Imitation of body postures and hand movements in children with specific language impairment

Within the domain-general theory of language impairment, this study examined body posture and hand movement imitation in children with specific language impairment (SLI) and in their age-matched peers. Participants included 40 children with SLI (5 years 3 months to 6 years 10 months of age) and 40 children with typical language development (5 years 3 months to 6 years 7 months of age). Five tests were used to examine imitation and its underlying cognitive and motor skills such as kinesthesia, working memory, and gross motor coordination. It was hypothesized that children with SLI show a weakness in imitation of body postures and that this deficit is not equally influenced by the underlying cognitive and motor skills. There was a group effect in each cognitive and motor task, but only gross motor coordination proved to be a strong predictor of imitation in children with SLI. In contrast, hand movement imitation was strongly predicted by performance in the Kinesthesia task in typically developing children. Thus, the findings show not only that children with SLI performed more poorly on the imitation tasks than their typically developing peers but also that the groups’ performances showed qualitative differences. The results of the current study provide additional support to the view that the weaknesses in children with SLI are not limited to the verbal domain.     

Mirror-drawing skill in children with specific language impairment: Improving generalization by incorporating variability into the practice session

This study aimed to investigate the procedural deficit hypothesis (PDH) in children with specific language impairment (SLI) by using a mirror-drawing task, a sensorimotor adaptation paradigm that does not involve sequence learning and has never before been used in SLI. A total of 30 school-aged children with SLI matched to 30 typically developing (TD) control children had to trace several figures seen only in mirror-reversed view in two practice sessions separated by a one-week interval. Two practice conditions were compared: a constant condition in which children had to trace the same figure throughout the learning trials, and a variable one in which they had to trace different figures in each trial. The results revealed a similar learning pattern between SLI and TD children in both practice conditions, suggesting that initial learning for a non-sequential procedural task is preserved in SLI. However, the children with SLI generalized the mirror-drawing skill in the same way as the TD children only if there was variability in the way the material was trained (variable practice). No significant schedule effects were observed in the control group.     

The procedural learning deficit hypothesis of language learning disorders: we see some problems

Impaired procedural learning has been suggested as a possible cause of developmental dyslexia (DD) and specific language impairment (SLI). This study examined the relationship between measures of verbal and non‐verbal implicit and explicit learning and measures of language, literacy and arithmetic attainment in a large sample of 7 to 8‐year‐old children. Measures of verbal explicit learning were correlated with measures of attainment. In contrast, no relationships between measures of implicit learning and attainment were found. Critically, the reliability of the implicit learning tasks was poor. Our results show that measures of procedural learning, as currently used, are typically unreliable and insensitive to individual differences. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=YnvV-BvNWSo     

Auditory lexical decisions in children with specific language impairment

This study examined spoken‐word recognition in children with specific language impairment (SLI) and normally developing children matched separately for age and receptive language ability. Accuracy and reaction times on an auditory lexical decision task were compared. Children with SLI were less accurate than both control groups. Two subgroups of children with SLI, distinguished by performance accuracy only, were identified. One group performed within normal limits, while a second group was significantly less accurate. Children with SLI were not slower than the age‐matched controls or language‐matched controls. Further, the time taken to detect an auditory signal, make a decision, or initiate a verbal response did not account for the differences between the groups. The findings are interpreted as evidence for language‐appropriate processing skills acting upon imprecise or underspecified stored representations.     

Executive Functions in School‐age Children: Influence of Age,Gender, School Type and Parental Education

Summary: This study aimed to evaluate whether age, gender, type of school and parental education could predict executive performance in school‐age children. Unconstrained, phonemic and semantic verbal fluency tasks (n = 402), as well as the Hayling Sentence Completion Test (n = 275) and the Random Number Generation task (n = 274) were administered to typically developing 6‐to‐12‐year‐old children. A hierarchical regression analysis was performed (p ≤ 0.05). The most significant explanatory models involved child age and parental education, as well as these two variables in addition to the type of school attended by the child. The main individual predictors of executive performance were age and school type. These results may be related to structural and functional alterations in the brain, an increased repertoire of cognitive strategies, the effects of education and the intensity of environmental cognitive stimulation. These findings may contribute to the development of stimulation and intervention programs for EF in clinical and educational settings.Copyright © 2017 John Wiley & Sons, Ltd.     

