Motor Issues in Specific Language Impairment: a Window into the Underlying Impairment

Language, Motor Ability and Related Deficits in Children at Familial Risk of Schizophrenia or Bipolar Disorder

BACKGROUND

It is known that impairments in linguistic ability and motor function tend to co-occur in children, and that children from families with parental mental illness such as schizophrenia tend to perform poorly in both domains, but the exact nature of these links has not yet been fully elucidated.

DESIGN

In this study, we leveraged the first wave of the Danish High Risk and Resilience Study (VIA 7), which includes both genetic data and measures covering multiple developmental domains. The VIA 7 cohort comprises 522 7-year-old children born to parents with schizophrenia (N = 202), bipolar disorder (N = 120) or neither (N = 200). We investigated the relationships between linguistic ability and motor function using correlation and regression analyses, focusing on developmental coordination disorder (DCD) and specific language impairment (SLI) and their potential associations with the three risk groups.

RESULTS

We found significant correlations between most measures of language and motor function and significant associations of DCD and SLI with language and movement measures, respectively, the largest effect being that of DCD on receptive language, with a significant interaction effect: DCD was associated with poorer performance in children from schizophrenia families compared to bipolar disorder and control families. Both disorders showed higher prevalence among children with familial high risk of mental illness. We did not find significant evidence of genetic overlap between DCD and SLI.

CONCLUSIONS

Our results suggest strong links between the domains of motor function and linguistic ability. Children of parents with schizophrenia are at high risk of comorbid language and movement disorders.

Impaired motor skills and proprioceptive function in Mandarin-speaking children with developmental language disorder

This study examined proprioceptive acuity and its relationship with motor function in Mandarin-speaking children with and without developmental language disorder (DLD). Fifteen children aged 9-12 years with DLD and 15 age- and sex-matched typically developing (TD) children participated in this study. Children's motor function was assessed using the second edition of the Movement Assessment Battery for Children (MABC-2). Their proprioceptive acuity was measured based on the absolute error (i.e., proprioceptive bias) and variable error (i.e., proprioceptive precision) when performing joint position matching tasks. Compared with the TD group, the DLD group exhibited impaired motor function and poorer proprioceptive acuity, as evidenced by the lower scores on the MABC-2 and the higher rates of absolute and variable errors in the joint position matching tasks. A significant association between the proprioceptive bias (absolute error) and the MABC-2 total score was also observed in the combined cohort of children with and without DLD. We conclude that DLD is associated with proprioceptive dysfunction.

Children With Developmental Language Disorder Show Deficits in the Production of Musical Rhythmic Groupings

PURPOSE

Children with developmental language disorder (DLD) show evidence of domain-general deficits in sequentially patterned motor skills. This study focuses on the production of rhythmically grouped sequences drawn from a music task, with the hypothesis that children with DLD will show a sequential pattern learning deficit that crosses language and action domains.

METHOD

Fifty-seven 4- to 5-year-old children (36 with DLD) drummed and clapped a developmentally appropriate musical rhythmic sequence 24 times (clapped 12 times, drummed 12 times). The accuracy of rhythmic events (markings of claps, drums, and pauses in a target sequence) was assessed through a modification of classic speech and language transcription procedures. The variability and prosodic structure of the rhythmic groupings were also measured.

RESULTS

Children with DLD produced less accurate and more variable rhythmic groupings compared to their typically developing (TD) peers. While the final-position grouping of the sequence was especially vulnerable for all children, those with DLD included more co-occurring errors in initial and final groupings of the same rhythmic sequence. Both TD children and children with DLD were less accurate in the clapping than the drumming task. Neither rhythmic drumming nor clapping accuracy correlated with motor skill in either group of children.

CONCLUSIONS

This study provides novel evidence of a manual rhythmic grouping deficit in DLD, one that is motivated by language-not motor or speech-factors. Cognitive abilities necessary to organize rhythmic events into higher order groupings are impaired across music and language in children with DLD. Rhythmic organization and sequencing may serve an important role in diagnosis and intervention in this population.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24158745.

