Effects of age on American Sign Language sentence repetition.

The study of deaf users of signed languages, who often experience delays in primary language (L1) acquisition, permits a unique opportunity to examine the effects of aging on the processing of an L1 acquired under delayed or protracted development. A cohort of 107 congenitally deaf adult signers ages 45-85 years who were exposed to American Sign Language (ASL) either in infancy, early childhood, or late childhood were tested using an ASL sentence repetition test. Participants repeated 20 sentences that gradually increased in length and complexity. Logistic mixed-effects regression with the variables of chronological age (CA) and age of acquisition (AoA) was used to assess sentence repetition accuracy. Results showed that CA was a significant predictor, with increased age being associated with decreased likelihood to reproduce a sentence correctly (odds ratio [OR] = 0.56, p = .010). In addition, effects of AoA were observed. Relative to native deaf signers, those who acquired ASL in early childhood were less likely to successfully reproduce a sentence (OR = 0.42, p = .003), as were subjects who learned ASL in late childhood (OR = 0.27, p < .001). These data show that aging affects verbatim recall in deaf users of ASL and that the age of sign language acquisition has a significant and lasting effect on repetition ability, even after decades of sign language use. These data show evidence for life-span continuity of early life effects. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Cross-linguistic metaphor priming in ASL-English bilinguals: Effects of the Double Mapping Constraint.

Meir's (2010) Double Mapping Constraint (DMC) states the use of iconic signs in metaphors is restricted to signs that preserve the structural correspondence between the articulators and the concrete source domain and between the concrete and metaphorical domains. We investigated ASL signers' comprehension of English metaphors whose translations complied with the DMC (Communication collapsed during the meeting) or violated the DMC (The acid ate the metal). Metaphors were preceded by the ASL translation of the English verb, an unrelated sign, or a still video. Participants made sensibility judgments. Response times (RTs) were faster for DMC-compliant sentences with verb primes compared to unrelated primes or the still baseline. RTs for DMC-violation sentences were longer when preceded by verb primes. We propose the structured iconicity of the ASL verbs primed the semantic features involved in the iconic mapping and these primed semantic features facilitated comprehension of DMC-compliant metaphors and slowed comprehension of DMC-violation metaphors.

The relation between working memory and language comprehension in signers and speakers.

This study investigated the relation between linguistic and spatial working memory (WM) resources and language comprehension for signed compared to spoken language. Sign languages are both linguistic and visual-spatial, and therefore provide a unique window on modality-specific versus modality-independent contributions of WM resources to language processing. Deaf users of American Sign Language (ASL), hearing monolingual English speakers, and hearing ASL-English bilinguals completed several spatial and linguistic serial recall tasks. Additionally, their comprehension of spatial and non-spatial information in ASL and spoken English narratives was assessed. Results from the linguistic serial recall tasks revealed that the often reported advantage for speakers on linguistic short-term memory tasks does not extend to complex WM tasks with a serial recall component. For English, linguistic WM predicted retention of non-spatial information, and both linguistic and spatial WM predicted retention of spatial information. For ASL, spatial WM predicted retention of spatial (but not non-spatial) information, and linguistic WM did not predict retention of either spatial or non-spatial information. Overall, our findings argue against strong assumptions of independent domain-specific subsystems for the storage and processing of linguistic and spatial information and furthermore suggest a less important role for serial encoding in signed than spoken language comprehension.