Executive function in children with and without developmental coordination disorder: A comparative study

Which outcomes are key to the pre-intervention assessment profile of a child with developmental coordination disorder? A systematic review and meta-analysis

BACKGROUND

Purpose of this study was to determine what key aspects of function should be incorporated to make up a pre-intervention assessment profile of a child with Developmental Coordination Disorder (DCD); more specifically, what aspects of functioning are implicated in DCD and what is their relative impact?

METHODS

A systematic review and meta-analysis were conducted, for which Pubmed, Web of Science, Scopus and Proquest were searched (last update: April 2023, PROSPERO: CRD42023461619). Case-control studies were included to determine point estimates for performances on field-based tests in different domains of functioning. Risk of bias was assessed, and level of evidence estimated. Random-effect meta-analyses were performed to calculate the pooled standardized mean differences for domains of functioning and subgrouping was done for clinically relevant subdomains. Heterogeneity was determined with I2.

RESULTS

121 papers were included for analyses. Data of 5 923 children with DCD were included (59.8% boys) and 23 619 Typically Developing (TD) children (45.8% boys). The mean (SD) age of the DCD group was 10.3y (1.2) and 9.3y (1.3) for the TD children. Moderate evidence was found for motor performance, executive functions, sensory processing and perceptions, cognitive functions and sports and leisure activities to be affected in children with DCD.

CONCLUSION

Differences between the two groups varied per domain of functioning. This emphasizes the diversity present within children with DCD and provides a rationale for explaining the heterogeneity in this patient group. Yet, results highlight the potential involvement of all these domains and call for clinicians to be alert not only to examine motor skill difficulties but also other aspects of function. Results indicate the need to develop an individualized pre-intervention multi-dimensional assessment profile for each child with DCD. It also supports the important role that clinicians play in an interdisciplinary team to tackle the difficulties encountered by children with DCD.

Roadside experiences of parents of children with developmental coordination disorder and/or attention deficit hyperactivity disorder

Introduction

Pedestrians are a vulnerable group at the roadside and previous research has identified that children with DCD and ADHD are at a heightened risk of pedestrian injuries. Despite this, limited research has explored parental perspectives of the pedestrian risks faced by children with DCD and/or ADHD. Understanding parents' perspectives provides a unique insight into the challenges children face every day and the concerns that parents perceive regarding their children's safety as pedestrians. Therefore, the aim of this study was to explore parents' perspectives of the pedestrian risks faced by their children with DCD and/or ADHD.

Methods

Semi-structured interviews were conducted with 14 parents of primary school and early secondary school aged children with age range 7-17. The participants were divided into three groups based on their children's conditions: DCD group (10-17 years, n = 3), ADHD group (7-13 years, n = 5), and co-occurring group (7-16 years, n = 6). All parents confirmed an existing diagnosis and completed the SNAP-IV and DCDQ as screening tools. The interviews explored parents' perspectives regarding their children's pedestrian behaviors, parents' concerns and preventative measures taken to improve the pedestrian safety of their children with DCD and/or ADHD. Reflexive thematic analysis was undertaken to analyze the interviews, from which three themes were developed.

Results

The first theme related to the challenges experienced by children at the roadside; parents emphasized the significance of structured and controlled pedestrian crossing sites, underlining their preference for designated crossings as safer options due to their heightened perceptions of risk associated with other road-crossing locations. The second theme: parental concerns and influences on children's road safety referred to their children's performance and safety at the roadside, leading to increased monitoring and a more protective approach to road crossing. The third theme: road safety education related to various strategies parents implemented to mitigate risks, while balancing independence and prioritizing their safety.

Discussion

While there were commonalities in the challenges faced by children with DCD and/or ADHD at the roadside, there were also notable differences. Parents of children with DCD discussed challenges with spatial awareness and motor skills, whereas parents of children with ADHD discussed challenges with impulsivity and inattention. Parents of children with co-occurring DCD and ADHD described a complex interplay of these challenges. It is evident from the interviews that children with DCD and/or ADHD require a distinct approach to develop their pedestrian skills effectively and parents reported specific strategies they used to address the risks associated with their children's roadside behavior. Promoting pedestrian safety for children with DCD and/or ADHD necessitates collaboration among parents, schools and local authorities to implement comprehensive measures ensuring their safety. These findings contribute to understanding parental experiences and needs, providing valuable guidance for targeted interventions and policies to enhance the road safety of children with DCD and/or ADHD.

