Procedural learning and automatization process in children with developmental coordination disorder and/or developmental dyslexia

ObjectiveThere is increasing evidence to suggest that developmental dyslexia (DD) and developmental coordination disorder (DCD) actually form part of a broader disorder. Their frequent association could be justified by a deficit of the procedural memory system, that subtends many of the cognitive, motor and linguistic abilities that are impaired in both DD and DCD. However, studies of procedural learning in these two disorders have yielded divergent results, and in any case no studies have so far addressed the issue of automatization (dual-task paradigm).MethodsWe administered a finger tapping task to participants aged 8–12 years (19 DCD, 18 DD, and 22 with both DD and DCD) to explore procedural learning and automatic movements in these three groups of children, comparing motor performances at the prelearning stage, after 2 weeks of training, and in a post-training dual-task condition.ResultsFirst, results indicated that all the children were able to learn a sequence of movements and even automatize their movements. Second, they revealed between-groups differences in procedural/automatization learning abilities, setting the DCD group apart from the other two. Third, contrary to our expectations concerning comorbidity, they suggested that the DD + DCD association does not have an additional impact on behavioral performances.     

Visuospatial working memory for locations,colours, and binding in typically developing children and in children with dyslexia and non‐verbal learning disability

This study examined forward and backward recall of locations and colours and the binding of locations and colours, comparing typically developing children – aged between 8 and 10 years – with two different groups of children of the same age with learning disabilities (dyslexia in one group, non‐verbal learning disability [NLD] in the other). Results showed that groups with learning disabilities had different visuospatial working memory problems and that children with NLD had particular difficulties in the backward recall of locations. The differences between the groups disappeared, however, when locations and colours were bound together. It was concluded that specific processes may be involved in children in the binding and backward recall of different types of information, as they are not simply the resultant of combining the single processes needed to recall single features.     

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.     

Working memory, reading, and mathematical skills in children with developmental coordination disorder

The aim of the present study was investigate the relationship between working memory and reading and mathematical skills in 55 children diagnosed with developmental coordination disorder (DCD). The findings indicate a pervasive memory deficit in all memory measures. In particular, deficits observed in visuospatial short-term and working memory tasks were significantly worse than in the verbal short-term memory ones. On the basis of these deficits, the sample was divided into high and low visuospatial memory ability groups. The low visuospatial memory group performed significantly worse on the attainment measures compared to the high visuospatial memory group, even when the contribution of IQ was taken into account. When the sample was divided into high and low verbal working memory ability groups, verbal working memory skills made a unique contribution to attainment only when verbal IQ was taken into account, but not when performance IQ was statistically controlled. It is possible that the processing demands of the working memory tasks together with the active motor component reflected in the visuospatial memory tasks and performance IQ subtest both play a crucial role in learning in children with DCD.     

Testing predictive control of movement in children with developmental coordination disorder using converging operations

Recent systematic reviews (Wilson et al., 2013, Dev. Med. Child Neurol., 55, 217; Adams et al., 2014, Neurosci. Biobehav. Rev., 47C, 225) suggest that a common underlying problem in developmental coordination disorder (DCD) is the internal modelling deficit. The study presented here is the first to test this hypothesis using a within‐subject design, assessing motor imagery, action planning, and rapid online control (ROC) in a sample of children screened rigorously for DCD. Participants were 66 children; 33 children (26 boys and seven girls) aged 6–11 years in the DCD group and 33 controls (gender and age matched). Motor imagery was assessed with the hand rotation task (HRT), action planning with an end‐state comfort effect test, and ROC with the double‐step pointing task. Results showed that children with DCD were slower and less accurate than controls in the HRT. Reduced forward planning for comfortable end‐state was also shown in DCD. Finally, no group differences were found on the ROC task. Collectively, children with DCD manifest deficits in the internal modelling of movements, but this varies under different task constraints, particularly those related to movement complexity.     

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.     

