Is the discrepancy criterion for defining developmental disorders valid?

The Relationship between Social and Motor Cognition in Primary School Age-Children

There is increased interest in the relationship between motor skills and social skills in child development, with evidence that the mechanisms underlying these behaviors may be linked. We took a cognitive approach to this problem, and examined the relationship between four specific cognitive domains: theory of mind, motor skill, action understanding, and imitation. Neuroimaging and adult research suggest that action understanding and imitation are closely linked, but are somewhat independent of theory of mind and low-level motor control. Here, we test if a similar pattern is shown in child development. A sample of 101 primary school aged children with a wide ability range completed tests of IQ (Raven's matrices), theory of mind, motor skill, action understanding, and imitation. Parents reported on their children's social, motor and attention performance as well as developmental concerns. The results showed that action understanding and imitation correlate, with the latter having a weak link to motor control. Theory of mind was independent of the other tasks. These results imply that independent cognitive processes for social interaction (theory of mind) and for motor control can be identified in primary school age children, and challenge approaches that link all these domains together.

Arithmetic Fact Retrieval

When diagnosing children with learning disorders (as per ICD-10), their scholastic performance has to be significantly below the level of intelligence. Although this discrepancy criterion has received much criticism in the field of literacy, few researchers in mathematics have examined it. We used a two (mathematical performance) by two (intelligence) factorial design to analyze the arithmetic fact retrieval of low-performing children in mathematics who met the criterion (developmental dyscalculia) or did not (mathematical difficulties) and of two groups of average-achieving children matched for intelligence. The four groups (each n = 27 third-graders) were matched for their attention span and their literacy skills. Children solved addition verification tasks with numbers up to 10 and 20 under standard and under dual task conditions requiring further working memory capacity to evaluate the potential use of counting strategies. Performance in addition tasks proved to be associated with mathematical achievement especially in the higher number range, whereas dual task performance did not point to the use of counting strategies among low performers in mathematics. No interaction between mathematics and intelligence was identified, which would have confirmed the discrepancy criterion. These results illustrate that stable knowledge of arithmetic facts is essential for mathematical achievement, regardless of whether the discrepancy criterion is met.

Developmental delays in children with ADHD

OBJECTIVE

ADHD is often comorbid with other disorders, but it is often assumed that academic, language, or motor c skills problems are secondary to ADHD rather than that attention problems are secondary to the other disorder or both disorders have a shared etiology. We assessed for comorbid developmental disorders and which cognitive processes were impaired in children with ADHD.

METHOD

Measures of intelligence, language, motor skills, social cognition, and executive functions were administered to children with ADHD (n = 53) and age/sex-matched typical children.

RESULTS

Clinically significant deficits were 2 to 7 times as common in children with ADHD as in typical children, and the structure of ability differed in the two groups. Abilities were less differentiated in children with ADHD.

CONCLUSION

The results indicate a need for comprehensive screening for developmental disorders in children with ADHD and imply that research needs to focus on how ADHD and developmental disorders may share an etiology.

Paediatrician's role in caring for children with learning difficulties

AIM

Children with learning difficulties are commonly seen in Australian paediatric outpatient settings. The practice patterns of paediatricians in assessing, referring and managing these children are unknown, and there is no consensus on best practice. We thus aimed to examine the consistency between Australian paediatricians': (i) assessment; (ii) referral; and (iii) management of children presenting with learning difficulties.

METHODS

All 373 paediatrician members of the Australian Paediatric Research Network were invited to participate in an online survey in 2010. Paediatricians who saw children with learning difficulties were asked questions about their assessment, referral and management practices.

RESULTS

Of 181 (49%) paediatricians to complete the survey, 140 (77%) reported seeing patients with learning difficulties. Most often, paediatricians supplemented their clinical assessments with audiology assessments (75%), teacher or parent questionnaires (60-65%), or teacher contact (51%). Paediatricians used medical investigations (40%), direct assessment tools (27%) or a school visit (4%) less often. Most paediatricians referred children with learning difficulties to educational psychology (84%), special education (61%) or speech therapy (66%) services but less often to occupational therapy (34%) or mental health (15%) services. The most common management strategies were to provide a report to the school (76%) or parents (66%) and to make recommendations around sleep hygiene (75%) and for tutoring (66%).

CONCLUSIONS

Australian paediatric practice in this area is diverse, with the greatest variability around management practices. These data provide a case for designing and implementing evidence-based guidelines for the paediatric care of children who struggle to learn in school.

