Testing the generalized slowing hypothesis in specific language impairment

Speed of processing in Developmental Language Disorder (DLD): The case of real-time grammatical processing

BACKGROUND

Developmental Language Disorder (DLD) impacts various aspects of children's language abilities, including the processing of inflectional morphology. Prior research suggests that children with DLD exhibit deficits in processing speed and sensitivity to grammatical inflections, yet the relationship between these deficits remains unclear.

AIMS

This study aimed to investigate the relationship between processing speed and sensitivity to inflectional morphology in children with DLD, focusing on their real-time processing abilities in response to regular past tense, third person singular, and regular plural inflections at different rates of sentence articulation.

METHOD

Eighteen children with DLD and 18 age-matched controls underwent word monitoring tasks that assessed sensitivity to grammaticality of inflections in sentences presented at normal and slow rates of articulation.

RESULTS

At a normal rate of articulation, children with DLD demonstrated slower response times and reduced sensitivity to grammaticality across all inflections compared to controls. When the articulation rate was slowed, children with DLD showed improved sensitivity, particularly to regular plural and third person singular inflections, although deficits in processing the regular past tense persisted.

CONCLUSIONS

The findings suggest a significant relationship between processing speed and inflectional morphology sensitivity in children with DLD. Slower articulation rates improved grammatical sensitivity for certain inflections, highlighting the potential of tailored interventions that consider processing speed limitations. Persistent difficulties with the regular past tense inflection indicate the need for targeted support for children with DLD in this area.

WHAT THIS PAPER ADDS

What is already known on this subject Children with Developmental Language Disorder (DLD) have a wide range of language difficulties, but deficits in inflectional morphology are regarded as a 'hallmark' of the disorder. Children with DLD are also very likely to show deficits in speed of processing, although it is not known if a 'slowness to process' can causally explain the language difficulties these children experience. What this study adds to existing knowledge When grammatical sensitivity was measured using an online real-time task, children with DLD showed widespread inflectional deficits when sentences were spoken at a normal conversational rate. When sentence articulation rate was slowed down, children with DLD were faster, more accurate and more sensitive to the grammaticality of constructions. However, deficits in the regular past tense remained persistent, even in this slow-rate condition. What are the clinical implications of this work? This study has implications for clinical and educational practices that work with children with DLD to improve their language skills. The findings of this study show that when children with DLD are given more time to process incoming information, their grammatical skills significantly improve. This study also shows that deficits in the regular past tense are persistent, and children are likely need extensive and intensive support with this particular grammatical feature.

Cognitive Processes Related to Memory Capacity Explain Nearly All of the Variance in Language Test Performance in School-Age Children With and Without Developmental Language Disorder

The purpose of this study was to investigate the dimensionality of the cognitive processes related to memory capacity and language ability and to assess the magnitude of the relationships among these processes in children developing typically (TD) and children with developmental language disorder (DLD). Participants were 234 children between the ages of 7;0 and 11;11 (117 TD and 117 DLD) who were propensity matched on age, sex, mother education and family income. Latent variables created from cognitive processing tasks and standardized measures of comprehension and production of lexical and sentential aspects of language were tested with confirmatory factor analysis (CFA) and structural regression. A five-factor CFA model that included the constructs of Fluid Intelligence, Controlled Attention, Working Memory, Long-Term Memory for Language Knowledge and Language Ability yielded better fit statistics than two four-factor nested models. The four cognitive abilities accounted for more than 92% of the variance in the language measures. A structural regression model indicated that the relationship between working memory and language ability was significantly greater for the TD group than the DLD group. These results are consistent with a broad conceptualization of the nature of language impairment in older, school-age children as encompassing a dynamic system in which cognitive abilities account for nearly all of the variance in linguistic abilities.

Lexical Access in Persian Speaking Children With and Without Specific Language Impairment

INTRODUCTION

Word retrieval problems are among the limitations observed in children with specific language impairment during the initial schooling years. These restrictions are predictive of reading problems and poor performance at school. Additionally, studies on lexical access in Persian speaking children are scarce. Therefore, this study aimed to investigate and compare naming accuracy and latency in children with and without specific language impairment.

METHODS

Twenty 7-9-year-old children with specific language impairment and 20 age-matched peers were recruited as the study participants. They were requested to name the 128 black and white line-drawing pictures from a Persian picture naming set for children, as rapidly as possible. We compared the effects of psycholinguistic variables on naming latency in the explored children with and without specific language impairment.

RESULTS

Linear mixed-effects modeling presented an interaction between the research groups and the psycholinguistic variables. Significant main effects were found for name agreement (P≤0.00) and the age of acquisition (P=0.05) in children with typical language development; significant effects for name agreement (P≤0.00) and log frequency (P≤0.00) were revealed in children with specific language impairment.

CONCLUSION

The obtained models indicated that psycholinguistic factors could differently affect the naming latency in children with and without specific language impairment. Factors that may have accounted for the findings are discussed in this paper.

Word Retrieval Difficulties and Cognitive Control in Specific Language Impairment

Purpose The study aims to test whether children with specific language impairment (SLI) show weaknesses in word retrieval and cognitive control and to find out whether impairments in the 2 domains are associated. Method Thirty-one children with SLI (age: M = 8;11 years;months, SD = 1;1) and 31 age- and IQ-matched typically developing children completed 2 word retrieval tasks and 3 cognitive control tasks. Word retrieval was assessed with a fluency task and a rapid automatized naming (RAN) task, whereas cognitive control was measured with a backward digit span, an n-back task, and a Stroop task. Results We found weaker performance in the SLI group than in the typically developing group in all the fluency conditions and in the size-color-shape RAN as well as on the backward digit span and n-back tasks. Performance on the letter fluency task was associated with backward digit span, whereas size-color-shape RAN performance was associated with backward digit span and n-back scores. Testing the relative contribution of the 3 cognitive control tasks together with verbal short-term memory span and vocabulary size showed that performance on both word retrieval tasks was best explained by nonword repetition and backward digit span measures. Conclusions These results suggest that both word retrieval and cognitive control are impaired in SLI and weaker cognitive control may contribute to word retrieval problems, although weaker short-term memory also has a crucial contribution to word retrieval difficulties during these tasks. If further research confirms this association with cognitive control, training of this ability should be included in the therapy of at least some children with SLI.

