A Developmental Framework For Linking Phonological And Morpho-syntactic Sequential Pattern Rules In DLD: Production

Inclusion Criteria

Because clinical precision is required, 4- to 8-year-olds will complete a large test battery.

• All children (TD, DLD, DLD + SSD, SSD) will score above 75 on the Nonverbal Scale of the Kaufman Assessment Battery for Children (KABC-II), which is above the Diagnostic and Statistical Manual cut-off for intellectual disability, even considering the standard error of measurement.
• Hearing will be within normal limits
• Oral structures will be within normal limits (Robbins \& Klee, 1987).
• The Childhood Autism Rating Scale (Schopler et al., 2010) and parent report, will be used to rule out autism.

Children with DLD will meet standard criteria.

• Children with DLD will score below the cutoff of 87 on the Structured Photographic Expressive Language Test-P2 (SPELT-P2; Dawson et al., 2005) that has demonstrated high diagnostic accuracy for DLD.
• Children with DLD will perform below 80% in their spontaneous production of finite verb morphemes.
• Performance on a nonword repetition task will also support DLD status. Scores below 70% for total phonemes correct across all nonword lengths are greater than 1 SD below the mean for typical children.
• Speech production skills will be measured via the Goldman-Fristoe Test of Articulation-3 (GFTA-3; Goldman \& Fristoe, 2015) and the inconsistency subtest of the Diagnostic Evaluation of Articulation and Phonology (DEAP, Dodd, et al., 2006). Many 4- to 6-year-old children with DLD are expected to perform below expected levels on the GFTA-3; for this study half of the children with DLD will show performance below expected levels and half above a standard score of 85. Children with SSD will show impaired performance on the GFTA-3, but typical performance on grammatically weighted language measures (SPELT-P2 and finite verb morphemes). The DEAP serves as a standardized measure of segmental inconsistency and will provide a post hoc analysis that may be related to sequence pattern variability.

Performance on the following measures will serve as covariates and will not be exclusionary for DLD or SSD:

• Peabody Picture Vocabulary Test, 4th ed (Dunn \& Dunn, 1997)
• Expressive Vocabulary Test, 2nd ed (Williams, 1997)
• Verbal and nonverbal memory span.
• Because of the emphasis on English phonological and morpho-syntactic patterns, all participants will be monolingual English learners or report dominant exposure to English from infancy. Exposure to other languages will be documented.

Exclusion Criteria for all participants

• Hearing impairment
• Intellectual impairment
• Autism
• Significant motor impairment.

Typical participants will be excluded if they show:

-Histories of developmental, speech, language, or hearing disorders.