5. Language Processing
We are interested in how all of language, but especially signs are stored in your head, how they are accessed when you want to sign something and how you understand them when someone else signs to you. We cannot fully understand language processing until both signed and spoken languages are studied.
Our research compares language processing in BSL and English to explore the role of modality: speech is vocal and acoustic, sign is visuo-spatial and gestural. Most theoretical conclusions about how language works are based on spoken/heard languages, but they may depend on this modality. A comprehensive programme of research that compares sign and spoken language can provide vital tests of the generality of claims about language.
At present we are addressing two main questions. First, how does language relate to other cognitive functions such as perception, action and imagery? Language is used to communicate, and in order to succeed, linguistic information must be integrated with what we see and do in our environment. But how do we do this? A dominant view is that language "works on its own" and that it links to thought, perception and action only once the language processor has done its work. However, this claim may depend on modality and not be universal: our research suggests closer links between language perception and action in sign than in spoken language. For example, whereas the sign SCISSORS evokes the image of using scissors, the English wordform "scissors" (its spelling and pronunciation) does not. We have found that for signers the way scissors are used is a more central property of meaning than it is for speakers, suggesting a different involvement of imagery in language processing. Related to this question is the role of space in sign and speech, which our work will address.
The second main question we address concerns the processes engaged in producing and comprehending sign language. Are these processes the same as observed in spoken languages? A very influential view in language studies is that in comprehension, we first develop an internal representation of the phonological form, then we extract its syntactic structure, and only then we work out the meaning of what we hear. In production, we would go, instead, from meaning to syntax to phonology. However, is this sequential process a universal property of language?
Comparisons of spoken and signed language can allow us to answer this question because in BSL, in contrast to English, uses multiple articulators and thus allows for larger amount of information to be expressed in parallel rather than sequentially.