Mechanisms of deficit of visuospatial attention shift in children with developmental coordination disorder: A neurophysiological measure of the endogenous Posner paradigm

The purpose of this study was to investigate and compare the mechanisms of brain activity, as revealed by a combination of the visuospatial attention shifting paradigm and event-related potentials (ERP) in children with developmental coordination disorder (DCD) and typically developing children. Twenty-eight DCD children and 26 typically developing children were recorded with regard to their behavioral performance and ERP measures during a variant of the endogenous Posner paradigm, in which they should react to visual targets preceded by spatial cues or presented uncued. Children with DCD showed longer reaction time and a deficit in inhibitory response capacity when compared to typically developing children. The electrophysiological characteristics also showed distinct modulatory effects upon attentional orienting, anticipatory mechanisms, and cognitive-to-motor transfer in children with DCD: longer cue-P3 and target-N1 latency, smaller target-P3 amplitude, an elongated interval between N2 and the motor response (N2-RT), and small areas on contingent negative variation (CNV). The combined analysis of behavioral performance and ERP data suggested that children with DCD had deficits of slower target identification (N1), less ability in interhemispheric (P3) and cognitive-to-motor transfer speed (N2-RT), as well as a less mature anticipatory and executive process (CNV).     

Anticipatory attention during the sleep onset period

To examine whether anticipatory attention or expectancy is a cognitive process that is automatic or requires conscious control, we employed a paired-stimulus event-related potential (ERP) paradigm during the transition to sleep. The slow negative ERP wave observed between two successive stimuli, the Contingent Negative Variation (CNV), reflects attention and expectancy to the second stimulus. Thirteen good sleepers were instructed to respond to the second stimulus in a pair during waking sessions. In a non-response paradigm modified for sleep, participants then fell asleep while tones played. As expected, N1 decreased and P2 increased in amplitude systematically with the loss of consciousness at sleep onset; the CNV was increasingly more positive. Sleep onset latency was correlated with the amplitude of the CNV. The systematic attenuation of the CNV waveform at sleep onset and its absence in sleep indicates that anticipatory attention requires endogenous conscious control.     

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.     

Reliance on visual feedback from ocular accommodation on motor skills in children with developmental coordination disorder and typically developing controls

Children with developmental coordination disorder (DCD) present with marked impairments in motor skills, including visual-motor integration. Oculomotor anomalies are more prevalent in children with DCD than typically developing children. Children with DCD further demonstrate altered use of visual feedback compared to typically developing controls. We investigated whether the accommodation system, a key component of the oculomotor system, contributes to visual feedback during fine and gross motor skills performance; and whether children with DCD demonstrate differences in reliance on visual feedback from accommodation. Minus dioptre lenses were used to maximally induce accommodation and impede accommodation dynamics. Children with DCD and typically developing controls performed motor skills tests assessing balance, upper limb coordination, visual-motor performance, gross and fine dexterity. Motor skills performance in controls was significantly affected by impeded accommodation in all tasks. Children with DCD demonstrated reliance on accommodation feedback in upper limb and visual-motor tasks only. Children with DCD may be less reliant on visual feedback obtained from accommodation due to adaptive mechanisms to overcome faulty information in the presence of oculomotor anomalies. These results strengthen our previous findings that accommodation anomalies contribute to motor skills impairment, and suggest that performance on these motor tasks is heavily reliant on visual feedback from accommodation.     

Effect of dual tasking on a dynamic balance task in children with and without DCD

The purpose of this study was to compare performance of children with Developmental Coordination Disorder (DCD) and typically developing (TD) children in a dual task paradigm with a dynamic balance task on the Wii Fit as primary task and a concurrent cognitive (counting) or a concurrent bimanual fine motor task as secondary tasks.Using a cross-sectional design, 25 children with DCD and 38 TD children were assessed with the Movement Assessment Battery for Children, 2nd edition (MABC-2) and Divided Attention (DA) task of the KiTAP. Next, the single- and dual-tasks were performed and the level of interference or facilitation of the dual tasks was calculated. Regression analysis determined the predictive value of the DA and MABC-2 component balance outcomes on the dual task performance. On the motor and attentional tasks, the group of children with DCD scored significantly below the level of the TD children. The dual task effect showed similar interference and facilitation of tasks in the different dual-task conditions in both groups.In the dual task-cognitive condition, the divided attention abilities and the MABC-2 balance score predicted 25% of the Wii Fit dynamic balance task performance, whereas in the dual task-motor condition this was higher (31.6%). In both conditions, DA was a stronger predictor than MABC balance score and appears to be an important factor to consider when developing motor task training for children with DCD.     

