A genome-wide sib-pair scan for quantitative language traits reveals linkage to chromosomes 10 and 13.

Although there is considerable evidence that individual differences in language development are highly heritable, there have been few genome-wide scans to locate genes associated with the trait. Previous analyses of language impairment have yielded replicable evidence for linkage to regions on chromosomes 16q, 19q, 13q (within lab) and at 13q (between labs). Here we report the first linkage study to screen the continuum of language ability, from normal to disordered, as found in the general population. 383 children from 147 sib-ships (214 sib-pairs) were genotyped on the Illumina(®) Linkage IVb Marker Panel using three composite language-related phenotypes and a measure of phonological memory (PM). Two regions (10q23.33; 13q33.3) yielded genome-wide significant peaks for linkage with PM. A peak suggestive of linkage was also found at 17q12 for the overall language composite. This study presents two novel genetic loci for the study of language development and disorders, but fails to replicate findings by previous groups. Possible reasons for this are discussed.

Relationship between parenting behaviours and specific language impairment in children.

This study investigated the relationship between parenting behaviours and specific language impairment (SLI) in children. Using a case-control design, data on 177 kindergarten children with SLI and 925 kindergarten children who were typically developing were collected using a parental questionnaire. Parents were interviewed about parenting practices classified into the following categories: conversing with children, teaching behaviours, the child's daily routine and discipline. The results revealed that parents of children who were normally developing had engaged their children in particular conversational activities more frequently than had parents with children with SLI. Parents of children diagnosed with SLI tended to teach their children school readiness skills (the alphabet and colours) and discipline their children more frequently. These relationships continued to hold after controlling for maternal education and family economic need with the exception of teaching children colour names. The results suggested that additional investigations that examine the association between these parental behaviours and children's language status through direct observation are warranted.

Speed of processing in children with specific language impairment.

The aim of the present study was to investigate the speed with which children with specific language impairment (SLI) respond on a range of tasks. Seventy-seven third-grade children participated in 10 different tasks (involving a total of 41 conditions), including nonlinguistic and linguistic activities. Mean response times (RTs) of children with SLI (n = 29) increased as a function of mean RTs of children with normal language (NLD, n = 29) under each of three different regression models; children with SLI responded more slowly across all task conditions, and also when linguistic and nonlinguistic tasks were analyzed separately. Children with nonspecific language impairment (NLI) were also included (n = 19). The results were similar to those for children with SLI, but the degree of slowing was greater. The results of the group analyses support the hypothesis that speed of processing in children with SLI is generally slower than that of children with normal language. However, some children with SLI do not appear to show deficits of this type.

The association of reading disability, behavioral disorders, and language impairment among second-grade children.

Children with language impairment (LI) have been shown to be at risk for reading disability (RD) and behavior disorder (BD). Previous research has not determined the specific pattern of these conditions associated with LI. This study sought to determine if the behavior disorder and reading problems represented different outcomes or if these conditions occurred together when found with LI. A group of 581 second-grade children, including 164 children with LI, were examined for spoken language, reading, and behavior disorder. The data for each of these areas were examined as dimensional traits and as clinical categorical traits. Reading and spoken language were found to be strongly correlated (r = .68); RD was found in 52 % of the children with LI and in only 9 % of the controls. Scores of parent ratings for BD were also significantly correlated with spoken language scores (r = .29). Clinical levels of BD were found in 29% of the children with LI and 19% of the controls. An examination of the co-occurrence of clinical levels of BD, RD, and LI showed BD in children with LI to be conditioned by the child's reading status. The data indicated that whereas RD was directly associated with BD, the association of LI with BD required the mediation of RD.

Language and reading acquisition in children with and without cochlear implants.

These data provide a coherent view of the spoken language and reading skills of children receiving cochlear implants. The data reveal both spoken language gains and clear benefit to these children with regard to reading. Improvement in reading is consistent with predictions based on prior research demonstrating a strong association between spoken language and reading. An intervention such as a cochlear implant has a direct effect on spoken language, and this can subsequently affect reading performance. This provides some of the first experimental evidence supporting the causal relationship between spoken language and reading.

Nonword repetition performance in school-age children with and without language impairment.

