General slowing in language impairment: methodological considerations in testing the hypothesis.

Although the general slowing hypothesis of language impairment (LI) is well established, the conventional method to test the hypothesis is controversial. This paper compares the usual method, ordinary least squares regression (OLS), with another method, hierarchical linear modeling with random coefficients (HLM). The analyses used available response time (RT) data from studies of perceptual-motor, cognitive, and language skills of LI and chronological-age-matched (CA) groups. The data set included RT measures from 25 studies investigating 20 different tasks (e.g., auditory detection, mental rotation, and word recognition tasks). OLS and HLM analyses of the RT data yielded very different results. OLS supported general slowing for the LI groups, and indicated that they were significantly slower than CA groups across studies by an overall estimate of 10%. HLM indicated a larger average extent of LI slowing (18%). However, the variability around this average was much greater than that yielded by OLS, and the extent of slowing was not statistically significant. Importantly, HLM showed a significant difference in the RT relation between LI and CA groups across studies, indicating that study-specific slowing, rather than general slowing across studies, was present. A separate HLM analysis of two types of language tasks, picture naming and word recognition, was performed. Although the extent of slowing was equivalent across these tasks, the slowing was minimal (2%) and not significant. Methodological limitations of each analysis to assess general slowing are highlighted.     

Lexico-semantic processing in children with specific language impairment: The overactivation hypothesis

The hypothesis indicating an overactivation of the lexico-semantic network in children with specific language impairment (SLI) was tested using an auditory pair-primed paradigm (PPP), where participants made a lexical-decision on the second word of a noun pair that could be semantically related, or not, to the first one. Though children with SLI were proven to be as accurate as children matched for receptive vocabulary age, they presented a larger priming effect in the PPP in terms of both reaction time and accuracy. These results preliminarily support the hypothesis of an overactivation of the lexico-semantic network.Learning outcomes: As a result of reading this paper the reader will be able to (1) understand how the pair-primed paradigm can contribute to investigate the online spreading of the activation within the lexico-semantic network; (2) be aware of the fact that during development it is unlikely that some cognitive domain are completely typical (residual normality), while others develop atypically; (3) the reader will be aware that children with SLI present some subtle abnormalities in the lexico-semantic network, which appears to be overactive.     

Familial aggregation in specific language impairment.

A case-control family study design, in which the current language-related abilities of all biological, primary relatives (mother, father, siblings) of probands with specific language impairment (SLI) and matched controls were assessed, was used to investigate familial aggregation for language disorders. Current test data from each family member showed the rate of language impairment for mothers, fathers, sisters, and brothers of the SLI probands to be significantly higher than for members of control families. Impairment rates for fathers and mothers were approximately equal, whereas rates for brothers were significantly higher than for sisters. In SLI proband families, Language Impairment (LI) occurred in 13.0% of offspring (excluding proband) with neither parent affected, 40% of offspring with one parent affected, and 71.4% of offspring in families in which both parents were language impaired. Rates of impairment as determined in current testing were compared directly to impairment rates estimated from family-history questionnaires collected from the same families. Group data showed impairment rates estimated from the family-history questionnaires to be similar to the rates based on actual testing. Furthermore, both appeared in line with rates based primarily on questionnaire data as reported previously in the literature. However, case-by-case analyses showed poor intrasubject agreement on classification as language impaired on the basis of current testing as compared to history information.     

Visuospatial immediate memory in specific language impairment.

PURPOSE: Investigations of the cognitive processes underlying specific language impairment (SLI) have implicated deficits in verbal short-term and working memory and in particular the storage and processing of phonological information. This study investigated short-term and working memory for visuospatial material for a group of children with SLI, to test whether the verbal memory impairments already established extend to the visuospatial domain. METHOD: Fifteen children with SLI and control groups of children matched on chronological age and language age completed tests of visuospatial short-term and working memory. RESULTS: The SLI group performed comparably with age-matched control children on all measures and at a higher level than the language-age control group on several measures. CONCLUSIONS: The visuospatial short-term and working memory abilities were at age-appropriate levels in this SLI group. This contrasts markedly with their impairments on tests of verbal short-term and working memory.     

Self-esteem in children with specific language impairment.

