|Title:||The Perception of Handshape in American Sign Language||Add Dissertation|
|Author:||Stephanie Baker||Update Dissertation|
|Email:||click here to access email|
|Institution:||University of Delaware, Department of Linguistics|
|Linguistic Subfield(s):||Applied Linguistics; Phonology; Psycholinguistics;|
American Sign Language
|Abstract:||Categorical perception (CP) refers to the finding that certain stimuli from a continuum are perceived as members of discrete categories. Thus, despite the fact that the stimuli vary continuously, they are perceived discretely. In adults, CP for speech sounds has also been shown to be language-specific and a result of linguistic experience with the particular speech contrast being tested. Additional research demonstrated that some non-human mammals exhibited CP for certain speech contrasts (e.g., Kuhl, 1981), and that humans also exhibited CP for non-linguistic stimuli such as colors (Bornstein, 1987) and faces (Beale & Keile, 1995; Etcoff & Magee, 1992). The current view of CP is that it is driven by domain general processing mechanisms (Kuhl, 2000). The role of linguistic experience for CP remains an unresolved issue, however. If linguistic experience were of no importance in CP, then the effects for speech stimuli should not be language-specific. The fact that at least some cases of CP are language-specific raises the potential that humans have developed special abilities for perceiving distinctions that are relevant to their native language.
The focus of the research for this dissertation is the role of linguistic experience for a set of contrasts that is simultaneously perceptual (visual) and linguistic. One experiment with two tasks investigated whether Deaf signers or hearing nonsigners exhibit CP for handshape contrasts in American Sign Language (ASL). CP performance was measured using forced choice identification and AX discrimination paradigms with digital images of a native signer articulating the handshapes.
The results showed that only the ASL signers exhibited categorical perception for the handshape contrasts. These results suggest that the ASL signers have developed unique abilities for perceiving distinctions that are relevant to ASL, similar to the abilities that hearing speakers have developed for perceiving spoken language. These results also suggest that linguistic CP is a result of dedicated mechanisms that are language-specific rather than general-perceptual, since only the ASL signers, who had linguistic experience with the stimuli, exhibited CP for the handshapes.