This study examined nonword repetition performance in a population-based sample of school-age children. A total of 581 second graders who were participating in a longitudinal, epidemiologic investigation of specific language impairment (SLI) were administered the Nonword Repetition Task (NRT) developed by Dollaghan & Campbell (1998). Performance was examined according to second-grade diagnostic category, presence/absence of language impairment, and treatment status. Results indicated that children with language impairment, as well as those in intervention, exhibited deficient nonword repetition skills compared to normal language controls. Findings also confirmed that the NRT is a culturally nonbiased measure of language processing. Results from likelihood ratio analyses indicated that NRT performance, though not sufficient on its own, may provide a useful index to assist in ruling in or ruling out language disorder.

Prevalence of speech delay in 6-year-old children and comorbidity with language impairment.

We estimate the prevalence of speech delay (L.D. Shriberg, D. Austin, B. A. Lewis, J. L. McSweeny, & D. L. Wilson, 1997b) in the United States on the basis of findings from a demographically representative population subsample of 1,328 monolingual English-speaking 6-year-old children. All children's speech and language had been previously assessed in the "Epidemiology of Specific Language Impairment" project (see J. B. Tomblin et al., 1997), which screened 7,218 children in stratified cluster samples within 3 population centers in the upper Midwest. To assess articulation, the Word Articulation subtest of the Test of Language Development-2: Primary (Newcomer & Hammill, 1988) was administered to each of the 1,328 children, and conversational speech samples were obtained for a subsample of 303 (23%) children. The 6 primary findings are as follows: (a) The prevalence of speech delay in 6-year-old children was 3.8%; (b) speech delay was approximately 1.5 times more prevalent in boys (4.5%) than girls (3.1%); (c) cross-tabulations by sex, residential strata, and racial/cultural backgrounds yielded prevalence rates for speech delay ranging from 0% to approximately 9%; (d) comorbidity of speech delay and language impairment was 1.3%, 0.51% with Specific Language Impairment (SLI); (e) approximately 11-15% of children with persisting speech delay had SLI; and (f) approximately 5-8% of children with persisting SLI had speech delay. Discussion includes implications of findings for speech-language phenotyping in genetics studies.

A comparison of language achievement in children with cochlear implants and children using hearing aids.

English language achievement of 29 prelingually deaf children with 3 or more years of cochlear implant (CI) experience was compared to the achievement levels of prelingually deaf children who did not have such CI experience. Language achievement was measured by the Rhode Island Test of Language Structure (RITLS), a measure of signed and spoken sentence comprehension, and the Index of Productive Syntax (IPSyn), a measure of expressive (signed and spoken) English grammar. When the CI users were compared with their deaf age mates who contributed to the norms of the RITLS, it was found that CI users achieved significantly better scores. Likewise, we found that CI users performed better than 29 deaf children who used hearing aids (HAs) with respect to English grammar achievement as indexed by the IPSyn. Additionally, we found that chronological age highly correlated with IPSyn levels only among the non-CI users, whereas length of CI experience was significantly correlated with IPSyn scores for CI users. Finally, clear differences between those with and without CI experience were found by 2 years of post-implant experience. These data provide evidence that children who receive CIs benefit in the form of improved English language comprehension and production.

Quality of life measurements of speech in the head and neck cancer patient population.

BACKGROUND: To employ patient-reported speech outcome data collected on head and neck cancer (HNC) surveys, there is a need to determine (1) the relationship of patient ratings to speech language pathologist (SLP) ratings and (2) whether patients' attitudes toward their speech are an important element of speech measurements. METHODS: Associations were analyzed between (1) patients' ratings of speech function on surveys and equivalent SLP ratings and (2) patients' ratings of speech function and their satisfaction with speech function. RESULTS: Patient-reported survey ratings were significantly associated with comparable SLP ratings. The associations were stronger for intelligibility than for voice quality. Patients' functional and attitudinal ratings were also significantly associated. The associations were relatively strong for composite speech items and intelligibility and moderate for voice quality. CONCLUSIONS: Patient-reported speech outcomes can be interpreted as being fairly equivalent to SLP evaluations. Attitudinal ratings appear to contribute an important aspect of the patients' perspective, with substantially different variances between function and attitude.

Can children with language impairment be accurately identified using temporal processing measures? A simulation study.

