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Rhythmic abilities are impaired in developmental coordination disorder (DCD) but learning deficit of procedural skills implying temporal sequence is still unclear. Current contradictory results suggest that procedural learning deficits in DCD highly depend on learning conditions. The present study proposes to test the role of sensory modality of stimulations (visual or auditory) on synchronization, learning, and retention of temporal verbal sequences in children with and without DCD. We postulated a deficit in learning particularly with auditory stimulations, in association with atypical cortical thickness of three regions of interesting: sensorimotor, frontal and parietal regions. Thirty children with and without DCD (a) performed a synchronization task to a regular temporal sequence and (b) practiced and recalled a novel non-regular temporal sequences with auditory and visual modalities. They also had a magnetic resonance imaging to measure their cortical thickness. Results suggested that children with DCD presented a general deficit in synchronization of a regular temporal verbal sequence irrespective of the sensory modality, but a specific deficit in learning and retention of auditory non-regular verbal temporal sequence. Stability of audio-verbal synchronization during practice correlated with cortical thickness of the sensorimotor cortex. For the first time, our results suggest that synchronization deficits in DCD are not limited to manual tasks. This deficit persists despite repeated exposition and practice of an auditory temporal sequence, which suggests a possible alteration in audio-verbal coupling in DCD. On the contrary, control of temporal parameters with visual stimuli seems to be less affected, which opens perspectives for clinical practice.

Research into haptic picture perception has mostly concerned adult participants, and little is known about haptic picture perception in visually impaired and sighted children. In the present study, we compared 13 visually impaired children (early blind and low vision) aged 9-10 years and 13 agematched blindfolded sighted children on their ability to identify raised-line pictures of common objects when information about object category was provided prior to picture presentation (semantic cueing). The visually impaired children had moderate practice with tactile pictures, whereas the sighted controls had no prior practice with tactile pictures. We sought to determine whether the benefits of semantic cueing would add to those of practice, resulting in higher performance in the visually impaired children compared to the sighted controls (hypothesis 1), or whether semantic cueing would compensate for the lack of practice with tactile pictures in the sighted children, leading to a possible disappearance of the advantage of the visually impaired children over the sighted controls (hypothesis 2). In line with hypothesis 1, the results showed that the visually impaired children outperformed the sighted controls on both identification accuracy and response time to correct naming. We concluded that the visually impaired children outperformed the sighted controls because they benefited from both semantic cueing and superior exploration skills. By contrast, in the sighted children, semantic cueing was not sufficient to compensate for their encoding difficulties.

Procedural learning has been mainly tested through motor sequence learning tasks in children with neurodevelopmental disorders, especially with isolated Developmental Coordination Disorder (DCD) and Reading Disorder (RD). Studies on motor adaptation are scarcer and more controversial. This study aimed to compare the performance of children with isolated and associated DCD and RD in a graphomotor adaptation task. In total, 23 children with RD, 16 children with DCD, 19 children with DCD-RD, and 21 typically developing (TD) children wrote trigrams both in the conventional (from left to right) and opposite (from right to left) writing directions. The results show that movement speed and accuracy were more impacted by the adaptation condition (opposite writing direction) in children with neurodevelopmental disorders than TD children. Our results also reveal that children with RD have less difficulty adapting their movement than children with DCD. Children with DCD-RD had the most difficulty, and analysis of their performance suggests a cumulative effect of the two neurodevelopmental disorders in motor adaptation. [ABSTRACT FROM AUTHOR]

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.

Educational systems in Lebanon are bilingual. They simultaneously impose two handwriting systems in Arabic and Latin. This historically driven situation could constitute a significant impact on the process and development of handwriting skills. Using an accurate and valid handwriting evaluation tool standardized for the Lebanese population is a necessity. This study presents normative and discriminant data for the Concise Evaluation Scale for Children's Handwriting (BHK) in Lebanese children, followed by a comparison to the BHK norms developed in France with unilingual children. The BHK was standardized with a sample of 763 Lebanese children from grades 1 to 5. Four trained raters were involved in the data collection. Data analysis addressed the development of norms, reliability, and pilot administration of discriminant validity. The BHK differentiates between Lebanese children with and without handwriting difficulties. In those without handwriting difficulties, the number of letters written in 5 minutes and writing proficiency increases throughout the first five school years and are gender related, favoring the girls. Lebanese children display better handwriting proficiency than French children, except for the handwriting quality that develops better among French children as of Grade 2. The BHK is a promising tool for the detection of dysgraphia and poor handwriting in Lebanese children.

The Little Developmental Coordination Disorder Questionnaire (LDCDQ) is a parental questionnaire designed to identify preschool children at risk of Developmental Coordination Disorder (DCD). This study aimed to translate and cross-culturally adapt the LDCDQ for French European informants (Little Developmental Coordination Disorder Questionnaire-French European [LDCDQ-FE]) and to undertake a pilot examination of its psychometric properties on a French sample. A thorough process of cultural adaptation was completed. The psychometric properties were examined with a sample of 154 French children aged to 5y11m (control = 121; clinically referred = 33). A sub-group of 34 children was assessed using the MABC-2 to measure convergent validity. Principal component analysis demonstrated a four-component structure, accounting for 67.5% of the variance. Internal consistency was acceptable to good (α = 0.74–0.89). Significant correlation between the LDCDQ-FE and the MABC-2 total scores showed convergent validity. Discriminant validity was supported by significant score differences between the clinically referred and a matched control sub-group. Using ROC curves, a cutoff of 67 was proposed for a sensitivity of 81.3% and a specificity of 77.8%. Results show initial evidence of the psychometric properties of the LDCDQ-FE and are encouraging of its use to identify young preschoolers at risk for DCD. In future studies, the test-retest reliability should be investigated, and study sample sizes expanded. [ABSTRACT FROM AUTHOR]