Working, declarative and procedural memory in specific language impairment

Executive Function in SLI: Recent Advances and Future Directions

This paper provides a review of recent research on executive function abilities in children with specific language impairment (SLI). Across several studies, children with SLI are reported to perform worse than typically developing peers on measures of sustained attention, working memory, inhibition, and attention shifting. However, few studies have considered multiple executive function components simultaneously and even fewer have examined the underlying relationship between executive function deficits and impaired language acquisition. We argue that in order to fully understand the nature of executive function deficits in SLI, the field must move past simply identifying weaknesses to instead test models of executive function development and explore the nature of the relationship between executive function and language. Future research directions are recommended in order to achieve these goals.

Memory in language-impaired children with and without autism

Background

A subgroup of young children with autism spectrum disorders (ASD) have significant language impairments (phonology, grammar, vocabulary), although such impairments are not considered to be core symptoms of and are not unique to ASD. Children with specific language impairment (SLI) display similar impairments in language. Given evidence for phenotypic and possibly etiologic overlap between SLI and ASD, it has been suggested that language-impaired children with ASD (ASD + language impairment, ALI) may be characterized as having both ASD and SLI. However, the extent to which the language phenotypes in SLI and ALI can be viewed as similar or different depends in part upon the age of the individuals studied. The purpose of the current study is to examine differences in memory abilities, specifically those that are key “markers” of heritable SLI, among young school-age children with SLI, ALI, and ALN (ASD + language normal).

Methods

In this cross-sectional study, three groups of children between ages 5 and 8 years participated: SLI (n = 18), ALI (n = 22), and ALN (n = 20). A battery of cognitive, language, and ASD assessments was administered as well as a nonword repetition (NWR) test and measures of verbal memory, visual memory, and processing speed.

Results

NWR difficulties were more severe in SLI than in ALI, with the largest effect sizes in response to nonwords with the shortest syllable lengths. Among children with ASD, NWR difficulties were not associated with the presence of impairments in multiple ASD domains, as reported previously. Verbal memory difficulties were present in both SLI and ALI groups relative to children with ALN. Performance on measures related to verbal but not visual memory or processing speed were significantly associated with the relative degree of language impairment in children with ASD, supporting the role of verbal memory difficulties in language impairments among early school-age children with ASD.

Conclusions

The primary difference between children with SLI and ALI was in NWR performance, particularly in repeating two- and three-syllable nonwords, suggesting that shared difficulties in early language learning found in previous studies do not necessarily reflect the same underlying mechanisms.

Electronic supplementary material

The online version of this article (doi:10.1186/s11689-015-9111-z) contains supplementary material, which is available to authorized users.

'MetaTaal': enhancing complex syntax in children with specific language impairment--a metalinguistic and multimodal approach

BACKGROUND

Currently, most research on the effective treatment of morphosyntax in children with specific language impairment (SLI) pertains to younger children. In the last two decades, several studies have provided evidence that intervention for older school-age children with SLI can be effective. These metalinguistic intervention approaches teach grammatical rules explicitly and use shapes and colours as two-dimensional visual support. Reading or writing activities form a substantial part of these interventions. However, some children with SLI are poor readers and might benefit more from an approach that is less dependent on literacy skills.

AIMS

To examine the effectiveness of a combined metalinguistic and multimodal approach in older school-age children with SLI. The intervention was adapted to suit poor readers and targeted the improvement of relative clause production, because relative clauses still pose difficulties for older children with SLI.

METHODS & PROCEDURES

Participants were 12 monolingual Dutch children with SLI (mean age 11;2). All children visited a special school for children with speech and language disorders in the Netherlands. A quasi-experimental multiple-baseline design was chosen to evaluate the effectiveness of the intervention. A set of tasks was constructed to test relative clause production and comprehension. Two balanced versions were alternated in order to suppress a possible learning effect from multiple presentations of the tasks. After 3 monthly baseline measurements, the children received individual treatment with a protocolled intervention programme twice a week during 5 weeks. The tests were repeated directly post-therapy and at a retention measurement 3 months later. During the intervention programme, the speech therapist delivering the treatment remained blind to the test results.

OUTCOMES & RESULTS

No significant changes were found during the baseline measurements. However, measurement directly post-therapy showed that 5 h of intervention produced significant improvement on the relative clause production tasks, but not on the relative clause comprehension task. The gains were also maintained 3 months later.

CONCLUSIONS & IMPLICATIONS

The motor and tactile/kinesthetic dimensions of the 'MetaTaal' metalinguistic intervention approach are a valuable addition to the existing metalinguistic approaches. This study supports the evidence that grammatical skills in older school-age children with SLI can be remediated with direct intervention using a metalinguistic approach. The current tendency to diminish direct intervention for older children with SLI should be reconsidered.

Singing abilities in children with Specific Language Impairment (SLI)

Specific Language Impairment (SLI) is a heritable neurodevelopmental disorder diagnosed when a child has difficulties learning to produce and/or understand speech for no apparent reason (Bishop et al., 2012). The verbal difficulties of children with SLI have been largely documented, and a growing number of studies suggest that these children may also have difficulties in processing non-verbal complex auditory stimuli (Corriveau et al., 2007; Brandt et al., 2012). In a recent study, we reported that a large proportion of children with SLI present deficits in music perception (Planchou et al., under revision). Little is known, however, about the singing abilities of children with SLI. In order to investigate whether or not the impairments in expressive language extend to the musical domain, we assessed singing abilities in eight children with SLI and 15 children with Typical Language Development (TLD) matched for age and non-verbal intelligence. To this aim, we designed a ludic activity consisting of two singing tasks: a pitch-matching and a melodic reproduction task. In the pitch-matching task, the children were requested to sing single notes. In the melodic reproduction task, children were asked to sing short melodies that were either familiar (FAM-SONG and FAM-TUNE conditions) or unfamiliar (UNFAM-TUNE condition). The analysis showed that children with SLI were impaired in the pitch-matching task, with a mean pitch error of 250 cents (mean pitch error for children with TLD: 154 cents). In the melodic reproduction task, we asked 30 healthy adults to rate the quality of the sung productions of the children on a continuous rating scale. The results revealed that singing of children with SLI received lower mean ratings than the children with TLD. Our findings thus indicate that children with SLI showed impairments in musical production and are discussed in light of a general auditory-motor dysfunction in children with SLI.