The relationship between executive function and the association of motor coordination difficulties and social communication deficits in autistic children

Background

Motor coordination difficulties could contribute to social communication deficits in autistic children. However, the exploration of the mechanism implicated in these claims has been limited by the lack of potential confounders such as executive function (EF).

Methods

We investigated the role that EF plays in the relationship between motor coordination and social communication in a school-aged autistic population via a structural model in a statistically robust manner. The results of questionnaires, including the Developmental Coordination Disorder questionnaire, the Behavior Rating Inventory of Executive Function, and the Social Responsiveness Scale, were collected to measure motor coordination, social communication deficits, and EF.

Results

A total of 182 autistic children (7.61±1.31 years, 87.9% boys) were included in the final analysis. In the model with EF as a mediator, the total effect (β=-0.599, P<0.001) and the direct effect (β=-0.331, P =0.003) of motor coordination function on social communication were both significant among autistic children without intellectual disability (ID), as were indirect effects through EF (β=-0.268, P<0.001).

Conclusion

EF partially mediates the motor coordination and social communication correlation among autistic children. We suggest that motor coordination should be included in the routine evaluation of autistic surveillance and rehabilitation procedures.

Locomotor-cognitive dual-tasking in children with developmental coordination disorder

Introduction

Children with Developmental Coordination Disorder (DCD) demonstrate deficits in predictive motor control and aspects of cognitive control compared with their typically developing (TD) peers. Adjustment to dynamic environments depends on both aspects of control and the deficits for children with DCD may constrain their ability to perform daily actions that involve dual-tasking. Under the assumption that motor-cognitive integration is compromised in children with DCD, we examined proportional dual-task costs using a novel locomotor-cognitive dual-task paradigm that enlisted augmented reality. We expect proportional dual-task performance costs to be greater for children with DCD compared to their TD peers.

Methods

Participants were 34 children aged 6-12 years (16 TD, 18 DCD) who walked along a straight 12 m path under single- and dual-task conditions, the cognitive task being visual discrimination under simple or complex stimulus conditions presented via augmented reality. Dual-task performance was measured in two ways: first, proportional dual-task costs (pDTC) were computed for cognitive and gait outcomes and, second, within-trial costs (p-WTC) were measured as the difference on gait outcomes between pre- and post-stimulus presentation.

Results

On measures of pDTC, TD children increased their double-limb support time when walking in response to a dual-task, while the children with DCD increased their locomotor velocity. On p-WTC, both groups increased their gait variability (step length and step width) when walking in response to a dual-task, of which the TD group had a larger proportional change than the DCD group. Greater pDTCs on motor rather than cognitive outcomes were consistent across groups and method of dual-task performance measurement.

Discussion

Contrary to predictions, our results failed to support dramatic differences in locomotor-cognitive dual-task performance between children with DCD and TD, with both groups tending to priorities the cognitive over the motor task. Inclusion of a within-trial calculation of dual-task interference revealed an expectancy effect for both groups in relation to an impending visual stimulus. It is recommended that dual-task paradigms in the future continue to use augmented reality to present the cognitive task and consider motor tasks of sufficient complexity to probe the limits of performance in children with DCD.

Far Transfer Effects of Trainings on Executive Functions in Neurodevelopmental Disorders: A Systematic Review and Metanalysis

Executive Functions are a set of interrelated, top-down processes essential for adaptive goal-directed behaviour, frequently impaired across different neurodevelopmental disorders with variable degrees of severity. Many executive-function-training studies in children with neurodevelopmental disorders have focused on near effects, investigating post-treatment improvements on directly trained processes, while enhancements of skills not directly trained, defined as far effects, are less considered, albeit these could be extremely relevant for reducing the negative impact of a disorder's core symptomatology. This systematic review and metanalysis aims to investigate the far effect outcomes after EF training in children with different types of neurodevelopmental disorders. 17 studies met the inclusion criteria for the systematic review, while 15 studies were selected in the metanalysis. An overall statistically significant effect size was found in the majority of far effect outcome measures considered in the studies. In particular, trainings on executive functions determine significant far effects on daily life functioning (0.46, 95% CI: [0.05-0.87]) and clinical symptoms (0.33, 95% CI: [0.15-0.51]). Despite a high variability of the results, intensity, frequency and the laboratory/life contexts dimension seem to be the most influential variables in determining far effects. This systematic review and metanalysis highlights the need to measure far effects of executive function training in neurodevelopmental disorders, selecting treatments not only on directly targeted processes, but also according to far impacts on the functional weakness of the disorder.

