Memory in language-impaired children with and without autism.

Alison Presmanes Hill,Beth Hoover Langhorst,Kyle Gorman,Eric Fombonne,Jan Van Santen

doi:10.1186/s11689-015-9111-z

Abstract

BackgroundA subgroup of young children with autism spectrum disorders (ASD) have significant language impairments (phonology, grammar, vocabulary), although such impairments are not considered to be core symptoms of and are not unique to ASD. Children with specific language impairment (SLI) display similar impairments in language. Given evidence for phenotypic and possibly etiologic overlap between SLI and ASD, it has been suggested that language-impaired children with ASD (ASD + language impairment, ALI) may be characterized as having both ASD and SLI. However, the extent to which the language phenotypes in SLI and ALI can be viewed as similar or different depends in part upon the age of the individuals studied. The purpose of the current study is to examine differences in memory abilities, specifically those that are key “markers” of heritable SLI, among young school-age children with SLI, ALI, and ALN (ASD + language normal).MethodsIn this cross-sectional study, three groups of children between ages 5 and 8 years participated: SLI (n = 18), ALI (n = 22), and ALN (n = 20). A battery of cognitive, language, and ASD assessments was administered as well as a nonword repetition (NWR) test and measures of verbal memory, visual memory, and processing speed.ResultsNWR difficulties were more severe in SLI than in ALI, with the largest effect sizes in response to nonwords with the shortest syllable lengths. Among children with ASD, NWR difficulties were not associated with the presence of impairments in multiple ASD domains, as reported previously. Verbal memory difficulties were present in both SLI and ALI groups relative to children with ALN. Performance on measures related to verbal but not visual memory or processing speed were significantly associated with the relative degree of language impairment in children with ASD, supporting the role of verbal memory difficulties in language impairments among early school-age children with ASD.ConclusionsThe primary difference between children with SLI and ALI was in NWR performance, particularly in repeating two- and three-syllable nonwords, suggesting that shared difficulties in early language learning found in previous studies do not necessarily reflect the same underlying mechanisms.Electronic supplementary materialThe online version of this article (doi:10.1186/s11689-015-9111-z) contains supplementary material, which is available to authorized users.

Highlights

A subgroup of young children with autism spectrum disorders (ASD) have significant language impairments, such impairments are not considered to be core symptoms of and are not unique to Autism spectrum disorders (ASDs)
For children with ASD, language impairment measured at ages 6–8 years has been found to be a more robust predictor of symptom and functional outcomes than language measured at earlier ages [18], suggesting that language abilities during the early school-age years play a pivotal role in development
As shown in Additional file 1, results were similar when analyses were conducted on a subset of children in each group, pairwise group-matched to a stronger criterion of p ≥ .25 for age and performance intelligence quotient (PIQ)

Summary

Introduction

A subgroup of young children with autism spectrum disorders (ASD) have significant language impairments (phonology, grammar, vocabulary), such impairments are not considered to be core symptoms of and are not unique to ASD. Given evidence for phenotypic and possibly etiologic overlap between SLI and ASD, it has been suggested that language-impaired children with ASD (ASD + language impairment, ALI) may be characterized as having both ASD and SLI. The purpose of the current study is to examine differences in memory abilities, those that are key “markers” of heritable SLI, among young school-age children with SLI, ALI, and ALN (ASD + language normal). Examining differences between children with SLI and ALI in the early school-age years may be important because the linguistic and behavioral profiles for each disorder may shift over time from childhood into adolescence. Given that the language phenotypes of children with SLI and ALI may be expected to overlap most significantly at younger ages and diverge over time, it is important to understand the nature of early language impairments in children with ASD and whether parallels in such impairments in children with SLI reflect shared mechanisms underlying difficulties in early language learning

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