Comparison of motor praxis and performance in children with varying levels of developmental coordination disorder

The praxis test is a less well-documented method to determine functional manifestations of childhood dyspraxia. For this study, children aged 6–8 years were recruited as follows: 17 children with DCD, 18 at risk of DCD and 35 without obvious problems in motor coordination. The Movement Assessment Battery for Children (MABC-2) was used to measure motor performance and identify the motor incoordination. This study developed a battery of tests to assess limb praxis using a praxis imagery questionnaire, gesture representation, and questions about knowledge of object use. In the comparison of subtests within the praxis test, significant differences were observed across groups on the praxis imagery questionnaire and gesture representation tests but not on knowledge of object use. Similar results were observed in the correlation analyses, in which a weak relationship between MABC-2 and praxis tests was observed. The DCD group had lower scores on the praxis imagery questionnaire, whereas the group at risk of DCD had lower scores on most gesture production tests. Our study provides a better understanding of the nature of the childhood dyspraxia and sheds light on its effect on motor coordination to identify praxis tests with specific clinical meanings in children with movement disorders.     

Motor imagery ability and internal representation of movement in children with probable developmental coordination disorder

It has been hypothesised that deficits in the functioning of the mirror neuron system (MNS) and internal modelling may contribute to the motor impairments associated with DCD. These processes can be explored behaviourally through motor imagery paradigms. Motor imagery proficiency of children with and without probable DCD (pDCD) was examined using a complex hand rotation task to explore whether motor imagery strategies could be used during more complex tasks. Forty-four boys aged 7–13 years participated, 22 with pDCD (mean = 9.90 years ± 1.57) and 22 controls (mean = 9.68 years ± 1.53). Participants completed the task twice: with and without motor imagery instructions. Stimuli were presented in two rotational axes – palm/back, and eight 45° rotational steps. Both groups showed evidence of following the biomechanical and postural constraints of actual movements. Responses of children with pDCD were slower and less accurate than controls, with group differences increasing alongside task complexity. A greater impact of biomechanical constraints for accuracy was observed in the DCD group. The response characteristics of children with pDCD likely reflects a reduced capacity to mentally manipulate a body schema and reduced visuo-motor processing capabilities. Behaviourally, these processes are linked to MNS and internal modelling function, suggesting deficits in these systems may contribute to the movement difficulties characteristic of DCD.     

Effects of exercise intervention on event-related potential and task performance indices of attention networks in children with developmental coordination disorder

The study investigated whether 10-week soccer training can benefit the inhibitory control and neuroelectric indices in children with developmental coordination disorder (DCD). Fifty-one children were divided into groups of typically developing (TD, n=21), DCD-training (n=16), and DCD non-training (n=14) individuals using the for Children test, and, before and after training, were assessed with the visuospatial attention orienting task with their lower extremities, while brain event-related potentials (ERPs) were concurrently recorded. The results indicated that, when compared to TD children, children with DCD responded significantly more slowly across conditions of the visuospatial attention orienting task and showed a deficit of inhibitory control capacity in their lower extremities, whereas no group differences were observed for the accuracy rate. Neuroelectric data indicated that, before training, P3 amplitude was smaller and P3 latency was slower for both DCD groups compared to TD children across conditions of the visuospatial attention orienting task; after training, the beneficial effects were seen in the strength of inhibitory control and P3 latency in the DCD-training group. The data suggest that soccer training resulted in significant improvements in ERP and task performance indices for the children with DCD.     

The prevalence of specific learning disorder in mathematics and comorbidity with other developmental disorders in primary school-age children

Mathematics difficulties are common in both children and adults, and they can have a great impact on people's lives. A specific learning disorder in mathematics (SLDM or developmental dyscalculia) is a special case of persistent mathematics difficulties, where the problems with maths cannot be attributed to environmental factors, intellectual disability, or mental, neurological or physical disorders. The aim of the current study was to estimate the prevalence rate of SLDM, any gender differences in SLDM, and the most common comorbid conditions. The DSM-5 provides details regarding these only for specific learning disorders in general, but not specifically for SLDM. We also compared the prevalence rates obtained on the basis of the DSM-IV and DSM-5 criteria. We investigated the performance of 2,421 primary school children on standardized tests of mathematics, English, and IQ, and several demographic factors over the primary school years. We applied the DSM-5 diagnostic criteria to identify children with a potential diagnosis of SLDM. Six per cent of our sample had persistent, severe difficulties with mathematics, and, after applying the exclusion criteria, 5.7% were identified as having an SLDM profile. Both persistent maths difficulties and consistently exceptionally high performance in maths were equally common in males and females. About half of the children with an SLDM profile had some form of language or communication difficulty. Some of these children also had a diagnosis of autism, social, emotional, and behavioural difficulties or attention deficit and hyperactivity disorder. Our findings have important implications for research and intervention purposes, which we discuss in the study.     