Individual and environmental parameters in children with and without developmental coordination disorder: associations with physical activity and body mass index

Introduction

Physical Activity (PA) is a complex behavior, and the relevance of other factors such as BMI, SES and children's behavior at school and home still lacks investigation for children, especially those at risk or with Developmental Coordination Disorder (DCD). The objective of this study was to examine whether socioeconomic status (SES), school's spaces for children's movement, active play, screen time, motor skill proficiency, perceived motor competence, and engagement in the physical education lessons were associated with PA and BMI in children with typical development (TD), at risk of DCD (r-DCD), and with DCD.

Methods

Children (N = 352; 4-10-year-old) from six public schools in a major urban city, in southern of Brazil, were assessed regarding motor skill proficiency (locomotor and ball skills), perceived motor competence, and weight status. PA and engagement in the lesson were assessed using pedometers and a behavior checklist of motor experience of success. Parents recorded the daily time that children spent on screen and in active play.

Results

The hierarchical multivariate linear regressions showed that age, sex, SES, Schools with more favorable space for children's movement, locomotor and ball skills, and successful engagement, were associated with PA for children with TD. Age, screen time, locomotor, and successful engagement were associated with BMI. For children at r-DCD, age, sex, SES, with more favorable space for children's movement, and locomotor were associated with PA. Age, active play and screen time were associated with BMI. For children with DCD, sex, SES, Schools with more favorable space for children's movement, screen time, and successful engagement were associated with PA. Age, sex, active play, and screen time were associated with BMI.

Conclusion

Different factors were associated with PA and BMI for children with different levels of motor impairment (r-DCD and DCD) and children with TD.

Exploring Executive Functioning of Adults With Probable Developmental Coordination Disorder Using the Jansari Assessment of Executive Functions

Many individuals with Developmental Coordination Disorder (DCD) demonstrate executive functioning difficulties on standardized assessments, yet these difficulties have not been investigated using ecologically-valid measures. 26 adults with probable DCD (pDCD), and 26 typically developing (TD) adults completed selected background measures and the Jansari assessment of Executive Functions (JEF©). JEF© is an ecologically-valid measure that provides measures of Planning, Prioritization, Selective-Thinking, Creative-Thinking, Adaptive-Thinking, and Action-, Event- and Time-Based Prospective Memory. pDCD participants were impaired relative to TD participants, with difficulties in Planning, Action-, and Event-Based Prospective Memory. These findings are consistent with self-reported difficulty and provide avenues for research investigating intervention.

Cognition and maths in children with Attention-Deficit/Hyperactivity disorder with and without co-occurring movement difficulties

BACKGROUND

Movement difficulties are common in ADHD, however, the implications of their co-occurrences on cognitive and maths performance is unknown.

AIMS

This study set out to examine whether cognitive and maths performance of children with high ADHD symptoms differs depending on the co-occurrence of movement difficulties given evidence that weaker visuospatial processing, known to be important for maths performance, differentiates ADHD and DCD. We also aimed to examine whether relationships between cognition and maths in ADHD differs depending on co-occurring movement difficulties.

METHODS

Participants were 43 drug naïve children between 6 and 12 years old (M = 101.53 months SD = 19.58). The ADHD-only group (n = 18) included children with high ADHD scores, and those in the ADHD+DCD group (n = 25) concurrently had high movement difficulty scores. All completed executive function and memory, including 2 visuo-spatial memory tasks from the CANTAB battery and Mathematics Problem Solving, Numeracy, and Maths Fluency tasks from the WIAT-III and specific factual, conceptual, and procedural maths component tasks.

