Phonetic categorisation and cue weighting in adolescents with Specific Language Impairment (SLI).

This study investigates phonetic categorisation and cue weighting in adolescents and young adults with Specific Language Impairment (SLI). We manipulated two acoustic cues, vowel duration and F1 offset frequency, that signal word-final stop consonant voicing ([t] and [d]) in English. Ten individuals with SLI (14.0-21.4 years), 10 age-matched controls (CA; 14.6-21.9 years) and 10 non-matched adult controls (23.3-36.0 years) labelled synthetic CVC non-words in an identification task. The results showed that the adolescents and young adults with SLI were less consistent than controls in the identification of the good category representatives. The group with SLI also assigned less weight to vowel duration than the adult controls. However, no direct relationship between phonetic categorisation, cue weighting and language skills was found. These findings indicate that some individuals with SLI have speech perception deficits but they are not necessarily associated with oral language skills.

The biological basis of language: insight from developmental grammatical impairments.

Specific language impairment (SLI), a genetic developmental disorder, offers insights into the neurobiological and computational organization of language. A subtype, Grammatical-SLI (G-SLI), involves greater impairments in 'extended' grammatical representations, which are nonlocal, hierarchical, abstract, and composed, than in 'basic' ones, which are local, linear, semantic, and holistic. This distinction is seen in syntax, morphology, and phonology, and may be tied to abnormalities in the left hemisphere and basal ganglia, consistent with new models of the neurobiology of language which distinguish dorsal and ventral processing streams. Delineating neurolinguistic phenotypes promises a better understanding of the effects of genes on the brain circuitry underlying normal and impaired language abilities.

Early activation of Broca's area in grammar processing as revealed by the syntactic mismatch negativity and distributed source analysis.

Though activation of Broca's region in the combinatorial processing of symbols (language, music) has been revealed by neurometabolic studies, most previous neurophysiological research found the earliest grammar indices in the temporal cortex, with inferior-frontal generators becoming active at relatively late stages. We use the attention- and task-free syntactic mismatch negativity (sMMN) event-related potential (ERP) to measure rapid and automatic sensitivity of the human brain to grammatical information in participants' native language (French). Further, sources underlying the MMN were estimated by applying the Parametrical Empirical Bayesian (PEB) approach, with the Multiple Sparse Priors (MSP) technique. Results showed reliable grammar-related activation focused on Broca's region already in the 150-190 ms time window, providing robust documentation of its involvement in the first stages of syntactic processing.

Number dissimilarities facilitate the comprehension of relative clauses in children with (Grammatical) Specific Language Impairment.

This study investigates whether number dissimilarities on subject and object DPs facilitate the comprehension of subject- and object-extracted centre-embedded relative clauses in children with Grammatical Specific Language Impairment (G-SLI). We compared the performance of a group of English-speaking children with G-SLI (mean age: 12;11) with that of two groups of younger typically developing (TD) children, matched on grammar and receptive vocabulary, respectively. All groups were more accurate on subject-extracted relative clauses than object-extracted ones and, crucially, they all showed greater accuracy for sentences with dissimilar number features (i.e., one singular, one plural) on the head noun and the embedded DP. These findings are interpreted in the light of current psycholinguistic models of sentence comprehension in TD children and provide further insight into the linguistic nature of G-SLI.

Phonological deficits in specific language impairment and developmental dyslexia: towards a multidimensional model.

An on-going debate surrounds the relationship between specific language impairment and developmental dyslexia, in particular with respect to their phonological abilities. Are these distinct disorders? To what extent do they overlap? Which cognitive and linguistic profiles correspond to specific language impairment, dyslexia and comorbid cases? At least three different models have been proposed: the severity model, the additional deficit model and the component model. We address this issue by comparing children with specific language impairment only, those with dyslexia-only, those with specific language impairment and dyslexia and those with no impairment, using a broad test battery of language skills. We find that specific language impairment and dyslexia do not always co-occur, and that some children with specific language impairment do not have a phonological deficit. Using factor analysis, we find that language abilities across the four groups of children have at least three independent sources of variance: one for non-phonological language skills and two for distinct sets of phonological abilities (which we term phonological skills versus phonological representations). Furthermore, children with specific language impairment and dyslexia show partly distinct profiles of phonological deficit along these two dimensions. We conclude that a multiple-component model of language abilities best explains the relationship between specific language impairment and dyslexia and the different profiles of impairment that are observed.

