Co-occurring disorders: a possible key to visual perceptual deficits in children with developmental coordination disorder?

A study was conducted to examine how visual perceptual functioning in children with DCD may be influenced by co-occurring learning problems such as reading disabilities (RD) and/or attention deficit hyperactivity disorder (ADHD). Participants included seven groups of children: 27 children with DCD only, 11 with ADHD only, 14 with RD only, 63 with DCD and at least one other disorder (i.e., DCD + ADHD, DCD + RD, DCD + ADHD + RD), and 73 typically developing controls. Visual perceptual skills were assessed using the Test of Visual Perceptual Skills (TVPS) and the Rey Osterreith Complex Figure (ROCF; copy and delayed recall). Children with DCD and at least one other disorder were found to have impairments on the TVPS compared to children with DCD only, ADHD only, and typically developing controls, particularly on subtests assessing visual memory. On the ROCF, children with DCD and at least one other disorder scored significantly lower than children with ADHD only or RD only. Children with DCD plus one other disorder were then subdivided into three groups: DCD + ADHD, DCD + RD, and DCD + ADHD + RD and compared to children with DCD only, ADHD only, and RD only. Results indicated that children with DCD + ADHD + RD had significant impairments on the TVPS compared to children with DCD only and children with ADHD only. On the ROCF, children with DCD + ADHD + RD scored significantly lower than all of the groups, except the DCD+RD group. These findings suggest that DCD on its own is not associated with visual perceptual problems; rather, it is the presence of co-occurring disorders that is a possible key to visual perceptual deficits in children with DCD. The number of co-occurring disorders present with DCD is associated with the severity of the visual perceptual dysfunction. Deficits in visual memory skills appear to be a specific area of difficulty for children with DCD and co-occurring RD and/or ADHD.     

Epileptic encephalopathies and their relationship to developmental disorders: do spikes cause autism?

Epileptic encephalopathies are progressive clinical and electroencephalographic syndromes where deterioration is thought to be caused by frequent seizures and abundant EEG epileptiform activity. Seizures occur in approximately 10-15% of children with pervasive developmental disorders (PDD) and 8-10% have epileptiform EEG abnormalities without seizures. Thirty percent of children with PDD have regression of social behavior and language at 2-3 years of age. Some authors speculate that the regression is caused by epileptiform activity even in the absence of overt clinical seizures ("autism with epileptic regression") and suggest that elimination of the epileptiform activity, either medically or surgically, should lead to improvement in behavior. This review examines the data showing that interictal epileptiform discharges are associated with transient clinical dysfunction and discusses the implications of these observations for autistic behavioral abnormalities. The results of resective surgery, vagal nerve stimulation, and multiple subpial transaction on children with autism and epileptiform EEG abnormalities are also discussed. I conclude that there is no evidence that interictal discharges per se cause (or contribute to) the complex behavioral phenotype of autism. There is no justification to support the use of anticonvulsant medication or surgery in children with PDD without seizures; that is, there is no evidence that treatment to eliminate EEG spikes will have a therapeutic effect on the behavioral abnormalities of PDD and autism.     

Neuropsychological status of French children with developmental dyslexia and/or developmental coordination disorder: Are both necessarily worse than one?

