Gina Conti-Ramsden

Psycholinguistic Markers for Specific Language Impairment (SLI)

In this study 160 children, aged 11 years with a definite history of specific language impairment (SLI), completed four tasks that could be potential positive psycholinguistic markers for this impairment: a third person singular task, a past tense task, a nonword repetition task, and a sentence repetition task. This allowed examination of more than one type of marker simultaneously, facilitating both comparisons between markers and also evaluation of combinations of markers in relation to identifying SLI. The study also provided data regarding the markers in relation to nonverbal IQ, made use of new normative data on all tasks, and examined marker accuracy in relation to current language status. The results show that markers vary in accuracy, with sentence repetition (a previously unused marker) proving to be the most useful. This psycholinguistic marker shows high levels of sensitivity (90%), specificity (85%), and overall accuracy (88%), as well as being able to identify the majority of children whose current language status falls in the normal range despite a history of SLI.

A genomewide scan identifies two novel loci involved in specific language impairment

Approximately 4% of English-speaking children are affected by specific language impairment (SLI), a disorder in the development of language skills despite adequate opportunity and normal intelligence. Several studies have indicated the importance of genetic factors in SLI; a positive family history confers an increased risk of development, and concordance in monozygotic twins consistently exceeds that in dizygotic twins. However, like many behavioral traits, SLI is assumed to be genetically complex, with several loci contributing to the overall risk. We have compiled 98 families drawn from epidemiological and clinical populations, all with probands whose standard language scores fall > or =1.5 SD below the mean for their age. Systematic genomewide quantitative-trait-locus analysis of three language-related measures (i.e., the Clinical Evaluation of Language Fundamentals-Revised [CELF-R] receptive and expressive scales and the nonword repetition [NWR] test) yielded two regions, one on chromosome 16 and one on 19, that both had maximum LOD scores of 3.55. Simulations suggest that, of these two multipoint results, the NWR linkage to chromosome 16q is the most significant, with empirical P values reaching 10(-5), under both Haseman-Elston (HE) analysis (LOD score 3.55; P=.00003) and variance-components (VC) analysis (LOD score 2.57; P=.00008). Single-point analyses provided further support for involvement of this locus, with three markers, under the peak of linkage, yielding LOD scores >1.9. The 19q locus was linked to the CELF-R expressive-language score and exceeds the threshold for suggestive linkage under all types of analysis performed-multipoint HE analysis (LOD score 3.55; empirical P=.00004) and VC (LOD score 2.84; empirical P=.00027) and single-point HE analysis (LOD score 2.49) and VC (LOD score 2.22). Furthermore, both the clinical and epidemiological samples showed independent evidence of linkage on both chromosome 16q and chromosome 19q, indicating that these may represent universally important loci in SLI and, thus, general risk factors for language impairment.

Working, declarative and procedural memory in specific language impairment

According to the Procedural Deficit Hypothesis (PDH), abnormalities of brain structures underlying procedural memory largely explain the language deficits in children with specific language impairment (SLI). These abnormalities are posited to result in core deficits of procedural memory, which in turn explain the grammar problems in the disorder. The abnormalities are also likely to lead to problems with other, non-procedural functions, such as working memory, that rely at least partly on the affected brain structures. In contrast, declarative memory is expected to remain largely intact, and should play an important compensatory role for grammar. These claims were tested by examining measures of working, declarative and procedural memory in 51 children with SLI and 51 matched typically-developing (TD) children (mean age 10). Working memory was assessed with the Working Memory Test Battery for Children, declarative memory with the Children’s Memory Scale, and procedural memory with a visuo-spatial Serial Reaction Time task. As compared to the TD children, the children with SLI were impaired at procedural memory, even when holding working memory constant. In contrast, they were spared at declarative memory for visual information, and at declarative memory in the verbal domain after controlling for working memory and language. Visuo-spatial short-term memory was intact, whereas verbal working memory was impaired, even when language deficits were held constant. Correlation analyses showed neither visuo-spatial nor verbal working memory was associated with either lexical or grammatical abilities in either the SLI or TD children. Declarative memory correlated with lexical abilities in both groups of children. Finally, grammatical abilities were associated with procedural memory in the TD children, but with declarative memory in the children with SLI. These findings replicate and extend previous studies of working, declarative and procedural memory in SLI. Overall, we suggest that the evidence largely supports the predictions of the PDH.

