Experimental Design and Testing Materials for Hofweber et al (2021)

This project investigates second language acquisition (SLA) in hearing adults who are learning a sign language. The universality – or not – of language-learning mechanisms has wide-reaching implications for the disciplines of theoretical linguistics, applied linguistics, psychology and language pedagogy. A substantial body of research has investigated SLA in adulthood, but with an almost exclusive focus on spoken languages. Sign languages – which are perceived and produced in the visuo-gestural modality – have been relatively neglected in SLA research, meaning that virtually nothing is known about whether the acquisition and developmental trajectory of signed languages resembles that of spoken languages. This is problematic because theories of SLA based solely on spoken languages make universal claims, yet it is not known whether they hold for sign SLA too. Investigating how sign languages are acquired therefore provides an excellent test for the empirical reach of theories of SLA.

This project focuses on the very earliest stages of sign SLA, when hearing adults who are initially sign-naive are exposed to input in the sign language. We will combine naturalistic but controlled input with experimental cross-sectional and longitudinal methods to study what adults learn on their first exposure to sign and how individual differences in cognitive skills affect their learning. For spoken SLA, individual cognitive differences play a significant role in predicting later learning success. We will therefore investigate the extent to which cognitive abilities (executive functions, working memory, language learning aptitude) predict sign language learning at the different stages of the learning process.

Our focus is on receptive language skills and implicit learning. Learners bring both pre-existing linguistic knowledge and sophisticated cognitive mechanisms to the task of breaking into the speech stream of a novel language. Can they use this knowledge and those same mechanisms to segment the sign stream, assign meaning to signs, and generalise beyond encountered signed exemplars? Specifically, we investigate the extent to which sign-naïve adults are able to recognise, comprehend and make lexical decisions about signs after a minimal amount of exposure to videoed sign input. Gullberg et al. (2010, 2012) have shown that adults exposed to an unfamiliar spoken language for the first time in a naturalistic, uninstructed situation show evidence of implicit learning of word forms, their meanings, and of how sounds in that language combine to form words. This strand adapts methods devised by Gullberg and her colleagues for spoken languages and applies them to a sign language for the first time.

The overall objective of this project is to investigate how sign-naïve adults “break into” a language that is not only unfamiliar to them but that is in a modality that is fundamentally different to their first language (i.e., English) and to any subsequent languages they have learned to date. The project’s significance is that it will undertake some of the first research in the area of sign SLA. Its findings will contribute to (1) our understanding of the earliest stages of SLA in any language, the relevance of which is that it will unearth what adult learners are able to do with unfamiliar and distinctive language input; (2) SLA more generally, in that we test whether claims about adults’ language-learning mechanisms and processes generalise to a different modality; (3) sign linguistics, in that there are still many open questions regarding the relationship between sign, manual gesture and spoken language.