Modeling the Early Language Trajectory of Language Development When the Measures Change and Its Relation to Poor Reading Comprehension

This study examined change in early language comprehension from 15 to 54 months for fifth-grade typical readers (n = 35), poor decoders (n = 11), or poor comprehenders (n = 16) from a nationally representative study of early child-care experiences. Changing measures of language comprehension were captured across early childhood for the 62 children. Multiple-group quasi-simplex and latent growth models were used on rank-transformed outcomes to examine children's relative rank change. Results showed that future poor comprehenders significantly declined in language comprehension over time relative to others who gradually improved. Efforts to improve language skills as a means to improve reading comprehension hinge upon the perspective that language weaknesses are a causal contributor to reading difficulties.

Novel Morpheme Learning in Monolingual and Bilingual Children

PURPOSE

The purpose of the present study was to examine the utility of a novel morpheme learning task for indexing typical language abilities in children characterized by diverse language backgrounds.

METHOD

Three groups of 5- to 6-year-old children were tested: monolingual speakers of English, native speakers of Spanish who also spoke English (Spanish-L1 bilinguals), and native speakers of English who also spoke Spanish (English-L1 bilinguals). All children were taught a new derivational morpheme /ku/ marking part-whole distinction in conjunction with English nouns. Retention was measured via a receptive task, and sensitivity and reaction time (RT) data were collected.

RESULTS

All three groups of children learned the novel morpheme successfully and were able to generalize its use to untaught nouns. Furthermore, language characteristics (degree of exposure and levels of performance on standardized measures) did not contribute to bilingual children's learning outcomes.

CONCLUSION

Together, the findings indicate that this particular version of the novel morpheme learning task may be resistant to influences associated with language background and suggest potential usefulness of the task to clinical practice.

Semantic Processing of Sentences in Preschoolers With Specific Language Impairment: Evidence From the N400 Effect

PURPOSE

Given the complexity of sentence processing and the specific problems that children with specific language impairment (SLI) experience, we investigated the time course and characteristics of semantic processing at the sentence level in Dutch preschoolers with SLI.

METHOD

We measured N400 responses to semantically congruent and incongruent spoken sentences (e.g., "My father is eating an apple/*blanket") in a group of 37 Dutch preschoolers with SLI and in a group of 25 typically developing (TD) peers. We compared the time course and amplitude of the N400 effect between the two groups.

RESULTS

The TD group showed a strong posterior N400 effect in time windows 300-500 ms and 500-800 ms. In contrast, the SLI group demonstrated only a reliable N400 effect in the later time window, 500-800 ms, and did not show a stronger presence at posterior electrodes.

CONCLUSION

The findings suggest that the neuronal processing of semantic information at sentence level is atypical in preschoolers with SLI compared with TD children.

Lexical conflict resolution in children with specific language impairment

The aim of our study is to examine the effect of conflict on naming latencies in children with specific language impairment (SLI) and typically developing (TD) children and to explore whether deficits in conflict resolution contribute to lexical problems in SLI. In light of previous results showing difficulties with inhibitory functions in SLI, we expected higher semantic conflict effect in the SLI than in the TD group. To investigate this question 13 children with SLI and 13 age- and gender-matched TD children performed a picture naming task in which the level of conflict was manipulated and naming latencies were measured. Children took longer to name pictures in high conflict conditions than in low conflict conditions. This effect was equally present in the SLI and TD groups. Our results suggest that word production is more effortful for children when conflict resolution is required but children with SLI manage competing lexical representations as efficiently as TD children. This result contradicts studies, which found difficulties with inhibitory functions and is in line with findings of intact inhibitory abilities in children with SLI. Further studies should rule out the possibility that in SLI lower level of conflict resulting from weaker lexical representations masks impairments in inhibition, and investigate the effect of linguistic conflict in other areas.

Language Impairment in the Attention-Deficit/Hyperactivity Disorder Context

PURPOSE

Attention-deficit/hyperactivity disorder (ADHD) is a ubiquitous designation that affects the identification, assessment, treatment, and study of pediatric language impairments (LIs).

METHOD

Current literature is reviewed in 4 areas: (a) the capacity of psycholinguistic, neuropsychological, and socioemotional behavioral indices to differentiate cases of LI from ADHD; (b) the impact of co-occurring ADHD on children's LI; (c) cross-etiology comparisons of the nonlinguistic abilities of children with ADHD and specific LI (SLI); and (d) the extent to which ADHD contributes to educational and health disparities among individuals with LI.

RESULTS

Evidence is presented demonstrating the value of using adjusted parent ratings of ADHD symptoms and targeted assessments of children's tense marking, nonword repetition, and sentence recall for differential diagnosis and the identification of comorbidity. Reports suggest that the presence of ADHD does not aggravate children's LI. The potential value of cross-etiology comparisons testing the necessity and sufficiency of proposed nonlinguistic contributors to the etiology of SLI is demonstrated through key studies. Reports suggest that children with comorbid ADHD+LI receive speech-language services at a higher rate than children with SLI.

CONCLUSION

The ADHD context is multifaceted and provides the management and study of LI with both opportunities and obstacles.

Kognitive Kompetenzen und Sprachentwicklung bei Kindern im Alter zwischen vier und fünf Jahren

Zusammenfassung. Ziel der vorliegenden Studie ist es den Zusammenhang von verschiedenen kognitiven Basiskompetenzen und sprachlichen Fähigkeiten bei Vorschülern zu untersuchen. Verglichen werden die kognitiven Kompetenzen von Kindern mit niedrigen Leistungen im Wortschatz und/oder in der Grammatik (n = 69) und einer sprachlich unbeeinträchtigten Vergleichsgruppe (n = 69). Weiter wird eine multiple hierarchische Regressionsanalyse gerechnet um die Bedeutung von kognitiven Basiskompetenzen für die Pragmatik zu untersuchen. Insgesamt zeigt sich, dass die Vergleichsgruppe über bessere kognitive Fähigkeiten verfügt als die Risikogruppe, insbesondere in der Verarbeitungsgeschwindigkeit. Im Bereich Pragmatik konnte das Arbeitsgedächtnis als wichtiger Prädiktor identifiziert werden. Anhand der Analysen wird deutlich, dass kognitive Basiskompetenzen für verschiedene sprachliche Bereiche von Bedeutung sind.

Control of Auditory Attention in Children With Specific Language Impairment

PURPOSE

Children with specific language impairment (SLI) appear to demonstrate deficits in attention and its control. Selective attention involves the cognitive control of attention directed toward a relevant stimulus and simultaneous inhibition of attention toward irrelevant stimuli. The current study examined attention control during a cross-modal word recognition task.