Non-word repetition in adolescents with specific language impairment (SLI).

BACKGROUND: Non-word repetition (NWR) difficulties are common, but not universal, among children with specific language impairment (SLI). However, older children and adolescents with SLI have rarely been studied. Studies disagree on the relationship between NWR difficulties and difficulties with other areas of language and literacy. There is also no consensus about the underlying reason for the difficulties (some) children with SLI have with NWR. Some scholars argue that difficulties with phonological short-term memory or storage cause NWR and other language difficulties, whereas others argue that difficulties with NWR may be due more to difficulties with phonological representations. AIMS: To investigate NWR abilities and their relationship to other language and literacy abilities in a group of older children with SLI and typically developing controls. To investigate the relative effects of increasing phonological complexity and the number of syllables on the ability of the participants to repeat non-words. METHODS & PROCEDURES: An NWR test (The Test of Phonological Structure; TOPhS), which systematically varies phonological complexity, was administered to 15 participants with SLI (aged 11-15 years), 30 language and 15 age controls. Standardized language and literacy tests and a specific test of verb agreement and tense marking (Verb Agreement and Tense Test; VATT) were also administered. OUTCOMES & RESULTS: The participants with SLI showed a bimodal distribution: half achieved age-appropriate NWR, while half scored significantly below language and age controls (d > 7). The two groups of participants with SLI (high versus low scorers) only differed in NWR (d > 5) and agreement (d > 3) and tense marking (d > 2.5), not on the standardized language and literacy measures administered. NWR was also highly correlated with verb agreement (r= 0.97) and tense marking (r= 0.89) among participants with SLI, but not among controls (r= 0.16 and 0.30 respectively). Phonological complexity was related to NWR accuracy, particularly among participants with SLI. The number of syllables had no independent effect on NWR performance for any group. CONCLUSIONS & IMPLICATIONS: Some children with SLI (who have good NWR) have language difficulties unrelated to any of the factors underlying NWR. Others have a (probably additional) deficit which affects NWR and also leads to greater difficulties with verb agreement and tense marking. The results indicate that difficulties with this particular NWR test are more likely to be due to a deficit with phonology per se, rather than with phonological short-term memory or storage.

An investigation to validate the grammar and phonology screening (GAPS) test to identify children with specific language impairment.

BACKGROUND: The extraordinarily high incidence of grammatical language impairments in developmental disorders suggests that this uniquely human cognitive function is "fragile". Yet our understanding of the neurobiology of grammatical impairments is limited. Furthermore, there is no "gold-standard" to identify grammatical impairments and routine screening is not undertaken. An accurate screening test to identify grammatical abilities would serve the research, health and education communities, further our understanding of developmental disorders, and identify children who need remediation, many of whom are currently un-diagnosed. A potential realistic screening tool that could be widely administered is the Grammar and Phonology Screening (GAPS) test--a 10 minute test that can be administered by professionals and non-professionals alike. Here we provide a further step in evaluating the validity and accuracy (sensitivity and specificity) of the GAPS test in identifying children who have Specific Language Impairment (SLI). METHODS AND FINDINGS: We tested three groups of children; two groups aged 3;6-6:6, a typically developing (n = 30) group, and a group diagnosed with SLI: (n = 11) (Young (Y)-SLI), and a further group aged 6;9-8;11 with SLI (Older (O)-SLI) (n = 10) who were above the test age norms. We employed a battery of language assessments including the GAPS test to assess the children's language abilities. For Y-SLI children, analyses revealed a sensitivity and specificity at the 5(th) and 10(th) percentile of 1.00 and 0.98, respectively, and for O-SLI children at the 10(th) and 15(th) percentile .83 and .90, respectively. CONCLUSIONS: The findings reveal that the GAPS is highly accurate in identifying impaired vs. non-impaired children up to 6;8 years, and has moderate-to-high accuracy up to 9 years. The results indicate that GAPS is a realistic tool for the early identification of grammatical abilities and impairment in young children. A larger investigation is warranted in children with SLI and other developmental disorders.