RESULTS

Children in the ADHD+DCD group scored significantly lower on visuospatial working memory (WM) capacity, than those in the ADHD-only group. Both groups were comparable on all other cognitive assessments of executive functions, memory, and processing speed. The groups did not differ in their maths attainment scores, nor on more specific maths skills. Comparison of the correlations between cognitive processes and maths revealed that the association between visuospatial WM updating and procedural skill efficiency was stronger for the ADHD-only group. Moreover, associations between visuospatial WM and maths problem solving attainment were stronger in the ADHD+DCD group.

CONCLUSIONS

Despite similarities in maths performance, children with ADHD+DCD could be distinguished by lower visuospatial WM. Differential associations with some of the maths domain implicate recruitment of different cognitive processes for some aspects of maths. This distinction can be particularly useful for conceptualising cognitive characteristics of different clinical groups and understanding cognitive pathways of maths difficulties. Implications for interventions are discussed.

Cognitive Orientation to Daily Occupational Performance: A Randomized Controlled Trial Examining Intervention Effects on Children with Developmental Coordination Disorder Traits

Children with traits of developmental coordination disorder (DCD-t) may experience occupational performance problems that go unrecognized and therefore may not be adequately supported. The cognitive orientation to daily occupational performance (CO-OP) approach has been effective in interventions for developmental coordination disorder (DCD). Based on an open-label, randomized controlled trial design, this study evaluated the effects of CO-OP on the occupational performance and motor skills of older kindergarten children with DCD-t using the School Assessment of Motor and Process Skills (S-AMPS) and the Movement Assessment Battery for Children, Second Edition. Children with a total DCDQ score of less than 40 or M-ABC2 scores in the 5th to 16th percentile were considered to have DCD-t. Furthermore, children with DCD-t and S-AMPS process skills less than 0.7 were considered to have DAMP (Deficits in Attention, Motor control and Perception)-t. After 3 months of CO-OP intervention, the performance and motor skills of children with DCD-t improved significantly. However, there were no significant changes noted in the motor skills of children with DAMP-t, although their occupational performance improved. These results suggest that CO-OP is effective even for older kindergarten children with DCD-t. However, further improvement of the CO-OP approach or a different strategy is required for children with ADHD comorbidity.

Improved attentional abilities after playing five weeks of active video games in children with and without developmental coordination disorder

BACKGROUND

Besides motor coordination problems, attentional impairments are reported in children with developmental coordination disorder (DCD), but the connection or trainability is still unclear.

AIM

To test changes on attentional abilities after playing active video games (AVG) in children with DCD and their peers (TD), to evaluate near transfer and the relationship between omissions in attentional and motor tests.

METHODS

Seventy children (35 DCD; 35 TD), 7-12 years old, were assessed on three types of attention: distractibility (DIS); divided-attention (DA); sustained-attention (SA) and on the Wii Fit test pre- and post-training.

RESULTS

A significant decrease of errors in attentional tasks was found after training, independent of group (TD/DCD) and console (Wii Fit/Xbox) with medium-strong effect sizes (DIS η²_p =.42; DA η²_p =.51; SA η²_p =.41). The groups responded similarly to the training but the DCD children scored poorer on the DA. A positive transfer-effect to the non-trained Wii Fit test was found in accuracy (missed gates), while speed proved console-specific. A medium/strong relation was found between omissions in attentional tasks and the missed gates (Wii Fit test).

CONCLUSION

More accurate responses on attentional tasks were found after AVG-training in both groups. A clear relationship between attentional abilities and motor performance was found.

Perspective: Acknowledging complexity to advance the understanding of developmental coordination disorder

Developmental Coordination Disorder (DCD) is a heterogeneous neurodevelopmental disorder known for primary symptoms of motor learning and execution difficulties. Recent research has consistently suggested DCD symptoms span broadly beyond motor difficulties, yet a majority of research and practice approaches the investigation, diagnosis, and treatment of DCD with a reductionist framework. Therefore, this paper suggests the paradigm of complexity theory as a means for better conceptualization, assessment, and treatment of DCD. First, the perspective of complexity theory and its relevance to DCD is described. Then, examples from recent research which attempt to acknowledge and capture the complex nature of DCD are highlighted. Finally, suggestions for considering and measuring complexity of DCD in future research and practice are provided. Overall, the perspective of complexity can propel the research forward and improve the understanding of DCD relevant to assessment and treatment. The complexity paradigm is highly relevant to describing the evolving and multidimensional picture of DCD, understanding heterogeneous symptom profiles, making connections to interconnected secondary symptoms, and beyond.