The validity of psychiatric diagnoses: the case of 'specific' developmental disorders

We tested whether developmental coordination disorder (DCD) and mixed receptive expressive language disorder (RELD) are valid diagnoses by assessing whether they are separated from each other, from other childhood disorders, and from normality by natural boundaries termed zones of rarity. Standardized measures of intelligence, language, motor skills, social cognition, and executive functioning were administered to children with DCD (n = 22), RELD (n = 30), autistic disorder (n = 30), mental retardation (n = 24), attention deficit/hyperactivity disorder (n = 53) and to a representative sample of children (n = 449). Discriminant function scores were used to test whether there were zones of rarity between the DCD, RELD, and other groups. DCD and RELD were reliably distinguishable only from the mental retardation group. Cluster and latent class analyses both resulted in only two clusters or classes being identified, one consisting mainly of typical children and the other of children with a disorder. Fifty percent of children in the DCD group and 20% in the RELD group were clustered with typical children. There was no evidence of zones of rarity between disorders. Rather, with the exception of mental retardation, the results imply there are no natural boundaries between disorders or between disorders and normality.

Can improving working memory prevent academic difficulties? A school based randomised controlled trial

Background

Low academic achievement is common and is associated with adverse outcomes such as grade repetition, behavioural disorders and unemployment. The ability to accurately identify these children and intervene before they experience academic failure would be a major advance over the current 'wait to fail' model. Recent research suggests that a possible modifiable factor for low academic achievement is working memory, the ability to temporarily store and manipulate information in a 'mental workspace'. Children with working memory difficulties are at high risk of academic failure. It has recently been demonstrated that working memory can be improved with adaptive training tasks that encourage improvements in working memory capacity. Our trial will determine whether the intervention is efficacious as a selective prevention strategy for young children at risk of academic difficulties and is cost-effective.

Methods/Design

This randomised controlled trial aims to recruit 440 children with low working memory after a school-based screening of 2880 children in Grade one. We will approach caregivers of all children from 48 participating primary schools in metropolitan Melbourne for consent. Children with low working memory will be randomised to usual care or the intervention. The intervention will consist of 25 computerised working memory training sessions, which take approximately 35 minutes each to complete. Follow-up of children will be conducted at 6, 12 and 24 months post-randomisation through child face-to-face assessment, parent and teacher surveys and data from government authorities. The primary outcome is academic achievement at 12 and 24 months, and other outcomes include child behaviour, attention, health-related quality of life, working memory, and health and educational service utilisation.

Discussion

A successful start to formal learning in school sets the stage for future academic, psychological and economic well-being. If this preventive intervention can be shown to be efficacious, then we will have the potential to prevent academic underachievement in large numbers of at-risk children, to offer a ready-to-use intervention to the Australian school system and to build international research partnerships along the health-education interface, in order to carry our further studies of effectiveness and generalisability.

Rationale, design and methods for a randomised and controlled trial to evaluate "Animal Fun"--a program designed to enhance physical and mental health in young children

Background

Children with poor motor ability have been found to engage less in physical activities than other children, and a lack of physical activity has been linked to problems such as obesity, lowered bone mineral density and cardiovascular risk factors. Furthermore, if children are confident with their fine and gross motor skills, they are more likely to engage in physical activities such as sports, crafts, dancing and other physical activity programs outside of the school curriculum which are important activities for psychosocial development. The primary objective of this project is to comprehensively evaluate a whole of class physical activity program called Animal Fun designed for Pre-Primary children. This program was designed to improve the child's movement skills, both fine and gross, and their perceptions of their movement ability, promote appropriate social skills and improve social-emotional development.

Methods

The proposed randomized and controlled trial uses a multivariate nested cohort design to examine the physical (motor coordination) and psychosocial (self perceptions, anxiety, social competence) outcomes of the program. The Animal Fun program is a teacher delivered universal program incorporating animal actions to facilitate motor skill and social skill acquisition and practice. Pre-intervention scores on motor and psychosocial variables for six control schools and six intervention schools will be compared with post-intervention scores (end of Pre-Primary year) and scores taken 12 months later after the children's transition to primary school Year 1. 520 children aged 4.5 to 6 years will be recruited and it is anticipated that 360 children will be retained to the 1 year follow-up. There will be equal numbers of boys and girls.

Discussion

If this program is found to improve the child's motor and psychosocial skills, this will assist in the child's transition into the first year of school. As a result of these changes, it is anticipated that children will have greater enjoyment participating in physical activities which will further promote long term physical and mental health.

Trial registration

This trial is registered in the Australian and New Zealand Clinical trials Registry (ACTRN12609000869279).

Can the Child Behavior Checklist be used to screen for motor impairment?

AIM

It has been suggested that one approach to identifying motor impairment in children is to use the Child Behavior Checklist (CBCL) as a screening tool. The current study examined the validity of the CBCL in identifying motor impairment.

METHOD

A total of 398 children, 206 females and 192 males, aged from 3 years 9 months to 14 years 10 months were assessed on the McCarron Assessment of Neuromuscular Development to determine their motor ability. Parents completed the CBCL.