Who did Buzz see someone? Grammaticality judgement of wh-questions in typically developing children and children with Grammatical-SLI.

This paper tests claims that children with Grammatical(G)-SLI are impaired in hierarchical structural dependencies at the clause level and in whatever underlies such dependencies with respect to movement, chain formation and feature checking; that is, their impairment lies in the syntactic computational system itself (the Computational Grammatical Complexity hypothesis proposed by van der Lely in previous work). We use a grammaticality judgement task to test whether G-SLI children's errors in wh-questions are due to the hypothesised impairment in syntactic dependencies at the clause level or lie in more general processes outside the syntactic system, such as working memory capacity. We compare the performance of 14 G-SLI children (aged 10-17 years) with that of 36 younger language-matched controls (aged 5-8 years). We presented matrix wh-subject and object questions balanced for wh-words (who/what/which) that were grammatical, ungrammatical, or semantically inappropriate. Ungrammatical questions contained wh-trace or T-to-C dependency violations that G-SLI children had previously produced in elicitation tasks. G-SLI children, like their language controls, correctly accepted grammatical questions, but rejected semantically inappropriate ones. However, they were significantly impaired in rejecting wh-trace and T-to-C dependency violations. The findings provide further support for the CGC hypothesis that G-SLI children have a core deficit in the computational system itself that affects syntactic dependencies at the clause level.

Grammatical feature dissimilarities make relative clauses easier: A comprehension study with Italian children.

The Relativized Minimality approach to A'-dependencies (Friedmann et al., 2009) predicts that headed object relative clauses (RCs) and which-questions are the most difficult, due to the presence of a lexical restriction on both the subject and the object DP which creates intervention. We investigated comprehension of center-embedded headed object RCs with Italian children, where Number and Gender feature values on subject and object DPs are manipulated. We found that, Number conditions are always more accurate than Gender ones, showing that intervention is sensitive to DP-internal structure. We propose a finer definition of the lexical restriction where external and syntactically active features (such as Number) reduce intervention whereas internal and (possibly) lexicalized features (such as Gender) do so to a lesser extent. Our results are also compatible with a memory interference approach in which the human parser is sensitive to highly specific properties of the linguistic input, such as the cue-based model (Van Dyke, 2007).

Assessing component language deficits in the early detection of reading difficulty risk.

This article focuses on some of the linguistic components that underlie letter-sound decoding skills and reading comprehension: specifically phonology, morphology, and syntax. Many children who have reading difficulties had language deficits that were detectable before they began reading. Early identification of language difficulties will therefore help identify children at risk of reading failure. Using a developmental psycholinguistic framework, the authors provide a model of how syntax, morphology, and phonology break down in children with language impairments. The article reports on a screening test of these language abilities for preschool or young school-aged children that identifies those at risk for literacy problems and in need of further assessment.

Backward and simultaneous masking in children with grammatical specific language impairment: no simple link between auditory and language abilities.

PURPOSE: We investigated claims that specific language impairment (SLI) typically arises from nonspeech auditory deficits by measuring tone-in-noise thresholds in a relatively homogeneous SLI subgroup exhibiting a primary deficit restricted to grammar (Grammatical[G]-SLI). METHOD: Fourteen children (mostly teenagers) with G-SLI were compared to age-, vocabulary-, and grammar-matched control children on their abilities to detect a brief tone in quiet and in the presence of a masking noise. The tone occurred either simultaneously with the noise or just preceding it (backward masking). Maskers with and without a spectral notch allowed estimates of frequency selectivity. RESULTS: Group thresholds for the G-SLI children were never worse than those obtained for younger controls but were higher in both backward and simultaneous masking than in age-matched controls. However, more than half of the G-SLI group (8/14) were within age-appropriate limits for all thresholds. Frequency selectivity in the G-SLI group was normal. Within control and G-SLI groups, no threshold correlated with measures of vocabulary, grammar, or phonology. Nor did the language deficit in the G-SLI children vary with the presence or absence of auditory deficits. CONCLUSION: The auditory processing deficits sometimes found in children with SLI appear unlikely to cause or maintain the language impairment.

