Courtenay Frazier Norbury

Exploring the borderlands of autistic disorder and specific language impairment: a study using standardised diagnostic instruments

BACKGROUND Two studies were conducted to test claims that pragmatic language impairment (PLI - previously referred to as semantic-pragmatic disorder) is simply another term for autistic disorder or pervasive developmental disorder not otherwise specified (PDDNOS). METHOD In Study 1, 21 children aged from 6 to 9 years with language impairments were subdivided on the basis of the Childrens Communication Checklist into 13 cases of pragmatic language impairment (PLI) and eight cases of typical specific language impairment (SLI-T). Parents completed the Autism Diagnostic Interview - Revised (ADI-R) and the Social Communication Questionnaire (SCQ), and the children were given the Autism Diagnostic Observation Schedule - Generic (ADOS-G). In Study 2, a further 11 children with SLI-T and 18 with PLI were assessed using the SCQ and ADOS-G. In addition, six children diagnosed with high-functioning autism and 18 normally developing children were assessed. RESULTS There was good agreement between ADI-R and SCQ diagnoses, but poor agreement between diagnoses based on these parental report measures and those based on ADOS-G. In many children, symptom profiles changed with age. Four PLI children from Study 1 and one from Study 2 met criteria for autistic disorder on both parental report (ADI-R or SCQ) and ADOS-G. Many of the others showed some autistic features, but there was a subset of children with pragmatic difficulties who were not diagnosed as having autism or PDDNOS by either instrument. These children tended to use stereotyped language with abnormal intonation/prosody, but they appeared sociable and communicative, had normal nonverbal communication, and showed few abnormalities outside the language/social communication domains. CONCLUSIONS Presence of pragmatic difficulties in a child with communication problems should prompt the clinician to evaluate autistic symptomatology, but it is dangerous to assume that all children with pragmatic difficulties have autism or PDDNOS.

Narrative skills of children with communication impairments

BACKGROUND Narrative assessment is sensitive to the communication impairments of children with specific language impairment and those with autistic spectrum disorders. Although both groups of children tend to show deficits in narrative, it is unclear whether these deficits are qualitatively different and how language and pragmatic ability may impact on narrative competence. Comparing these two groups of children with children who exhibit pragmatic language impairment without autism may help to clarify these issues. AIMS This study explored the relationship between structural language ability and pragmatic competence in narrative in children with communication impairments and typically developing children. METHODS AND PROCEDURES Diagnostic status was determined using the Childrens Communication Checklist. All children were asked to generate a narrative to the wordless picture book Frog, Where are You? (Mayer 1969). Narratives were analysed according to their global structure, local linguistic structure and the childs ability to provide evaluative comments, especially about mental or emotional states. OUTCOMES AND RESULTS No group differences were seen in global structure or evaluation. Children with specific language impairment and autistic disorder made more syntactic errors, and children with autism were significantly more likely to provide ambiguous references in the story. No significant relationships were evident between the Childrens Communication Checklist and narrative measures. The complexity of language used was related to evaluation in the clinical groups. CONCLUSIONS Narrative is a good way of assessing linguistic ability in older children with communication impairments. Core language abilities rather than pragmatic skill or diagnostic status are likely to influence narrative development.

Phonological Processing, Language, and Literacy: A Comparison of Children with Mild-to-moderate Sensorineural Hearing Loss and Those with Specific Language Impairment

Phonological skills, language ability, and literacy scores were compared for four groups: 19 children with mild-to-moderate sensorineural hearing loss (SNH), 20 children with specific language impairment (SLI), 20 controls matched on chronological age to the SNH group (CA), and 15 controls matched on receptive vocabulary level to a subset of the SLI group (CB). In common with the SLI group, mean scores of children with mild-to-moderate hearing loss were significantly poorer on tests of phonological short-term memory, phonological discrimination, and phonological awareness than CA controls. No differences between group means were observed in SNH and CA control groups on vocabulary, digit and sentence recall, sentence comprehension, and literacy scores. However, there was considerable individual variation within the SNH group. Nearly 50% of the SNH group showed phonological impairment associated with poorer expressive and receptive vocabulary and higher hearing thresholds than remaining children without phonological impairment. Nonword repetition deficits were observed in SNH subgroups with and without phonological impairment and were of a similar magnitude to those observed in children with SLI. Indeed, poorer repetition in children with SLI could only be differentiated from children with SNH on phonologically complex nonwords. Overall, findings suggested major problems in nonword repetition and phonological impairment occurred without clinically significant deficits in wider language and literacy abilities in children with mild-to-moderate sensorineural hearing loss. Implications for theories of SLI are discussed.

Inferential processing and story recall in children with communication problems: a comparison of specific language impairment, pragmatic language impairment and high-functioning autism.

An investigation is reported into the story comprehension abilities of four groups of children: those with typical specific language impairment (SLI-T), those with pragmatic language impairments who were not autistic (PLI), those with high-functioning autism (HFA) and typically developing controls. The story comprehension task required children to answer questions about the literal content of the story, as well as questions involving two types of inferences: text-connecting and gap-filling. The control children outscored the three clinical groups on story comprehension, but the group means of the clinical groups did not differ. However, categorical examination of the data revealed that children with pragmatic difficulties related to HFA were more likely to have specific inferencing deficits. Error analysis suggested that all children could make inferences, but these were not always relevant to the story context. This supports the notion of weak central coherence underlying deficits in inferencing. There were no group differences on story recall. However, there was a strong relationship between story comprehension and recall, in that those who had better comprehension tended to have better recall. It is concluded that comprehension aids recall by enabling the listener to build a more stable mental representation of the story. The pragmatic deficits seen in autism compromise this process.