Non-word repetition and language development in children with specific language impairment (SLI).

Non-word repetition has previously been found to correlate with language outcomes both in children who are language impaired and in those who are developing normally. This paper concerns a group of children identified as having specific language impairment (SLI) and follows the methods of Adams and Gathercole (2000) by taking children with the highest and the lowest non-word repetition scores at age 11. These childrens language and literacy abilities were then compared. Despite the fact that high and low scorers were matched on Performance IQ tasks (Block Design and Picture Completion), all linguistic measures except for vocabulary assessments showed significant differences between the groups. The fact that these differences were present despite block design scores being identical for the two groups suggests that more than a general working memory deficit underlies the language difficulties. Furthermore, significant differences were noted on a digit-span task requiring processing and production of number words. A specific phonological memory difficulty may therefore be present over and above a subtle but more general processing limitation. The implications for SLI theory and practice are discussed.

A Longitudinal Study of Behavioral, Emotional and Social Difficulties in Individuals with a History of Specific Language Impairment (SLI).

UNLABELLED Children with specific language impairment (SLI) have often been reported to have associated behavioral, emotional and social difficulties. Most previous studies involve observations at a single time point, or cross sectional designs, and longitudinal evidence of the developmental trajectories of particular difficulties is limited. The Strengths and Difficulties Questionnaire was used to measure behavioral (hyperactivity and conduct), emotional and social (peer) problems in a sample of individuals with a history of SLI at four time points from childhood (age 7) to adolescence (age 16). A decrease in behavioral and emotional problems was observed from childhood to adolescence, although emotional problems were still evident in adolescence. In contrast, there was an increase in social problems. Reading skills and expressive language were related only to behavioral problems. Pragmatic abilities were related to behavioral, emotional and social difficulties. As a group, those with a history of SLI have poorer long term social and, to a lesser extent, emotional outcomes. In contrast, behavioral difficulties appear to decrease to normative levels by adolescence. Different aspects of early language abilities and reading skills exert different types and degrees of influence on behavioral, emotional and social difficulties. LEARNING OUTCOMES Readers will be able to: (1) understand the types of behavioral, emotional and social difficulties present in individuals with a history of SLI; (2) be familiar with the developmental trajectory of these difficulties from childhood to adolescence; and (3) understand the relationships between behavioral, emotional and social difficulties and early language and literacy ability.

Follow-up of children attending infant language units: outcomes at 11 years of age

A large cohort of 242 children who had been attending infants language units at 7 years of age was followed up when the children were in their final year of primary school. Two hundred (83%) of the children were reassessed at 11 years of age on a wide battery of language and literacy measures, on a test of non-verbal ability, an autism checklist and a communication checklist. In total, 89% of children still scored < 1 SD from the mean on at least one test of language and the majority (63%) scored poorly on three or more assessments demonstrating widespread difficulties. Compared with non-verbal abilities at 7 years of age, a large proportion of the cohort also performed poorly on performance IQ subtests (28%). A further 10 children scored highly on a checklist for autistic spectrum disorder. Thus, only 115 (58%) children could be said to meet criteria for specific language impairment. A small group of 16 children appeared to have entirely resolved their difficulties. These outcomes and their implications for education and long-term impact of the disorder are discussed.

Highly significant linkage to the SLI1 locus in an expanded sample of individuals affected by specific language impairment

Specific language impairment (SLI) is defined as an unexplained failure to acquire normal language skills despite adequate intelligence and opportunity. We have reported elsewhere a full-genome scan in 98 nuclear families affected by this disorder, with the use of three quantitative traits of language ability (the expressive and receptive tests of the Clinical Evaluation of Language Fundamentals and a test of nonsense word repetition). This screen implicated two quantitative trait loci, one on chromosome 16q (SLI1) and a second on chromosome 19q (SLI2). However, a second independent genome screen performed by another group, with the use of parametric linkage analyses in extended pedigrees, found little evidence for the involvement of either of these regions in SLI. To investigate these loci further, we have collected a second sample, consisting of 86 families (367 individuals, 174 independent sib pairs), all with probands whose language skills are >/=1.5 SD below the mean for their age. Haseman-Elston linkage analysis resulted in a maximum LOD score (MLS) of 2.84 on chromosome 16 and an MLS of 2.31 on chromosome 19, both of which represent significant linkage at the 2% level. Amalgamation of the wave 2 sample with the cohort used for the genome screen generated a total of 184 families (840 individuals, 393 independent sib pairs). Analysis of linkage within this pooled group strengthened the evidence for linkage at SLI1 and yielded a highly significant LOD score (MLS = 7.46, interval empirical P<.0004). Furthermore, linkage at the same locus was also demonstrated to three reading-related measures (basic reading [MLS = 1.49], spelling [MLS = 2.67], and reading comprehension [MLS = 1.99] subtests of the Wechsler Objectives Reading Dimensions).