Auditory and visual information do not affect self-paced bilateral finger tapping in children with DCD

Children with Developmental Coordination Disorder (DCD) are more variable in timing their fingers to an external cue. In this study, we investigated the intrinsic coordination properties of self-selected anti-phase finger tapping with and without vision and audition in children with and without DCD and compared their performance to that of adults. Ten children with DCD (Mean age = 7.12 ± 0.3 years), 10 age- and sex-matched typically developing (TD) children, and 10 adults participated in this study. Participants tapped their fingers in anti-phase at a self-selected speed under four different sensory conditions: (1) with vision and audition, (2) with vision but no audition, (3) with audition but no vision, and (4) without vision and audition. We assessed intertap interval (ITI), variability of ITI, mean relative phasing (RP) between the fingers and the variability in RP. Children with DCD adopted a similar mean frequency, but were less accurate and more variable than the other groups. The different sensory conditions did not affect performance in any of the groups. We conclude that visual and auditory feedback of tapping are not salient information sources for bilateral self-selected tapping and that children with DCD are intrinsically less accurate and more variable in their tapping frequency and coordination.     

Coupling of the reach and grasp phase during catching in children with developmental coordination disorder

The authors studied 2-handed catching behavior in 10 children with developmental coordination disorder (DCD), aged 7-10 years old, and their typically developing peers (TDC). Participants performed 15 catches, and the authors examined kinematics of both transport and grasp phases. In terms of the transport phase, movement initiation and movement time was longer and peak deceleration was earlier in children with DCD. In addition, such children initiated the grasp phase earlier, and their maximal grasp aperture was larger. In children with DCD, the time to maximal grasp aperture was more variable, and that aperture was earlier when the authors examined it with respect to the transport phase of the catch. The data suggest that children with DCD may use a decomposition strategy to simplify the movement control of the transport and grasp phases of a catch.     

Procedural learning,consolidation, and transfer of a new skill in Developmental Coordination Disorder

The aim of this study was to explore the differences in procedural learning abilities between children with DCD and typically developing children by investigating the steps that lead to skill automatization (i.e., the stages of fast learning, consolidation, and slow learning). Transfer of the skill to a new situation was also assessed. We tested 34 children aged 6–12 years with and without DCD on a perceptuomotor adaptation task, a form of procedural learning that is thought to involve the cerebellum and the basal ganglia (regions whose impairment has been associated with DCD) but also other brain areas including frontal regions. The results showed similar rates of learning, consolidation, and transfer in DCD and control children. However, the DCD children's performance remained slower than that of controls throughout the procedural task and they reached a lower asymptotic performance level; the difficulties observed at the outset did not diminish with practice.     

Role of visual-perceptual skills (non-motor) in children with developmental coordination disorder

The purposes of this study were to examine test-retest reliability of the Test of Visual-Perceptual Skills (Non-Motor)-Revised (TVPS-R), to explore motor-free visual-perceptual skills, and to categorize subtypes thereof in children with developmental coordination disorder (DCD). One hundred and seventy-eight children, aged 9 and 10 years, identified as having DCD with the Movement Assessment Battery for Children (M-ABC), were assessed, along with 200 typically developing children. The results showed good test-retest reliability for the total perceptual quotient scores of the TVPS-R, but not for all subtests. Children with DCD performed significantly poorer compared to typically developing children on the visual-perceptual test, but the deficits were not common to all children with DCD. This study supported the stance that we should consider the heterogeneous characteristics of children with DCD when designing experimental studies or developing educational interventions.     

Position Sense Dysfunction Affects Proximal and Distal Arm Joints in Children with Developmental Coordination Disorder

It is unclear, whether proprioceptive dysfunction in developmental coordination disorder (DCD) is localized affecting only specific joints or whether it is generalized affecting proximal and distal joints. Thus, this study assessed position sense acuity at the elbow and wrist in twenty children with DCD (age: 9–11 yrs.) using a joint position matching paradigm. Position sense bias (systematic error) at either joint was not significantly higher in DCD children when compared to typically developing children (TD). However, DCD children exhibited significantly lower position sense precision (random error) than TD children at both elbow and wrist. That is, response reliability to proprioceptive stimuli is altered in DCD. Our findings are consistent with a view that proprioceptive dysfunction in DCD is generalized in nature.     