Inhibitory response capacities of bilateral lower and upper extremities in children with developmental coordination disorder in endogenous and exogenous orienting modes

This study was designed to investigate separately the inhibitory response capacity and the lateralization effect in children with developmental coordination disorder (DCD) in the endogenous and exogenous modes of orienting attention. Children with DCD on the lower extremities (DCD-LEs), along with age-matched controls, completed four tasks that involved various applications of asynchronous stimuli to the feet or hands at various intervals. The results demonstrated that children with DCD-LEs had a significantly longer reaction time than the controls for all tasks, and were not alert to the appearance of the target. However, they displayed a deficit in volitional shifts of attention (endogenous mode), but not in automatic dislocation of attention (exogenous mode), whenever they performed the tasks with either their lower or their upper-limbs-even 6 months after the initial study. These findings confirm the deficit in the inhibitory response capacity in terms of volitional movement of attention by children with DCD. Additionally, the negative effect of lateralization on the bilateral extremities was not present in children with DCD-LEs. Significantly differences in response ability were detected only between the dominant and non-dominant sides of upper-limbs, but not between the lower-limbs, suggesting a future avenue for further experimentation on bilateral extremities.     

A cross‐cultural comparison of verbal learning and memory functions in reading disabled American and Norwegian adolescents

The present study reports the results of a cross‐cultural analysis of the role of phonetic and semantic cues in verbal learning and memory. A newly developed memory test procedure, the Bergen‐Tucson Verbal Learning Test (BTVLT), expands earlier test procedures as phonetic cues are applied in addition to semantic cues in a cued recall procedure. Samples of reading disabled and typically developed adolescents from the US and from Norway were recruited as voluntary participants. The results indicate that the stimulus materials chosen for the memory test are working well in both American and in Norwegian samples, yielding acquisition results comparable to similar list learning procedures, and also yielding high internal consistency across learning trials. The procedure also reliably differentiates between reading disabled samples in both languages, and also yields cross‐cultural differences that seem to reflect differences in transparency and differences in the orthography of the included languages. The BTVLT with its focus on phonetic coding is a promising supplement to established tests of verbal memory for assessment of reading and language impaired individuals.     

Associations of physical activity and gross motor skills with executive function in preschool children from low‐income South African settings

Executive function is foundational for cognitive development. Previous research has shown both gross motor skills and physical activity to be related to executive function. However, evidence for these relationships in the preschool years, as well as in low‐ and middle‐income countries is lacking. Therefore, this study aimed to investigate the relationships between components of executive function (inhibition, shifting and working memory) and gross motor skills (locomotor skills and object control skills) in a sample of preschool children from urban and rural low‐income settings in South Africa. Results revealed that inhibition and working memory, but not shifting, were associated with gross motor skills. More specifically: inhibition was associated with both locomotor [β = 0.20, p = 0.047] and object control skills [β = 0.24, p = 0.024], whereas working memory was only associated with locomotor skills [β = 0.21, p = 0.039]. Physical activity was not associated with inhibition and shifting but was negatively associated with working memory. These results elaborate a growing evidence base linking executive function and gross motor skills in the early years, and it is the first to look at specific associations of locomotor and object control skills with executive function in the South African context (a low‐ and middle‐income country).     