Three simulation experiments were conducted to determine the basis of the high predictive accuracy (98%) of temporal processing variables for the identification of language impairment obtained by Tallal, Stark, and Mellits (1985). In the first two experiments, the stepwise discriminant analysis using a set of 160 arrays of random numbers to predict a dichotomous language status (either normal or disordered) resulted in an average accuracy rate of 86.3% in contrast with the 98% rate obtained by Tallal, Stark, and Mellits. The third experiment showed that a 95% accuracy rate could be obtained from an array of 160 variables that each may only account for about 1.5% variance in the language ability. These results emphasize the need for confirmatory studies when large data sets are used to identify a small set of predictor variables.

The production of English inflectional morphology, speech production and listening performance in children with cochlear implants.

OBJECTIVE: To compare how children who use either cochlear implants (CIs) or hearing aids (HAs) express English inflectional morphemes during conversation, i.e., with voice, with sign, or with both. A secondary objective was to investigate the relationship between morpheme use in pediatric CI users and their speech perception skills, length of experience with the device, and accuracy of phoneme production. DESIGN: Group 1 consisted of 25 children who used CIs, and Group 2 consisted of 13 children who used HAs. All children were prelingually deafened and all used simultaneous communication. A 12 minute spontaneous conversation was elicited, transcribed and coded. Between group comparisons were performed to evaluate differences in modality and number of morphemes used. Additionally, use of morpheme endings was related to length of CI experience, accuracy of phoneme production, and closed-set speech recognition performance. RESULTS: Children who had CI experience produced significantly more English inflected morphemes than children in the HA group. CI participants also expressed the inflected endings by using voice-only mode 91% of the time, whereas HA participants used voice-only mode 1% of the time. In the CI group, a strong relationship was found between number of morpheme endings used and speech recognition scores, length of CI experience and accuracy of phoneme production. The results of this study indicate that input from the CI facilitates children's ability to perceive and comprehend bound morphemes.

Heritability of poor language achievement among twins.

In order to examine the basis of familial associations with poor language achievement, 62 twinship pairs and 3 sets of triplets were studied in which at least one member presented poor oral language status in the absence of other developmental or sensory impairments. Rates of concordance for poor language were compared between the monozygotic (MZ) and dizygotic (DZ) pairs. Concordance for the MZ pairs was .96, whereas it was .69 for the DZ pairs. The DeFries-Fulker method for computing heritability of extreme scores was employed yielding a h2g of .45. Similar results were obtained for those pairs containing only children with performance IQs above 85, but with at least one member having language below -1 SD. A comparison of DZ twins with singleton sibling pairs with at least one affected member and of similar age showed that DZ twins were more similar with respect to language achievement than singleton pairs. Thus, twinning appeared to have influenced twin resemblance among those where at least one member presented poor language achievement. These results support the hypothesis that genetic factors contribute to the liability of poor language achievement in children who do not present other developmental or sensory disorders.

The association of parental tobacco use and SLI.

Studies on specific language impairments (SLI) have demonstrated that SLI aggregate in families. This may be due to the presence of prenatal and postnatal features of a shared environment, such as parental smoking, that has been associated with lowered cognitive and language outcomes in children of smokers. This study explored the relationship between parental smoking and specific language impairments (SLI) in children. Using a case-control design, data on 177 children with SLI and 925 children who were typically developing were collected using a parental questionnaire concerning parental smoking habits. Maternal and paternal smoking during pregnancy, during children's development and continuous smoking during pregnancy and development were significantly related to SLI. However, when parental education was controlled for, these significant associations no longer existed. It is suggested that parental smoking, although not independently associated with SLI, may be an indicator of a parenting environment that places children at risk for language impairments.

Epidemiology of specific language impairment: prenatal and perinatal risk factors.

The prenatal and perinatal risk factors likely to be associated with specific language impairment (SLI) were examined in this study. A review of existing research showed that there have been few studies on this topic. Among children with SLI, greater rates of near relatives with language learning problems has been found. Data obtained from a case-control study of 177 children with SLI and 925 children without sensory, developmental disorders, or language impairment were studied using a parental questionnaire concerning exposures during the prenatal and perinatal period for the index children. Differences between the children with SLI and controls were found for parental characteristics regarding education, positive history of language and learning problems, tobacco smoking, and breast feeding. No support was found for elevated rates of maternal exposure to disease or occupational chemical substances.

Prevalence of specific language impairment in kindergarten children.