A compensatory role for declarative memory in neurodevelopmental disorders

Most research on neurodevelopmental disorders has focused on their abnormalities. However, what remains intact may also be important. Increasing evidence suggests that declarative memory, a critical learning and memory system in the brain, remains largely functional in a number of neurodevelopmental disorders. Because declarative memory remains functional in these disorders, and because it can learn and retain numerous types of information, functions, and tasks, this system should be able to play compensatory roles for multiple types of impairments across the disorders. Here, we examine this hypothesis for specific language impairment, dyslexia, autism spectrum disorder, Tourette syndrome, and obsessive-compulsive disorder. We lay out specific predictions for the hypothesis and review existing behavioral, electrophysiological, and neuroimaging evidence. Overall, the evidence suggests that declarative memory indeed plays compensatory roles for a range of impairments across all five disorders. Finally, we discuss diagnostic, therapeutic and other implications.

Effective learning and retention of braille letter tactile discrimination skills in children with developmental dyslexia

Children with developmental dyslexia (DD) may differ from typical readers in aspects other than reading. The notion of a general deficit in the ability to acquire and retain procedural ('how to') knowledge as long-term procedural memory has been proposed. Here, we compared the ability of elementary school children, with and without reading difficulties (DD, typical readers), to improve their tactile discrimination with practice and tested the children's ability to retain the gains. Forty 10-11-year-olds practiced the tactile discrimination of four braille letters, presented as pairs, while blindfolded. In a trial, participants were asked to report whether the target stimuli were identical or different from each other. The structured training session consisted of six blocks of 16 trials each. Performance was re-tested at 24 hours and two weeks post-training. Both groups improved in speed and in accuracy. In session 1, children with DD started as significantly less accurate and were slower than the typical readers but showed rapid learning and successfully closed the gap. Only two children with DD failed to benefit from training and were not included in subsequent data analyses. At 24 hours post-training both groups showed effective retention of the gains in speed and accuracy. Importantly, children with DD were able to retain the gains in speed and accuracy, over a two-week interval as effectively as typical readers. Thus, children with DD were as effective in the acquisition and retention of tactile discrimination of braille letters as typical readers of the same age. The results do not support the notion of a general procedural learning disability in DD.

Core subjects at the end of primary school: identifying and explaining relative strengths of children with specific language impairment (SLI)

BACKGROUND

In general, children with specific language impairment (SLI) tend to fall behind their typically developing (TD) peers in educational attainment. Less is known about how children with SLI fare in particular areas of the curriculum and what predicts their levels of performance.

AIMS

To compare the distributions of performance of children with SLI in three core school subjects (English, Mathematics and Science); to test the possibility that performance would vary across the core subjects; and to examine the extent to which language impairment predicts performance.

METHODS & PROCEDURES

This study was conducted in England and reports historical data on educational attainments. Teacher assessment and test scores of 176 eleven-year-old children with SLI were examined in the three core subjects and compared with known national norms. Possible predictors of performance were measured, including language ability at ages 7 and 11, educational placement type, and performance IQ.

OUTCOMES & RESULTS

Children with SLI, compared with national norms, were found to be at a disadvantage in core school subjects. Nevertheless, some children attained the levels expected of TD peers. Performance was poorest in English; relative strengths were indicated in Science and, to a lesser extent, in Mathematics. Language skills were significant predictors of performance in all three core subjects. PIQ was the strongest predictor for Mathematics. For Science, both early language skills at 7 years and PIQ made significant contributions.

CONCLUSIONS & IMPLICATIONS

Language impacts on the school performance of children with SLI, but differentially across subjects. English for these children is the most challenging of the core subjects, reflecting the high levels of language demand it incurs. Science is an area of relative strength and mathematics appears to be intermediate, arguably because some tasks in these subjects can be performed with less reliance on verbal processing. Many children with SLI do have the potential to reach or exceed educational targets that are set at national levels for TD children.

Verbal declarative memory impairments in specific language impairment are related to working memory deficits

This study examined verbal declarative memory functioning in SLI and its relationship to working memory. Encoding, recall, and recognition of verbal information was examined in children with SLI who had below average working memory (SLILow WM), children with SLI who had average working memory (SLIAvg. WM) and, a group of non-language impaired children with average working memory (TDAvg. WM). The SLILow WM group was significantly worse than both the SLIAvg. WM and TDAvg. WM groups at encoding verbal information and at retrieving verbal information following a delay. In contrast, the SLIAvg. WM group showed no verbal declarative memory deficits. The study demonstrates that verbal declarative memory deficits in SLI only occur when verbal working memory is impaired. Thus SLI declarative memory is largely intact and deficits are likely to be related to working memory impairments.

The role of memory in processing relative clauses in children with specific language impairment

PURPOSE

This study investigated the relationship between 2 components of memory--phonological short-term memory (pSTM) and working memory (WM)--and the control of relative clause constructions in children with specific language impairment (SLI).

METHOD

Children with SLI and 2 control groups--an age-matched and a younger group of children with typical development--repeated sentences, including relative clauses, representing 5 syntactic roles and 2 levels of matrix clause complexity. The Working Memory Test Battery for Children was administered.