Electrical brain responses in language-impaired children reveal grammar-specific deficits.

BACKGROUND: Scientific and public fascination with human language have included intensive scrutiny of language disorders as a new window onto the biological foundations of language and its evolutionary origins. Specific language impairment (SLI), which affects over 7% of children, is one such disorder. SLI has received robust scientific attention, in part because of its recent linkage to a specific gene and loci on chromosomes and in part because of the prevailing question regarding the scope of its language impairment: Does the disorder impact the general ability to segment and process language or a specific ability to compute grammar? Here we provide novel electrophysiological data showing a domain-specific deficit within the grammar of language that has been hitherto undetectable through behavioural data alone. METHODS AND FINDINGS: We presented participants with Grammatical(G)-SLI, age-matched controls, and younger child and adult controls, with questions containing syntactic violations and sentences containing semantic violations. Electrophysiological brain responses revealed a selective impairment to only neural circuitry that is specific to grammatical processing in G-SLI. Furthermore, the participants with G-SLI appeared to be partially compensating for their syntactic deficit by using neural circuitry associated with semantic processing and all non-grammar-specific and low-level auditory neural responses were normal. CONCLUSIONS: The findings indicate that grammatical neural circuitry underlying language is a developmentally unique system in the functional architecture of the brain, and this complex higher cognitive system can be selectively impaired. The findings advance fundamental understanding about how cognitive systems develop and all human language is represented and processed in the brain.

The count-mass distinction in typically developing and grammatically specifically language impaired children: new evidence on the role of syntax and semantics.

UNLABELLED: By the age of three, typically developing children can draw conceptual distinctions between "kinds of individual" and "kinds of stuff" on the basis of syntactic structures. They differ from adults only in the extent to which syntactic knowledge can be over-ridden by semantic properties of the referent. However, the relative roles of syntax and semantics in determining the nature of the count-mass distinction in language acquisition are still not well-understood. This paper contributes to this debate by studying novel noun acquisition in a subgroup of children, aged 8-15 years, with specific language impairment, whose core deficits are limited to within the grammatical system (G-SLI), We conducted two experiments: a production task and a word extension task. Such children might be expected to rely to a greater extent than their age-matched peers on semantic properties of referents in order to assign noun interpretations, since by hypothesis they have greater difficulty in accessing and utilizing syntactic category distinctions than typically developing children. In the production task, the Children with G-SLI demonstrated rigid over-application of a pluralization rule which masked even basic knowledge of semantic information about individuated objects versus non-individuated substances. Age-matched control children only performed in this way when all syntactic and conceptual/perceptual cues were neutralized. In the word extension task, which required a non-verbal response, the Children with G-SLI showed evidence of only very limited abilities to use syntactic or semantic information for word-learning. Thus, developmental deficits in the grammatical system can be seen to impact on lexical acquisition as well as syntactic development. LEARNING OUTCOMES: As a result of this activity, the reader will be able to: (1) describe how syntactic (grammatical) impairment affects the ability to use syntactic cues for lexical acquisition, resulting in difficulties representing the structure of even simple phrases; (2) discuss the interaction between language components throughout development, and the cumulative impact of impairment in one or more aspect of language, which results in secondary impairments in other parts of the system; (3) consider the effects of an impairment in the ability to use syntactic cues for narrowing down word meanings, and how this can result in a much bigger problem affecting the subtle semantics of words and word classes.

Narrative discourse in adults with high-functioning autism or Asperger syndrome.

We report a study comparing the narrative abilities of 12 adults with high-functioning autism (HFA) or Asperger Syndrome (AS) versus 12 matched controls. The study focuses on the use of referential expressions (temporal expressions and anaphoric pronouns) during a story-telling task. The aim was to assess pragmatics skills in people with HFA/AS in whom linguistic impairments are more subtle than in classic autism. We predicted no significant differences in general narrative abilities between the two groups, but specific pragmatic deficits in people with AS. We predicted they use fewer personal pronouns, temporal expressions and referential expressions, which require theory of mind abilities. Results confirmed both predictions. These findings provide initial evidence of how social impairments can produce mild linguistic impairments.