RESULTS

The 'Clumsy' item on the CBCL was found to predict motor ability independent of the child's age, sex, and scores on other items of the CBCL. However, the sensitivity of the 'Clumsy' item in terms of identifying motor impairment was found to be a low 16.7% compared with specificity of 93.2%. The item 'Not liked' was also found to be a significant predictor of motor impairment.

INTERPRETATION

Although the 'Clumsy' and 'Not liked' items were found to have a relationship with motor ability, they should not be relied upon to categorize children as motor impaired versus not impaired. It is possible that these items may be better indicators of motor impairment in children with developmental disorders such as attention-deficit-hyperactivity disorder, but clinical samples are needed to address this.

Working memory functioning in children with learning disabilities: does intelligence make a difference?

BACKGROUND

Children with learning disabilities are identified by their severe learning problems and their deficient school achievement. On the other hand, children with sub-average school achievement and sub-average intellectual development are thought to suffer from a general intellectual delay rather than from specific learning disabilities. The open question is whether these two groups are characterised by differences in their cognitive functioning. The present study explored several functions of working memory.

METHOD

A working memory battery with tasks for the phonological loop, the visual-spatial sketchpad and central executive skills was presented in individual sessions to 27 children with learning disabilities and normal IQ (ICD-10: mixed disorders of scholastic skills), 27 children with learning disabilities and low IQ (intellectual disabilities), and a control group of 27 typically developing children with regular school achievement levels and normal IQ.

RESULTS

The results reveal an overall deficit in working memory of the two groups with learning disabilities compared with the control group. However, unexpectedly, there were no differences between the two groups of children with disabilities (normal vs. low IQ).

CONCLUSIONS

These findings do not support the notion of different cognitive functioning because of differences in intelligence of these two groups. In the ongoing discussion about the role of intelligence (especially as to the postulated discrepancy between intelligence and school achievement in diagnosis and special education), our findings might lead to rethinking the current practice of treating these two groups as fundamentally different.

Description of children identified by physicians as having developmental coordination disorder

The aim of this study was to describe in detail a large group of children aged 4 to 12 years who were diagnosed with developmental coordination disorder (DCD) by physicians following a rigorous multidisciplinary procedure. As part of a community-based DCD knowledge translation program, physicians received specialized training and were invited to identify children with probable DCD who were referred for further investigation to help confirm the diagnosis. Of 116 children (87 males, 29 females; age range 4y 1mo - 12y 11mo, mean age 8y) identified as having probable DCD by physician participants, 88 (76%) were subsequently diagnosed with DCD and 77.3% of these demonstrated a high degree of motor impairment. All children who were diagnosed experienced difficulties in self-care and/or academic or leisure activities. The male:female ratio was 3:1 and the incidence of preterm births among this sample was 12.5%. We conclude that, given the expense involved with ruling out differential diagnoses, it can be difficult to adhere rigorously to diagnostic criteria for DCD in clinical practice and research. This description of a group of children actually diagnosed with DCD helps to clarify the characteristics of these children as well as issues related to the refinement of diagnostic criteria.

What can autism and dyslexia tell us about intelligence?

This paper argues that understanding developmental disorders requires developing theories and models that explicitly represent the role of general intelligence in the cognitive phenotype of the disorder. In the case of autism it is argued that the low-IQ scores of people with autism are not likely to be due to a deficit in the cognitive process that is arguably the major cause of mental retardation - namely, speed of processing - but rather low IQ reflects the pervasive and cascading effects of the deficit in the information-processing module that causes autism. In the case of dyslexia, two radically different models of reading disorder (ability = disability and a modular deficit model) are likely to be influenced by the effect of general intelligence on reading performance in ways that will remain unclear without an explicit model of how general intelligence influences reading.

Specific language difficulties and school achievement in children born at 25 weeks of gestation or less

OBJECTIVE

To determine whether language and educational problems are specific or due to general cognitive deficits in children born at 25 weeks' gestation or less.

STUDY DESIGN

A national cohort study assessed 241 of 308 (78%) surviving children at a median age of 6 years, 4 months along with 160 of these children's classmates. Formal tests included standard cognitive, language, phonetic, and speech assessments. The children's school achievement was rated by classroom teachers.

RESULTS

Mean cognitive scores for index children were 82 (standard deviation [SD] +/- 19) compared with 106 (SD +/- 12) for the peer group. Extremely preterm children had an increased risk of language problems (odds ratio [OR] = 10; 95% confidence interval [CI] = 3 to 32), speech problems (OR = 4.4; 95% CI = 3 to 7), and overall school difficulties (OR = 25; 95% CI = 12 to 54). Extremely preterm boys were twice as likely to show deficits as extremely preterm girls, but no such sex-based differences were apparent in the comparison group. Differences in general cognitive scores explained specific language or phonetic awareness deficits, but not speech ratings or educational difficulties, in the extremely preterm children.