METHOD

Twenty participants with SLI (ages 9-12 years) and 20 age-matched peers with typical language development (TLD) listened to words through headphones and were instructed to attend to the words in 1 ear while ignoring the words in the other ear. They were simultaneously presented with pictures and asked to make a lexical decision about whether the pictures and auditory words were the same or different. Accuracy and reaction time were measured in 5 conditions, in which the stimulus in the unattended channel was manipulated.

RESULTS

The groups performed with similar accuracy. Compared with their peers with TLD, children with SLI had slower reaction times overall and different within-group patterns of performance by condition.

CONCLUSIONS

Children with TLD showed efficient inhibitory control in conditions that required active suppression of competing stimuli. Participants with SLI had difficulty exerting control over their auditory attention in all conditions, with particular difficulty inhibiting distractors of all types.

Evidence for shared deficits in identifying emotions from faces and from voices in autism spectrum disorders and specific language impairment

BACKGROUND

While autism spectrum disorder (ASD) and specific language impairment (SLI) have traditionally been conceptualized as distinct disorders, recent findings indicate that the boundaries between these two conditions are not clear-cut. While considerable research has investigated overlap in the linguistic characteristics of ASD and SLI, relatively less research has explored possible overlap in the socio-cognitive domain, particularly in terms of the emotion recognition abilities of these two groups of children.

AIMS

To investigate facial and vocal emotion recognition in children with ASD, children with SLI and typically developing (TD) children. To do so, the ASD group was subdivided into those with 'normal' (ALN) and those with 'impaired' (ALI) language to explore the extent to which language ability influenced performance on the emotion recognition task.

METHODS & PROCEDURES

Twenty-nine children with ASD (17 ALN and 12 ALI), 18 children with SLI and 66 TD children completed visual and auditory versions of an emotion recognition task. For the visual version of the task, the participants saw photographs of people expressing one of six emotions (happy, sad, scared, angry, surprised, disgusted) on the whole face. For the auditory modality, the participants heard a neutral sentence that conveyed one of the six emotional expressions in the tone of the voice. In both conditions, the children were required to indicate how the person they could see/hear was feeling by selecting a cartoon face that was presented on the computer screen.

OUTCOMES & RESULTS

The results showed that all clinical groups were less accurate than the TD children when identifying emotions on the face and in the voice. While the ALN children were less accurate than the TD children only when identifying expressions that require inferring another's mental state (surprise, disgust) emotional expressions, the ALI and the SLI children were less accurate than the TD children when identifying the basic (happy, sad, scared, angry) as well as the inferred emotions.

CONCLUSIONS & IMPLICATIONS

The results indicate that children with ALI and children with SLI share emotion recognition deficits, which are likely to be driven by the poor language abilities of these two groups.

Lexical access in children with hearing loss or specific language impairment, using the cross-modal picture-word interference paradigm

In this study we compared lexical access to spoken words in 25 deaf children with cochlear implants (CIs), 13 hard-of-hearing (HoH) children and 20 children with specific language impairment (SLI). Twenty-one age-matched typically developing children served as controls. The children with CIs and the HoH children in the present study had good speech perception abilities. We used a cross-modal picture-word interference paradigm to examine lexical access. Results showed that children with SLI revealed overall slower reaction times and produced more errors than the children with CIs, the HoH children, and the control children. Reaction times of children with CIs and the HoH children did not differ from those of the control children. Thus, problems with spoken language processing, as is the case in children with SLI, seem to affect lexical access more than limitations in auditory perception, as is the fundamental problem in children with hearing loss. We recommend that improvement of lexical access in children with SLI deserves specific attention in therapy and education.

Information processing speed as a predictor of IQ in children with and without specific language impairment in grades 3 and 8

PURPOSE

This study investigated (1) whether nonlinguistic processing speed predicts nonverbal IQ in TD children and children with SLI and (2) if the proposed relationship is different at two time points.

METHOD

The participants consisted of a subset of a longitudinal dataset, 55 typically developing children and 55 children with SLI. Children completed four nonverbal speed tasks and four subtests of the WISC-III. The WISC-III subtests requiring timed and untimed responses were examined separately.

RESULTS

Linear mixed model analyses indicated that in both groups, processing speed predicted nonverbal IQ subtests that reward speedy responses, but not IQ subtests that do not. The relationships between processing speed and IQ with speed bonuses did not differ at grades 3 and 8, and these relationships also were not significantly different in children with SLI and their TD peers.

CONCLUSIONS

The results suggest that the presence of processing speed limitations in many children with SLI raises questions about the utility of timed nonverbal IQ measures as tools for diagnosis of SLI. Future studies should investigate other cognitive assessments that could be used as inclusionary criteria for SLI.

LEARNING OUTCOMES

The reader will be able to (1) describe the relationship between processing speed and nonverbal IQ in children with TD and SLI and (2) discuss problems using an IQ criterion to diagnose children as having SLI.

Evidence for distinct cognitive profiles in autism spectrum disorders and specific language impairment

Findings that a subgroup of children with an autism spectrum disorder (ASD) have linguistic capabilities that resemble specific language impairment (SLI) have led some authors to hypothesise that ASD and SLI have a shared aetiology. While considerable research has explored overlap in the language phenotypes of the two conditions, little research has examined possible overlap in cognitive characteristics. In this study, we explored nonword and sentence repetition performance, as well as performance on the Children's Embedded Figures Test (CEFT) for children with ASD or SLI. As expected, 'language impaired' children with ASD (ALI) and children with SLI performed worse than both 'language normal' ASD (ALN) and typically developing (TD) children on the nonword and sentence repetition tests. Further, the SLI children performed worse than all other groups on the CEFT. This finding supports distinct cognitive profiles in ASD and SLI and may provide further evidence for distinct aetiological mechanisms in the two conditions.

Can children with SLI detect cognitive conflict? Behavioral and electrophysiological evidence

PURPOSE

This study examined whether children with specific language impairment (SLI) are deficient in detecting cognitive conflict between competing response tendencies in a GO/No-GO task.

METHOD

Twelve children with SLI (ages 10-12), 22 children with typical language development matched group-wise on age (TLD-A), and 16 younger children with TLD (ages 8-9) matched group-wise on language skills (TLD-L) were tested using a behavioral GO/No-GO paradigm with simultaneous collection of event-related potentials. The N2 component was used as a neural index of the ability to detect conflict between GO and No-GO response tendencies.

RESULTS

Hit rates did not differentiate the 3 groups. The TLD-L children demonstrated the highest false-alarm rates. The N2 component was attenuated and showed delayed divergence of GO and No-GO amplitudes in SLI relative to TLD-A children in response to stimuli presented at various probability levels. The N2 effect in children with SLI resembled that of children with TLD who were approximately 3 years younger.