The purpose of this preliminary study was to probe the self-perceptions of a group of children with specific language impairment (SLI) and their typically developing peers. A measure of self-esteem was administered to 46 children between the ages of 6 and 9 years old and 34 children between the ages 10 and 13. In the younger group, there were no statistically significant differences between children with SLI and typically developing children in the way they perceived themselves across domains of competence and acceptance. In the older group, children with SLI perceived themselves more negatively in scholastic competence, social acceptance, and behavioral conduct than did children with typical language development. Differences were evident in areas that were most affected by language impairment.     

Familial aggregation in specific language impairment

Self-report data from the families of children participating in the San Diego Longitudinal Study of specific developmental language impairment were used to assess familial aggregation in the disorder. Families of impaired children reported higher rates of affected first-degree relatives than did families of matched controls. Significantly higher incidence of maternal and paternal childhood language and/or learning disabilities, as well as sibling disability rates, were reported. The extent to which familial aggregation reflects genetic or environmental influences in specific language disorders remains to be determined.     

Nonmainstream dialect use and specific language impairment.

Most work looking at specific language impairment (SLI) has been done in the context of mainstream dialects. This paper extends the study of SLI to two nonmainstream dialects: a rural version of Southern African American English (SAAE) and a rural version of Southern White English (SWE). Data were language samples from 93 4- to 6-year-olds who lived in southeastern Louisiana. Forty were classified as speakers of SAAE, and 53 were classified as speakers of SWE. A third were previously diagnosed as SLI; the others served as either age-matched (6N) or language-matched (4N) controls. The two dialects differed in frequency of usage on 14 of the 35 coded morphosyntactic surface patterns; speakers of these dialects could be successfully discriminated (94%) from each other in a discriminant analysis using just four of these patterns. Across dialects, four patterns resulted in main effects that were related to diagnostic condition (SLI vs. 6N), and a slightly different set of four patterns showed effects that were related to developmental processes (4N vs. 6N). More interestingly, the surface characteristics of SLI were found to manifest in the two dialects in different ways. A discriminant function based solely on SAAE speakers tended to misclassify SWE children with SLI as having normal language, and a discriminant function based on SWE speakers tended to misclassify SAAE unaffected children as SLI. Patterns within the SLI profile that cut across the two dialects included difficulties with tense marking and question formation. The results provide important direction for future studies and argue for the inclusion of contrastive as well as noncontrastive features of dialects within SLI research.     

Basic auditory processing skills and specific language impairment: a new look at an old hypothesis.

PURPOSE: To explore the sensitivity of children with specific language impairment (SLI) to amplitude-modulated and durational cues that are important for perceiving suprasegmental speech rhythm and stress patterns. METHOD: Sixty-three children between 7 and 11 years of age were tested, 21 of whom had a diagnosis of SLI, 21 of whom were matched for chronological age to the SLI sample, and 21 of whom were matched for language age to the SLI sample. All children received a battery of nonspeech auditory processing tasks along with standardized measures of phonology and language. RESULTS: As many as 70%-80% of children diagnosed with SLI were found to perform below the 5th percentile of age-matched controls in auditory processing tasks measuring sensitivity to amplitude envelope rise time and sound duration. Furthermore, individual differences in sensitivity to these cues predicted unique variance in language and literacy attainment, even when age, nonverbal IQ, and task-related (attentional) factors were controlled. CONCLUSION: Many children with SLI have auditory processing difficulties, but for most children, these are not specific to brief, rapidly successive acoustic cues. Instead, sensitivity to durational and amplitude envelope cues appear to predict language and literacy outcomes more strongly. This finding now requires replication and exploration in languages other than English.     

Working memory capacity and language processes in children with specific language impairment.

This study examined the interaction between working memory and language comprehension in children with specific language impairment (SLI), focusing on the function of the central executive component and its interaction with the phonological loop (A. D. Baddeley, 1986) in complex working memory tasks. Thirteen children with SLI and 13 age-matched (age range = 7;0 [years;months] to 10;0) children with typical language development participated. The tasks combined traditional nonword repetition tests and sentence comprehension by using sentences that differed in length and syntactic complexity. The children with SLI exhibited larger processing and attentional capacity limitations than their age-matched peers. Increased word length and syntactic complexity resulted in a large performance decrease in nonword repetition in both groups. There were some variations in the error pattern, which may indicate qualitative differences between the 2 groups. The performance of the children with SLI in nonword repetition, across the different tasks, indicated a limitation in simultaneous processing rather than difficulty in encoding and analyzing the phonological structure of the nonwords. Furthermore, syntactic complexity had a greater effect on performance accuracy than did sentence length.     