Specific language impairment and school outcomes. I: Identifying and explaining variability at the end of compulsory education

BACKGROUND This investigation reports the results of national educational examinations in secondary schooling for young people who have been participating in the Manchester Language Study. AIMS The emphasis of the study is on furthering understanding of educational outcomes at the end of compulsory education. METHODS & PROCEDURES A total of 120 adolescents with a history of specific language impairment (SLI) and 121 adolescents with typical development (TD) who were in their final year of compulsory secondary schooling (mean age = 17;4 years) participated. National educational examination results throughout secondary schooling were collected along with a range of psycholinguistic skills from 11 to 16/17 years. OUTCOMES & RESULTS Forty-four per cent of young people with SLI obtained at least one of the expected qualifications at the end of secondary education, indicating some improvements compared with reports on earlier cohorts. Regression analyses revealed that literacy and language skills were predictive of educational attainment after controlling for IQ and maternal education. Nearly one-quarter of the sample of adolescents with SLI was not entered for any examinations at the end of compulsory education. A very strong association between earlier patterns of entry for examinations and patterns of examination entry at school leaving age was found. CONCLUSIONS In addition to performance IQ, concurrent and early literacy and language skills have significant effects on the academic attainments of young people with a history of SLI. The transition from primary to secondary schooling is a crucial time for assessment and evaluation of individual childrens needs and levels of support required.

CMIP and ATP2C2 modulate phonological short-term memory in language impairment

Specific language impairment (SLI) is a common developmental disorder characterized by difficulties in language acquisition despite otherwise normal development and in the absence of any obvious explanatory factors. We performed a high-density screen of SLI1, a region of chromosome 16q that shows highly significant and consistent linkage to nonword repetition, a measure of phonological short-term memory that is commonly impaired in SLI. Using two independent language-impaired samples, one family-based (211 families) and another selected from a population cohort on the basis of extreme language measures (490 cases), we detected association to two genes in the SLI1 region: that encoding c-maf-inducing protein (CMIP, minP = 5.5 × 10−7 at rs6564903) and that encoding calcium-transporting ATPase, type2C, member2 (ATP2C2, minP = 2.0 × 10−5 at rs11860694). Regression modeling indicated that each of these loci exerts an independent effect upon nonword repetition ability. Despite the consistent findings in language-impaired samples, investigation in a large unselected cohort (n = 3612) did not detect association. We therefore propose that variants in CMIP and ATP2C2 act to modulate phonological short-term memory primarily in the context of language impairment. As such, this investigation supports the hypothesis that some causes of language impairment are distinct from factors that influence normal language variation. This work therefore implicates CMIP and ATP2C2 in the etiology of SLI and provides molecular evidence for the importance of phonological short-term memory in language acquisition.

Social and behavioural difficulties in children with language impairment

This paper examines the secondary social and behavioural difficulties of a large cohort of children attending language units in England. In stage 1 of the study, 242 children with language impairments were assessed on a measure of peer competence, a behavioural measure, a cognitive measure and also using teacher opinion of emotional/behavioural status in school year 2 (age 6-7). A year later, 214 of the children were followed up at age 7-8 years. The group is examined as a whole and in terms of subgroups according to type of language impairment. While the group pattern for behavioural difficulties showed that children in language units do not generally have clinical-level behavioural problems, the scores were significantly different by subgroup, with children exhibiting mainly expressive difficulties showing the least secondary behavioural problems and children with mixed expressive and receptive problems showing the greatest increase in behavioural scores from stage 1 to stage 2. Children with complex receptive and complex language impairments were the most likely to score over the clinical threshold when examined by frequency and these children were also rated as having more marked social difficulties with peers than the other subgroups. Agreement between questionnaire score and teacher opinion was high. Patterns of social and behavioural impairment showed no associations with gender or cognitive ability. The implications of the findings are discussed in relation to other studies on social or behavioural impairment in this population.