CONCLUSIONS

School-age children with SLI exhibit a maturational lag in detecting conflict between competing response alternatives. Deficient conflict detection may in turn hinder these children's ability to resolve conflict among semantic representations that are activated during language processing.

Production and processing of subject-verb agreement in monolingual Dutch children with specific language impairment

PURPOSE

In this study, the authors investigated whether errors with subject-verb agreement in monolingual Dutch children with specific language impairment (SLI) are influenced by verb phonology. In addition, the productive and receptive abilities of Dutch acquiring children with SLI regarding agreement inflection were compared.

METHOD

An SLI group (6-8 years old), an age-matched group with typical development, and a language-matched, younger, typically developing (TD) group participated in the study. Using an elicitation task, the authors tested use of third person singular inflection after verbs that ended in obstruents (plosive, fricative) or nonobstruents (sonorant). The authors used a self-paced listening task to test sensitivity to subject-verb agreement violations.

RESULTS

Omission was more frequent after obstruents than nonobstruents; the younger TD group used inflection less often after plosives than fricatives, unlike the SLI group. The SLI group did not detect subject-verb agreement violations if the ungrammatical structure contained a frequent error (omission), but if the ungrammatical structure contained an infrequent error (substitution), subject-verb agreement violations were noticed.

CONCLUSIONS

The use of agreement inflection by children with TD or SLI is affected by verb phonology. Differential effects in the 2 groups are consistent with a delayed development in Dutch SLI. Parallels between productive and receptive abilities point to weak lexical agreement inflection representations in Dutch SLI.

Gender and agreement processing in children with developmental language disorder

Two experiments tested whether Russian-speaking children with Developmental Language Disorder (DLD) are sensitive to gender agreement when performing a gender decision task. In Experiment 1, the presence of overt gender agreement between verbs and/or adjectival modifiers and postverbal subject nouns memory was varied. In Experiment 2, agreement violations were introduced and the targets varied between words, pseudo-words, or pseudo-words with derivational suffixes. In both experiments, children with DLD did not differ from typically developing children in their reaction time or sensitivity to agreement features. In both groups, trials with feminine gender resulted in a higher error rate. Children with DLD displayed lower overall accuracy, which was related to differences in phonological memory in both experiments. Furthermore, in Experiment 1 group differences were not maintained after phonological memory was entered as a covariate. The results are discussed with respect to various processing and linguistic theories of DLD.

Motor sequencing deficit as an endophenotype of speech sound disorder: a genome-wide linkage analysis in a multigenerational family

OBJECTIVES

The aim of this pilot study was to investigate a measure of motor sequencing deficit as a potential endophenotype of speech sound disorder (SSD) in a multigenerational family with evidence of familial SSD.

METHODS

In a multigenerational family with evidence of a familial motor-based SSD, affectation status and a measure of motor sequencing during oral motor testing were obtained. To further investigate the role of motor sequencing as an endophenotype for genetic studies, parametric and nonparametric linkage analyses were carried out using a genome-wide panel of 404 microsatellites.

RESULTS

In seven of the 10 family members with available data, SSD affectation status and motor sequencing status coincided. Linkage analysis revealed four regions of interest, 6p21, 7q32, 7q36, and 8q24, primarily identified with the measure of motor sequencing ability. The 6p21 region overlaps with a locus implicated in rapid alternating naming in a recent genome-wide dyslexia linkage study. The 7q32 locus contains a locus implicated in dyslexia. The 7q36 locus borders on a gene known to affect the component traits of language impairment.

CONCLUSION

The results are consistent with a motor-based endophenotype of SSD that would be informative for genetic studies. The linkage results in this first genome-wide study in a multigenerational family with SSD warrant follow-up in additional families and with fine mapping or next-generation approaches to gene identification.

Rapid naming by children with and without specific language impairment

PURPOSE

Previous studies have reported that children with specific language impairment (SLI) name pictures more slowly than do chronological age-matched (CAM) peers. Rapid naming depends on 2 factors known to be problematic for children with SLI-lexical retrieval and nonlinguistic speed of processing. Although all studies implicate a speed-of-processing deficit as a contributing factor, researchers do not agree on the influence of language factors. The purpose of the current study was to explore word frequency (WF) and phonotactic pattern frequency (PPF) as potential lexical factors contributing to the naming deficits experienced by children with SLI.

METHOD

Three groups of children-20 children with SLI (Mage = 9;8 [years;months]), 20 younger vocabulary-matched (VM) controls, and 20 CAM controls-named pictures whose labels varied by WF and PPF.

RESULTS

Reaction time results revealed significant main effects of group (CAM < SLI = VM) and WF (high WF < low WF). Effects due to WF were comparable for all groups, but a significant Group × PPF interaction revealed that PPF effects were greater for children with SLI than for VM or CAM children.

CONCLUSION

Results replicate previous findings of a naming deficit in children with SLI. Furthermore, results suggest that children with SLI are more vulnerable to increased competition from words with frequent phonotactic patterns, which also come from dense phonological neighborhoods.

Sentence comprehension in specific language impairment: a task designed to distinguish between cognitive capacity and syntactic complexity

PURPOSE

This study examined sentence comprehension in children with specific language impairment (SLI) in a manner designed to separate the contribution of cognitive capacity from the effects of syntactic structure.

METHOD

Nineteen children with SLI, 19 typically developing children matched for age (TD-A), and 19 younger typically developing children (TD-Y) matched according to sentence comprehension test scores responded to sentence comprehension items that varied in either length or their demands on cognitive capacity, based on the nature of the foils competing with the target picture.

RESULTS

The TD-A children were accurate across all item types. The SLI and TD-Y groups were less accurate than the TD-A group on items with greater length and, especially, on items with the greatest demands on cognitive capacity. The types of errors were consistent with failure to retain details of the sentence apart from syntactic structure.

CONCLUSIONS

The difficulty in the more demanding conditions seemed attributable to interference. Specifically, the children with SLI and the TD-Y children appeared to have difficulty retaining details of the target sentence when the information reflected in the foils closely resembled the information in the target sentence.

Past tense production by English second language learners with and without language impairment

PURPOSE

This study investigated whether past tense use could differentiate children with language impairment (LI) from their typically developing (TD) peers when English is children's second language (L2) and whether L2 children's past tense profiles followed the predictions of Bybee's (2007) usage-based network model.

