory of language evolution. Behavioral and Brain Sciences 28.2, 130-1.

How long does it take to learn a sign language?

Sign languages are not a visual representation or a manual codes for spoken language. They are languages in their own right, with rules for word and sentence formation. It takes as much time, energy and motivation to learn BSL or another sign language as it does any other second or foreign language.

What are the challenges facing BSL?

At the beginning of the 21st century, there are two contrasting futures for British Sign Language in the UK.

On one hand, there is increased interest and demand from the hearing community for courses in sign language, increased use of sign language in public contexts such as television, and public events, and increased pride of the Deaf community in their distinctive language and culture. Additionally, legislation ensures that BSL access is provided in police settings, education and employment. In Scotland there is even a BSL Act.

On the other hand, there are pressures, such as the decrease in opportunities for Deaf children to use sign language with their peers as a result of the shift to mainstream education, the increased uptake of cochlear implants, and possible decrease in the Deaf population as a result of decreasing birth patterns, medical intervention and advances in genetics.

It is to be hoped and expected that sign languages will continue to be living languages. 

Does using a visual language influence the way we think about the world?

Languages that are spoken or signed differ from each other in the way the properties of objects and events need to be expressed.

This need to pay attention to the way in which we express things in different languages can be seen in spoken languages. For example, in English the gender of nouns is not marked - nouns are not masculine, feminine or neuter. So in English a word such as "friend" can be used in quite a general way, whereas in Italian - which does mark the gender of nouns - the speaker needs to pay attention to whether the friend is male or female, and this will change the form of the word for friend in Italian. Because every noun in Italian has a gender - not just those relating to people - Italian speakers are always forced to pay more attention to the gender of the noun than English speakers.  

In sign languages a spatial/visual modality is used to talk about things and actions. So where a spatial expression is called upon - such as the shape of objects or spatial layout - signers will express properties such as the location of objects in a room in a way that takes their actual position into account far more than spoken languages.  

An example of this is that in English one would say that there is a table in the kitchen, whereas in BSL, the signer may refer to the table in a way that reflects its actual physical position in the kitchen. For this reason, signers may pay greater attention to these aspects of the world than speakers of most languages. These differences may underscore some differences in brain networks used in processing language for signers and speakers.

Does the brain process signed and spoken language in the same way?

Remarkably the answer to this is 'mostly, yes'! Deaf signers who have suffered damage to the brain show very similar language problems as hearing speakers with damage to the same brain regions. For example, damage to the front of the brain on the left side can lead to problems with both sign and speech production. We can also use new methods, for example functional magnetic resonance imaging (fMRI), to look at healthy brains to find out which parts of the brain are active when people are processing signed and spoken language. These studies also suggest that very similar networks in the brain are used for the two languages, even though they are delivered in very different ways.

However, the networks used are not identical. Sign language processing uses the visual parts of the brain more than speech and, not surprisingly, spoken language uses auditory parts of the brain more than sign language.

In addition to these sensory differences, there are other subtle ways in which brain processing of signed and spoken language differs. For example, there is growing evidence that a part of the brain called the parietal lobe (at the back of the brain, towards the top), which is involved in processing spatial relationships, is more involved in sign language processing than spoken language processing.

It is likely that findings comparing how signed and spoken language are processed by looking at behaviour, such as accuracy or reaction times, will also highlight differences between how the languages are processed. Further research into the brain should be able to explore this in the future.

Further reading:

Campbell, Ruth, Mairéad MacSweeney, Dafydd Waters; Sign Language and the Brain: A Review. J Deaf Stud Deaf Educ 2008; 13 (1): 3-20. doi: 10.1093/deafed/enm035

How is BSL written down or recorded?

By and large signed languages are not written and there is no standard way of writing them down. There is no written version of BSL.

When we talk about literacy in deaf people, this nearly always refers to reading and writing the dominant spoken language of that community, such as English. This does not mean that it is impossible to record sign languages, however.

There are transcription and notation systems for sign languages, but these are mainly used by sign language researchers.

One of these is Stokoe notation. Stokoe notation was the first (Kyle & Woll 1988:88) phonemic script used for sign languages. It was created by William Stokoe for American Sign Language (ASL), with Latin letters and numerals used for the shapes they have in American fingerspelling, and iconic symbols to transcribe the position, movement, and orientation of the hands. It was first published as the organising principle of A Dictionary of American Sign Language on Linguistic Principles, by Stokoe et al. in 1960. The Stokoe notation was later adapted to British Sign Language (BSL) in Kyle & Woll (1985). The use of Stokoe notation is mostly restricted to linguists and academics.

More accessible to the lay person is Sutton SignWriting[1]. This is a system developed in 1974 by Valerie Sutton that uses iconic symbols to represent the handshapes, movements, and facial expressions of signed languages. Proponents of Sutton SignWriting find they can use the "alphabet" or list of symbols to write any signed language in the world. The system is used to varying degrees in many countries by different institutions and individuals, including in the UK, but opinions differ a great deal about how useful and practical it is.

The lack of a standard notation/transcription system is very noticeable when trying to access printed sign language dictionaries such as the Dictionary of British Sign Language/English (Brien 1992). Photos help but even they can't provide the same information as a moving image.

By contrast the development of video technology in recent years has made it possible for us to record sign language more directly, via video recording.

New software, such as ELAN, makes it possible to add written information (e.g., translations) to video and to have this written material aligned to the precise point in the video where a specific sign is being produced.

Using digital video and ELAN to record BSL was the primary aim of the British Sign Language Corpus Project (2008-2011). The BSL Corpus consists of digital video data showing 249 deaf signers from 8 regions around the UK, with a balance of signers of different ages, genders, and language backgrounds. Signers took part in 4 activities: personal narratives, free conversation, interviews about issues involving deaf identity and language, and a lexical elicitation task where signers were asked to give their signs for 101 concepts. These video data (and some associated annotations and translations) are available online. More annotations and translations are being added as more research is done on the Corpus.