Multi-limb coordination and rhythmic variability under varying sensory availability conditions in children with DCD

Children with Developmental Coordination Disorder (DCD) have sensory processing deficits; how do these influence the interface between sensory input and motor performance? Previously, we found that children with DCD were less able to organize and maintain a gross motor coordination task in time to an auditory cue, particularly at higher frequencies [Whitall, J., Getchell, N., McMenamin, S., Horn, C., Wilms-Floet, A., & Clark, J. (2006). Perception-action coupling in children with and without DCD: Frequency locking between task relevant auditory signals and motor responses in a dual motor task. Child: Care, Health, and Development, 32, 679-692]. In the present study, we examine the same task (clapping in-phase to marching on a platform) under conditions involving the removal of vision and hearing. Eleven children with DCD (mean=7.21, SD=0.52 years), 7 typically developing (TD) children (mean=6.95+/-0.72 years), and 10 adults performed continuous clapping while marching under four conditions: with vision and hearing, without vision, without hearing, and without both. Results showed no significant condition effects for any measure taken. The DCD group was more variable in phasing their claps and footfalls than both the adult group and the TD group. There were also significant group effects for inter-clap interval coefficient of variation and inter-footfall interval coefficient of variation, with the DCD group being the most variable for both measures. Coherence analysis between limb combinations (e.g., left arm-right arm, right arm-left leg) revealed that the adults exhibited significantly greater coherence for each combination than both of the children's groups. The TD group showed significantly greater coherence than the DCD group for every limb combination except foot-foot and left hand-right foot. Measures of approximate entropy indicated that adults differed from children both with and without DCD in the structure of the variability across a trial with adults showing more complexity. Children with DCD are able to accomplish a self-initiated gross-motor coordination task but with increased variability for most but not all measures compared to typically developing children. The availability of visual and/or auditory information does not play a significant role in stabilizing temporal coordination of this task, suggesting that these are not salient sources of information for this particular task.     

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.     

Changes in dynamic balance control over time in children with and without Developmental Coordination Disorder

The aim of this study was to examine differences in underlying adaptations of dynamic balance in children with and without Developmental Coordination Disorder (DCD) during a Wii Fit game and to measure changes over time and after intervention.Twenty-eight children with DCD and 21 typically developing (TD) children participated in the study. Analyses of force plate variables showed that the TD group initially used a longer path length for the ski slope descent and tended toward more variation in Center of Pressure (CoP) displacement in lateral direction than the children with DCD. In contrast, the TD group showed a trend of fewer reversals per cm in both AP and lateral direction. After the nonintervention period, the TD group improved performance by decreasing the path length, while the DCD group improved by increasing the path length and by decreasing the number of reversals. After intervention, no changes were found in sway characteristics. Individual analyses within the DCD group showed that the path length per run fell more often within the 95% confidence Interval of the faultless runs. In conclusion both TD and DCD children modify the underlying kinetics of dynamic balance control, but in different ways and both lead to better performance.     

Tactile localization performance in children with developmental coordination disorder (DCD) corresponds to their motor skill and not their cognitive ability

When localizing touches to the hands, typically developing children and adults show a “crossed hands effect” whereby identifying which hand received a tactile stimulus is less accurate when the hands are crossed than uncrossed. This demonstrates the use of an external frame of reference for locating touches to one’s own body. Given that studies indicate that developmental vision plays a role in the emergence of external representations of touch, and reliance on vision for representing the body during action is atypical in developmental coordination disorder (DCD), we investigated external spatial representations of touch in children with DCD using the “crossed hands effect”. Nineteen children with DCD aged 7–11 years completed a tactile localization task in which posture (uncrossed, crossed) and view (hands seen, unseen) were varied systematically. Their performance was compared to that of 35 typically developing controls (19 of a similar age and cognitive ability, and 16 of a younger age but similar fine motor ability). Like controls, the DCD group exhibited a crossed hands effect, whilst their overall tactile localization performance was weaker than their peers of similar age and cognitive ability, but in line with younger controls of similar motor ability. For children with movement difficulties, these findings indicate tactile localization impairments in relation to age expectations, but apparently typical use of an external reference frame for localizing touch.     

Motor imagery during action observation enhances imitation of everyday rhythmical actions in children with and without developmental coordination disorder

Children with developmental coordination disorder (DCD) exhibit deficits both in imitation and motor imagery (MI) compared to typically developing children. Combined action observation and motor imagery (AO + MI) instructions can however enhance automatic imitation in both groups. In the present study we investigated the effects of AO + MI instructions on intentional imitation in children both with (n = 13) and without DCD (n = 12). On each trial participants observed and/or imagined before executing a familiar rhythmical pantomime action. These target actions were either habitually fast (tooth brushing or window wiping) or habitually slow (paint brushing or face washing), in the vertical or horizontal plane. Within each habitual speed, the target action speed was subtly manipulated across trials (fast vs. slow). Instruction condition was manipulated across three blocks of 16 trials: (1) observe before imitating the target action; (2) observe then imagine the action before imitating; (3) observe while imagining the same action before imitating (AO + MI). Kinematic analyses revealed typically developing children imitated the observed cycle times significantly better than children with DCD. A main effect of instruction showed imitation improved for AO + MI compared to the other two instructions. Within-group analyses found a significant advantage in DCD for AO + MI compared to observe then imagine. In typically developing children, imitation was significantly enhanced for AO + MI compared to observe then imitate. Combined AO + MI instructions therefore represent a promising new approach to refining performance of everyday rhythmical actions in children both with and without DCD, with implications for movement therapy and sports training.     