What risk factors for Developmental Language Disorder can tell us about the neurobiological mechanisms of language development

Language is a complex multidimensional cognitive system that is connected to many neurocognitive capacities. The development of language is therefore strongly intertwined with the development of these capacities and their neurobiological substrates. Consequently, language problems, for example those of children with Developmental Language Disorder (DLD), are explained by a variety of etiological pathways and each of these pathways will be associated with specific risk factors. In this review, we attempt to link previously described factors that may interfere with language development to putative underlying neurobiological mechanisms of language development, hoping to uncover openings for future therapeutical approaches or interventions that can help children to optimally develop their language skills.

Developmental Language Disorder Is Associated With Slower Processing Across Domains: A Meta-Analysis of Time-Based Tasks

PURPOSE

Individuals with developmental language disorder (DLD) often exhibit slower processing on time-based tasks in comparison with age-matched peers. Processing speed has been linked to various linguistic skills and might serve as a global indicator of individual differences in language abilities. Despite an extensive literature on processing speed in DLD, it remains unclear whether slower processing is domain general or restricted to linguistic and/or auditory tasks.

METHOD

This meta-analysis used robust variance estimation to compare response/reaction times (RTs) of DLD and age-matched groups (N = 812 DLD, 870 neurotypical; M _age [DLD] = 8.9 years, range: 4.3-22.7 years). Moderators included task (simple RT, choice RT, naming, congruent/baseline conditions of interference control tasks), stimulus type (linguistic/nonlinguistic), stimulus modality (auditory/nonauditory), and response modality (verbal/nonverbal). Age and publication year were covariates.

RESULTS

The overall effect based on 46 studies and 144 estimates indicated longer mean RTs in DLD groups (g = .47, p < .001, 95% CI [.38, .55]). Moderator analyses indicated larger effects when tasks required verbal as opposed to nonverbal responses. No other moderators approached significance. All subgroup analyses were significant, indicating longer mean RTs in DLD groups across tasks, stimulus types, stimulus modalities, and response modalities.

CONCLUSIONS

Individuals with DLD exhibit longer RTs across verbal and nonverbal tasks, which may contribute to observed difficulties in language, motor skills, and executive functioning. Simple processing speed measures should be included in screening for language delays but may not be suitable for differential diagnosis, given that slower processing may occur across multiple disorders.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21809355.

Procedural learning and school-age language outcomes in children with and without a history of late talking

BACKGROUND

'Late talkers' (LTs) are toddlers with late language emergence that cannot be explained by other impairments. It is difficult to predict which of these children continue to present long-term restrictions in language abilities and will later be identified as having a developmental language disorder. Procedural memory weaknesses have been suggested to underlie developmental language disorders, but have not been investigated in LTs.

AIMS

We investigated the relationships between aspects of procedural memory and school-age language abilities in children with and without a history of LT. We hypothesized that children with a history of LT exhibit (1) restrictions in procedural memory when compared with children with typical early development (TED); and (2) a positive association between procedural memory and school-age language abilities.

METHODS & PROCEDURES

We recruited 79 children (7;5-10;5), 43 of whom had a history of LT. Aspects of procedural memory, procedural learning and motor planning were assessed using the serial reaction time and the end-state comfort tasks. School-age language abilities were measured using standardized tests.

OUTCOMES & RESULTS

Counter to expectations, motor planning was not associated with a history of LT or school-age language abilities, and the children with TED did not show stronger procedural learning as compared with peers with a history of LT. However, weaker school-age language abilities were associated with weak procedural learning in TED group.

CONCLUSIONS & IMPLICATIONS

Factors other than deficits in procedural memory are likely to underlie LT. Procedural learning shows promise as a potential predictor of language development in children that are not identified as LTs.

WHAT THIS PAPER ADDS

What is already known on the subject Poor procedural learning has been associated with developmental language disorders and suggested to underlie language difficulties. However, to our knowledge, this study is the first to investigate procedural learning and its associations with language outcomes in LTs. What this paper adds to existing knowledge Consistent with prior research, we found an association between language abilities and procedural learning in school-aged children, but found no evidence for poor procedural learning in children with a history of LT. Furthermore, the school-age language outcomes were only associated with procedural learning in children with no history of LT. What are the potential or actual clinical implications of this work? Our findings suggest that factors other than limitations in procedural learning underlie LT. However, procedural learning could be a useful predictor for school-aged language outcomes in children not identified as LTs.

