A developmental account of the role of sequential dependencies in typical and atypical language learners

Abstract

The Gerken lab has shown that infants are able to learn sound patterns that obligate local sequential dependencies that are no longer readily accessible to adults. The Goffman lab has shown that children with developmental language disorder (DLD) exhibit deficits in learning sequential dependencies that influence the acquisition of words and grammar, as well as other types of domain general sequences. Thus, DLD appears to be an impaired ability to detect and deploy sequential dependencies over multiple domains. We meld these two lines of research to propose a novel account in which sequential dependency learning is required for many phonological and morphosyntactic patterns in natural language and is also central to the language and domain general deficits that are attested in DLD. However, patterns that are not dependent on sequential dependencies but rather on networks of stored forms are learnable by children with DLD as well as by adults.

Keywords: Language development; artificial grammar; developmental language disorder; infants; motor skill; phonotactics; sequencing.

Figure 1.

Methodological approach to assessing articulatory variability. 10 productions of the sentence “Buy bobby a puppy” from a child with typical development (TD) and a child with developmental language disorder (DLD). The top panels are non-normalized productions. The middle panels are time- and amplitude-normalized. The bottom panels illustrate the spatiotemporal index (STI). Details further explained in the text.

Figure 2.

Methodological approach to assessing manual variability. 10 amplitude- and time-normalized productions of a patterned sequence of hand motion performing button presses in a serial reaction time task. The target buttons are 1–4-2–3-1.