Atypical inter‐hemispheric communication correlates with altered motor inhibition during learning of a new bimanual coordination pattern in developmental coordination disorder

Impairment of motor learning skills in developmental coordination disorder (DCD) has been reported in several studies. Some hypotheses on neural mechanisms of motor learning deficits in DCD have emerged but, to date, brain‐imaging investigations are scarce. The aim of the present study is to assess possible changes in communication between brain areas during practice of a new bimanual coordination task in teenagers with DCD (n = 10) compared to matched controls (n = 10). Accuracy, stability and number of mirror movements were computed as behavioural variables. Neural variables were assessed by electroencephalographic coherence analyses of intra‐hemispheric and inter‐hemispheric fronto‐central electrodes. In both groups, accuracy of the new coordination increased concomitantly with right intra‐hemispheric fronto‐central coherence. Compared to typically developing teenagers, DCD teenagers presented learning difficulties expressed by less stability, no stabilization of the new coordination and a greater number of mirror movements despite practice. These measures correlated with reduced inter‐hemispheric communication, even after practice of the new coordination. For the first time, these findings provide neuro‐imaging evidence of a kind of inter‐hemispheric ‘disconnection’ related to altered inhibition of mirror movements during motor learning in DCD.     

Children with autism can track others' beliefs in a competitive game

Theory of mind (ToM) development, assessed via ‘litmus’ false belief tests, is severely delayed in autism, but the standard testing procedure may underestimate these children's genuine understanding. To explore this, we developed a novel test involving competition to win a reward as the motive for tracking other players' beliefs (the ‘Dot‐Midge task’). Ninety‐six children, including 23 with autism (mean age: 10.36 years), 50 typically developing 4‐year‐olds (mean age: 4.40) and 23 typically developing 3‐year‐olds (mean age: 3.59) took a standard ‘Sally‐Ann’ false belief test, the Dot‐Midge task (which was closely matched to the Sally‐Ann task procedure) and a norm‐referenced verbal ability test. Results revealed that, of the children with autism, 74% passed the Dot‐Midge task, yet only 13% passed the standard Sally‐Ann procedure. A similar pattern of performance was observed in the older, but not the younger, typically developing control groups. This finding demonstrates that many children with autism who fail motivationally barren standard false belief tests can spontaneously use ToM to track their social partners’ beliefs in the context of a competitive game.     

Children's implicit attitude acquisition: Evaluative statements succeed,repeated pairings fail

From the earliest ages tested, children and adults show similar overall magnitudes of implicit attitudes toward various social groups. However, such consistency in attitude magnitude may obscure meaningful age‐related change in the ways that children (vs. adults) acquire implicit attitudes. This experiment investigated children's implicit attitude acquisition by comparing the separate and joint effects of two learning interventions, previously shown to form implicit attitudes in adults. Children (N = 280, ages 7–11 years) were taught about novel social groups through either evaluative statements (ES; auditorily presented verbal statements such as ‘Longfaces are bad, Squarefaces are good’), repeated evaluative pairings (REP; visual pairings of Longface/Squareface group members with valenced images such as a puppy or snake), or a combination of ES+REP. Results showed that children acquired implicit attitudes following ES and ES+REP, with REP providing no additional learning beyond ES alone. Moreover, children did not acquire implicit attitudes in four variations of REP, each designed to facilitate learning by systematically increasing verbal scaffolding to specify (a) the learning goal, (b) the valence of the unconditioned stimuli, and (c) the group categories of the conditioned stimuli. These findings underscore the early‐emerging role of verbal statements in children's implicit attitude acquisition, as well as a possible age‐related limit in children's acquisition of novel implicit attitudes from repeated pairings.     

Verbal fluency deficits in children with specific language impairment: slow rapid naming or slow to name?

This study examined aspects of verbal fluency performance of children with Specific Language Impairment (SLI) and typically developing children matched on age and Block Design scores. While children with SLI showed deficits in verbal fluency compared to their peers, they showed the same pattern of performance on phonemic compared to semantic fluency trials. Children with SLI and normally developing children also demonstrated equivalent rates of clustering and switching, measures hypothesized to reflect aspects of frontal lobe functioning, when the overall number of exemplars was taken into account. The absence of a condition by group effect supports general processing limitation accounts of SLI, while the absence of group differences on cluster size and switches supports language-based processing accounts of SLI.     

Verbal Fluency Deficits in Children With Specific Language Impairment: Slow Rapid Naming or Slow to Name?

This study examined aspects of verbal fluency performance of children with Specific Language Impairment (SLI) and typically developing children matched on age and Block Design scores. While children with SLI showed deficits in verbal fluency compared to their peers, they showed the same pattern of performance on phonemic compared to semantic fluency trials. Children with SLI and normally developing children also demonstrated equivalent rates of clustering and switching, measures hypothesized to reflect aspects of frontal lobe functioning, when the overall number of exemplars was taken into account. The absence of a condition by group effect supports general processing limitation accounts of SLI, while the absence of group differences on cluster size and switches supports language-based processing accounts of SLI.     