RESULTS

All 3 groups showed significant associations between pSTM and both types of matrix clause construction. For children with SLI, significant associations emerged between (a) WM and more complex matrix clause constructions, (b) WM and relative clauses including a range of syntactic roles, and (c) pSTM and the least difficult syntactic role. In contrast, the age-matched control group could repeat almost all syntactic roles without invoking the use of either memory component.

CONCLUSIONS

The role of pSTM and WM in the production of relative clauses by children with SLI is influenced by the degree of difficulty of the structure to be recalled. In therapy, the effect of WM limitations can be minimized by approaching each structure within the context of a simple matrix clause.

When words lead to solutions: executive function deficits in preschool children with specific language impairment

Several studies indicate that school-age children with specific language impairment (SLI) have difficulties with tasks that rely on executive functions. Whether executive function deficits in children with SLI emerge during preschool age remains unclear. Our aim was to fill this gap by investigating executive function performances in two age groups of preschoolers with and without SLI. Children with SLI (N=60; young: 53.6±5.3 months; old: 65.4±3.8 months) and age-matched control children (N=58) were tested for problem-representation ability, using the Flexible Item Selection Task (FIST), rule-use skills, using a Stroop-like Day-Night test (D/N), and planning skills, using the Tower of London test (TOL). Older children performed better than younger children did across tasks. Children with SLI had poorer performance, compared to typically developing children, on measures of problem representation, planning skills, and use of rules. Our results clearly indicate that executive function impairment is evident during the preschool period. Although old children with SLI performed better than young children with SLI, their performances were still poor, compared to those of control peers. These findings suggest that children with SLI have altered executive functioning at 53.6 months.

Evidence of compensatory processing in adults with developmental language impairment: testing the predictions of the procedural deficit hypothesis

BACKGROUND

The Procedural Deficit Hypothesis (PDH) proposes that individuals with primary developmental language impairment (DLI) have a deficient procedural memory, compromising their syntactic abilities. Individuals with DLI may compensate for procedural memory deficits by engaging declarative memory for syntactic tasks. Arguments are part of the lexicon whereas adjuncts rely on syntactic processing. As a result, individuals with DLI may have unusual difficulty processing adjuncts. Alternatively, processing for adjuncts may be typical for individuals with DLI but show frequency effects, indicating compensatory use of declarative memory.

AIMS

Our goal was to test the predictions of the PDH by comparing argument and adjunct processing times for adults with and without DLI, and to seek evidence of compensatory use of declarative memory for adjunct processing. We further evaluated group performance on measures of visual procedural and declarative memory.

METHODS AND PROCEDURES

Forty-four adults, 21 with DLI, completed a self-paced listening task, a procedural memory task, and a declarative memory task. The self-paced listening task tracked the word-by-word processing time for sentences that included prepositional phrases acting as arguments or adjuncts. We used regression analysis to determine effects of group membership and argument or adjunct status on processing times. Correlation analyses evaluated relationships between argument and adjunct frequency on processing times by group.

RESULTS AND OUTCOMES

We found no effect of group membership on the processing time for arguments and adjuncts in the self-paced listening task. Argument phrases were processed more easily by both groups. There were frequency effects for adjunct processing for the group with DLI, but not the group with typical language. We did not find the expected frequency effects for argument processing. The group with DLI also performed more poorly in both the procedural and declarative memory tasks. Secondary analyses found that non-verbal intelligence was related to outcomes on the declarative memory but not the procedural memory task.

CONCLUSIONS AND IMPLICATIONS

We found mixed evidence on the predictions of the PDH. Adults with DLI may compensate for procedural memory deficits but it is unclear whether this depends on declarative memory or language processing experience. Compensatory processing is an important element of the language profile for adults with DLI.

LEARNING OUTCOMES

The readers will be able to describe how processing arguments and adjuncts in sentences may depend on different memory systems, and how adults with developmental language impairment may compensate for syntactic processing deficits.

Differential verbal working memory effects on linguistic production in children with Specific Language Impairment

Deficits in verbal working memory (vWM) have often been reported in children with Specific Language Impairments (SLIs) and might significantly contribute to their linguistic difficulties. The linguistic and narrative skills of a group of children with diagnosis of SLI were compared to those of a group of children with typical development. The linguistic assessment included a comprehensive analysis of their lexical, grammatical and narrative abilities. Overall, the participants with SLI had difficulties at all three levels of linguistic processing. The effect of vWM was marginal on lexical processing, significant on grammatical structuring, and null on narrative construction.

Differences in the performance of children with specific language impairment and their typically developing peers on nonverbal cognitive tests: a meta-analysis

PURPOSE

This study used meta-analysis to investigate the difference in nonverbal cognitive test performance of children with specific language impairment (SLI) and their typically developing (TD) peers.

METHOD

The meta-analysis included studies (a) that were published between 1995 and 2012 of children with SLI who were age matched (and not nonverbal cognitive matched) to TD peers and given a norm-referenced nonverbal cognitive test and (b) that reported sufficient data for an effect size analysis. Multilevel modeling was used to examine the performance of children with SLI relative to their typically developing, age-matched peers on nonverbal IQ tests.

RESULTS

Across 138 samples from 131 studies, on average children with SLI scored 0.69 standard deviations below their TD peers on nonverbal cognitive tests after adjusting for the differences in the tests used, the low-boundary cutoff scores, the age of the participants, and whether studies matched the two groups on socioeconomic status.

DISCUSSION

The lower performance of children with SLI relative to TD children on nonverbal IQ tests has theoretical implications for the characterization of SLI and clinical and political implications regarding how nonverbal cognitive tests are used and interpreted for children with this disorder.