Intervention for verb argument structure in children with persistent SLI: a randomized control trial.

PURPOSE: The authors aimed to establish whether 2 theoretically motivated interventions could improve use of verb argument structure in pupils with persistent specific language impairment (SLI). METHOD: Twenty-seven pupils with SLI (ages 11;0-16;1) participated in this randomized controlled trial with "blind" assessment. Participants were randomly assigned to 1 of 3 therapy groups: syntactic-semantic, semantic, and control. All pupils received 9 weekly half-hour individual therapy sessions. They were assessed on a specifically designed video test pretherapy, posttherapy, and at follow-up. RESULTS: Pupils receiving the syntactic-semantic and semantic therapies made significant progress (d>1.0), which was maintained at follow-up and generalized to control verbs. Both therapies improved linking of arguments to syntax, and the syntactic-semantic therapy tended to increase use of optional arguments. Pupils receiving the control therapy made no progress. CONCLUSION: Both methods of argument structure therapy were effective. Comparisons of their effectiveness in specific areas led to the hypotheses that the pupils' initial difficulties with linking resulted from ill-defined semantic representations, whereas their limited use of arguments may have resulted from syntactic difficulties. When therapy is theoretically grounded, it can inform theories, be time limited, and be effective for older children with SLI.

On-line processing of wh-questions in children with G-SLI and typically developing children.

BACKGROUND: The computational grammatical complexity (CGC) hypothesis claims that children with G(rammatical)-specific language impairment (SLI) have a domain-specific deficit in the computational system affecting syntactic dependencies involving 'movement'. One type of such syntactic dependencies is filler-gap dependencies. In contrast, the Generalized Slowing Hypothesis claims that SLI children have a domain-general deficit affecting processing speed and capacity. AIMS: To test contrasting accounts of SLI we investigate processing of syntactic (filler-gap) dependencies in wh-questions. METHODS & PROCEDURES: Fourteen 10;2-17;2 G-SLI children, 14 age-matched and 17 vocabulary-matched controls were studied using the cross-modal picture-priming paradigm. OUTCOMES & RESULTS: G-SLI children's processing speed was significantly slower than the age controls, but not younger vocabulary controls. The G-SLI children and vocabulary controls did not differ on memory span. However, the typically developing and G-SLI children showed a qualitatively different processing pattern. The age and vocabulary controls showed priming at the gap, indicating that they process wh-questions through syntactic filler-gap dependencies. In contrast, G-SLI children showed priming only at the verb. CONCLUSIONS: The findings indicate that G-SLI children fail to establish reliably a syntactic filler-gap dependency and instead interpret wh-questions via lexical-thematic information. These data challenge the Generalized Slowing Hypothesis account, but support the CGC hypothesis, according to which G-SLI children have a particular deficit in the computational system affecting syntactic dependencies involving 'movement'. As effective remediation often depends on aetiological insight, the discovery of the nature of the syntactic deficit, along side a possible compensatory use of semantics to facilitate sentence processing, can be used to direct therapy. However, the therapeutic strategy to be used, and whether such similar strengths and weaknesses within the language system are found in other SLI subgroups are empirical issues that warrant further research.

Development of the Grammar and Phonology Screening (GAPS) test to assess key markers of specific language and literacy difficulties in young children.

BACKGROUND: Despite a large body of evidence regarding reliable indicators of language deficits in young children, there has not been a standardized, quick screen for language impairment. The Grammar and Phonology Screening (GAPS) test was therefore designed as a short, reliable assessment of young children's language abilities. AIMS: GAPS was designed to provide a quick screening test to assess whether pre- and early school entry children have the necessary grammar and pre-reading phonological skills needed for education and social development. This paper reports the theoretical background to the test, the pilot study and reliability, and the standardization. METHODS: This 10-min test comprises 11 test sentences and eight test nonsense words for direct imitation and is designed to highlight significant markers of language impairment and reading difficulties. To standardize the GAPS, 668 children aged 3.4-6.6 were tested across the UK, taking into account population distribution and socio-economic status. The test was carried out by a range of health and education professionals as well as by students and carers using only simple, written instructions. RESULTS: GAPS is effective in detecting a range of children in need of further in-depth assessment or monitoring for language difficulties. The results concur with those from much larger epidemiological studies using lengthy testing procedures. CONCLUSIONS: The GAPS test (1) provides a successful screening tool; (2) is designed to be administered by professionals and non-professionals alike; and (3) facilitates identification of language impairment or at-risk factors of reading impairment in the early educational years. Thus, the test affords a first step in a process of assessment and targeted intervention to enable children to reach their potential.