Visual Processing Impairment in Children With Suspected Auditory Processing Disorder: A Transdisciplinary Dimensional Approach to Diagnosis

PURPOSE

The purpose of this study is to explore the utility of impairment(s) in language (LI), manual dexterity (IMD), and visual perceptual skills (IVPS) as a reference standard for diagnosing auditory processing disorder (APD).

METHOD

Data from 104 participants with suspected APD (males = 57, females = 47; 6-16 years) were retrospectively analyzed. Index auditory processing (AP) tests included Auditory Figure Ground 0 dB, Competing Words-Directed Ear (CW-DE), and Time-Compressed Sentences (TCS). General Communication Composite (GCC) of the Children's Communication Checklist-2, manual dexterity (MD) component of the Movement Assessment Battery for Children-Second Edition, and Test for Visual Perceptual Skills-Third Edition (TVPS-3) were used to identify LI, IMD, and IVPS, respectively.

RESULTS

Eighty-one (77.8%), 58 (55.8%), and 37 (35.6%) participants had LI, IVPS, and IMD, respectively. Four factors explaining 67.69% of the variance were extracted. TVPS-3 (except visual closure [VClo]) represented the first; AFG 0, VClo, and MD the second; CW-DE and GCC the third; and TCS the fourth. APD diagnosed by combining AP tests and comorbidities had better accuracy compared to AP tests alone. The combined approach had overall diagnostic accuracy of 92.2%, 88.4%, and 81.7% for the 9th, 5th, and 2nd percentile AP test cutoffs, respectively.

CONCLUSIONS

First-order AP tests in this study were related to language, MD, and visual perceptual skills. Given the overlap of LI, IMD, and IVPS with impaired AP, these comorbidities are an effective reference standard for APD. APD can be diagnosed following failing one AP test if one or more comorbidities exist. Ninth percentile AP test cutoff had better diagnostic accuracy compared to the currently used 2nd percentile cutoff.

Phonological characteristics of novel gesture production in children with developmental language disorder: Longitudinal findings

Children with developmental language disorder (DLD; aka specific language impairment) are characterized based on deficits in language, especially morphosyntax, in the absence of other explanatory conditions. However, deficits in speech production, as well as fine and gross motor skill, have also been observed, implicating both the linguistic and motor systems. Situated at the intersection of these domains, and providing insight into both, is manual gesture. In the current work, we asked whether children with DLD showed phonological deficits in the production of novel gestures and whether gesture production at 4 years of age is related to language and motor outcomes two years later. Twenty-eight children (14 with DLD) participated in a two-year longitudinal novel gesture production study. At the first and final time points, language and fine motor skills were measured and gestures were analyzed for phonological feature accuracy, including handshape, path, and orientation. Results indicated that, while early deficits in phonological accuracy did not persist for children with DLD, all children struggled with orientation while handshape was the most accurate. Early handshape and orientation accuracy were also predictive of later language skill, but only for the children with DLD. Theoretical and clinical implications of these findings are discussed.

Structure of Cognitive Functions in Monolingual Preschool Children With Typical Development and Children With Developmental Language Disorder

Purpose Developmental language disorder (DLD) is defined by persistent difficulties with language, but a growing body of evidence suggests that it is also associated with domain-general and nonverbal information-processing deficits. However, the interconnections between cognitive functions, both nonverbal and language related, are still unclear. With the aim of gaining more comprehensive insight into the cognitive deficits related to DLD, we investigated and compared the cognitive structure of children with DLD and typically developing (TD) children. Method As a part of the Helsinki longitudinal SLI study, monolingual Finnish preschoolers (N = 154; TD group: n = 66, DLD group: n = 88) were assessed with 23 tasks measuring nonverbal and verbal reasoning, language processing, memory, visuomotor functions, attention, and social cognition. Exploratory factor analysis and structural equation modeling were performed to examine latent constructs and to test measurement invariance between the TD and DLD groups. Results Measurement invariance was not found across the TD and DLD groups. Best fitting structure for TD children included factors reflecting verbal abilities, processing speed/short-term memory, visuomotor functions, and visuoconstructive abilities/nonverbal reasoning. The DLD group's structure comprised nonverbal abilities, naming/expressive language, verbal comprehension, and verbal/declarative memory. Conclusions The findings suggest that the structure of cognitive functions differs in TD children and children with DLD already at preschool age. Nonverbal functions seem more unified, whereas verbal functions seem more varying in preschoolers with DLD compared to TD children. The results can be used in future research for prognosis of DLD and planning interventions.