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.     

Naming errors of children with specific language impairment.

This paper explores why children with SLI are less accurate than peers in naming pictures. Subjects included 66 children with SLI (aged 4:3 to 9:7) with 2 subgroups, one with expressive-only language deficits (SLIexp) and one with receptive and expressive language deficits (SLImix), and 66 children with no language impairment (NLI). Children with SLI made more errors than children with NLI, and proportionally more of their errors were names of objects associated with the pictured object (e.g., shoe/foot) and names that were phonologically related to the target than were those with NLI. The relative frequency of error types was related to pattern of language deficit; in comparison to their NLI peers, a greater proportion of SLIexp errors were phonological errors, and a greater proportion of the SLImix errors were semantic associated, semantic perceptual, and nonsemantic perseverative. The proportion of semantic-associated errors also discriminated a subgroup of the children with SLI from a matched subgroup of the children with SLImix. Interpretations and potential implications are discussed.     

Grammatical morphology and the lexicon in children with specific language impairment.

We examined the use of grammatical morphology by preschool-age English-speaking children with specific language impairment (SLI) as a function of their lexical diversity. Relative to a group of normally developing (ND) preschoolers, these children's use of finite-verb morphology logged behind expectations based on the number of different verbs they used. Noun-related morphology fell below expectations based on overall lexical diversity. Differences between the ND children and children with SLI were also seen for the slope of the increases in finite-verb morphology as a function of lexical diversity, with shallower slopes in the SLI data. The findings of this study add to existing evidence suggesting that a measure of finite grammatical-morphology use has promise as a clinical marker of SLI in English.     

Grammatical morphology deficits in Spanish-speaking children with specific language impairment.

The focus of this study was the use of grammatical morphology by Spanish-speaking preschoolers with specific language impairment (SU). Relative to both same-age peers and younger typically developing children with similar mean lengths of utterance (MLUs), the children with SU showed more limited use of several different grammatical morphemes. These limitations were most marked for noun-related morphemes such as adjective-agreement inflections and direct object clitics. Most errors on the part of children in all groups consisted of substitutions of a form that shared most but not all of the targets grammatical features (e.g., correct tense and number but incorrect person). Number errors usually involved singular forms used in plural contexts; person errors usually involved third person forms used in first person contexts. The pattern of limitations of the children with SU suggests that, for languages such as Spanish, additional factors might have to be considered in the search for clinical markers for this disorder. Implications for evaluation and treatment of language disorders in Spanish-speaking children are also discussed.     

The comprehension of wh-questions in children with specific language impairment.

Current theories of specific language impairment (SLI) in children fall into 2 general classes: those that attribute SLI to processing limitations and those that attribute the disorder to deficits in grammatical knowledge. In this study, the authors examined children's comprehension of subject and object Wh-questions because they offer the means of determining the relative contribution to performance of knowledge and of processing. Comprehension of subject and object Wh-questions presumably requires knowledge of grammatical movement. However, through manipulation of the length of the questions, it is also possible to vary the processing demands of the questions. If a simple deficit in knowledge of movement is involved, children should show poorer comprehension on object questions than on subject questions, regardless of sentence length. However, if processing limitations are involved, length should affect comprehension of object questions but not subject questions. Children with SLI and typically developing (TD) children matched on receptive vocabulary test scores participated in a comprehension task consisting of short and long subject and object Wh-questions. The two groups performed similarly on short questions, each showing high accuracy in both subject and object conditions. However, the children with SLI showed poorer performance on long object questions compared to long subject questions. They were also less accurate on long object questions than were children in the TD group. We argue that demands on linguistic processing abilities play an important role in the difficulties experienced by children with SLI.     

Verb agreement morphology in Hebrew-speaking children with specific language impairment.