METHOD

A group of L2 children with LI (L2-LI) and a matched group of L2-TD peers were administered the past tense probe from the Test of Early Grammatical Impairment (Rice & Wexler, 2001) and the Peabody Picture Vocabulary Test (Dunn & Dunn, 1997). A representative input corpus provided distributional information for each verb used. Background information was obtained via parent questionnaire.

RESULTS

The L2-LI group used fewer tense-marked verbs than did the L2-TD group. In both groups, vocabulary size and word frequency predicted accuracy with regular and irregular verbs. Children omitted regular past tense marking most often after alveolar stops, dropping the allomorph /Id/; L2-TD children omitted /t/ more often than /d/. Finally, first language typology predicted past tense accuracy.

CONCLUSIONS

Past tense use could potentially differentiate between English L2 children with and without LI. The impact of vocabulary, frequency, and phonological factors supported the network model and indicated profile differences between L2-LI and L2-TD children.

The impact of dual tasking on sentence comprehension in children with specific language impairment

PURPOSE

In this study, the authors assessed the hypothesis of a limitation in attentional allocation capacity as underlying poor sentence comprehension in children with specific language impairment (SLI).

METHOD

Fifteen children with SLI, 15 age-matched controls, and 15 grammar-matched controls participated in the study. Sixty sentences were presented in isolation, and 60 sentences were presented with a concurrent choice reaction time task in which colored stimuli randomly appeared at the center of the computer screen.

RESULTS

Sentence comprehension was affected by the dual-task condition to a greater extent in children with SLI relative to age controls but not relative to grammatical controls.

CONCLUSION

This study does not support limitations in attentional allocation capacity as representing a core deficit in SLI. Rather, the data show that these children show attentional allocation capacity comparable to that of younger children having similar language level, suggesting that SLI is characterized by a slowed development of both attentional and language domains.

Specific language impairment

The acquisition of language is one of the most important achievements in young children, in part because most children appear to acquire language with little effort. Some children are not so fortunate, however. There is a large group of children who also have difficulty learning language, but do not have obvious neurological, cognitive, sensory, emotional, or environmental deficits. Clinicians often refer to these children as language disordered or language impaired. Researchers tend to refer to these children as specific language impaired (SLI). Children with SLI have intrigued researchers for many years because there is no obvious reason for their language learning difficulties. SLI has been found to be an enduring condition that begins in early childhood and often persists into adolescence and adulthood. The language problems of children with SLI are not limited to spoken language; they also affect reading and writing and thus much of academic learning. Knowledge of the characteristics of SLI should aid physicians, pediatricians, and early childhood specialists to identify these children during the preschool years and ensure that they receive appropriate services. With high-quality language intervention and literacy instruction, most children with SLI should be able to perform and function adequately in school and beyond.

Oral and hand movement speeds are associated with expressive language ability in children with speech sound disorder

This study tested the hypothesis that children with speech sound disorder have generalized slowed motor speeds. It evaluated associations among oral and hand motor speeds and measures of speech (articulation and phonology) and language (receptive vocabulary, sentence comprehension, sentence imitation), in 11 children with moderate to severe SSD and 11 controls. Syllable durations from a syllable repetition task served as an estimate of maximal oral movement speed. In two imitation tasks, nonwords and clapped rhythms, unstressed vowel durations and quarter-note clap intervals served as estimates of oral and hand movement speed, respectively. Syllable durations were significantly correlated with vowel durations and hand clap intervals. Sentence imitation was correlated with all three timed movement measures. Clustering on syllable repetition durations produced three clusters that also differed in sentence imitation scores. Results are consistent with limited movement speeds across motor systems and SSD subtypes defined by motor speeds as a corollary of expressive language abilities.

Literacy outcomes of children with early childhood speech sound disorders: impact of endophenotypes

PURPOSE

To demonstrate that early childhood speech sound disorders (SSD) and later school-age reading, written expression, and spelling skills are influenced by shared endophenotypes that may be in part genetic.

METHOD

Children with SSD and their siblings were assessed at early childhood (ages 4-6 years) and followed at school age (7-12 years). The relationship of shared endophenotypes with early childhood SSD and school-age outcomes and the shared genetic influences on these outcomes were examined.

RESULTS

Structural equation modeling demonstrated that oral motor skills, phonological awareness, phonological memory, vocabulary, and speeded naming have varying influences on reading decoding, spelling, spoken language, and written expression at school age. Genetic linkage studies demonstrated linkage for reading, spelling, and written expression measures to regions on chromosomes 1, 3, 6, and 15 that were previously linked to oral motor skills, articulation, phonological memory, and vocabulary at early childhood testing.

CONCLUSIONS

Endophenotypes predict school-age literacy outcomes over and above that predicted by clinical diagnoses of SSD or language impairment. Findings suggest that these shared endophenotypes and common genetic influences affect early childhood SSD and later school-age reading, spelling, spoken language, and written expression skills.

P300 as a measure of processing capacity in auditory and visual domains in specific language impairment

This study examined the electrophysiological correlates of auditory and visual working memory in children with Specific Language Impairments (SLI). Children with SLI and age-matched controls (11;9-14;10) completed visual and auditory working memory tasks while event-related potentials (ERPs) were recorded. In the auditory condition, children with SLI performed similarly to controls when the memory load was kept low (1-back memory load). As expected, when demands for auditory working memory were higher, children with SLI showed decreases in accuracy and attenuated P3b responses. However, children with SLI also evinced difficulties in the visual working memory tasks. In both the low (1-back) and high (2-back) memory load conditions, P3b amplitude was significantly lower for the SLI as compared to CA groups. These data suggest a domain-general working memory deficit in SLI that is manifested across auditory and visual modalities.

The contribution of processing impairments to SLI: insights from attention-deficit/hyperactivity disorder

Slowed speed of processing and impaired rapid temporal processing (RTP) have been proposed to underlie specific language impairment (SLI), but it is not clear that these dysfunctions are unique to SLI. We considered the contribution of attention-deficit/hyperactivity disorder (ADHD), which frequently co-occurs with language impairments, to performances on processing tasks. School-aged children who had SLI without concurrent ADHD (n=14), ADHD without concurrent SLI (n=14), and typical development (TD, n=28) performed two nonverbal speeded tasks and one auditory RTP task. RTP impairments were found in many children with SLI and ADHD, and some children with TD. Children with ADHD demonstrated slower processing speed than children with SLI or TD. Overall, findings questioned the uniqueness of these processing dysfunctions to language impairments and the validity of the behavioural paradigms traditionally used to estimate processing dysfunctions. Accounts of SLI should be further scrutinized by considering the influence of other disorders.