This epidemiologic study estimated the prevalence of specific language impairment (SLI) in monolingual English-speaking kindergarten children. From a stratified cluster sample in rural, urban, and suburban areas in the upper midwest, 7,218 children were screened. The language screening failure rate was 26.2%. Children who failed the screening and a similar number of controls were then administered a diagnostic battery (n = 2,084) that provided for a diagnosis of SLI using common diagnostic standards. Results provided an estimated overall prevalence rate of 7.4%. The prevalence estimate for boys was 8% and for girls 6%. Variation in prevalence was found among children of different racial/cultural backgrounds; however, these background variables were found to be correlated with parental education, which was also associated with SLI. The parents of 29% of the children identified as SLI reported they had previously been informed that their child had a speech or language problem. The prevalence estimates obtained fell within recent estimates for SLI, but demonstrated that this condition is more prevalent among females than has been previously reported. Also, the clinical identification of these children remains low among kindergarteners.

A system for the diagnosis of specific language impairment in kindergarten children.

A valid and reliable diagnostic standard for language impairment is required for the conduct of epidemiologic research on specific language disorder. A rationale is provided for such a diagnostic system labeled the EpiSLI system. This system employed five composite scores representing norm-referenced performance in three domains of language (vocabulary, grammar, and narration) and two modalities (comprehension and production). Children who have two or more composite scores below-1.25 standard deviations were considered as children with language disorder. The performance of the EpiSLI diagnostic system was examined on a sample of 1,502 kindergarten children and it was shown that this diagnostic system yielded results that were consistent with clinician rating and previous research results.

Auditory evoked responses to frequency-modulated tones in children with specific language impairment.

Averaged cortically evoked potentials to frequency-modulated tones (+/- 100 Hz around a center frequency of 1 kHz) were obtained from 12 children with SLI and 12 age-matched children who were normal language learners. It was hypothesized, based on Stefanatos, Green, and Ratcliff (1989), that the children with receptive and expressive specific language impairment (SLI) would show very small or no measurable averaged response amplitudes. Also, it was predicted that children who were normal language learners would show large response amplitudes that were both significantly greater than those obtained during a stimulus control condition and greater than those obtained from the children with SLI. The prediction concerning children with SLI proved incorrect. The responses of the children with SLI were no different from those obtained from the normal language learners, and responses from both groups were significantly greater than those obtained in the control condition. These results indicate that, with respect to neural systems involved with selective response to auditory frequency shifts of approximately 100 Hz and occurring over 250 msec, children with SLI are not different from children who are normal language learners.

Clinical decision making: describing the decision rules of practicing speech-language pathologists.

The diagnostic decision-making standards used by practicing clinicians to determine language impairment were investigated. Randomly selected ASHA members who worked with children were asked to review hypothetical and real case profiles of children ages 4 to 9:11 (years: months) with language performance skills ranging from slightly above average to substantially below average. Based on the child's age and language and intelligence test information, clinicians were asked to decide if the child was language impaired (LI) and, if so, to provide a severity rating. Results show significant interrater agreement among the 27 clinicians' LI decisions (generalized kappa = 0.14, p < .0001) and moderate intrarater reliability within clinician's LI decisions (phi = .68). Most of the clinicians' diagnostic decision-making standards could be modeled using stepwise logistic regression. These decision rules can provide guidance for those who wish to employ diagnostic standards that reflect those used in clinical practice. Also, these results provide insight into the manner in which clinicians use information for the determination of language impairment.

Diagnosing specific language impairment in adults for the purpose of pedigree analysis.

Two sets of diagnostic measures were administered to a group of 35 adults with well-documented histories of specific language impairment and to a control group of 35 normal language users. These measures involved the comprehension and production of words and sentences in formal and spontaneous speaking activities as well as measures of verbal memory and auditory temporal perceptual ability. One set of tasks was administered in a standard face-to-face setting and the other set was given over the telephone. Multivariate and univariate tests indicated that the adults with a history of specific language impairment performed more poorly on all tasks administered. A discriminant analysis of the two sets of measures indicated that four measures in each set identified language-impaired individuals with 97% accuracy for the face-to-face battery and 95% accuracy for the telephone battery. These results suggest that it should be possible to diagnose specific language impairment in the adult family members of children with specific language impairment and therefore permit accurate construction of pedigrees for specific language impairment.