Non-linguistic cognitive measures as predictors of functionally defined developmental language disorder in monolingual and bilingual children

BACKGROUND & AIMS

Given that standardized language measures alone are inadequate for identifying functionally defined developmental language disorder (fDLD), this study investigated whether non-linguistic cognitive abilities (procedural learning, motor functions, executive attention, processing speed) can increase the prediction accuracy of fDLD in children in linguistically diverse settings.

METHODS & PROCEDURES

We examined non-linguistic cognitive abilities in mono- and bilingual school-aged children (ages 8-12) with and without fDLD. Typically developing (TD) children (14 monolinguals, 12 bilinguals) and children with fDLD (28 monolinguals, 12 bilinguals) completed tasks measuring motor functions, procedural learning, executive attention and processing speed. Children were assigned as fDLD based on parental or professional concerns regarding children's daily language functioning. If no concerns were present, children were assigned as TD. Standardized English scores, non-verbal IQ scores and years of maternal education were also obtained. Likelihood ratios were used to examine how well each measure separated the fDLD versus TD groups. A binary logistic regression was used to test whether combined measures enhanced the prediction of identifying fDLD status.

OUTCOMES & RESULTS

A combination of linguistic and non-linguistic measures provided the best distinction between fDLD and TD for both mono- and bilingual groups. For monolingual children, the combined measures include English language scores, functional motor abilities and processing speed, whereas for bilinguals, the combined measures include English language scores and procedural learning.

CONCLUSIONS & IMPLICATIONS

A combination of non-linguistic and linguistic measures significantly improved the distinction between fDLD and TD for both mono- and bilingual groups. This study supports the possibility of using non-linguistic cognitive measures to identify fDLD in linguistically diverse settings.

WHAT THIS PAPER ADDS

What is already known on the subject Given that standardized English language measures may fail to identify functional language disorder, we examined whether supplementing English language measures with non-linguistic cognitive tasks could resolve the problem. Our study is based on the hypothesis that non-linguistic cognitive abilities contribute to language processing and learning. This is further supported by previous findings that children with language disorder exhibit non-linguistic cognitive deficits. What this paper adds to existing knowledge The results indicated that a combination of linguistic and non-linguistic cognitive abilities increased the prediction of functional language disorder in both mono- and bilingual children. What are the potential or actual clinical implications of this work? This study supports the possibility of using non-linguistic cognitive measures to identify the risk of language disorder in linguistically diverse settings.

Oral Motor and Gesture Abilities Independently Associated With Preschool Language Skill: Longitudinal and Concurrent Relationships at 21 Months and 3-4 Years

Purpose Early motor abilities (gesture, oral motor, and gross/fine skills) are related to language abilities, and this is not due to an association with cognitive or symbolic abilities: Oral motor skills are uniquely associated with language abilities at 21 months of age. It is important to determine whether this motor-language relationship continues beyond the earliest stage of language development to understand language acquisition better and better predict which children may have lasting language difficulties. Method In this longitudinal study, we assessed language comprehension and production, oral motor skill, gross/fine motor skill, and meaningless manual gesture at ages 3 years (N = 89) and 4 years (N = 71), comparing the contribution of motor skill and earlier (at 21 months of age) language ability. We also examined covariates: nonverbal cognitive ability, socioeconomic status, and stimulation in the home as measured on the Home Screening Questionnaire. Results Motor abilities continue to have a significant relationship with language abilities independent of other factors in the preschool years. Meaningless manual gesture ability, gross/fine motor skill, and oral motor skill were still associated with language skill at 3 years of age; these relationships are not explained by the contribution of cognitive abilities or earlier language abilities. Conclusions Relationships between early motor skill and language development persist into preschool years and are not explained by other cognitive or home factors, nor by a relationship with earlier language ability. This finding should lead to a better understanding of the origins of language abilities.