Impaired statistical learning of non-adjacent dependencies in adolescents with specific language impairment

Being able to track dependencies between syntactic elements separated by other constituents is crucial for language acquisition and processing (e.g., in subject-noun/verb agreement). Although long assumed to require language-specific machinery, research on statistical learning has suggested that domain-general mechanisms may support the acquisition of non-adjacent dependencies. In this study, we investigated whether individuals with specific language impairment (SLI)-who have problems with long-distance dependencies in language-also have problems with statistical learning of non-adjacent relations. The results confirmed this hypothesis, indicating that statistical learning may subserve the acquisition and processing of long-distance dependencies in natural language.

Procedural learning deficits in specific language impairment (SLI): a meta-analysis of serial reaction time task performance

Meta-analysis and meta-regression were used to evaluate whether evidence to date demonstrates deficits in procedural memory in individuals with specific language impairment (SLI), and to examine reasons for inconsistencies of findings across studies. The Procedural Deficit Hypothesis (PDH) proposes that SLI is largely explained by abnormal functioning of the frontal-basal ganglia circuits that support procedural memory. It has also been suggested that declarative memory can compensate for at least some of the problems observed in individuals with SLI. A number of studies have used Serial Reaction Time (SRT) tasks to investigate procedural learning in SLI. In this report, results from eight studies that collectively examined 186 participants with SLI and 203 typically-developing peers were submitted to a meta-analysis. The average mean effect size was .328 (CI95: .071, .584) and was significant. This suggests SLI is associated with impairments of procedural learning as measured by the SRT task. Differences among individual study effect sizes, examined with meta-regression, indicated that smaller effect sizes were found in studies with older participants, and in studies that had a larger number of trials on the SRT task. The contributions of age and SRT task characteristics to learning are discussed with respect to impaired and compensatory neural mechanisms in SLI.

Sequence-specific procedural learning deficits in children with specific language impairment

This study tested the procedural deficit hypothesis of specific language impairment (SLI) by comparing children’s performance in two motor procedural learning tasks and an implicit verbal sequence learning task. Participants were 7- to 11-year-old children with SLI (n = 48), typically developing age-matched children (n = 20) and younger typically developing children matched for receptive grammar (n = 28). In a serial reaction time task, the children with SLI performed at the same level as the grammar-matched children, but poorer than age-matched controls in learning motor sequences. When tested with a motor procedural learning task that did not involve learning sequential relationships between discrete elements (i.e. pursuit rotor), the children with SLI performed comparably with age-matched children and better than younger grammar-matched controls. In addition, poor implicit learning of word sequences in a verbal memory task (the Hebb effect) was found in the children with SLI. Together, these findings suggest that SLI might be characterized by deficits in learning sequence-specific information, rather than generally weak procedural learning.

Working memory performance and executive function behaviors in young children with SLI

The present study compared the performances of young children with specific language impairment (SLI) to that of typically developing (TD) children on cognitive measures of working memory (WM) and behavioral ratings of executive functions (EF). The Automated Working Memory Assessment was administered to 58 children with SLI and 58 TD children aged 4 and 5 years. Additionally, parents completed the Behavior Rating Inventory of Executive Function - Preschool Version. The results showed the SLI group to perform significantly worse than the TD group on both cognitive and behavioral measures of WM. The deficits in WM performance were not restricted to the verbal domain, but also affected visuospatial WM. The deficits in EF behaviors included problems with inhibition, shifting, emotional control, and planning/organization. The patterns of associations between WM performance and EF behaviors differed for the SLI versus TD groups. WM performance significantly discriminated between young children with SLI and TD, with 89% of the children classified correctly. The data indicate domain general impairments in WM and problems in EF behaviors in young children with SLI. Attention should thus be paid to WM - both verbal and visuospatial - and EF in clinical practice. Implications for assessment and remediation were discussed.

Hippocampal volume and memory performance in children with perinatal stroke

BACKGROUND

Pediatric neurologists and neonatologists often are asked to predict cognitive outcome after perinatal brain injury (including likely memory and learning outcomes). However, relatively few data exist on how accurate predictions can be made. Furthermore, although the consequences of brain injury on hippocampal volume and memory performance have been studied extensively in adults, little work has been done in children.

METHODS

We measured the volume of the hippocampus in 27 children with perinatal stroke and 19 controls, and measured their performance on standardized verbal and non-verbal memory tests.

RESULTS

We discovered the following: (1) As a group, children with perinatal stroke had smaller left and right hippocampi compared with control children. (2) Individually, children with perinatal stroke demonstrated 1 of 3 findings: no hippocampal loss, unilateral hippocampal loss, or bilateral hippocampal volume loss compared with control children. (3) Hippocampal volume inversely correlated with memory test performance in the perinatal stroke group, with smaller left and right hippocampal volumes related to poorer verbal and non-verbal memory test performance, respectively. (4) Seizures played a significant role in determining memory deficit and extent of hippocampal volume reduction in patients with perinatal stroke.

CONCLUSIONS

These findings support the view that, in the developing brain, the left and right hippocampi preferentially support verbal and nonverbal memory respectively, a consistent finding in the adult literature but a subject of debate in the pediatric literature. This is the first work to report that children with focal brain injury incurred from perinatal stroke have volume reduction in the hippocampus and impairments in certain aspects of declarative memory.

Improving comprehension in adolescents with severe receptive language impairments: a randomized control trial of intervention for coordinating conjunctions

BACKGROUND

Little evidence exists for the effectiveness of therapy for children with receptive language difficulties, particularly those whose difficulties are severe and persistent.

AIMS

To establish the effectiveness of explicit speech and language therapy with visual support for secondary school-aged children with language impairments focusing on comprehension of coordinating conjunctions in a randomized control trial with an assessor blind to group status.