Does the Degree and/or Direction of Handedness in Children With Developmental Coordination Disorder Influence Motor and Cognitive Performance? A Pilot Study

Research has shown that nonright-handedness in children with developmental coordination disorder (DCD) is associated with poorer motor and cognitive performance. This study investigated the influence of degree and direction of handedness on performance using the Home Handedness Questionnaire, the Hit-the-Dot test, the Movement Assessment Battery for Children, and the digital Trail-Making Test. Eighteen children with DCD and 21 typically developing children aged 8–12 years participated in this study. The distribution of degree and direction of handedness in the group of DCD children were not different from that found in the typically developing group. In the Hit-the-Dot test, typically developing children significantly performed better than children with DCD, no matter which hand was dominant or to which degree. A significant inconsistent-handed advantage in the subdomain balance was found for children with DCD. Inconsistent handedness also seems to be an advantage for children with DCD on the digital Trail-Making Test performance. The relationship between the subcategories of the Movement Assessment Battery for Children and the digital Trail-Making Test part B is stronger for consistent than for inconsistent handedness. Our findings suggest that children with DCD and inconsistent handedness might benefit from greater crosstalk across hemispheres. In addition, these predispositions can be reinforced or discouraged throughout development and via occupational therapy.

The relationship between executive function, neurodevelopmental disorder traits, and academic achievement in university students

Difficulties with executive function have often been identified in individuals with various neurodevelopmental disorders such as Autism Spectrum Disorder (ASD), Attention-Deficit Hyperactivity Disorder (ADHD), and Developmental Co-ordination Disorder (DCD). Additionally, in childhood and adolescence, executive functioning is an important predictor of academic achievement. However, less research has explored these relationships in adult students, and those with a high level of neurodevelopmental disorder traits but no clinical diagnosis. Therefore, the current study aimed to assess whether ASD, ADHD, and DCD traits can predict academic achievement in university students, and whether traits of these neurodevelopmental conditions moderate the relationship between executive function and academic achievement. Both neurotypical students and those with a clinical diagnosis of a neurodevelopmental disorder were able to participate, with the majority being neurotypical. Participants completed four self-report questionnaires and provided a measure of academic achievement based on their university assignment results. Traits of ASD, ADHD, and DCD alone did not predict achievement, however, traits of ADHD and DCD significantly moderated the relationship between executive function and academic achievement. ASD traits did not significantly moderate this relationship. Implications and suggestions for future research are also discussed.

How are you getting by? Coping in developmental coordination disorder versus attention-deficit/hyperactivity disorder

Objective

Developmental Coordination Disorder (DCD) and Attention-Deficit/Hyperactivity Disorder (ADHD) persist into adulthood; however, little research exists to describe how adults with DCD and/or ADHD cope with their symptoms. Therefore, the purpose of this study was to investigate coping mechanisms reported by adults with DCD, ADHD, or both conditions. We expected there would be strategies specific to each condition and a broader scope of mechanisms reported by those with co-occurring DCD+ADHD.

Method

N = 161 participants completed the online survey, including n = 31 with DCD only, n = 116 with ADHD only, and n = 14 with DCD+ADHD.

Results

Most participants reported adaptive strategies. Of these, behavioral adaptations were most relevant to ADHD, while environmental modifications were common in DCD. Cognitive reframing and social support were similarly relevant to those with DCD and DCD+ADHD. Coping strategy categories were most uniform for the DCD+ADHD group.

Conclusions

Coping profiles highlight several noteworthy differences between DCD and ADHD which may be relevant for treatment.

Developmental Coordination Disorder (DCD): Relevance for clinical psychologists in Europe

Background

Developmental Coordination Disorder (DCD) is a common neurodevelopmental disorder primarily characterized by fine and gross motor coordination difficulties. Yet, many aspects remain unclear regarding the clinical presentation of secondary symptoms and their implications for Clinical Psychology. Therefore, the purpose of this review is to provide an update about the current understanding of DCD for clinical psychologists and psychotherapists across Europe, particularly based on new insights stemming from the last decade of research.