Earlier reports of verb morphology use by Hebrew-speaking children with specific language impairment (SLI) have suggested that these children mark agreement with the subject as accurately as younger control children matched according to mean length of utterance (MLU). This issue was examined in greater detail in the present study by including a wider range of agreement inflections from the present and past tense paradigms and employing verbs of different patterns (binyanim). It was hypothesized that children with SLI would be more limited than would MLU controls in their use of agreement inflections within past tense because the past tense agreement paradigm of Hebrew requires the simultaneous manipulation of three features-person, number, and gender. Differences between the groups were not expected for the use of agreement inflections within present tense, because only two features-number and gender-must be manipulated in the present tense paradigm. A group of preschool-age children with SLI was found to have more difficulty than did MLU controls in the use of most past tense agreement inflections. Within present tense, the two groups differed in their use of agreement inflections in only one pattern. For both groups, most errant productions differed from the target form by only one feature, usually person or tense. We found no feature that was consistently problematic for the children. The findings are discussed within a limited processing capacity framework.     

Semantic representation and naming in children with specific language impairment.

When 16 children with SLI (mean age = 6;2) and 16 normally developing age-mates named age-appropriate objects, the SLI cohort made more naming errors. For both cohorts, semantic misnaming and indeterminate responses were the predominant error types. The contribution of limited semantic representation to these naming errors was explored. Each participant drew and defined each item from his or her semantic and indeterminate error pools and each item from his or her correctly named pool. When compared, the drawings and definitions of items from the error pools were poorer, suggesting limited semantic knowledge. The profiles of information included in definitions of items from the correct pool and the error pools were highly similar, suggesting that representations associated with misnaming differed quanlitatively, but not qualitatively, from those associated with correct naming. Eleven members of the SLI cohort also participated in a forced-choice recognition task. Performance was significantly lower on erroneous targets than on correctly named targets. When performance was compared across all three post-naming tasks (drawing, defining, recognition), the participants evinced sparse semantic knowledge for roughly half of all semantic misnaming and roughly one third of all indeterminate responses. In additional cases, representational gaps were evident. This study demonstrates that the degree of knowledge represented in the child's semantic lexicon makes words more or less vulnerable to retrieval failure and that limited semantic knowledge contributes to the frequent naming errors of children with SLI.     

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.     

Speech disruptions in the narratives of english-speaking children with specific language impairment.

PURPOSE: This study examined the types, frequencies, and distribution of speech disruptions in the spoken narratives of children with specific language impairment (SLI) and their age-matched (CA) and language-matched (LA) peers. METHOD: Twenty 4th-grade children with SLI, 20 typically developing CA children, and 20 younger typically developing LA children were included in this study. Speech disruptions (i.e., silent pauses and vocal hesitations) occurring in the narratives of these children were analyzed. RESULTS: Children with SLI exhibited speech disruption rates that were higher than those of their age-matched peers but not higher than those of their language-matched peers. The difference in disruption rates between the SLI and CA groups was restricted to silent pauses of 500-1000 ms. Moreover, children with SLI produced more speech disruptions than their peers before phrases but not before sentences, clauses, or words. CONCLUSIONS: These findings suggest that there is a relationship between language ability and speech disruptions. Higher disruption rates at phrase boundaries in children with SLI than in their age-matched peers reflect lexical and syntactic deficits in children with SLI.     

Basic numeracy in children with specific language impairment: heterogeneity and connections to language.

PURPOSE: This study examined basic numerical skills in children with specific language impairment (SLI) and how well linguistic factors explain the variance in these children's number skills. METHOD: The performance of children with SLI (n=29) was compared with that of typically developing children along a continuum ranging from preschool to 3rd grade (n=20, 47, 40, and 33). This facilitated both linguistic and educational age comparisons. To study number skills within the SLI group more closely, this group was divided into subgroups on the basis of their performance in verbal and nonverbal numerical skills. The performance of the different SLI subgroups on the linguistic and nonverbal reasoning task was analyzed. RESULTS: As a single group, the children with SLI lagged behind their educational age controls in both verbal and nonverbal numerical skills. Subgroup analyses revealed that the ability to retrieve arithmetic facts from the memory was connected to naming fluency, whereas the differences in nonverbal numerical skills were not explained by the cognitive skills measured (nonverbal reasoning skill, verbal short-term memory, vocabulary, comprehension, and naming fluency). CONCLUSIONS: This study demonstrates that children with SLI form a very heterogeneous group in their numerical skills, and thus specific hypotheses concerning the influence of linguistic deficits on developing numerical skills are required. The cognitive components of serial naming speed present a promising domain for further exploration.