METHODS & PROCEDURES

Fourteen participants (aged 11;3-16;1) with severe RELI (mean standard scores: CELF4 ELS = 48, CELF4 RLS = 53 and TROG-2 = 57), but higher non-verbal (Matrices = 83) and visual perceptual skills (Test of Visual Perceptual Skills (TVPS) = 86) were randomly assigned to two groups: therapy versus waiting controls. In Phase 1, the therapy group received eight 30-min individual sessions of explicit teaching with visual support (Shape Coding) with their usual SLT. In Phase 2, the waiting controls received the same therapy. The participants' comprehension was tested pre-, post-Phase 1 and post-Phase 2 therapy on (1) a specific test of the targeted conjunctions, (2) the TROG-2 and (3) a test of passives.

OUTCOMES & RESULTS

After Phase 1, the therapy group showed significantly more progress than the waiting controls on the targeted conjunctions (d = 1.6) and overall TROG-2 standard score (d = 1.4). The two groups did not differ on the passives test. After Phase 2, the waiting controls made similar progress to those in the original therapy group, who maintained their previous progress. Neither group showed progress on passives. When the two groups were combined, significant progress was found on the specific conjunctions (d = 1.3) and TROG-2 raw (d = 1.1) and standard scores (d = 0.9). Correlations showed no measures taken (including Matrices and TVPS) correlated significantly with progress on the targeted conjunctions or the TROG-2.

CONCLUSIONS & IMPLICATIONS

Four hours of Shape Coding therapy led to significant gains on comprehension of coordinating conjunctions which were maintained after 4 months. Given the significant progress at a group level and the lack of reliable predictors of progress, this approach could be offered to other children with similar difficulties to the participants. However, the intervention was delivered one-to-one by speech and language therapists, thus the effectiveness of this therapy method with other methods of delivery remains to be evaluated.

Sources of variation in developmental language disorders: evidence from eye-tracking studies of sentence production

Skilled sentence production involves distinct stages of message conceptualization (deciding what to talk about) and message formulation (deciding how to talk about it). Eye-movement paradigms provide a mechanism for observing how speakers accomplish these aspects of production in real time. These methods have recently been applied to children with autism spectrum disorder (ASD) and specific language impairment (LI) in an effort to reveal qualitative differences between groups in sentence production processes. Findings support a multiple-deficit account in which language production is influenced not only by lexical and syntactic constraints, but also by variation in attention control, inhibition and social competence. Thus, children with ASD are especially vulnerable to atypical patterns of visual inspection and verbal utterance. The potential to influence attentional focus and prime appropriate language structures are considered as a mechanism for facilitating language adaptation and learning.

Pediatric traumatic brain injury: language outcomes and their relationship to the arcuate fasciculus

Pediatric traumatic brain injury (TBI) may result in long-lasting language impairments alongside dysarthria, a motor-speech disorder. Whether this co-morbidity is due to the functional links between speech and language networks, or to widespread damage affecting both motor and language tracts, remains unknown. Here we investigated language function and diffusion metrics (using diffusion-weighted tractography) within the arcuate fasciculus, the uncinate fasciculus, and the corpus callosum in 32 young people after TBI (approximately half with dysarthria) and age-matched healthy controls (n=17). Only participants with dysarthria showed impairments in language, affecting sentence formulation and semantic association. In the whole TBI group, sentence formulation was best predicted by combined corpus callosum and left arcuate volumes, suggesting this "dual blow" seriously reduces the potential for functional reorganisation. Word comprehension was predicted by fractional anisotropy in the right arcuate. The co-morbidity between dysarthria and language deficits therefore seems to be the consequence of multiple tract damage.

Long-term memory: A review and meta-analysis of studies of declarative and procedural memory in specific language impairment

This review examined the status of long-term memory systems in specific language impairment (SLI), in particular declarative memory and aspects of procedural memory. Studies included in the review were identified following a systematic search of the literature and findings combined using meta-analysis. This review showed individuals with SLI are poorer than age matched controls in the learning and retrieval of verbal information from the declarative memory. However, there is evidence to suggest that the problems with declarative learning and memory for verbal information in SLI might be due to difficulties with verbal working memory and language. The learning and retrieval of non-verbal information from declarative memory appears relatively intact. In relation to procedural learning and memory, evidence indicates poor implicit learning of verbal information. Findings pertaining to nonverbal information have been mixed. This review of the literature indicates there are now substantial grounds for suspecting that multiple memory systems may be implicated in the impairment.

Children with specific language impairment are not impaired in the acquisition and retention of Pavlovian delay and trace conditioning of the eyeblink response

Three converging lines of evidence have suggested that cerebellar abnormality is implicated in developmental language and literacy problems. First, some brain imaging studies have linked abnormalities in cerebellar grey matter to dyslexia and specific language impairment (SLI). Second, theoretical accounts of both dyslexia and SLI have postulated impairments of procedural learning and automatisation of skills, functions that are known to be mediated by the cerebellum. Third, motor learning has been shown to be abnormal in some studies of both disorders. We assessed the integrity of face related regions of the cerebellum using Pavlovian eyeblink conditioning in 7-11year-old children with SLI. We found no relationship between oral language skills or literacy skills with either delay or trace conditioning in the children. We conclude that this elementary form of associative learning is intact in children with impaired language or literacy development.

Fine motor deficits in reading disability and language impairment: same or different?

