Examining Signer-Specificity Effects in the Perception of Words in American Sign Language

Variability in talker identity, which is commonly referred to as one type of indexical variation, has demonstrable effects on the speed and accuracy of spoken word recognition. In the current study, I conducted two experiments designed to examine whether talker variability has an effect on the perception of words in American Sign Language. Native and non-native signers participated in two long-term repetition-priming experiments in which they performed two separate blocks of lexical decision trials. In Experiment 1, all participants were native signers. In Experiment 2, all participants were late signers. In both experiments, all participants performed both an easy and a hard lexical decision task. In the easy lexical decision task, the non-signs did not resemble real signs, making the task relatively easy. In the hard lexical task, the non-signs resembled real signs, making the task relatively difficult. In both experiments, some of the signs (and non-signs) in the second block also appeared in the first block (primed conditions) and some were new stimuli that had not appeared in the first block (control condition). Half the primed stimuli were produced by the same signer in the two blocks (matched condition) and half were produced by a different signer (mismatched condition). Based on previous research in spoken word recognition, I made the following predictions: 1) primed stimuli would be responded to more quickly than unprimed stimuli, 2) signs in the match condition would be responded to more quickly than signs in the mismatch condition (i.e., a signer-specificity effect), and the signer-specificity effect was expected to be greater when processing was relatively slow, that is 3) in Experiment 2, with late signing participants, and 4) in the hard lexical decision task. The results inform theories and models of sign language perception, add to the knowledge of the circumstances in which variability is expected to have an effect on the recognition of words, and provide an opportunity to evaluate whether time