Developmental dyslexia (DD) and developmental coordination disorder (DCD) co-occur frequently, raising the underlying question of shared etiological bases. We investigated the cognitive profile of children with DD, children with DCD, and children with the dual association (DD + DCD) to determine the inherent characteristics of each disorder and explore the possible additional impact of co-morbidity on intellectual, attentional, and psychosocial functioning. The participants were 8- to 12-year-olds (20 DD, 22 DCD, and 23 DD + DCD). Cognitive abilities were assessed by the Wechsler Intelligence Scale for Children – Fourth Edition (WISC-IV) and the Continuous Performance Test – Second Edition (CPT-II) and behavioral impairments were evaluated by the Child Behavior Checklist (CBCL). No differences were found between the three groups on attention testing (CPT-II) or psychosocial characteristics (CBCL), but a higher percentage of DD + DCD children had pathological scores on psychosocial scales. Significant between-group differences were observed on Processing Speed Index scores and the block design and symbol search subtests, where DD children fared better than DCD children. No significant differences were evident between the co-morbid vs. the pure groups. Our results clearly show significant differences between children with DD only and children with DCD only. In particular, visuo-spatial disabilities and heterogeneity of intellectual profile seem to be good markers of DCD. However, it should be noted that despite these distinct and separate characteristics, a common cognitive profile (weaknesses and strengths) is likely shared by both neurodevelopmental disorders. Surprisingly, concerning co-morbidity, DD + DCD association is not associated with a decrease in intellectual or attentional capacities.     

Development of motor imagery and anticipatory action planning in children with developmental coordination disorder – A longitudinal approach

Children with impaired motor coordination (or Development Coordination Disorder – DCD) have difficulty with the predictive control of movements, evidenced by cross-sectional studies that show impaired motor imagery and action planning abilities. What remains unclear is whether this deficit in predictive control reflects immaturity of the motor system (a developmental delay) or some deviation from normal development (a disorder). To advance this discussion the present study used a longitudinal design to examine the development of motor imagery and action planning in children with DCD. Thirty children were included in the DCD group (aged 6–11 years) and age- and gender-matched to 30 controls. The DCD group had a mABC-2 score ≤ 16th percentile, the control group > 20th percentile. Motor imagery was assessed with the hand rotation task, action planning with a test for end-state comfort. Children participated in three measurements, with one year in between measurements. Results showed that children with DCD were slower and less accurate than their typically developing peers in all subsequent years but were able to improve their motor imagery ability over time. Furthermore, children with DCD showed less planning for ESC at the start of the present study, but were able to catch up with their peers during two-year follow up. These results exemplify that improvement of motor imagery and action planning ability is possible in DCD, and they lend theoretical support to the use of new training techniques that focus on training motor imagery to improve motor skills in children with DCD.     

Development of motor imagery ability in children with developmental coordination disorder – A goal-directed pointing task

Children with developmental coordination disorder (DCD) have difficulties with the predictive control of movements. This was shown in studies that target motor imagery and motor planning, and appears to become particularly evident with increases in task complexity. In this study, we used a complex mental chronometry paradigm to examine the development of motor imagery ability in children with DCD, using a longitudinal design. Thirty children were included in the DCD group (aged 6–11 years) and age- and gender-matched to 30 controls. The DCD group had a Movement Assessment Battery for Children-2 score ≤16th percentile and the control group ≥25th percentile. Results of this study showed that children with DCD indeed had a significantly lower correlation between executed and imagined movements. Importantly, the increase in the correlation and linear fit during subsequent measurements was comparable for the DCD and control group. Together, these findings suggest a delayed developmental onset of motor imagery ability in DCD, but a similar rate of development over time compared to the control group. Based on these results, it seems likely that explicit motor imagery instructions can be used to improve predictive control in children with DCD.     

Barking up the wrong tree? Lexical ambiguity resolution in children with language impairments and autistic spectrum disorders

Lexical ambiguity resolution was investigated in 9- to 17-year-olds with language impairment (LI, n=20), autistic spectrum disorder (ASD) plus language impairment (ALI, n=28), ASD and verbal abilities within the normal range (ASO, n=20), and typically developing children (TD, n=28). Experiment 1 investigated knowledge of dominant and subordinate meanings of ambiguous words. The LI and ALI groups knew fewer subordinate meanings than did the ASO and TD groups. Experiment 2 used a modified version of the paradigm to investigate contextual facilitation and suppression of irrelevant meanings. All groups demonstrated contextual facilitation, responding quickly and more accurately to words following a biased context. However, children with ALI and LI did not use context as efficiently as did their peers without language deficit. Furthermore, for the LI and ALI groups, errors in the suppression condition reflected poor contextual processing. These findings challenge the assumptions of weak central coherence theory and demonstrate the need for stringent language controls in the study of autistic cognition.     