LEARNING OUTCOMES

Readers will (1) become familiar with areas of overlap between SLI and ADHD, (2) understand some of the confounds associated with behavioural measures of processing speed in children, and (3) recognize the value in testing models of language disorders by including participants with other types of disorders.

Verbal repetition skill in language impaired children: evidence of inefficient lexical processing?

Speeded verbal repetition of spoken words in simple and primed conditions was used to examine lexical processing deficits in children with specific language impairment (SLI). During simple verbal repetition, children with SLI (n = 18) were slower at repeating abstract verbs compared to concrete verbs. This same effect was not observed for nouns. Age matched typically developing (TD) children (n = 18) showed no effect of concreteness for either verbs or nouns. During primed verbal repetition the children heard prime-target word pairs (e.g., lion-tiger) on each trial. Semantically related primes speeded verbal repetition for the TD but not SLI group, suggesting inefficient spreading activation within lexical semantics for children with SLI. Phonologically related primes (e.g., tiny) slowed verbal repetition of the target (e.g., tiger) in both groups, suggesting children with SLI were similar to their age-matched peers in lexical phonological competition. The results are generally supportive of graded deficits in lexical processing skill in SLI consistent with connectionist accounts, and approaches to therapy that combine semantic and phonological dimensions at the word level.

Working memory and specific language impairment: an update on the relation and perspectives on assessment and treatment

PURPOSE

Children with specific language impairment (SLI) demonstrate significant language impairments despite normal-range hearing and nonverbal IQ. Many of these children also show marked deficits in working memory (WM) abilities. However, the theoretical and clinical characterization of the association between WM and language limitations in SLI is still sparse. Our understanding of this association would benefit greatly from an updated and thorough review of the literature.

METHOD

We review the newest developments in these areas from both a theoretical and clinical perspective. Our intent is to provide researchers and practicing clinicians (a) a conceptual framework within which the association between WM and language limitations of children with SLI can be understood and (b) potentially helpful suggestions for assessing and treating the memory-language difficulties of children with SLI.

CONCLUSIONS

In the past 10 years, important new theoretical insights into the range and nature of WM deficits and relation between these limitations and the language difficulties in SLI have occurred. New, robust diagnostic assessment tools and computerized treatment methods designed to enhance children's WM functioning have also been developed. The assessment, diagnosis, and treatment of the language difficulties in SLI should consider the potential influence of WM.

Verbal and nonverbal semantic processing in children with developmental language impairment

In an effort to clarify whether semantic integration is impaired in verbal and nonverbal auditory domains in children with developmental language impairment (a.k.a., LI and SLI), the present study obtained behavioral and neural responses to words and environmental sounds in children with language impairment and their typically developing age-matched controls (ages 7-15 years). Event-related brain potentials (ERPs) were recorded while children performed a forced-choice matching task on semantically matching and mismatching visual-auditory, picture-word and picture-environmental sound pairs. Behavioral accuracy and reaction time measures were similar for both groups of children, with environmental sounds eliciting more accurate responses than words. In picture-environmental sound trials, behavioral performance and the brain's response to semantic incongruency (i.e., the N400 effect) of the children with language impairment were comparable to those of their typically developing peers. However, in picture-word trials, children with LI tended to be less accurate than their controls and their N400 effect was significantly delayed in latency. Thus, the children with LI demonstrated a semantic integration deficit that was somewhat specific to the verbal domain. The particular finding of a delayed N400 effect is consistent with the storage deficit hypothesis of language impairment (Kail & Leonard, 1986) suggesting weakened and/or less efficient connections within the language networks of children with LI.

Sprachstandserhebungsverfahren für Fünf- bis Zehnjährige (SET 5 – 10)

Der Erwerb der Sprache stellt eine der wesentlichen Entwicklungsherausforderungen der ersten Lebensjahre dar und steht in enger Wechselwirkung zu vielfältigen anderen Entwicklungs- und Leistungsbereichen. Epidemiologische Studien zeigen, dass kein anderer Entwicklungsbereich so häufig von Störungen betroffen ist wie der Sprachliche. Sprachstörungen sind oftmals mit gravierenden Folgen sowohl für die kognitive, speziell die schulische, als auch für die sozial-emotionale Entwicklung verbunden. Die Notwendigkeit einer Intervention bei Sprachentwicklungsstörungen ist unstrittig. Eine Indikationsstellung ist jedoch nur mit zuverlässigen diagnostischen Instrumenten möglich. Der SET 5 – 10 dient der aussagekräftigen Diagnostik des Sprachstands bei Fünf- bis Zehnjährigen. Die Konstruktionsstichprobe setzte sich aus 275 Kindern zusammen. Die Aufgabenanalyse ergab eine gute Verteilung der Schwierigkeitsindizes sowie zufriedenstellende Trennschärfe-Koeffizienten.

Response time in adults with a history of language difficulties

The purpose of the study was to investigate speed of processing in college students with a history of problems with language. Affected individuals (n=16) were identified through a self-reported history of language and/or reading difficulties, and compared to a group of 16 unaffected individuals. Measures of language ability and a battery of response time tasks were administered. Results showed that the affected group had lower language performance and slower response time than the unaffected group. Better language performance was associated with faster response time, and this relationship was stronger in the affected group. These findings are consistent with the literature showing that language impairment often persists into adulthood. Further investigation of the relation between processing speed and language ability may help describe vulnerabilities for adults with language problems, as well as ways to promote compensation for those vulnerabilities.

LEARNING OUTCOMES

Readers will (1) increase understanding of associations between processing speed and language in children and adults; (2) become familiar with a method for assessing processing speed; and (3) increase understanding of possible vulnerabilities in adults with a history of language and/or reading problems.

When "Simon says" doesn't work: alternatives to imitation for facilitating early speech development

PURPOSE

To provide clinicians with evidence-based strategies to facilitate early speech development in young children who are not readily imitating sounds. Relevant populations may include, but are not limited to, children with autism spectrum disorders, childhood apraxia of speech, and late-talking toddlers.

METHOD

Through multifaceted search procedures, we found experimental support for 6 treatment strategies that have been used to facilitate speech development in young children with developmental disabilities. Each strategy is highlighted within this article through a summary of the underlying rationale(s), empirical support, and specific examples of how it could be applied within intervention.

CONCLUSIONS

Given the relatively sparse experimental data focused on facilitating speech in children who do not readily imitate, theoretical support emerges as particularly key and underscores the need for clinicians to consider why they are doing what they are doing. In addition, this review emphasizes the need for the research community to bridge the gap between pressing clinical needs and the limited evidence base that is currently available.