The effect of a motor skills training program in the improvement of practiced and non-practiced tasks performance in children with developmental coordination disorder (DCD)

The purpose of the present study was to examine the effect of a group-based task oriented skills training program on motor and physical ability for children with DCD. It was also investigated if there was an effect on fine motor and handwriting tasks that were not specifically practiced during the training program. Forty-one children aged 6–10 years took part in this study. Children were assigned to three groups: an experimental training group consisting of 14 children with DCD, a control non-training group consisted of 13 children with DCD and a control non-training group consisting of 14 typically developed children. The measurements included were, the Movement Assessment Battery for Children (MABC), the Modified Agility Test (MAT), the Triple Hop Distance (THD), the 5 Jump-test (5JT) and the Handwriting Performance Test. All measures were administered pre and post an 8-week training program. The results showed that 10 children of the DCD training-group improved their performance in MABC test, attaining a score above the 15th percentile after their participation in the training program. DCD training-group showed a significant improvement on all cluster scores (manual dexterity (t (13) = 5.3, p < .001), ball skills (t (13) = 2.73, p < .05) and balance (t (13) = 5.13, p < .001). Significant performance improvements were also found in MAT, THD, 5JT (t (13) = –4.55; p < .01), handwriting quality (t (12) = –2.73; p < .05) and speed (t (12) = –4.2; p < .01) after the training program. In conclusion, improvement in both practiced and non-practiced skills, in the training program, may reflect improvement in motor skill but also transfer to other skills.     

Establishing initial auditory‐visual conditional discriminations and emergence of initial tacts in young children with autism spectrum disorder

Children with autism spectrum disorder (ASD) often display impaired listener skills, and few studies have evaluated procedures for establishing initial auditory‐visual conditional discrimination skills. We developed and evaluated a treatment package for training initial auditory‐visual conditional discriminations based on the extant research on training such discriminations in children with ASD with at least some preexisting skills in this area. The treatment package included (a) conditional‐only training, (b) prompting the participant to echo the sample stimulus as a differential observing response, (c) prompting correct selection responses using an identity‐match prompt, (d) using progressively delayed prompts, and (e) repeating trials until the participant emitted an independent correct response. Results indicated all participants mastered all listener targets, and the two participants for whom we tested the emergence of corresponding tacts showed mastery of most tacts without direct training. We discuss these results relative to prior research on listener skills and tacts.     

Recovery from post‐traumatic stress disorder in children following road traffic accidents: the role of talking and feeling understood

Forty children were assessed 6 weeks and 8 months after involvement in a road traffic accident (RTA). Ten of the 21 children suffering post‐traumatic stress disorder (PTSD) at 6 weeks continued to fulfil diagnostic criteria at 8 months. There was no evidence of delayed onset of PTSD in children who had not developed this condition at 6 weeks. Talking about the accident and feeling understood were associated with recovery. Providing children with opportunities to talk about their accident may be helpful in preventing or reducing psychological distress. Copyright © 2001 John Wiley & Sons, Ltd.     

The day‐to‐day concurrence of bodily complaints and affect in patients with severe somatoform disorder

Based on the concept of somatization, psychological distress can be experienced as symptoms of physical illness. This suggests a close‐fitting intra‐individual association between bodily complaints and mood in patients with somatoform disorder (SFD). The contemporaneous day‐to‐day complaints‐mood association was investigated in patients with severe chronic SFD using an ecological momentary assessment (EMA) design. Eleven patients, who had recently received specialized tertiary care treatment for severe chronic SFD, kept an online electronic diary for four consecutive weeks. They were prompted at intervals throughout the day to complete questions on their momentary primary symptoms (pain and fatigue), and mood state (negative and positive). For each measure, day‐mean aggregated values were computed and analyzed using linear multilevel (mixed model) regression analysis. Fixed factor results showed that symptoms were associated with both negative mood state (β = 0.47) and positive mood state (β = –0.59). Random results, however, indicated large inter‐individual differences, with correlations varying between 0.17 and 0.99 for negative affect, and between –0.88 and 0.14 for positive affect. A substantial day‐to‐day contemporaneous association between symptoms and affect across subjects, as well as large inter‐individual differences in this association, were demonstrated in patients with severe chronic SFD. EMA‐data showing the relationship between both negative and (inverse) positive mood and complaints has potential clinical relevance: providing SFD patients with feedback consisting of their personal day‐to‐day concurrency graph may promote their understanding of their own complaints in a broader context than the somatic area.