Several studies have found evidence of motor deficits in poor readers. There is no obvious reason for motor and literacy skills to go together, and it has been suggested that both deficits could be indicative of an underlying problem with cerebellar function and/or procedural learning. However, the picture is complicated by the fact that reading problems often co-occur with oral language impairments, which have also been linked with motor deficits. This raises the question of whether motor deficits characterise poor readers when language impairment has been accounted for - and vice versa. We considered these questions by assessing motor deficits associated with reading disability (RD) and language impairment (LI). A large community sample provided a subset of 9- to 10-year-olds, selected to oversample children with reading and/or language difficulties, to give 37 children with comorbid LI + RD, 67 children with RD only, 32 children with LI only, and 117 typically-developing (TD) children with neither type of difficulty. These children were given four motor tasks that taxed speed, sequence, and imitation abilities to differing extents. Different patterns of results were found for the four motor tasks. There was no effect of RD or LI on two speeded fingertip tapping tasks, one of which involved sequencing of movements. LI, but not RD, was associated with problems in imitating hand positions and slowed performance on a speeded peg-moving task that required a precision grip. Fine motor deficits in poor readers may be more a function of language impairment than literacy problems.

The role of verbal and nonverbal memory in the Family Pictures Subtest: Data from children with specific language impairment

This study examined the contribution of verbal and visual memory to performance on the Family Pictures subtest of the Children's Memory Scale. This subtest purports to assess declarative memory functioning in the visual/nonverbal domain. A total of 115 nine-year-old children participated in this study. Fifty-eight had specific language impairment (SLI), whilst the remaining 57 were typically developing (TD), with no history of language difficulties. Results showed that the children with SLI, who had intact declarative memory for visual but not verbal information, obtained significantly lower scores on the Family Pictures subtest when compared to the TD group. Regression analyses revealed that across the entire sample, individual differences on the Family Pictures subtest was best predicted by a measure of verbal working memory. These results question whether the Family Pictures subtest can be considered a measure of visual memory in pediatric populations. These results have implications for the interpretation of scores on this subtest regarding the nature of the types of neurocognitive difficulties children may exhibit.

Aspects of grammar sensitive to procedural memory deficits in children with specific language impairment

Procedural deficit hypothesis claims that language deficit in children with specific language impairment is affiliated to sequence learning problems. However, studies did not explore on aspects of grammar vulnerable to sequence learning deficits. The present study makes predictions for aspects of grammar that could be sensitive to procedural deficits based on core ideas of procedural deficit hypothesis. The hypothesis for the present study was that the grammatical operations that require greater sequencing abilities (such as inflectional operations) would be more affected in children with language impairment. Further, the influence of sequencing difficulties would be even greater in agglutinating inflectional languages. An adapted serial reaction time task for sequence learning measurements along with grammatical tasks on derivation, inflection, and sentence complexity were examined on typically developing and language impaired children. Results were in favor of procedural deficit hypothesis and its close relation to non-adjacent grammatical operations. The findings were discussed using procedural deficits, declarative compensatory mechanism, and statistical learning deficits.

Clinical markers in Italian-speaking children with and without specific language impairment: a study of non-word and real word repetition as predictors of grammatical ability

BACKGROUND

In many languages a weakness in non-word repetition serves as a useful clinical marker of specific language impairment (SLI) in children. However, recent work in Italian has shown that the repetition of real words may also have clinical utility. For young typically developing Italian children, real word repetition is more predictive of particular grammatical abilities than is non-word repetition. This finding is important because these particular grammatical abilities--the production of present-tense third-person plural inflections and direct-object clitic pronouns--are precisely those that are problematic for Italian-speaking children with SLI. Along with their grammatical requirements, these two morpheme types present a significant phonological/prosodic challenge for these children.

AIMS

To replicate the findings with young typically developing Italian children and to determine whether real word repetition is also more predictive of the use of these two morpheme types than is non-word repetition in a group of Italian-speaking children with SLI.

METHODS & PROCEDURES

Seventeen Italian-speaking children with SLI and 17 younger typically developing children matched for mean length of utterance participated in tasks of real word and non-word repetition as well as tasks requiring the production of direct-object clitic pronouns and present-tense third-person plural inflections.

OUTCOMES & RESULTS

Children with SLI were less accurate than their younger peers on all measures. Importantly, for the younger typically developing children, real word repetition explained a significant amount of variance in the use of third-person plural inflections and direct-object clitic pronouns. For the children with SLI, in contrast, non-word repetition was a significant predictor, whereas real word repetition was not a contributing factor.

CONCLUSIONS & IMPLICATIONS

It is argued that in Italian SLI, the grammatical details showing the greatest weakness present phonological/prosodic obstacles as well as grammatical challenges to these children. Consequently, non-word repetition emerges as a predictor of these grammatical weaknesses in SLI, unlike the profile observed in typically developing Italian children.

Delay or deficit? Spelling processes in children with specific language impairment

Few studies have explored the phonological, morphological and orthographic spellings skills of children with specific language impairment (SLI) simultaneously. Fifteen children with SLI (mean age=113.07 months, SD=8.61) completed language and spelling tasks alongside chronological-age controls and spelling-age controls. While the children with SLI showed a deficit in phonological spelling, they performed comparably to spelling-age controls on morphological spelling skills, and there were no differences between the three groups in producing orthographically legal spellings. The results also highlighted the potential importance of adequate non-word repetition skills in relation to effective spelling skills, and demonstrated that not all children with spoken language impairments show marked spelling difficulties. Findings are discussed in relation to theory, educational assessment and practice.

LEARNING OUTCOMES

As a result of this activity, readers will describe components of spoken language that predict children's morphological and phonological spelling performance. As a result of this activity, readers will describe how the spelling skills of children with SLI compare to age-matched and spelling age-matched control children. Readers will be able to interpret the variability in spelling performance seen in children with SLI.