Method

We provide a narrative review of articles published in the last decade on the topic of DCD, and relevant aspects to clinical psychologist, including lesser known aspects of DCD (e.g., executive functions, psychological consequences, and adult DCD).

Results

DCD is a highly prevalent, disruptive, and complex disorder, which should be investigated further in many areas (e.g., co-occurrence to ADHD). Existing evidence points toward a key role of executive functioning difficulties at all ages. Most patients report secondary psychological problems, but little headway has been made in examining the effectiveness of psychotherapy for DCD.

Conclusions

Insights and remaining research gaps are discussed. It is critical for psychologists and clinical researchers to raise awareness for DCD, take note of the growing literature, and foster continued interdisciplinary approaches to research and treatment of DCD.

Awareness about Developmental Coordination Disorder (DCD) is low among some European Psychologists.

Growing knowledge about DCD should be disseminated among psychotherapists.

Behavioral and Neuroimaging Research on Developmental Coordination Disorder (DCD): A Combined Systematic Review and Meta-Analysis of Recent Findings

AIM

The neurocognitive basis of Developmental Coordination Disorder (DCD; or motor clumsiness) remains an issue of continued debate. This combined systematic review and meta-analysis provides a synthesis of recent experimental studies on the motor control, cognitive, and neural underpinnings of DCD.

METHODS

The review included all published work conducted since September 2016 and up to April 2021. One-hundred papers with a DCD-Control comparison were included, with 1,374 effect sizes entered into a multi-level meta-analysis.

RESULTS

The most profound deficits were shown in: voluntary gaze control during movement; cognitive-motor integration; practice-/context-dependent motor learning; internal modeling; more variable movement kinematics/kinetics; larger safety margins when locomoting, and atypical neural structure and function across sensori-motor and prefrontal regions.

INTERPRETATION

Taken together, these results on DCD suggest fundamental deficits in visual-motor mapping and cognitive-motor integration, and abnormal maturation of motor networks, but also areas of pragmatic compensation for motor control deficits. Implications for current theory, future research, and evidence-based practice are discussed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier: CRD42020185444.

Do executive functions and gross motor skills predict writing and mathematical performance in children with developmental coordination disorder?

Aim: To examine whether executive functions, and gross motor skills were predictors for school performance in children with DCD, with risk for DCD (r-DCD), and with typical development (TD).Methods: Participants were 63 children with DCD (M_age = 8.70, SD_age = .64), 31 children with r-DCD (M_age = 8.90, SD_age = 0.74), and 63 typical development children (M_age = 8.74, SD_age = .63). Wechsler Abbreviated Scale of Intelligence, Movement Assessment Battery for Children-2, Test of Gross Motor Development-3, Oral Word Span in Sentences, Odd-One-Out, Go/No-Go, Hayling Test, Trail Making Test, Five Digits Test, and the Test of School Performance-II were utilized.Results: In DCD, processing speed (β = -.42, p = .005), and auditory-motor inhibition (β = -.36, p = .009), and auditory-verbal inhibition (β = -.38, p = .023) predicted math performance; and auditory-motor (β = -.40, p = .38) and visuospatial working memory (β = -.33 p = .011) predicted writing performance. In r-DCD, auditory-motor (β = - .67; p = .002) and visual-motor (β = -.40; p = .040) inhibition predicted math performance; visual-motor inhibition predicted writing performance (β = -.47; p = .015).Conclusion: Lower inhibitory control and visuospatial working memory scores affect children with DCD and r-DCD' school performance.

Attentional and executive functions in children and adolescents with developmental coordination disorder and the influence of comorbid disorders: A systematic review of the literature

Developmental coordination disorder (DCD) is a neurodevelopmental disorder affecting primarily motor skills, but attentional and executive impairments are common in affected individuals. Moreover, the presence of neurodevelopmental comorbidities is frequent in this population, which certainly influences the cognitive profile of the children concerned. Previous studies have reported deficits in visuospatial/nonverbal and planning tasks. This systematic review of the literature aims to determine if impairments can be found in other attentional and executive functions as well. The type of cognitive tasks, the tasks’ modality (verbal/nonverbal), and the influence of comorbid disorders on attentional and executive profiles are systematically considered. Forty-one studies were identified through the PubMed/Medline and PsycINFO databases according to pre-established eligibility criteria. The results reveal weaknesses in inhibitory control, working memory, planning, nonverbal fluency, and general executive functioning in children with DCD. The presence of comorbid disorders seemingly contributes to the verbal working memory difficulties findings. This review contributes to a better understanding of the cognitive impairments in DCD and of the needs of children with this disorder, allowing to optimize practitioners’ therapeutic interventions.