The irrelevant sound effect in short-term memory: Is there developmental change?

With two experiments, effects of irrelevant speech and classroom noise on serial recall of common nouns presented pictorially were investigated in children and adults. Experiment 1 used fixed list lengths for children (first graders) and adults. Experiment 2 used list lengths adjusted to participants' (second–third graders, adults) individual spans. In both experiments, children and adults were equally impaired by irrelevant speech. This contrasts with a related study (differences in methodology) by Elliott (2002), who reported severe increase in the detrimental impact of irrelevant speech with decreasing age. In both experiments, classroom noise had no effect in overall analyses. For Experiment 1, however, separate group analyses revealed impairment in children. Results suggest that effects of irrelevant sounds on serial recall stem from two separate mechanisms: Specific interference due to the sounds' automatic access to short-term memory, and/or attention capture. Only for the latter there is developmental change.     

Does subtype of developmental coordination disorder count: is there a differential effect on outcome following intervention?

It is well known that developmental coordination disorder (DCD) is a heterogeneous condition in which children frequently present with co-occurring conditions in addition to their motor difficulties. This study considered whether there would be a differential effect of a group treatment program on subtypes of perceptual and movement problems or associated co-occurring conditions. A subset of children (n=43) from a larger clinical sample (n=100) with DCD participated in a 214 year cross-over intervention study which followed the cognitive orientation to daily occupational performance (CO-OP) approach. Original subtypes were determined by contrasting the current sample with previously published subtyping studies in DCD [Hoare, D. (1994). Subtypes of developmental coordination disorder. Adapted Physical Activity Quarterly, 11, 158-169; Macnab, J. J., Miller, L. T., & Polatajko, H. J. (2001). The search for subtypes of DCD: Is cluster analysis the answer? Human Movement Science, 20, 49-72]. No advantage was conferred to any subtype although children with more profound and complex difficulties at initial assessment, despite progress following intervention, were most likely to have continuing difficulties at the end of the project.     

Does perceived direct gaze boost detection in adults and children with and without autism? The stare-in-the-crowd effect revisited

This study extended that of von Grünau and Anston (1995) and explored whether perceived direct gaze is easily detected by individuals with and without autism, utilizing a visual-search paradigm. Participants detected target faces with either direct gaze or averted gaze. Laterally averted faces were used to eliminate the involvement of lower perceptual characteristics such as symmetry, which were inherent with the “straight gaze” used by von Grünau and Anston. Both typically developed adults and children detected targets with direct gaze more quickly than those with averted gaze, but face inversion distorted this asymmetrical performance, suggesting the contribution of configurative facial processing. In contrast, children with autism were not affected by the gaze direction presented by realistic facial stimuli. They were, however, faster to detect straight gaze defined solely by local features, which suggests that their impairment might be specific to the detection of direct gaze presented within a facial context.     

Working memory in multilingual children: is there a bilingual effect?

This research investigates whether early childhood bilingualism affects working memory performance in 6- to 8-year-olds, followed over a longitudinal period of 3 years. The study tests the hypothesis that bilinguals might exhibit more efficient working memory abilities than monolinguals, potentially via the opportunity a bilingual environment provides to train cognitive control by combating interference and intrusions from the non-target language. A total of 44 bilingual and monolingual children, matched on age, sex, and socioeconomic status, completed assessments of working memory (simple span and complex span tasks), fluid intelligence, and language (vocabulary and syntax). The data showed that the monolinguals performed significantly better on the language measures across the years, whereas no language group effect emerged on the working memory and fluid intelligence tasks after verbal abilities were considered. The study suggests that the need to manage several language systems in the bilingual mind has an impact on children's language skills while having little effects on the development of working memory.     

Working memory in multilingual children: Is there a bilingual effect?