Generalized Slowing Rather Than Inhibition Is Associated With Language Outcomes in Both Late Talkers and Children With Typical Early Development

Purpose While most of the children who are identified as late talkers at the age of 2 years catch up with their peers before school age, some continue to have language difficulties and will later be identified as having developmental language disorder. Our understanding of which children catch up and which do not is limited. The aim of the current study was to find out if inhibition is associated with late talker outcomes at school age. Method We recruited 73 school-aged children (ages 7-10 years) with a history of late talking (n = 38) or typical development (n = 35). Children completed measures of language skills and a flanker task to measure inhibition. School-age language outcome was measured as a continuous variable. Results Our analyses did not reveal associations between inhibition and school-age language index or history of late talking. However, stronger school-age language skills were associated with shorter overall response times on the flanker task, in both congruent and incongruent trials. This effect was not modulated by history of late talking, suggesting that a relationship between general response times and language development is similar in both children with typical early language development and late talkers. Conclusions Inhibition is not related to late talker language outcomes. However, children with better language outcomes had shorter general response times. We interpret this to reflect differences in general processing speed, suggesting that processing speed holds promise for predicting school-age language outcomes in both late talkers and children with typical early development. Supplemental Material https://doi.org/10.23641/asha.14226722.

Why Language Processing Recruits Modality Specific Brain Regions: It Is Not About Understanding Words, but About Modelling Situations

Whether language comprehension requires the participation of brain structures that evolved for perception and action has been a subject of intense debate. While brain-imaging evidence for the involvement of such modality-specific regions has grown, the fact that lesions to these structures do not necessarily erase word knowledge has invited the conclusion that language-induced activity in these structures might not be essential for word recognition. Why language processing recruits these structures remains unanswered, however. Here, we examine the original findings from a slightly different perspective. We first consider the 'original' function of structures in modality-specific brain regions that are recruited by language activity. We propose that these structures help elaborate 'internal forward models' in motor control (c.f. emulators). Emulators are brain systems that capture the relationship between an action and its sensory consequences. During language processing emulators could thus allow accessing associative memories. We further postulate the existence of a linguistic system that exploits, in a rule-based manner, emulators and other nonlinguistic brain systems, to gain complementary (and redundant) information during language processing. Emulators are therefore just one of several sources of information. We emphasize that whether a given word-form triggers activity in modality-specific brain regions depends on the linguistic context and not on the word-form as such. The role of modality-specific systems in language processing is thus not to help understanding words but to model the verbally depicted situation by supplying memorized context information. We present a model derived from these assumptions and provide predictions and perspectives for future research.

The Speech "Bamana": Using the Syllable Repetition Task to Identify Underlying Phonological Deficits in Children With Speech and Language Impairments

Purpose This study compared performance on the Syllable Repetition Task (SRT) by preschoolers with diverse speech and language abilities to identify underlying impairments in speech processes. Method Three groups of 13 children ages 4 and 5 years with (a) typically developing (TD) speech and language, (b) speech sound disorder (SSD), and (c) comorbid developmental language disorder and speech sound disorder (DLD + SSD) completed the SRT. We calculated competence, memory, encoding, and transcoding scores, as well as word-initial stress pattern and vowel accuracy. Results A 3 × 3 (Group × Syllable length) factorial multivariate analysis of covariance revealed group differences for all measures and syllable length differences for memory, transcoding, and competence. There were no interactions between group and syllable length. TD children obtained the highest scores on each measure, though children with DLD + SSD performed similarly to TD children on encoding when vocabulary was included as a covariate. Children with SSD only outperformed children with DLD + SSD on competence and transcoding, and these two groups performed similarly on memory. A separate exploratory analysis using a 3 × 3 multivariate analysis of covariance revealed that children with DLD + SSD were more likely than children in the other groups to produce weak word-initial stress and vowel errors during syllable repetition. Conclusion Children with SSD and DLD + SSD exhibit underlying phonological deficits on the SRT compared to TD children. Results support the claim that memory and encoding are deficits in SSD. In addition, transcoding deficits were identified among children with no known oromotor impairment. Therefore, more research is required to identify the relationship between SRT performance and explicit measures of phonological processing.

