in the UK Once signed languages are recognized as natural human
languages, a world of exploration opens up. Signed languages
provide a powerful tool for investigating the nature of human
language and language processing, the relation between cognition
and language, and the neural organization of language. The value
of sign languages lies in their modality. Specifically, for
perception, signed languages depend upon high-level vision and
motion processing systems, and for production, they require the
integration of motor systems involving the hands and face. These
facts raise many questions: What impact does this different
biological base have for grammatical systems? For online
language processing? For the acquisition of language? How does
it affect nonlinguistic cognitive structures and processing? Are
the same neural systems involved? These are some of the
questions that this book aims at addressing. The answers provide
insight into what constrains grammatical form, language
processing, linguistic working me