A challenge to current models of past tense inflection: the impact of phonotactics.

Is past tense production better modelled by a Single Mechanism or a Words and Rules model? We present data concerning a phenomenon that has not been considered by either model-regular past tense verbs with contrasting phonotactics. One set of verbs contains clusters at the inflected verb end that also occur in monomorphemic words ('monomorphemically legal clusters', MLC) whereas the other has clusters that can only occur in inflected forms ('monomorphemically illegal clusters', MIC). We argue that if children apply a morphological rule, phonotactics will not affect performance. Conversely, if children store past tense forms, they will perform better on verbs with MLCs because these clusters are more frequent. We investigated three populations--typically developing children, Grammatical-SLI (G-SLI) and Williams Syndrome (WS)--using past tense elicitation tasks. In Experiment 1 we reanalyse data from van der Lely and Ullman [van der Lely, H. K. J. & Ullman, M. (2001). Past tense morphology in specifically language impaired and normally developing children. Language and Cognitive Processes, 16: 177-217] and show that G-SLI children perform better on MLC verbs, whereas for typically developing children phonotactics do not affect performance. In Experiment 2 we replicate these findings in new groups of G-SLI and typically developing children. In Experiment 3 we reanalyse data from Thomas et al. [Thomas, M. S. C., Grant, J., Barham, Z., Gsodl, M., Laing, E., Lakusta, L., Tyler, L.K., Grice, S., Paterson, S. & Karmiloff-Smith, A. (2001) Past tense formation in Williams Syndrome. Language and Cognitive Processes, 16: 143-176] and show that phonotactics do not affect performance in individuals with WS. We argue that the results elucidate the underlying nature of morphology in these populations, and are better accommodated within a Words and Rules model of past tense acquisition.

Domain-specific cognitive systems: insight from Grammatical-SLI.

Specific language-impairment (SLI) is a disorder of language acquisition in children who otherwise appear to be normally developing. Controversy surrounds whether SLI results from impairment to a "domain-specific" system devoted to language itself or from some more "domain-general" system. I compare these two views of SLI, and focus on three components of grammar that are good candidates for domain-specificity: syntax, morphology and phonology. I argue that the disorder is heterogeneous, and that deficits of different subgroups potentially stem from different underlying causes. Interestingly, although poor sensory or non-verbal abilities often co-occur with SLI, there is no evidence that these impairments cause the grammatical deficits found in SLI. Moreover, evidence suggests that impairment in at least one subgroup is specific to grammar.

Grammatical language impairment and the specificity of cognitive domains: relations between auditory and language abilities.

Grammatical-specific language impairment (G-SLI) in children, arguably, provides evidence for the existence of a specialised grammatical sub-system in the brain, necessary for normal language development. Some researchers challenge this, claiming that domain-general, low-level auditory deficits, particular to rapid processing, cause phonological deficits and thereby SLI. We investigate this possibility by testing the auditory discrimination abilities of G-SLI children for speech and non-speech sounds, at varying presentation rates, and controlling for the effects of age and language on performance. For non-speech formant transitions, 69% of the G-SLI children showed normal auditory processing, whereas for the same acoustic information in speech, only 31% did so. For rapidly presented tones, 46% of the G-SLI children performed normally. Auditory performance with speech and non-speech sounds differentiated the G-SLI children from their age-matched controls, whereas speed of processing did not. The G-SLI children evinced no relationship between their auditory and phonological/grammatical abilities. We found no consistent evidence that a deficit in processing rapid acoustic information causes or maintains G-SLI. The findings, from at least those G-SLI children who do not exhibit any auditory deficits, provide further evidence supporting the existence of a primary domain-specific deficit underlying G-SLI.