Aphasia in a user of British Sign Language: Dissociation between sign and gesture

This paper reports a single case investigation of "Charles", a Deaf man with sign language aphasia following a left CVA. Anomia, or a deficit in sign retrieval, was a prominent feature of his aphasia, and this showed many of the well-documented characteristics of speech anomia. For example, sign retrieval was sensitive to familiarity, it could be cued, and there were both semantic and phonological errors. Like a previous case in the literature (Corina, Poizner, Bellugi, Feinberg, Dowd, & O'Grady-Batch, 1992), Charles demonstrated a striking dissociation between sign and gesture, since his gesture production was relatively intact. This dissociation was impervious to the iconicity of signs. So, Charles' sign production showed no effect of iconicity, and gesture production was superior to sign production even when the forms of the signs and gestures were similar. The implications of these findings for models of sign and gesture production are discussed.