Grammatical Morpheme Effects on Sentence Processing by School-Aged Adolescents with Specific Language Impairment

Sixteen-year-olds with specific language impairment (SLI), nonspecific language impairment (NLI), and those showing typical language development (TD) responded to target words in sentences that were either grammatical or contained a grammatical error immediately before the target word. The TD participants showed the expected slower response times (RTs) when errors preceded the target word, regardless of error type. The SLI and NLI groups also showed the expected slowing, except when the error type involved the omission of a tense/agreement inflection. This response pattern mirrored an early developmental period of alternating between using and omitting tense/agreement inflections that is characteristic of SLI and NLI. The findings could not be readily attributed to factors such as insensitivity to omissions in general or insensitivity to the particular phonetic forms used to mark tense/agreement. The observed response pattern may represent continued difficulty with tense/agreement morphology that persists in subtle form into adolescence.

Effects of onset- and rhyme-related distractors on phonological processing in children with specific language impairment

PURPOSE

This study used the cross-modal picture-word interference task of P. J. Brooks and B. MacWhinney (2000) to compare effects of phonologically related words on lexical access in children with specific language impairment (SLI).

METHOD

Children (7;1 [years;months]-11;2) named pictures while ignoring auditory distractors. Three stimulus asynchrony conditions varied the timing of distractors relative to the pictures. Experiment 1 presented onset-related (bell-bed), unrelated (clown-bed), neutral (go-bed), and identical (bed-bed) distractors. Experiment 2 presented rhyme-related instead of onset-related distractors (clock-sock).

RESULTS

Children with SLI produced longer reaction times (RTs) and more errors than their typical language development (TLD) peers. For children with SLI, onset-related distractors led to slower RTs than unrelated distractors (inhibition) when presented before the picture, and faster RTs (facilitation) when presented after the picture. Children with TLD showed facilitation from onset-related distractors when presented after the picture but no inhibition when presented before the picture. Both groups failed to show facilitation from rhyme-related distractors.

CONCLUSIONS

The priming effects from onset-related distractors and lack of effects from rhyme-related distractors in SLI supports "just-in-time" incremental processing, similar to children with TLD. However, children with SLI experience phonological interference from members of a lexical cohort while accessing words. Results are discussed with respect to observed word finding and word learning difficulties in SLI.

Comparison of performance on two nonverbal intelligence tests by adolescents with and without language impairment

Definitions of specific language impairment (SLI), for both research and clinical purposes, often state that nonverbal IQ scores must be within normal limits. This use of nonverbal IQ has been criticized on several grounds, including lack of equivalence between tests. In the current study, a sample of 204 adolescents with and without language impairment took two nonverbal IQ tests. Scores on the tests were compared, as was the classification of individuals into diagnostic categories according to the two tests. Results indicated that there were significant differences between test scores for clinical subgroups, and classification of individuals as having SLI varied substantially depending on the test used. The findings are interpreted as providing further evidence that nonverbal IQ should be used only cautiously, if at all, in defining SLI.

LEARNING OUTCOMES

Readers will (1) understand problems with the use of nonverbal IQ criteria in diagnosis of SLI and (2) be able to cite data showing that different nonverbal IQ tests can lead to different diagnoses.

Central timing deficits in subtypes of primary speech disorders

Childhood apraxia of speech (CAS) is a proposed speech disorder subtype that interferes with motor planning and/or programming, affecting prosody in many cases. Pilot data (Peter & Stoel-Gammon, 2005) were consistent with the notion that deficits in timing accuracy in speech and music-related tasks may be associated with CAS. This study replicated and expanded earlier findings. Eleven children with speech disorders and age-and gender-matched controls participated in non-word imitation, clapped rhythm imitation, and paced repetitive tapping tasks. Results suggest a central timing deficit, expressed in both the oral and the limb modality, and observable in two different types of timing measures, overall rhythmic structures and small-scale durations. Associations among timing measures were strongest in the participants with speech disorders, who also showed lower timing accuracy than the controls in all measures. The number of observed CAS characteristics was associated with timing deficits.

Recast density and acquisition of novel irregular past tense verbs

PURPOSE

Children with specific language impairment (SLI) lag behind children with typical language (TL) in their grammatical development, despite equivalent early exposure to recasts in conversation (M. E. Fey, T. E. Krulik, D. F. Loeb, & K. Proctor-Williams, 1999) and the ability to learn from recasts in intervention as quickly as do children with TL (K. E. Nelson, S. Camarata, J. Welsh, L. Butovsky, & M. Camarata, 1996). This experiment tested whether this apparent paradox could be attributed to variations in the density of recasts in conversation versus intervention.

METHOD

Thirteen children (7-8 years of age) with SLI and 13 language-similar children (5-6 years of age) with TL were exposed to 3 recast densities of novel irregular past tense verbs (none, conversation-like, intervention-like) over 5 sessions. Outcomes were based on spontaneous conversational productions and a post-test probe.

RESULTS

As predicted, at conversation-like densities, children with TL more accurately produced the target verbs they heard in recasts than in nonrecast models (d = 0.58), children with SLI showed no differences, and children with TL produced the verbs more accurately than did children with SLI (d = 0.54). Contrary to expectations, at higher intervention-like recast densities, the SLI group did not improve their accuracy, and the TL group performances were significantly poorer (d = 0.47).

CONCLUSION

At conversational levels, recasts facilitated greater verb learning than models alone but only in the TL group. Increasing recast density to the modest levels in this brief intervention experiment did not benefit children with SLI and led to poorer learning for children with TL. To optimize learning, efficiency of recast distribution as well as rate must be considered.

Examining the language performances of children with and without specific language impairment: contributions of phonological short-term memory and speed of processing

PURPOSE

This study investigated the effects of processing speed and phonological short-term memory (PSTM) on children's language performance.

METHOD

Forty-eight school-age children with specific language impairment (SLI) and age peers completed auditory detection reaction time (RT) and nonword repetition tasks, the Clinical Evaluation of Language Fundamentals-Revised (CELF-R; E. Semel, E. Wiig, & W. Secord, 1987), and a word recognition RT task. Correlation and regression were used to determine unique and shared contributions to variance among measures.

RESULTS

Children with SLI were outperformed by age peers on each task. Auditory detection RT was correlated with nonword repetition (NWR) in each group. However, both variables covaried with age, and auditory detection RT did not contribute unique variance to NWR in either group. For the SLI group, NWR predicted unique variance in CELF-R performance (about 15%); auditory detection RT predicted a smaller amount of unique variance in the word recognition RT task (about 9%).