Evoked Potentials Differentiate Developmental Coordination Disorder From Attention-Deficit/Hyperactivity Disorder in a Stop-Signal Task: A Pilot Study

Developmental Coordination Disorder and Attention-Deficit/Hyperactivity Disorder are unique neurodevelopmental disorders with overlaps in executive functions and motor control. The conditions co-occur in up to 50% of cases, raising questions of the pathological mechanisms of DCD versus ADHD. Few studies have examined these overlaps in adults with DCD and/or ADHD. Therefore, to provide insights about executive functions and motor control between adults with DCD, ADHD, both conditions (DCD + ADHD), or typically developed controls, this study used a stop-signal task and parallel EEG measurement. We assessed executive performance via go accuracy and go reaction time, as well as motor response inhibition via stop-signal reaction time. This was complemented with analysis of event-related potentials (ERPs). Based on existing investigations of adults with DCD or ADHD, we expected (1) groups would not differ in behavioral performance on stop and go trials, but (2) differences in ERPs, particularly in components N200 (index of cognitive control) and P300 (index of attention and inhibition) would be evident. The sample included N = 50 adults with DCD (n = 12), ADHD (n = 9), DCD + ADHD (n = 7), and control participants (n = 22). We replicated that there were no between-group differences for behavioral-level executive performance and motor response inhibition. However, on a physiological level, ERP components N200 and P300 differed between groups, particularly during successful response inhibition. These ERPs reflect potential endophenotypic differences not evident in overt behavior of participants with ADHD and/or DCD. This suggests a disorder specific employment of inhibition or general executive functions in groups of adults with DCD, DCD + ADHD, ADHD, or control participants.

Error-Related Cognitive Control and Behavioral Adaptation Mechanisms in the Context of Motor Functioning and Anxiety

Motor proficiency reflects the ability to perform precise and coordinated movements in different contexts. Previous research suggests that different profiles of motor proficiency may be associated with different cognitive functioning characteristics thus suggesting an interaction between cognitive and motor processes. The current study investigated this interaction in the general population of healthy adults with different profiles of motor proficiency by focusing on error-related cognitive control and behavioral adaptation mechanisms. In addition, the impact of these processes was assessed in terms of trait anxiety and worries. Forty healthy adults were divided into high and low motor proficiency groups based on an assessment of their motor skills. Using electroencephalography during a flanker task, error-related negativity (ERN) was measured as the neural indicator of cognitive control. Post-error slowing (PES) was measured to represent behavioral adaptation. Participants also completed an anxiety assessment questionnaire. Participants in the high motor proficiency group achieved better task accuracy and showed relatively enhanced cognitive control through increased ERN. Contrastingly, individuals in the lower motor proficiency group achieved poorer accuracy whilst showing some evidence of compensation through increased PES. Trait anxiety reflecting general worries was found to be correlated with motor functioning, but the study could not provide evidence that this was related to cognitive or behavioral control mechanisms. The interaction between cognitive and motor processes observed in this study is unique for healthy and sub-clinical populations and provides a baseline for the interpretation of similar investigations in individuals with motor disorders.

The contribution of motor functions to academic achievement in primary school: State of the art and future directions

This review is intended to point out the role played by motor skills proficiency in the academic achievement of typically and atypically developing pupils who are attending primary school. First, the interplay between motor and cognitive development will be presented. Next, the cognitive phenotype, not yet deeply investigated, of a neurodevelopmental condition associated with the atypical development of motor functions (known as Developmental Coordination Disorder) will be illustrated. Thus, the contribution of motor functions to academic learning and the impact of motor difficulties for pupils attending primary school will be discussed. In addition, the importance of developing observational tools to be used in educational settings and the need for effective interventions designed to empower motor functioning and academic achievement of atypically developing pupils with motor deficits will be highlighted. Finally, future directions within the educational agencies for the early detection of the atypically developing motor trajectories and their treatment will be traced.