We have been studying Christopher for nearly twenty years, documenting – and marvelling at – his remarkable linguistic ability. The fruits of our earlier research resulted in a dozen articles and a book, The Mind of a Savant (Smith & Tsimpli, 1995), in which we spelt out our interpretation of his skewed abilities. This work raised more questions than it answered, and one in particular has preoccupied us ever since: how would Christopher with his flair for languages but with severe apraxia, some of the characteristics of autism, and limited intellectual ability, cope with a signed language? The tension is obvious: he has a huge talent for language but signed languages require precisely those social, visuo-spatial and kinaesthetic abilities in which he is most lacking. Hence we decided to teach him British Sign Language (BSL) and observe the results.

Some of the findings reported here have been published in articles (Morgan et al., 2002a, 2002b, 2007; Smith, 2003) but most of it is new. We have also presented parts of this material at conferences and seminars at UCL (University College London), Korea National University Seoul, the Aristotle University of Thessaloniki, the University of Oxford, the University of Cambridge, the University of Reading, the University of the West of England in Bristol and Gallaudet University in Washington DC. We are grateful to the various audiences for their input.