CONCLUSION

Processing speed and PSTM measures covaried with chronological age. Processing speed was associated with offline language performance only through association with PSTM. Processing speed contributed to online language performance, suggesting that speed is associated with processing more familiar language material (i.e., lexical content and structure) than less familiar material (e.g., various content on the CELF-R).

Speed of processing, working memory, and language impairment in children

PURPOSE

Children with language impairment (LI) often perform below the level of typically developing peers on measures of both processing speed and working memory. This study examined the relationship between these 2 types of measures and attempted to determine whether such measures can account for the LI itself.

METHOD

Fourteen-year-old children with LI and their typically developing peers participated in a wide range of processing speed and working memory tasks and were administered a comprehensive language test battery. Confirmatory factor analyses were used to compare 3 nested models designed to examine the dimensionality of the speed and working memory measures. A model that included a general speed factor was also evaluated.

RESULTS

The models meeting our evaluation criteria treated speed and working memory as separable factors. Furthermore, nonverbal as well as verbal processing factors emerged from these analyses. Latent variable regression analyses showed that each of the appropriate models accounted for 62% of the variance in the children's concurrent composite language test scores, with verbal working memory making the largest contribution.

CONCLUSIONS

These findings shed light on the relationship among different types of processing and suggest that processing factors can contribute to the understanding of language disorders.

Effects of acoustic manipulation on the real-time inflectional processing of children with specific language impairment

PURPOSE

This study reports the findings of an investigation designed to examine the effects of acoustic enhancement on the processing of low-phonetic-substance inflections (e.g., 3rd-person singular -s, possessive -s) versus a high-phonetic-substance inflection (e.g., present progressive -ing) by children with specific language impairment (SLI) in a word recognition, reaction time (RT) processing task. The effects of acoustic enhancement on the processing of the same morphemes as well as an additional morpheme (comparative -er) were examined in an offline grammaticality judgment task. The grammatical function of 1 of the higher-phonetic-substance inflections, -ing, was presumed to be hypothesized relatively early by children; the function of the other, -er, was presumed to be hypothesized relatively late.

METHOD

Sixteen children with SLI (age(M) = 9 years;0 months) and 16 chronological age (CA; age(M) = 8;11) children participated. For both tasks, children listened to sentences containing the target morphemes as they were produced naturally (natural condition) or with acoustic enhancement (enhanced condition).

RESULTS

On the RT task, the children with SLI demonstrated RT sensitivity only to the presence of the high-substance inflection, irrespective of whether it was produced naturally or with enhancement. Acoustic enhancement had no effect on these children's processing of low-substance inflections. The CA children, by contrast, showed sensitivity to low-substance inflections when they were produced naturally and with acoustic enhancement. These children also showed sensitivity to the high-substance inflection in the natural condition, but in the enhanced condition they demonstrated significantly slower RT. On the grammaticality judgment task, the children with SLI performed worse than the CA children overall and showed especially poor performance on low-substance inflections. Acoustic enhancement had a beneficial effect on the inflectional processing of the children with SLI, but it had no effect on CA children.

CONCLUSION

The findings are interpreted to suggest that the reduced language processing capacity of children with SLI constrains their ability to process low-substance grammatical material in real time. This factor should be considered along with any difficulty that might be attributable to the grammatical function of the inflection.

Processing Limitations in Children With Specific Language Impairment: The Role of Executive Function

Research suggests that children with specific language impairment (SLI) have processing limitations; however, the mechanisms involved have not been well defined or investigated in a theory-guided manner. The theory of constructive operators was used as a framework to explore processes underlying limited processing capacity in children with SLI. Mental attentional capacity, mental attentional interruption, and 2 specific executive functions (shifting and updating) were examined in 45 children with SLI and 45 children with normally developing language, aged 7 to 12 years. The results revealed overall group differences in performance on measures of mental attention, interruption, and updating, but not shifting. The findings supported the premise that mental attention predicted language competence, but that this relationship was mediated partially by updating.

Response time in 14-year-olds with language impairment

PURPOSE

To determine whether children with language impairment were slower than typically developing peers at age 14, and whether slowing, if present, was similar across task domains; whether differences in response time (RT) across domains were the same for children with specific language impairment (SLI) and nonspecific language impairment (NLI); and whether RT performance at age 9 predicted performance at age 14.

METHOD

Fourteen-year-old children with SLI (n = 20), NLI (n = 15), and typical development (NLD; n = 31) were administered several linguistic and nonlinguistic speeded tasks. The children had received the same tasks at age 9. RT performance was examined.

RESULTS

Both the SLI and the NLI groups were significantly slower than the NLD group in motor, nonverbal cognitive, and language task domains, and there was no significant difference among domains. Individual analyses showed that most, but not all, children with SLI and NLI were slower than the NLD group mean. Slowing at age 9 and age 14 were moderately correlated.

CONCLUSIONS

The results suggest that slow RT is a persistent characteristic of many children with language impairment; however, the nature of the relationship between RT and language performance requires further investigation.

Children's naming and word-finding difficulties: descriptions and explanations

PURPOSE

There is a substantial minority of children for whom lexical retrieval problems impede the normal pattern of language development and use. These problems include accurately producing the correct word even when the word's meaning is understood. Such problems are often referred to as word-finding difficulties (WFDs). This article examines the nature of naming and lexical retrieval difficulties in these and other groups of children.

METHOD

A review of the relevant literature on lexical access difficulties in children with word-finding difficulties was conducted. Studies were examined in the terms of population parameters and comparison groups included in the study.

RESULTS AND CONCLUSIONS

Most discussions of the cognitive processes causing lexical retrieval difficulties refer to semantics, phonology, and processing speed. The authors propose that understanding of these topics will be further advanced by the use of appropriate methodology to test developmental models. In this way it will be possible to identify the processes that contribute to successful lexical retrieval and the processes that result in retrieval difficulties.

Functional MRI of task switching in children with Specific Language Impairment (SLI)

The objective of this study was to examine executive functioning in children with Specific Language Impairment (SLI) using functional MRI. Six children with SLI and seven control children participated in this study and received a task-switching paradigm. No specific deficit in executive control was observed at the behavioral level in children with SLI. However, the neuroimaging data did show remarkable differences between the SLI and control children. The children with SLI recruited frontal and cingulate areas, normally associated with executive control, even when the task did not require them in the children without SLI. This might indicate that the task was more demanding for the SLI group and that compensatory mechanisms were engaged for successful task performance.