Do children with dyslexia and/or specific language impairment compensate for place assimilation? Insight into phonological grammar and representations

Abstract

English speakers have to recognize, for example, that te[m] in te[m] pens is a form of ten, despite place assimilation of the nasal consonant. Children with dyslexia and specific language impairment (SLI) are commonly proposed to have a phonological deficit, and we investigate whether that deficit extends to place assimilation, as a way of probing phonological representations and phonological grammar. Children with SLI plus dyslexia, SLI only, and dyslexia only listened to sentences containing a target word in different assimilatory contexts—viable, unviable, and no change—and pressed a button to report hearing the target. The dyslexia-only group did not differ from age-matched controls, but the SLI groups showed more limited ability to accurately identify words within sentences. Once this factor was taken into account, the groups did not differ in their ability to compensate for assimilation. The results add to a growing body of evidence that phonological representations are not necessarily impaired in dyslexia. SLI children's results suggest that they too are sensitive to this aspect of phonological grammar, but are more liberal in their acceptance of alternative phonological forms of words. Furthermore, these children's ability to reject alternative phonological forms seems to be primarily limited by their vocabulary size and phonological awareness abilities.

Keywords:

• Phonological representations
• Place assimilation
• Dyslexia
• Specific language impairment

Acknowledgments

We are very grateful to Mike Coleman for his programming wizardry. We thank Anastasia Archonti, Hillit Dayan, Sally Harcourt-Brown, Angela Pozzuto, and Sophie Tang for their assistance in testing participants. We are most grateful to all the children who participated in this project, as well as their schools and their parents. We are also grateful to the feedback from various audiences to whom we have presented this work, at Reading University, the University of Amsterdam, the Laboratoire des Sciences Cognitives et Psycholinguistique in Paris, and the 16th Manchester Phonology Meeting. The editor, Brenda Rapp, and two anonymous reviewers provided extremely helpful comments on previous versions of the paper. This research was conducted at the Centre for Developmental Language Disorders and Cognitive Neuroscience, London. The first author and the research were supported by an Economic and Social Research Council (ESRC) grant awarded to H.v.d.L. (RES–000–23–0575).

Notes

¹SLI also occurs in signed languages, among deaf children who are acquiring a signed language as their native language (Mason et al., 2010).

²Here and in the rest of this paper, we use the terms “appropriate” or “viable” for a phonological context in which the target assimilation may occur, according to the phonology of the particular language under consideration (for example, here, in Dutch, a bilabial stop is an appropriate context for regressive place assimilation). Conversely, an inappropriate or unviable context is a context where such assimilation does not normally occur (here, a fricative is not an appropriate context for place assimilation in Dutch).

³For the purpose of this analysis, the group factor is a four-level nominal variable coding for each of the three pathological groups and the control group.

⁴The negative partial correlation between age and word-reporting d′ can be explained by the fact that the raw scores in the model carry most of the age-related variance. However, absolute performance levels off with age, hence the additional negative contribution of age.