Distinct genetic influences on grammar and phonological short‐term memory deficits: evidence from 6‐year‐old twins

Children with language impairments have limitations of phonological short‐term memory (STM) and have distinctive problems with certain aspects of grammar. Both deficits have been proposed as phenotypic markers of heritable language impairment. We studied 173 twin pairs, selected to be over‐representative of children with risk of developmental language impairment, using a battery of standardized language and intelligence tests, a test of nonword repetition to index phonological STM and two elicitation tasks to assess use of verb tense marking. As predicted, the phonological STM and the verb tense measures both discriminated children with risk of language impairment from low risk children, and DeFries–Fulker analysis showed that impairments on both tasks were significantly heritable. However, there was minimal phenotypic and etiological overlap between the two deficits, suggesting that different genes are implicated in causing these two kinds of language difficulty. From an evolutionary perspective, these data are consistent with the view that language is a complex function that depends on multiple underlying skills with distinct genetic origins.

Executive functions in children with communication impairments, in relation to autistic symptomatology 2: Response inhibition

Although impairment in executive functions has been described in autism, there has been debate as to whether response inhibition is specifically affected. We compared four groups: highfunctioning autism; pragmatic language impairment; specific language impairment; and control. Inhibition was assessed using two subtests from the Test of Everyday Attention for Children, one requiring a verbal response and the other a non-verbal response. Although we found evidence of inhibitory deficits, these were neither specific to autism, nor linked to particular aspects of autistic symptomatology. Rather, they appeared to be associated with poor verbal skills and inattention. It is suggested that future studies need to control for structural language skills and attention deficit when evaluating cognitive deficits in autism. Reliance on control groups matched solely on vocabulary level or nonverbal mental age may obscure the important role played by language skills in executive functions.

The relationship between theory of mind and metaphor: Evidence from children with language impairment and autistic spectrum disorder

Happe (1993) proposed that theory of mind (ToM) understanding was necessary for comprehension of metaphorical expressions. The current study investigated the role of both ToM and language ability in metaphor understanding. Ninety-four children aged 8–15 years with communication impairments were grouped according to language ability and autistic symptomatology in the first instance, and then according to ToM performance. Their performance on a metaphor task was compared to 34 typically developing age-matched peers. These analyses showed that only children with language impairment, with or without concurrent autistic features, were impaired on the metaphor task. Furthermore, possession of first-order ToM skills did not ensure metaphor comprehension. Instead, semantic ability was a stronger predictor of performance on the metaphor task. These results are considered with reference to the view that ToM understanding is necessary for the comprehension of metaphor.

Why reading comprehension fails - Insights from developmental disorders

Developmental difficulties with reading comprehension are not uncommon. This article examines the nature of reading comprehension deficits in three groups of children: children identified as having relatively specific impairments in reading comprehension, children with autism spectrum disorder, and children with specific language impairment. Our review emphasizes that in all three groups, poor reading comprehension is often associated with weaknesses in oral language. We conclude that a useful framework for understanding the complex relationship between language and reading in children with developmental disorders is provided by a model that sees variations in phonological and nonphonological language skills relating to different patterns of reading behavior. This framework also provides a useful basis for identifying children with poor reading comprehension, and for planning appropriately targeted interventions.

Eye-movement patterns are associated with communicative competence in autistic spectrum disorders

BACKGROUND Investigations using eye-tracking have reported reduced fixations to salient social cues such as eyes when participants with autism spectrum disorders (ASD) view social scenes. However, these studies have not distinguished different cognitive phenotypes. METHODS The eye-movements of 28 teenagers with ASD and 18 typically developing peers were recorded as they watched videos of peers interacting in familiar situations. Within ASD, we contrasted the viewing patterns of those with and without language impairments. The proportion of time spent viewing eyes, mouths and other scene details was calculated, as was latency of first fixation to eyes. Finally, the association between viewing patterns and social-communicative competence was measured. RESULTS Individuals with ASD and age-appropriate language abilities spent significantly less time viewing eyes and were slower to fixate the eyes than typically developing peers. In contrast, there were no differences in viewing patterns between those with language impairments and typically developing peers. Eye-movement patterns were not associated with social outcomes for either language phenotype. However, increased fixations to the mouth were associated with greater communicative competence across the autistic spectrum. CONCLUSIONS Attention to both eyes and mouths is important for language development and communicative competence. Differences in fixation time to eyes may not be sufficient to disrupt social competence in daily interactions. A multiple cognitive deficit model of ASD, incorporating different language phenotypes, is advocated.

Do individuals with autism process words in context? Evidence from language-mediated eye-movements

It is widely argued that people with autism have difficulty processing ambiguous linguistic information in context. To investigate this claim, we recorded the eye-movements of 24 adolescents with autism spectrum disorder and 24 language-matched peers as they monitored spoken sentences for words corresponding to objects on a computer display. Following a target word, participants looked more at a competitor object sharing the same onset than at phonologically unrelated objects. This effect was, however, mediated by the sentence context such that participants looked less at the phonological competitor if it was semantically incongruous with the preceding verb. Contrary to predictions, the two groups evidenced similar effects of context on eye-movements. Instead, across both groups, the effect of sentence context was reduced in individuals with relatively poor language skills. Implications for the weak central coherence account of autism are discussed.