Jennie E. Pyers

Language Promotes False-Belief Understanding Evidence From Learners of a New Sign Language

Developmental studies have identified a strong correlation in the timing of language development and false-belief understanding. However, the nature of this relationship remains unresolved. Does language promote false-belief understanding, or does it merely facilitate development that could occur independently, albeit on a delayed timescale? We examined language development and false-belief understanding in deaf learners of an emerging sign language in Nicaragua. The use of mental-state vocabulary and performance on a low-verbal false-belief task were assessed, over 2 years, in adult and adolescent users of Nicaraguan Sign Language. Results show that those adults who acquired a nascent form of the language during childhood produce few mental-state signs and fail to exhibit false-belief understanding. Furthermore, those whose language developed over the period of the study correspondingly developed in false-belief understanding. Thus, language learning, over and above social experience, drives the development of a mature theory of mind.

The Face of Bimodal Bilingualism Grammatical Markers in American Sign Language Are Produced When Bilinguals Speak to English Monolinguals

Bimodal bilinguals, fluent in a signed and a spoken language, provide unique insight into the nature of syntactic integration and language control. We investigated whether bimodal bilinguals who are conversing with English monolinguals produce American Sign Language (ASL) grammatical facial expressions to accompany parallel syntactic structures in spoken English. In ASL, raised eyebrows mark conditionals, and furrowed eyebrows mark wh-questions; the grammatical brow movement is synchronized with the manual onset of the clause. Bimodal bilinguals produced more ASL-appropriate facial expressions than did nonsigners and synchronized their expressions with the onset of the corresponding English clauses. This result provides evidence for a dual-language architecture in which grammatical information can be integrated up to the level of phonological implementation. Overall, participants produced more raised brows than furrowed brows, which can convey negative affect. Bimodal bilinguals suppressed but did not completely inhibit ASL facial grammar when it conflicted with conventional facial gestures. We conclude that morphosyntactic elements from two languages can be articulated simultaneously and that complete inhibition of the nonselected language is difficult.

Bimodal bilinguals reveal the source of tip-of-the-tongue states

Bilinguals report more tip-of-the-tongue (TOT) failures than monolinguals. Three accounts of this disadvantage are that bilinguals experience between-language interference at (a) semantic and/or (b) phonological levels, or (c) that bilinguals use each language less frequently than monolinguals. Bilinguals who speak one language and sign another help decide between these alternatives because their languages lack phonological overlap. Twenty-two American Sign Language (ASL)-English bilinguals, 22 English monolinguals, and 11 Spanish-English bilinguals named 52 pictures in English. Despite no phonological overlap between languages, ASL-English bilinguals had more TOTs than monolinguals, and equivalent TOTs as Spanish-English bilinguals. These data eliminate phonological blocking as the exclusive source of bilingual disadvantages. A small advantage of ASL-English over Spanish-English bilinguals in correct retrievals is consistent with semantic interference and a minor role for phonological blocking. However, this account faces substantial challenges. We argue reduced frequency of use is the more comprehensive explanation of TOT rates in all bilinguals.

Relations between language and cognition in native-signing children with autism spectrum disorder

Two populations have been found to exhibit delays in theory of mind (ToM): deaf children of hearing parents and children with autism spectrum disorder (ASD). Deaf children exposed to sign from birth by their deaf parents, however, show no such delay, suggesting that early language exposure is key to ToM development. Sign languages also present frequent opportunities with visual perspective‐taking (VPT), leading to the question of whether sign exposure could benefit children with ASD. We present the first study of children with ASD exposed to sign from birth by their deaf parents. Seventeen native‐signing children with a confirmed ASD diagnosis and a chronological‐ and mental age‐matched control group of 18 typically developing (TD) native‐signing deaf children were tested on American Sign Language (ASL) comprehension, two minimally verbal social cognition tasks (ToM and VPT), and one spatial cognition task (mental rotation). The TD children outperformed the children with ASD on ASL comprehension (p < 0.0001), ToM (p = 0.02), and VPT (p < 0.01), but not mental rotation (p = 0.12). Language strongly correlated with ToM (p < 0.01) and VPT (p < 0.001), but not mental rotation (p = ns). Native exposure to sign is thus insufficient to overcome the language and social impairments implicated in ASD. Contrary to the hypothesis that sign could provide a scaffold for ToM skills, we find that signing children with ASD are unable to access language so as to gain any potential benefit sign might confer. Our results support a strong link between the development of social cognition and language, regardless of modality, for TD and ASD children. Autism Res 2016, 9: 1304–1315.