Artificial grammar learning in children: abstraction of rules or sensitivity to perceptual features?

We examined sensitivity to grammatical sequences of colors in an artificial grammar learning task in a sample of 120 children aged between 5 and 8 years. The aim of the experiment was to test whether the children would preferentially learn the specific salient features of the items they were exposed to or the rules that generated these items. The children were divided into two experimental groups (identical grammar but training items differing in their surface features) and a control group (random items). The results showed that regardless of age, participants learned the most frequent salient features of the items, as well as some kind of abstract relational information. However, the 8-year-olds presented a more complex result profile, with one of the experimental groups apparently developing sensitivity to grammatical rules. These results are discussed with reference to the main current models of implicit learning. Overall, the results provided more support for stimulus-specific processing models than for rule-based models.     

A cross‐syndrome study of the differential effects of sleep on declarative memory consolidation in children with neurodevelopmental disorders

Sleep plays an active role in memory consolidation. Because children with Down syndrome (DS) and Williams syndrome (WS) experience significant problems with sleep and also with learning, we predicted that sleep‐dependent memory consolidation would be impaired in these children when compared to typically developing (TD) children. This is the first study to provide a cross‐syndrome comparison of sleep‐dependent learning in school‐aged children. Children with DS (n = 20) and WS (n = 22) and TD children (n = 33) were trained on the novel Animal Names task where they were taught pseudo‐words as the personal names of ten farm and domestic animals, e.g. Basco the cat, with the aid of animal picture flashcards. They were retested following counterbalanced retention intervals of wake and sleep. Overall, TD children remembered significantly more words than both the DS and WS groups. In addition, their performance improved following night‐time sleep, whereas performance over the wake retention interval remained stable, indicating an active role of sleep for memory consolidation. Task performance of children with DS did not significantly change following wake or sleep periods. However, children with DS who were initially trained in the morning continued to improve on the task at the following retests, so that performance on the final test was greater for children who had initially trained in the morning than those who trained in the evening. Children with WS improved on the task between training and the first retest, regardless of whether sleep or wake occurred during the retention interval. This suggests time‐dependent rather than sleep‐dependent learning in children with WS, or tiredness at the end of the first session and better performance once refreshed at the start of the second session, irrespective of the time of day. Contrary to expectations, sleep‐dependent learning was not related to baseline level of performance. The findings have significant implications for educational strategies, and suggest that children with DS should be taught more important or difficult information in the morning when they are better able to learn, whilst children with WS should be allowed a time delay between learning phases to allow for time‐dependent memory consolidation, and frequent breaks from learning so that they are refreshed and able to perform at their best.     

Nonword repetition in specific language impairment: More than a phonological short-term memory deficit

The possible role of phonological short-term memory in the nonword repetition deficit of children with specific language impairment (SLI) was investigated in a study comparing serial recall and nonword repetition of sequences of auditorily presented CV syllables. The SLI group showed impairments in both serial recall and nonword repetition relative to typically developing children of the same age, however the SLI deficit in nonword repetition was greater and persisted even when differences on an independent measure of short-term memory were taken into account. These findings cannot be readily explained in terms of a sole deficit in short-term memory, and point instead to differences between the serial recall and nonword repetition paradigms as potential factors contributing to this disorder of learning.     

Procedural learning: A developmental study of motor sequence learning and probabilistic classification learning in school-aged children

In this study, we investigated motor and cognitive procedural learning in typically developing children aged 8–12 years with a serial reaction time (SRT) task and a probabilistic classification learning (PCL) task. The aims were to replicate and extend the results of previous SRT studies, to investigate PCL in school-aged children, to explore the contribution of declarative knowledge to SRT and PCL performance, to explore the strategies used by children in the PCL task via a mathematical model, and to see whether performances obtained in motor and cognitive tasks correlated. The results showed similar learning effects in the three age groups in the SRT and in the first half of the PCL tasks. Participants did not develop explicit knowledge in the SRT task whereas declarative knowledge of the cue–outcome associations correlated with the performances in the second half of the PCL task, suggesting a participation of explicit knowledge after some time of exposure in PCL. An increasing proportion of the optimal strategy use with increasing age was observed in the PCL task. Finally, no correlation appeared between cognitive and motor performance. In conclusion, we extended the hypothesis of age invariance from motor to cognitive procedural learning, which had not been done previously. The ability to adopt more efficient learning strategies with age may rely on the maturation of the fronto-striatal loops. The lack of correlation between performance in the SRT task and the first part of the PCL task suggests dissociable developmental trajectories within the procedural memory system.     