Bilingualism and Processing Speed in Typically Developing Children and Children With Developmental Language Disorder

Purpose The aim of the current study was to investigate whether dual language experience modulates processing speed in typically developing (TD) children and in children with developmental language disorder (DLD). We also examined whether processing speed predicted vocabulary and sentence-level abilities in receptive and expressive modalities. Method We examined processing speed in monolingual and bilingual school-age children (ages 8-12 years) with and without DLD. TD children (35 monolinguals, 24 bilinguals) and children with DLD (17 monolinguals, 10 bilinguals) completed a visual choice reaction time task. The Clinical Evaluation of Language Fundamentals, the Peabody Picture Vocabulary Test, and the Expressive Vocabulary Test were used as language measures. Results The children with DLD exhibited slower response times relative to TD children. Response time was not modified by bilingual experience, neither in children with typical development nor children with DLD. Also, we found that faster processing speed was related to higher language abilities, but this relationship was not significant when socioeconomic status was controlled for. The magnitude of the association did not differ between the monolingual and bilingual groups across the language measures. Conclusions Slower processing speed is related to lower language abilities in children. Processing speed is minimally influenced by dual language experience, at least within this age range. Supplemental Material https://doi.org/10.23641/asha.12210311.

Phonological and orthographic reading routes in French-speaking children with severe developmental language disorder

PURPOSE

This study aims to assess written word recognition in French-speaking children with severe developmental language disorder (DLD), using a task of reading in silence. The objective is to determine if the balance between the phonological reading route and the orthographic route of these children is similar to that of typically developing children, on the basis of the so-called "dual route" model.

METHOD

A visual lexical decision task was used in 19 children with severe DLD (average age: 11.01 years), 19 control children of the same reading level (RC children, average age: 8.12 years), and 19 children of the same chronological age (AC children, average age: 10.84 years). This task included words and pseudowords associated with these words: pseudohomophones, pseudowords phonologically close but visually distant to the true words, visually close but phonologically distant pseudowords.

RESULTS

The groups did not process the pseudowords in the same way. Children with severe DLD were more successful than RC children for pseudohomophones. They tended to be less successful for phonologically close and visually distant pseudowords. They were similarly successful for visually close and phonologically distant pseudowords. Children with severe DLD were less successful than AC children with each type of pseudowords.

CONCLUSIONS

These results suggest that children with severe DLD do not simply present a homogeneous delay in their ability to recognize written words but rather a deviant development compared to RC children, with a stronger reliance on the orthographic reading route compared to the phonological one. It is likely that the phonological difficulties of children with severe DLD have hindered the development of their phonological reading route which, in turn, have hindered the development of their orthographic route.

Embodied Semantics in a Second Language: Critical Review and Clinical Implications

The role of the sensorimotor system in second language (L2) semantic processing as well as its clinical implications for bilingual patients has hitherto been neglected. We offer an overview of the issues at stake in this under-investigated field, presenting the theoretical and clinical relevance of studying L2 embodiment and reviewing the few studies on this topic. We highlight that (a) the sensorimotor network is involved in L2 processing, and that (b) in most studies, L2 is differently embodied than L1, reflected in a lower degree or in a different pattern of L2 embodiment. Importantly, we outline critical issues to be addressed in order to guide future research. We also delineate the subsequent steps needed to confirm or dismiss the value of language therapeutic approaches based on embodiment theories as a complement of speech and language therapies in adult bilinguals.