This research investigates whether early childhood bilingualism affects working memory performance in 6- to 8-year-olds, followed over a longitudinal period of 3 years. The study tests the hypothesis that bilinguals might exhibit more efficient working memory abilities than monolinguals, potentially via the opportunity a bilingual environment provides to train cognitive control by combating interference and intrusions from the non-target language. A total of 44 bilingual and monolingual children, matched on age, sex, and socioeconomic status, completed assessments of working memory (simple span and complex span tasks), fluid intelligence, and language (vocabulary and syntax). The data showed that the monolinguals performed significantly better on the language measures across the years, whereas no language group effect emerged on the working memory and fluid intelligence tasks after verbal abilities were considered. The study suggests that the need to manage several language systems in the bilingual mind has an impact on children's language skills while having little effects on the development of working memory.     

Does the coordination of verbal and motor information explain the development of counting in children?

Counting is often considered to be the coordination of two actions: saying the number-words and pointing to each object. We report three experiments to test the hypothesis that this coordination requires the use of the central executive (A. D. Baddeley, 1990), and that the cost of coordination decreases with age. Participants were 5- and 9-year-old children and adults. At all ages tested, the manipulation of the difficulty of each component affected counting performance but did not make coordination more difficult. These results suggest that, at least from the age 5, counting is a procedure in which the control of coordination is not attention demanding.     

Early educational intervention with disadvantaged children—To what effect?

The adequate development of children is essential for the survival of a society. Dramatic negative changes in current societies have increased both the number of disadvantaged children and the severity of their disadvantage, thus threatening children's adequate development and the achievement of stability and productivity within their societies. Considerable scientific data support the idea that negative outcomes for children can be prevented. Effective prevention depends largely on early educational intervention, often supplemented by health and social services and parental involvement. This article (a) summarizes the key conclusions from 25 years of scientific inquiry, (b) acknowledges controversial issues in the scientific and policy arenas, (c) recommends practical strategies for enhancing children's everyday environments, and (d) proposes an integrative conceptual framework to guide future research and early educational intervention.     

Narrative retelling in children with neurodevelopmental disorders: Is there a role for nonverbal temporal‐sequencing skills?

Oral narrative retelling is often problematic for children with communicative and neurodevelopmental disorders. However, beyond a suggested role of language level, little is known about the basis of narrative performance. In this study we examine whether oral narrative retelling might be associated not just with language level but also with skills related to nonverbal narrative temporal sequencing. A diagnostically heterogeneous sample of Swedish‐speaking children with a full scale IQ >70 was included in the study (N = 55; age 6–9 years). Narrative retelling skills were measured using the three subscores from the bus story test (BST). Independent predictors included (1) temporal sequencing skills according to a picture arrangement test and (2) a language skills factor consisting of definitional vocabulary and receptive grammar. Regression analyses show that language skills predicted BST Sentence Length and Subordinate Clauses subscores, while both temporal sequencing and language were independently linked with the BST Information subscore. When subdividing the sample based on nonverbal temporal sequencing level, a significant subgroup difference was found only for BST Information. Finally, a principal component analysis shows that temporal sequencing and BST Information loaded on a common factor, separately from the language measures. It is concluded that language level is an important correlate of narrative performance more generally in this diagnostically heterogeneous sample, and that nonverbal temporal sequencing functions are important especially for conveying story information. Theoretical and clinical implications are discussed.     

Do the Wechsler scales underestimate the difference between verbal and performance abilities in children with language–related disorders?