Mechanisms that underlie coordination in children with developmental coordination disorder

The authors examined potential mechanisms underlying motor coordination in children with developmental coordination disorder (DCD). Because children with DCD experience difficulty processing visual, auditory, and vibrotactile information, the authors explored patterns of choice reaction time (RT) in young (6-7 years) and older (9-10 years) children with and without DCD by using a compatibility-incompatibility paradigm and different sensory modalities. Young children responded more slowly than older children to visual, auditory, and vibrotactile stimuli. Children with DCD took longer than typical children to process visual and vibrotactile stimuli under more complex stimulus-response mappings. Young children with DCD responded more slowly than typical children to visual and vibrotactile information under incompatible conditions. Children with DCD responded faster than unaffected children to auditory stimuli. The results suggest that there is a developmental nature in the processing of visual and auditory input and imply that the vibrotactile sensory modality may be key to the motor coordination difficulties of children with DCD.     

Delayed N2 response in Go condition in a visual Go/Nogo ERP study in children who stutter

Purpose of the studyThe main aim of the study was to investigate the attentional and inhibitory abilities and their underlying processes of children who stutter by using behavioural measurement and event-related potentials (ERP) in a visual Go/Nogo paradigm.MethodsParticipants were 11 children who stutter (CWS; mean age 8.1, age range 6.3–9.5 years) and 19 typically developed children (TDC; mean age 8.1, age range 5.8–9.6 years). They performed a visual Go/Nogo task with simultaneous EEG recording to obtain ERP responses.ResultsResults showed that CWS had longer N2 and P3 latencies in the Go condition compared to the TDC. In contrast, the groups did not differ significantly in the Nogo condition or behavioural measures.ConclusionsOur findings did not confirm less efficient inhibitory control in CWS but suggest atypical attentional processing such as stimulus evaluation and response selection.Educational Objectives: The reader will be able to (a) describe recent findings on attention and inhibitory control in children who stutter, (b) describe the measurement of attentional processing, including inhibitory control, and (c) describe the findings on attentional processing in children who stutter as indexed by the event-related potentials in a visual Go/Nogo paradigm.     

多动症儿童的智力水平、行为与认知事件相关电位的研究

通过对多动症 (MBD)儿童的智力、行为和认知事件相关电位的分析研究,发现多动症儿童的智力水平正常但均数都低于正常儿童,行为问题的检出率和行为量表指数高于一般正常儿童,反映大脑认知功能的事件相关电位的N2、P3的潜伏期较之正常儿童组均延长,且差异均达到显著性水平。     

Activities of daily living in children with developmental coordination disorder: dressing, personal hygiene, and eating skills

In order to understand how age, culture, and problems in motor coordination impact the performance of activities of daily living, we used focus groups and in-depth interviews with Australian and Canadian parents to examine activities of daily living of younger (5-7 years of age) and older (8-9 years of age) children with and without DCD. By comparison with their typically developing age group, children with DCD had more difficulty with dressing, personal hygiene, and eating skills. Difficulties with postural control and fine-motor skills were reported to contribute to poorer performance of activities of daily living. As expected, competence in the performance of activities of daily living improved in the older children with and without DCD and there were few differences in the performance of daily living tasks between typical children in Australia and Canada. Overall, the motor difficulties of children with DCD had a significant impact on performance of a wide range of daily activities.     

预期焦虑对面孔表情加工的影响

预期焦虑是由于对未发生结果的负性投射造成的焦虑情绪。本文比较了被试在不同预期焦虑水平下观看愉快、中性及恐惧面孔时的行为和脑电数据。发现在高预期焦虑水平下,恐惧面孔诱发的N170波幅显著大于低预期焦虑水平,而愉快和中性面孔在两种水平下诱发的波幅差异不显著;且预期焦虑水平对恐惧面孔诱发的N170波幅的调节强度与个体的特质焦虑得分显著相关。这些结果表明,预期焦虑水平会影响面孔表情加工,且不同情绪面孔受到的影响不同。我们推测,预期焦虑水平会通过影响杏仁核等脑区的激活来调节颞上回对恐惧面孔的加工。