Pronoun Production and Comprehension in American Sign Language: The Interaction of Space, Grammar, and Semantics.

Spoken language research has investigated how pronouns are influenced by grammar and semantics/pragmatics. In contrast, sign language research has focused on unambiguous pronominal reference arising from spatial co-reference. However, understanding signed pronouns contributes to cross-linguistically valid models of pronoun production and comprehension. In two sentence-continuation experiments, the present study investigated how linguistic use of space (modality-specific), antecedent grammatical role and verb implicit causality bias (modality-independent) affect American Sign Language (ASL) pronouns. Production of pronouns was determined by antecedent grammatical role, and overt pronouns were marginally more frequent for referents articulated in specific areas of signing space compared to neutral space. Signers interpreted pronouns using spatial information and, notably, verb bias, despite spatial co-reference supposedly removing the ambiguity that verb bias resolves. These findings demonstrate that ASL pronouns are subject to modality-independent factors, despite their use of space, and lend support to models of pronominal reference positing a production/comprehension asymmetry.

Emerging ASL Distinctions in Sign-Speech Bilinguals' Signs and Co-speech Gestures in Placement Descriptions.

Previous work on placement expressions (e.g., "she put the cup on the table") has demonstrated cross-linguistic differences in the specificity of placement expressions in the native language (L1), with some languages preferring more general, widely applicable expressions and others preferring more specific expressions based on more fine-grained distinctions. Research on second language (L2) acquisition of an additional spoken language has shown that learning the appropriate L2 placement distinctions poses a challenge for adult learners whose L2 semantic representations can be non-target like and have fuzzy boundaries. Unknown is whether similar effects apply to learners acquiring a L2 in a different sensory-motor modality, e.g., hearing learners of a sign language. Placement verbs in signed languages tend to be highly iconic and to exhibit transparent semantic boundaries. This may facilitate acquisition of signed placement verbs. In addition, little is known about how exposure to different semantic boundaries in placement events in a typologically different language affects lexical semantic meaning in the L1. In this study, we examined placement event descriptions (in American Sign Language (ASL) and English) in hearing L2 learners of ASL who were native speakers of English. L2 signers' ASL placement descriptions looked similar to those of two Deaf, native ASL signer controls, suggesting that the iconicity and transparency of placement distinctions in the visual modality may facilitate L2 acquisition. Nevertheless, L2 signers used a wider range of handshapes in ASL and used them less appropriately, indicating that fuzzy semantic boundaries occur in cross-modal L2 acquisition as well. In addition, while the L2 signers' English verbal expressions were not different from those of a non-signing control group, placement distinctions expressed in co-speech gesture were marginally more ASL-like for L2 signers, suggesting that exposure to different semantic boundaries can cause changes to how placement is conceptualized in the L1 as well.

Implicit causality biases and thematic roles in American Sign Language.

Implicit causality (IC) biases, the tendency of certain verbs to elicit re-mention of either the first-mentioned noun phrase (NP1) or the second-mentioned noun phrase (NP2) from the previous clause, are important in psycholinguistic research. Understanding IC verbs and the source of their biases in signed as well as spoken languages helps elucidate whether these phenomena are language general or specific to the spoken modality. As the first of its kind, this study investigates IC biases in American Sign Language (ASL) and provides IC bias norms for over 200 verbs, facilitating future psycholinguistic studies of ASL and comparisons of spoken versus signed languages. We investigated whether native ASL signers continued sentences with IC verbs (e.g., ASL equivalents of 'Lisa annoys Maya because…') by mentioning NP1 (i.e., Lisa) or NP2 (i.e., Maya). We found a tendency towards more NP2-biased verbs. Previous work has found that a verb's thematic roles predict bias direction: stimulus-experiencer verbs (e.g., 'annoy'), where the first argument is the stimulus (causing annoyance) and the second argument is the experiencer (experiencing annoyance), elicit more NP1 continuations. Verbs with experiencer-stimulus thematic roles (e.g., 'love') elicit more NP2 continuations. We probed whether the trend towards more NP2-biased verbs was related to an existing claim that stimulus-experiencer verbs do not exist in sign languages. We found that stimulus-experiencer structure, while permitted, is infrequent, impacting the IC bias distribution in ASL. Nevertheless, thematic roles predict IC bias in ASL, suggesting that the thematic role-IC bias relationship is stable across languages as well as modalities.

Reference tracking in early stages of different modality L2 acquisition: Limited over-explicitness in novice ASL signers' referring expressions.

Previous research on reference tracking has revealed a tendency towards over-explicitness in second language (L2) learners. Only limited evidence exists that this trend extends to situations where the learner's first and second languages do not share a sensory-motor modality. Using a story-telling paradigm, this study examined how hearing novice L2 learners accomplish reference tracking in American Sign Language (ASL), and whether they transfer strategies from gesture. Our results revealed limited evidence of over-explicitness. Instead there was an overall similarity in the L2 learners' reference tracking to that of a native signer control group, even in the use of lexical nominals, pronouns and zero anaphora - areas where research on spoken L2 reference tracking predicts differences. Our data also revealed, however, that L2 learners have problems with the referential value of ASL classifiers, and with target-like use of zero anaphora from different verb types, as well as spatial modification. This suggests that over-explicitness occurs in the early stages of different modality L2 acquisition to a limited extent. We found no evidence of gestural transfer. Finally, we found that L2 learners reintroduce more than native signers, which could indicate that they, unlike native signers are not yet capable of utilizing the affordances of the visual modality to reference multiple entities simultaneously.

Who's on First? Investigating the referential hierarchy in simple native ASL narratives.

Discussions of reference tracking in spoken languages often invoke some version of a referential hierarchy. In this paper, we asked whether this hierarchy applies equally well to reference tracking in a visual language, American Sign Language, or whether modality differences influence its structure. Expanding the results of previous studies, this study looked at ASL referential devices beyond nouns, pronouns, and zero anaphora. We elicited four simple narratives from eight native ASL signers, and examined how the signers tracked reference throughout their stories. We found that ASL signers follow general principles of the referential hierarchy proposed for spoken languages by using nouns for referent introductions, and zero anaphora for referent maintenance. However, we also found significant differences such as the absence of pronouns in the narratives, despite their existence in ASL, and differential use of verbal and constructed action zero anaphora. Moreover, we found that native signers' use of classifiers varied with discourse status in a way that deviated from our expectations derived from the referential hierarchy for spoken languages. On this basis, we propose a tentative hierarchy of referential expressions for ASL that incorporates modality specific referential devices.