Lexical recognition in sign language: effects of phonetic structure and morphology

Two experiments are reported which investigate lexical recognition in American Sign Language (ASL). Exp. 1 examined identification of monomorphemic signs and investigated how the manipulation of phonological parameters affected sign identification. Over-all sign identification was much faster than what has been found for spoken language. The phonetic structure of sign (the simultaneous availability of Handshape and Location information) and the phonotactics of the ASL lexicon are argued to account for this difference. Exp. 2 compared the time course of recognition for monomorphemic and morphologically complex signs. ASL morphology is largely nonconcatenative which raises particularly interesting questions for word recognition. We found that morphologically complex signs had longer identification times than matched monomorphemic signs. Also, although roots and affixes are often articulated simultaneously in ASL, they were not identified simultaneously. Base forms of morphologically complex signs were identified initially followed by recognition of the morphological inflection. Finally, subjects with deaf parents (Native signers) were able to isolate signs faster than subjects with hearing parents (Late signers). This result suggests that early language experience can influence the initial stages of lexical access and sign identification.