Visuospatial working memory in specific language impairment: a meta-analysis

We conducted a meta-analysis of the data from studies comparing visuospatial working memory (WM) in children with specific language impairment (SLI) and typically developing (TD) children. The effect sizes of 21 studies (including 32 visuospatial storage tasks and 9 visuospatial central executive (CE) tasks) were identified via computerized database searches and the reference sections of the identified studies. Meta-analyses and moderator analyses were conducted to examine the magnitude of the differences in visuospatial storage and CE, and their relation to the inclusion criteria used for SLI and the age of the children. The results showed significant effect sizes for visuospatial storage (d=0.49) and visuospatial CE (d=0.63), indicating deficits in both components of visuospatial WM in children with SLI. The moderator analyses showed that greater impairment in visuospatial storage was associated with more pervasive language impairment, whereas age was not significant associated with visuospatial WM. The finding of deficits in visuospatial WM suggests domain-general impairments in children with SLI. It raises questions about the language-specificity of a diagnosis of SLI. Careful attention should thus be paid to both verbal and visuospatial WM in clinical practice, and especially in those children with pervasive language impairments.

Abnormal subcortical components of the corticostriatal system in young adults with DLI: a combined structural MRI and DTI study

Developmental Language Impairment (DLI) is a neurodevelopmental disorder affecting 12% to 14% of the school-age children in the United States. While substantial studies have shown a wide range of linguistic and non-linguistic difficulty in individuals with DLI, very little is known about the neuroanatomical mechanisms underlying this disorder. In the current study, we examined the subcortical components of the corticostriatal system in young adults with DLI, including the caudate nucleus, the putamen, the nucleus accumbens, the globus pallidus, and the thalamus. Additionally, the four cerebral lobes and the hippocampus were also comprised for an exploratory analysis. We used conventional magnetic resonance imaging (MRI) to measure regional brain volumes, as well as diffusion tensor imaging (DTI) to assess water diffusion anisotropy as quantified by fractional anisotropy (FA). Two groups of participants, one with DLI (n=12) and the other without (n=12), were recruited from a prior behavioral study, and all were matched on age, gender, and handedness. Volumetric analyses revealed region-specific abnormalities in individuals with DLI, showing pathological enlargement bilaterally in the putamen and the nucleus accumbens, and unilaterally in the right globus pallidus after the intracranial volumes were controlled. Regarding the DTI findings, the DLI group showed decreased FA values in the globus pallidus and the thalamus but these significant differences disappeared after controlling for the whole-brain FA value, indicating that microstructural abnormality is diffuse and affects other regions of the brain. Taken together, these results suggest region-specific corticostriatal abnormalities in DLI at the macrostructural level, but corticostriatal abnormalities at the microstructural level may be a part of a diffuse pattern of brain development. Future work is suggested to investigate the relationship between corticostriatal connectivity and individual differences in language development.

Intact procedural motor sequence learning in developmental coordination disorder

The purpose of the present study was to explore the possibility of a procedural learning deficit among children with developmental coordination disorder (DCD). We tested 34 children aged 6-12 years with and without DCD using the serial reaction time task, in which the standard keyboard was replaced by a touch screen in order to minimize the impact of perceptuomotor coordination difficulties that characterize this disorder. The results showed that children with DCD succeed as well as control children at the procedural sequence learning task. These findings challenge the hypothesis that a procedural learning impairment underlies the difficulties of DCD children in acquiring and automatizing daily activities. We suggest that the previously reported impairment of children with DCD on the serial reaction time task is not due to a sequence learning deficit per se, but rather due to methodological factors such as the response mode used in these studies.

Procedural learning in specific language impairment: effects of sequence complexity

According to the procedural deficit hypothesis (PDH), abnormal development in the procedural memory system could account for the language deficits observed in specific language impairment (SLI). Recent studies have supported this hypothesis by using a serial reaction time (SRT) task, during which a slower learning rate is observed in children with SLI compared to controls. Recently, we obtained contrasting results, demonstrating that children with SLI were able to learn a sequence as quickly and as accurately as controls. These discrepancies could be related to differences in the statistical structure of the SRT sequence between these studies. The aim of this study was to further assess, in a group of 21 children with SLI, the PDH with second-order conditional sequences, which are more difficult to learn than those used in previous studies. Our results show that children with SLI had impaired procedural memory, as evidenced by both longer reaction times and no sign of sequence-specific learning in comparison with typically developing controls. These results are consistent with the PDH proposed by Ullman and Pierpont (2005) and suggest that procedural sequence-learning in SLI children depends on the complexity of the to-be-learned sequence.

Memory and language in middle childhood in individuals with a history of specific language impairment

This study reports on the sensitivity of sentence repetition as a marker of specific language impairment (SLI) in different subgroups of children in middle childhood and examines the role of memory and grammatical knowledge in the performance of children with and without language difficulties on this task. Eleven year old children, 197 with a history of SLI and 75 typically developing (TD) peers were administered sentence repetition, phonological short term memory (PSTM) and grammatical morphology tasks. Children with a history of SLI were divided into four subgroups: specific language impairment, non-specific language impairment, low cognition with resolved language and resolved. Performance on the sentence repetition task was significantly impaired in all four subgroups of children with a history of SLI when compared to their age peers. Regression analyses revealed grammatical knowledge was predictive of performance for TD children and children with a history of SLI. However, memory abilities were significantly predictive of sentence repetition task performance for children with a history of SLI only. Processes involved in sentence repetition are more taxing of PSTM for individuals with a history of SLI in middle childhood in a way that does not appear to be the case for TD children.

Video Games for Children and Adolescents With Special Educational Needs

Almost all children play video games at some point and many play regularly. Not only are games ubiquitous in children’s leisure environments but the motivational and skill-enhancing potentialities of this technology are being exploited increasingly in education. Good quality games, which are challenging, instructive, and absorbing, can make learning enjoyable and effective. But is this the case for children who struggle in school? This paper reviews the emerging literature on video game uses by children with special educational needs. With reference to both entertainment games and “serious” games, we consider (i) the implications of developmental and learning disabilities for game play, (ii) the potential of games to address special cognitive and educational needs, and (iii) the social potential of game play. Gaps in current knowledge are identified and directions for future research are outlined.

