Modality-dependent and -independent factors in the organisation of the signed language lexicon: insights from semantic and phonological fluency tasks in BSL.

We used fluency tasks to investigate lexical organisation in Deaf adults who use British sign language (BSL). The number of responses produced to semantic categories did not differ from reports in spoken languages. However, there was considerable variability in the number of responses across phonological categories, and some signers had difficulty retrieving items. Responses were richly clustered according to semantic and/or phonological properties. With respect to phonology, there was significantly more clustering around the parameters "handshape" and "location" compared to "movement". We conclude that the BSL lexicon is organised in similar ways to the lexicons of spoken languages, but that lexical retrieval is characterised by strong links between semantics and phonology; movement is less readily retrieved than handshape and location; and phonological fluency is difficult for signers because they have little metaphonological awareness in BSL and because signs do not display the onset salience that characterises spoken words.