The present paper examines the validity of the Wechsler scales with children with language-related disorders, with whom the scales were not originally normed. The general question is whether we can take measures of IQ, normed with a normal sample, and then validly use them as indicators of the same constructs with samples significantly different from the normed sample. In previous papers it was pointed out that the pattern structurally simple > moderately complex > complex tests can be observed in their IQ profiles within both the Verbal scale and the Performance scale. In this paper, it is hypothesized that this scatter of scores leads to an underestimation of the global V-P IQ differences for children with language-related disorders because there are more structurally complex tests on the Performance scale than on the Verbal scale. To test this hypothesis, "purer" V-P IQ differences were calculated by comparing the scores on Verbal and Performance tests of equal structural complexity. WPPSI and WISC-R data from four groups of children were analyzed: language-impaired children (n = 128), reading-impaired children (n = 112), children from dyslexic families (n = 51), and normal children (n = 49). When the effect of the difference in structural complexity was controlled for, it was found that the distribution of the revised V-P IQ difference was significantly more toward the negative end of the spectrum than the traditional V-P IQ differences for language-impaired and reading-impaired children, and approaching a significant level for children from dyslexic families. As hypothesized, there were no significant differences between the two distributions of V-P IQ differences for normal children. Practical and theoretical implications are discussed.     

Does aggression cause a preference for viewing media violence?

Virtually all of the research concerned with media violence has attempted to determine whether the viewing of violence is associated with or causes aggression. Little experimental research has been directed at understanding why persons view media violence. The present research experimentally tested the hypotheses that physical aggression and fantasy aggression would lead to a preference for viewing violence. In Experiment 1, undergraduate men and women were induced to express aggressive, nonaggressive, or no fantasies and were then given an opportunity to select film clips for viewing. The films chosen by men contained more violence than those chosen by women. In addition, aggressive fantasies in males, compared to nonaggressive fantasies, increased the preference for viewing violence. Experiment 2, using only males, replicated the results of the first study and also found that men who were given an opportunity to aggress physically, compared to those who had no such opportunity, were more likely to choose to view films containing violent content. These results provide an additional perspective on the relationship between the observation of violence and the expression of aggression by suggesting that the causal effects are bidirectional: Just as the viewing of violence may increase aggression, so, too, aggressive behavior may increase the preference for viewing violence.     

Academic achievement in Blacks and Whites: Are the developmental processes similar?

Genetic and environmental influences on academic achievement were investigated in four groups of siblings: (1) White full siblings, (2) White half-siblings, (3) Black full siblings, and (4) Black half-siblings. Our expectation was that the variances and covariances among three achievement tests would have the same structure across the four groups. This expectation was confirmed by a quantitative genetic model that imposed equal factor loadings across groups. This best fitting model had two factors: a Genetic factor representing genetic variation and a Shared Environment factor representing environmental differences among families. Reading recognition, reading comprehension, and mathematics tests all loaded on the Genetic factor, but primarily mathematics loaded on the Shared Environment factor. The quantitative genetic model was next fit to the achievement test means. Its successful fit suggested that the genetic and environmental influences involved in producing individual variation were the same as those producing the group-mean differences. In this sample, genes accounted for 66% to 74% of the observed group difference in verbal achievement and 36% of the difference in mathematics achievement. Shared environment accounted for the remainder, 34% to 26% of the difference in verbal achievement and 64% of that in mathematics achievement.     

The gender effect in 3D-Mental-rotation performance with familiar and gender-stereotyped objects – a study with elementary school children

The study examined the influence of gender-stereotyped stimuli rotated in depth on children’s mental-rotation performance. Participants included 321 elementary school children who completed three-dimensional mental-rotation tasks with either male- or female-stereotyped stimuli (M-MRT-3D/F-MRT-3D). Results suggest that in-depth tasks are very difficult for second graders. No gender effect was found in the mental-rotation performance of 7- to 9-year-old children; however, task understanding indicates gender differences. For fourth graders, a significant interaction of gender and stimulus type could be demonstrated. Furthermore, results indicate that fourth-grade boys tend to guess more often in tasks with stimuli consistent to the respective own gender. In addition, regression analyses showed that next to grade and perceptual speed, the perceived level of stimulus familiarity predicted performance. Considering a possible link between dimensionality and familiarity, the influence of the gender-stereotyped stimuli on children’s confidence and task understanding as well as on transformational processes and strategy efficiency is discussed.