In 2014 DCAL launched BSL SignBank, an online dictionary which uses video clips to show what each sign looks like. SignBank consists of over 2500 BSL signs based on signs from the BSL Corpus, with more being added all the time as more research is done on the Corpus.

Further reading:

Brien, David. (1992). Dictionary of British Sign Language/English. Boston: Faber and Faber

Frishberg, Nancy, Nini Hoiting & D. I. Slobin. (2012). Transcription. In Roland Pfau, Markus Steinbach & Bencie Woll (eds.), Sign language: An international handbook, 1045-75. Berlin: Mouton de Gruyter.

Kyle, Jim, & Woll, Bencie. (1985). Sign Language: the study of deaf people and their language. Cambridge: Cambridge University Press.

Schembri, Adam, Jordan Fenlon, Ramas Rentelis, Sally Reynolds & Kearsy Cormier. (2013). Building the British Sign Language Corpus. Language Documentation and Conservation 7, 136-54.

[1] http://signwriting.org/

Are there accents in BSL?

An accent in spoken languages is a particular style of pronunciation that gives cues about the speaker's background such as their region of origin, age, schooling and/or social class. For example, the vowel in 'bus' and 'nut' (and many other words with the same vowel) is generally pronounced differently by speakers from Manchester compared to London, even though the words in each part of England are the same.

BSL definitely has strong regional variation, but the variants are better considered to be dialects rather than accents. The reason for this is that the variants are more about what you say (i.e. signs - equivalent to words in spoken languages) rather than how you say it (i.e. pronunciation).

Signs for colours, numbers, countries and place names, among others, show a high amount of variation in BSL. For example, quite different signs are produced in different parts of the UK for the concepts 'green', 'seventeen', 'America' and 'Birmingham' - see BSL SignBank for documentation of many of these regional variants. Historically different variants appear to have developed independently in different deaf schools around the country. However, some of these patterns appear to be changing. Evidence from the BSL Corpus suggests that younger deaf signers all over the country are using fewer traditional regional signs compared to older deaf signers. This is one reason why documentation of BSL (e.g. via BSL SignBank and the BSL Corpus) is so important, so that we can document this regional variation and keep a record of older forms of BSL in the long term. 

So far there is very little evidence that the exact equivalent of accent exists in sign languages. One possible equivalent is a 'hearing' or 'late learner' accent. People who learn sign languages as adults consistently produce signs using bigger movements produced by joints closer to the body (e.g. the shoulder and elbow joints) than native signers/early learners who in the same situation might use joints further away from the body (e.g. wrist and finger joints).

Further readings:


Bayley, Robert, Schembri, Adam C, & Lucas, Ceil. (2015). Variation and change in sign languages. In Adam Schembri & Ceil Lucas (Eds.), Sociolinguistics and Deaf Communities. Cambridge: Cambridge University Press.

Johnston, Trevor, & Schembri, Adam. (2007). Australian Sign Language (Auslan): An introduction to sign language linguistics. Cambridge: Cambridge University Press.

Stamp, Rose, Schembri, Adam., Fenlon, Jordan., Rentelis, Ramas., Woll, Bencie., & Cormier, Kearsy. (2014). Lexical Variation and Change in British Sign Language. PLoS ONE, 9(4), e94053. http://doi.org/10.1371/journal.pone.0094053

What are the advantages of early BSL acquisition?

Deaf children, even with a cochlear implant, may find acquiring spoken language difficult. While speech is being acquired it is important children are exposed to BSL so as to acquire the skills of effective communication and also begin to grasp concepts especially those linked to abstract ideas such as time and space.

Early BSL input can act as a bridge later to speech and literacy. Children with signing parents have been found in several studies to have good communication, language, literacy and social-emotional development.

This means hearing parents and professionals need specific training in child friendly BSL. The NDCS family sign language curriculum was designed with this in mind. 

Further reading:

Morgan, Gary, & Woll, Bencie. (2002). Directions in sign language acquisition. Philadelphia: John Benjamins Pub. Co.

Does sign language interfere with or help learning a spoken language in children?

There is no research evidence that learning to sign interferes with deaf children's spoken language development. On the contrary it may assist children learn difficult to understand concepts and act as a bridge to learning these words in spoken language.

Signing with hearing babies is a fun way to get to know your child, in the same way reading books or singing nursery rhymes is always going to be beneficial. There is no evidence that hearing babies have faster language or cognitive development than other groups who do 'child-centered activities such as nursery rhymes.

See the NTID/RIT Educating Deaf Children website for more research centred responses to this question.

Further reading:

Cardin Velia, Smittenaar Rebecca, C., Orfanidou Eleni, Rönnberg Jerker, Capek Cheryl M., Rudner, Mary & Woll, Bencie (2015). Differential activity in Heschl's gyrus between deaf and hearing individuals is due to auditory deprivation, rather than language.modality. NeuroImage. http://dx.doi.org/10.1016/j.neuroimage.2015.08.073

Campbell, Ruth, MacSweeney, Mairead & Woll, Bencie. (2014). Cochlear Implantation (CI) for prelingual deafness: brain organization and the role of first language acquisition. Frontiers in Human Neuroscience. doi: 10.3389/fnhum.2014.00834

Lyness C Rebecca, Woll, Bencie, Cardin. Velia & Campbell Ruth (2013). How does visual language affect crossmodal plasticity and cochlear implant success? Neuroscience and Biobehavioral Reviews 37(10): 2621-2630. http://dx.doi.org/10.1016/j.neubiorev.2013.08.011