Referential shift in Nicaraguan Sign Language: a transition from lexical to spatial devices

Even the simplest narratives combine multiple strands of information, integrating different characters and their actions by expressing multiple perspectives of events. We examined the emergence of referential shift devices, which indicate changes among these perspectives, in Nicaraguan Sign Language (NSL). Sign languages, like spoken languages, mark referential shift grammatically with a shift in deictic perspective. In addition, sign languages can mark the shift with a point or a movement of the body to a specified spatial location in the three-dimensional space in front of the signer, capitalizing on the spatial affordances of the manual modality. We asked whether the use of space to mark referential shift emerges early in a new sign language by comparing the first two age cohorts of deaf signers of NSL. Eight first-cohort signers and 10 second-cohort signers watched video vignettes and described them in NSL. Narratives were coded for lexical (use of words) and spatial (use of signing space) devices. Although the cohorts did not differ significantly in the number of perspectives represented, second-cohort signers used referential shift devices to explicitly mark a shift in perspective in more of their narratives. Furthermore, while there was no significant difference between cohorts in the use of non-spatial, lexical devices, there was a difference in spatial devices, with second-cohort signers using them in significantly more of their narratives. This suggests that spatial devices have only recently increased as systematic markers of referential shift. Spatial referential shift devices may have emerged more slowly because they depend on the establishment of fundamental spatial conventions in the language. While the modality of sign languages can ultimately engender the syntactic use of three-dimensional space, we propose that a language must first develop systematic spatial distinctions before harnessing space for grammatical functions.

The Road to Language Learning Is Not Entirely Iconic: Iconicity, Neighborhood Density, and Frequency Facilitate Acquisition of Sign Language:

Iconic mappings between words and their meanings are far more prevalent than once estimated and seem to support children’s acquisition of new words, spoken or signed. We asked whether iconicity’s prevalence in sign language overshadows two other factors known to support the acquisition of spoken vocabulary: neighborhood density (the number of lexical items phonologically similar to the target) and lexical frequency. Using mixed-effects logistic regressions, we reanalyzed 58 parental reports of native-signing deaf children’s productive acquisition of 332 signs in American Sign Language (ASL; Anderson & Reilly, 2002) and found that iconicity, neighborhood density, and lexical frequency independently facilitated vocabulary acquisition. Despite differences in iconicity and phonological structure between signed and spoken language, signing children, like children learning a spoken language, track statistical information about lexical items and their phonological properties and leverage this information to expand their vocabulary.

Viewpoint in the Visual-Spatial Modality: The Coordination of Spatial Perspective.

Sign languages express viewpoint-dependent spatial relations (e.g., left, right) iconically but must conventionalize from whose viewpoint the spatial relation is being described, the signers or the perceivers. In Experiment 1, ASL signers and sign-naïve gesturers expressed viewpoint-dependent relations egocentrically, but only signers successfully interpreted the descriptions nonegocentrically, suggesting that viewpoint convergence in the visual modality emerges with language conventionalization. In Experiment 2, we observed that the cost of adopting a nonegocentric viewpoint was greater for producers than for perceivers, suggesting that sign languages have converged on the most cognitively efficient means of expressing left-right spatial relations. We suggest that nonlinguistic cognitive factors such as visual perspective-taking and motor embodiment may constrain viewpoint convergence in the visual-spatial modality.

The road to language learning is not entirely iconic: Iconicity, neighborhood density, and frequency facilitate sign language acquisition

Research reported in this publication was supported by the National Institute On Deafness And Other Communication Disorders of the National Institutes of Health under Award Number R21DC016104. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This work is also supported by a James S. McDonnell Foundation Award to Dr. Jennie Pyers.