Bilingualism alters children's frontal lobe functioning for attentional control

Bilingualism is a typical linguistic experience, yet relatively little is known about its impact on children's cognitive and brain development. Theories of bilingualism suggest that early dual‐language acquisition can improve children's cognitive abilities, specifically those relying on frontal lobe functioning. While behavioral findings present much conflicting evidence, little is known about its effects on children's frontal lobe development. Using functional near‐infrared spectroscopy (fNIRS), the findings suggest that Spanish–English bilingual children (n = 13, ages 7–13) had greater activation in left prefrontal cortex during a non‐verbal attentional control task relative to age‐matched English monolinguals. In contrast, monolinguals (n = 14) showed greater right prefrontal activation than bilinguals. The present findings suggest that early bilingualism yields significant changes to the functional organization of children's prefrontal cortex for attentional control and carry implications for understanding how early life experiences impact cognition and brain development.     

The role of procedural memory in grammar and numeracy skills

The objective of this study was to examine the contribution of procedural memory to grammar and numeracy skills, which both involve the manipulation of abstract patterns. Seventy-six typically developing children between 5 and 7 years of age were assessed on grammar with a past tense production task and a sentence comprehension task, on numeracy with a counting task and a calculation task, and on procedural memory with a serial reaction time task. Moderate correlations were found between the measures of grammar and numeracy. Moreover, 4 hierarchical linear regressions indicated that procedural memory was associated with calculation but not with counting or grammar skills when age and working memory were taken into account. These novel findings suggest that procedural memory may have a role to play in the development of some numeracy skills. Several possible explanations for the absence of contribution to grammar are considered.     

Motor skill learning in children with and without Developmental Coordination Disorder

ObjectiveThe question whether children with DCD have motor learning deficits is difficult to answer based on the current body of knowledge. The aim of this study was to examine the impact of practice on motor skill acquisition, retention and transfer in children with and without DCD using a variety of games in a virtual environment.MethodPerformance on a criterion task (Wii ski game) and MABC-2 balance subscore was compared between children with DCD (n = 33) and TD children (n = 28) following 10 weeks of playing active video games. Repeated measures ANOVA was used to compare changes in the two groups.ResultsThe children with DCD demonstrated lower performance on the criterion task than the TD group (p = 0.031). A time by group interaction indicated that the difference in performance on the criterion task became larger over time (p = 0.039). No differences were found in retention between groups. Large improvement (Cohen d 1.11) was observed for the children with DCD on the MABC-2 balance subscore.ConclusionBased on the criterion task results, typically developing children seem more proficient in learning new skills compared to children with DCD. More research is needed to confirm that children with DCD have a problem to transfer skills to other contexts.     

Limits on efficient human mindreading: Convergence across Chinese adults and Semai children

We tested Apperly and Butterfill's (2009, Psychological Review, 116, 753) theory that humans have two mindreading systems whereby the efficient‐system guiding anticipatory glances displays signature limits that do not apply to the flexible system guiding verbal predictions. Experiments 1 and 2 tested urban Mainland‐Chinese adults (n = 64) and Experiment 3 tested Semai children living in the rainforests of Peninsular Malaysia (3‐ to 4‐year‐olds, n = 60). Participants – across different ages, groups and methods – anticipated others’ false‐beliefs about object‐location but not object‐identity. Convergence in signature limits signalled that the early‐developing efficient system involved minimal theory‐of‐mind. Chinese adults and older Semai children showed flexibility in their direct predictions. The flexible mindreading system in ascribing others’ beliefs as such was task‐sensitive and implicated maturational and cultural contributions.     

Grammaticality sensitivity in children with early focal brain injury and children with specific language impairment

Grammaticality judgments and processing times associated with violation detection were examined in typically developing children, children with focal brain lesions (FL) acquired early in life, and children with specific language impairment (SLI). Grammatical sensitivity in the FL group, while below typically developing children, was above levels seen in children with SLI. Age effects were noted with developmental changes in sensitivity extending into adolescence. Developmental delays in grammatical processing were particularly pronounced for children with SLI, who showed sensitivity levels below those of younger typically developing children. Sensitivity to agreement violations was also protracted in the SLI group providing further evidence of the vulnerability of morphology, a pattern not unlike that seen in adult aphasics. Findings for the FL group provide compelling evidence of neural and behavioral plasticity in children with early unilateral brain injury. Moreover, results from these children underscore how very different compensatory organization may be compared to profiles seen in adult aphasics who have comparable lesions. In contrast, although it was expected that the SLI children would perform below the typically developing children, the disadvantage seen with respect to the FL group suggests that the underlying pathology responsible for SLI may be more pervasive and less plastic than the focal pathology of children with early brain damage.