Language as a Predictor of Motor Recovery: The Case for a More Global Approach to Stroke Rehabilitation

Stroke is the third leading cause of death in the developed world and the primary cause of adult disability. The most common site of stroke is the middle cerebral artery (MCA), an artery that supplies a range of areas involved in both language and motor function. As a consequence, many stroke patients experience a combination of language and motor deficits. Indeed, those suffering from Broca's aphasia have an 80% chance of also suffering hemiplegia. Despite the prevalence of multifaceted disability in patients, the current trend in both clinical trials and clinical practice is toward compartmentalization of dysfunction. In this article, we review evidence that aphasia and hemiplegia do not just coexist, but that they interact. We review a number of clinical reports describing how therapies for one type of deficit can improve recovery in the other and vice versa. We go on to describe how language deficits should be seen as a warning to clinicians that the patient is likely to experience motor impairment and slower motor recovery, aiding clinicians to optimize their choice of therapy. We explore these findings and offer a tentative link between language and arm function through their shared need for sequential action, which we term fluency. We propose that area BA44 (part of Broca's area) acts as a hub for fluency in both movement and language, both in terms of production and comprehension.

Children with specific language impairment are more likely to reach motor milestones late

BACKGROUND

Delayed language development without an obvious cause is considered an isolated developmental disorder and is called specific language impairment (SLI). SLI is probably the most prevalent developmental disorder in childhood with a generally cited prevalence of 7%. This study aimed to investigate whether SLI is always an isolated disorder or if children with SLI also have delayed motor development.

METHODS

We used data of an earlier study with a prospective nested case-control design in which developmental data were collected from child health care files. Cases were children (4-11 years) with diagnosed SLI. They were matched by sex and date of birth with control children attending mainstream education. Data of both groups on seven gross and six fine motor milestones which had been registered in the Dutch Developmental Instrument between the ages of 15-36 months were retrieved from child health care files. McNemar tests were performed to test for differences in reaching motor milestones at the age norm between the case and control group.

RESULTS

Data from 253 children in each group were available. A significant difference was found between both groups in the proportion failing to reach three of the seven investigated gross motor milestones at the age norm (p < 0.05). The proportion of children not reaching the motor milestone at the age norm was significantly higher for five of the six fine motor milestones in children with SLI compared with control children (p < 0.05).

CONCLUSIONS

More children with SLI are late in reaching motor milestones than children without SLI. This means that it is debatable whether SLI can be regarded as a "specific" impairment, which is not associated with other developmental problems. A broader developmental assessment is therefore indicated when diagnosing SLI.

Bilingualism and Procedural Learning in Typically Developing Children and Children With Language Impairment

PURPOSE

The aim of this study was to investigate whether dual language experience affects procedural learning ability in typically developing children and in children with specific language impairment (SLI).

METHOD

We examined procedural learning in monolingual and bilingual school-aged children (ages 8-12 years) with and without SLI. The typically developing children (35 monolinguals, 24 bilinguals) and the children with SLI (17 monolinguals, 10 bilinguals) completed a serial reaction time task.

RESULTS

The typically developing monolinguals and bilinguals exhibited equivalent sequential learning effects, but neither group with SLI exhibited learning of sequential patterns on the serial reaction time task.

CONCLUSION

Procedural learning does not appear to be modified by language experience, supporting the notion that it is a child-intrinsic language learning mechanism that is minimally malleable to experience.

Procedural Motor Learning in Children With Specific Language Impairment

PURPOSE

Specific language impairment (SLI) is a developmental disorder that affects language and motor development in the absence of a clear cause. An explanation for these impairments is offered by the procedural deficit hypothesis (PDH), which argues that motor difficulties in SLI are due to deficits in procedural memory. The aim of this study was to test the PDH by examining the procedural motor learning abilities of children with and without SLI.

METHOD

Thirteen children with SLI and 14 age-matched typically developing children completed the following procedural measures: (a) a knot-tying task as a measure of motor sequencing and (2) a mirror-drawing task as a measure of visual-motor adaptation.

RESULTS

Although children with SLI produced significantly more errors on certain knot-tying tasks, they performed comparably on others. Also, children with SLI performed comparably with typically developing children on the mirror-drawing task.

CONCLUSIONS

The PDH requires reframing. The sequence learning deficits in SLI are modest and specific to more difficult tasks. Visual-motor adaptation, on the other hand, appears to be unaffected in SLI.