The role of verbal and nonverbal memory in the Family Pictures Subtest: data from children with specific language impairment

This study examined the contribution of verbal and visual memory to performance on the Family Pictures subtest of the Children's Memory Scale. This subtest purports to assess declarative memory functioning in the visual/nonverbal domain. A total of 115 nine-year-old children participated in this study. Fifty-eight had specific language impairment (SLI), whilst the remaining 57 were typically developing (TD), with no history of language difficulties. Results showed that the children with SLI, who had intact declarative memory for visual but not verbal information, obtained significantly lower scores on the Family Pictures subtest when compared to the TD group. Regression analyses revealed that across the entire sample, individual differences on the Family Pictures subtest was best predicted by a measure of verbal working memory. These results question whether the Family Pictures subtest can be considered a measure of visual memory in pediatric populations. These results have implications for the interpretation of scores on this subtest regarding the nature of the types of neurocognitive difficulties children may exhibit.

Reinforcement learning in young adults with developmental language impairment

The aim of the study was to examine reinforcement learning (RL) in young adults with developmental language impairment (DLI) within the context of a neurocomputational model of the basal ganglia-dopamine system (Frank, Seeberger, & O'Reilly, 2004). Two groups of young adults, one with DLI and the other without, were recruited. A probabilistic selection task was used to assess how participants implicitly extracted reinforcement history from the environment based on probabilistic positive/negative feedback. The findings showed impaired RL in individuals with DLI, indicating an altered gating function of the striatum in testing. However, they exploited similar learning strategies as comparison participants at the beginning of training, reflecting relatively intact functions of the prefrontal cortex to rapidly update reinforcement information. Within the context of Frank's model, these results can be interpreted as evidence for alterations in the basal ganglia of individuals with DLI.

Procedural visual learning in children with specific language impairment

PURPOSE

According to the procedural deficit hypothesis (PDH), difficulties in the procedural learning (PL) system may contribute to the language difficulties observed in children with specific language impairment (SLI).

METHOD

Fifteen children with SLI and their typically developing (TD) peers were compared on visual PL tasks-specifically, deterministic serial reaction time (SRT) tasks. In the first experiment, children with SLI and their TD peers performed the classical SRT task using a keyboard as response mode. In the second experiment, they performed the same SRT task but gave their responses through a touchscreen (instead of a keyboard) to reduce the motor and cognitive demands of the task.

RESULTS

Although in Experiment 1, children with SLI demonstrated learning, they were slower and made more errors than did their TD peers. Nevertheless, these relative weaknesses disappeared when the nature of the response mode changed ( Experiment 2).

CONCLUSIONS

In this study, the authors report that children with SLI may exhibit sequential learning. Moreover, the generally slower reaction times observed in previous deterministic SRT studies may be explained by the response mode used. Thus, our findings are not consistent with the predictions of the PDH, and these findings suggest that language impairments in SLI are not sustained by poor procedural learning abilities.

Dissociation between the procedural learning of letter names and motor sequences in developmental dyslexia

Motor sequence learning has been studied extensively in Developmental dyslexia (DD). The purpose of the present research was to examine procedural learning of letter names and motor sequences in individuals with DD and control groups. Both groups completed the Serial Search Task which enabled the assessment of learning of letter names and motor sequences independently of each other. Control participants learned both the letter names as well as the motor sequence. In contrast, individuals with DD were impaired in learning of the letter names sequence and showed a reliable transfer of the motor sequence. Previous studies proved that motor sequence learning is impaired in DD. The present study demonstrated that this deficit is more pronounced when the task to be learned involves linguistic units. This result implies that the procedural learning system of language is more deficient than the motor procedural learning system in individuals with DD. The dissociation between motor and letter names sequence learning in those with DD also implies that the systems underlying these two tasks are separable.

Grammar predicts procedural learning and consolidation deficits in children with Specific Language Impairment

The Procedural Deficit Hypothesis (PDH) posits that Specific Language Impairment (SLI) can be largely explained by abnormalities of brain structures that subserve procedural memory. The PDH predicts impairments of procedural memory itself, and that such impairments underlie the grammatical deficits observed in the disorder. Previous studies have indeed reported procedural learning impairments in SLI, and have found that these are associated with grammatical difficulties. The present study extends this research by examining consolidation and longer-term procedural sequence learning in children with SLI. The Alternating Serial Reaction Time (ASRT) task was given to children with SLI and typically developing (TD) children in an initial learning session and an average of three days later to test for consolidation and longer-term learning. Although both groups showed evidence of initial sequence learning, only the TD children showed clear signs of consolidation, even though the two groups did not differ in longer-term learning. When the children were re-categorized on the basis of grammar deficits rather than broader language deficits, a clearer pattern emerged. Whereas both the grammar impaired and normal grammar groups showed evidence of initial sequence learning, only those with normal grammar showed consolidation and longer-term learning. Indeed, the grammar-impaired group appeared to lose any sequence knowledge gained during the initial testing session. These findings held even when controlling for vocabulary or a broad non-grammatical language measure, neither of which were associated with procedural memory. When grammar was examined as a continuous variable over all children, the same relationships between procedural memory and grammar, but not vocabulary or the broader language measure, were observed. Overall, the findings support and further specify the PDH. They suggest that consolidation and longer-term procedural learning are impaired in SLI, but that these impairments are specifically tied to the grammatical deficits in the disorder. The possibility that consolidation and longer-term learning are problematic in the disorder suggests a locus of potential study for therapeutic approaches. In sum, this study clarifies our understanding of the underlying deficits in SLI, and suggests avenues for further research.