CONCLUSIONS

Language or phonetic difficulties are not specific and indicate general cognitive functional difficulties. The findings have implications for models of global deviation of brain development in extremely preterm children.

Interviewing alleged victims with intellectual disabilities

BACKGROUND

When interviewing alleged victims of crime, it is important to obtain reports that are as accurate and complete as possible. This can be especially difficult when the alleged victims have intellectual disabilities (ID). This study explored how alleged victims with ID are interviewed by police officers in Sweden and how this may affect their ability to report information as accurately as possible.

METHODS

Twelve interviews with 11 alleged victims were selected from a larger sample. The complainants were interviewed when their chronological ages ranged from 6.1 to 22 years. A quantitative analysis examined the type of questions asked and the numbers of words and details they elicited in response.

RESULTS

Instead of open-ended questions, the interviewers relied heavily on focused questions, which are more likely to elicit inaccurate information. When given the opportunity, the witnesses were able to answer directive questions informatively.

CONCLUSIONS

Interviewers need special skills in order to interview alleged victims who have ID. In addition to using more open-ended questions, interviewers should speak in shorter sentences.

Fragile X--a challenge to models of the mind and to best clinical practice

Cornish et al. (2008, this issue) provide an excellent review of Fragile X a common but very complex cause of intellectual disability. They report on a cohort of such males of normal intelligence quotient (IQ) and socioeconomic status (SES), but who have deficits in selective attention and growing impairment in response inhibition. This paper has theoretical views for our models of the mind and clinical implications for families where Fragile X may never have been considered as a possible cause of some of the problems in male and female family members and possibly as well for other disorders such as attention deficit hyperactivity disorder (ADHD) and autism.

Working memory, processing speed, and set-shifting in children with developmental coordination disorder and attention-deficit-hyperactivity disorder

It has been suggested that the high levels of comorbidity between attention-deficit-hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) may be attributed to a common underlying neurocognitive mechanism. This study assessed whether children with DCD and ADHD share deficits on tasks measuring working memory, set-shifting, and processing speed. A total of 195 children aged between 6 years 6 months and 14 years 1 month (mean 10y 4mo [SD 2y 2mo]) were included in this study. A control group (59 males, 79 females), a DCD group (12 males, six females), an ADHD-predominantly inattentive group (16 males, four females), and an ADHD-combined group (15 males, four females), were tested on three executive functioning tasks. Children with DCD were significantly slower on all tasks, supporting past evidence of a timing deficit in these children. With few exceptions, children with ADHD did not perform more poorly than control children. These findings demonstrate the importance of identifying children with motor deficits when examining tasks involving a timing component.

Can autism, language and coordination disorders be differentiated based on ability profiles?

Children with autistic disorder (AD), mixed receptive-expressive language disorder (RELD), or developmental coordination disorder (DCD) have impairments in common. We assess which abilities differentiate the disorders. Children aged 3-13 years diagnosed with AD (n = 30), RELD (n = 30), or DCD (n = 22) were tested on measures of language, intelligence, social cognition, motor coordination, and executive functioning. Results indicate that the AD and DCD groups have poorer fine and gross motor coordination and better response inhibition than the RELD group. The AD and DCD groups differ in fine and gross motor coordination, emotion understanding, and theory of mind scores (AD always lower), but discriminant function analysis yielded a non-significant function and more classification errors for these groups. In terms of ability scores, the AD and DCD groups appear to differ more in severity than in kind.

A Cumulative Risk Factor Model for Early Identification of Academic Difficulties in Premature and Low Birth Weight Infants

OBJECTIVES

Premature and low birth weight children have a high prevalence of academic difficulties. This study examines a model comprised of cumulative risk factors that allows early identification of these difficulties.

METHODS

This is a secondary analysis of data from a large cohort of premature (<37 weeks gestation) and LBW (<2500 g) children. The study subjects were 8 years of age and 494 had data available for reading achievement and 469 for mathematics. Potential predictor variables were categorized into 4 domains: sociodemographic, neonatal, maternal mental health and early childhood (ages 3 and 5). Regression analysis was used to create a model to predict reading and mathematics scores.

RESULTS

Variables from all domains were significant in the model, predicting low achievement scores in reading (R (2) of 0.49, model p-value < .0001) and mathematics (R (2) of 0.44, model p-value < .0001). Significant risk factors for lower reading scores, were: lower maternal education and income, and Black or Hispanic race (sociodemographic); lower birth weight and male gender (neonatal); lower maternal responsivity (maternal mental health); lower intelligence, visual-motor skill and higher behavioral disturbance scores (early childhood). Lower mathematics scores were predicted by lower maternal education, income and age and Black or Hispanic race (sociodemographic); lower birth weight and higher head circumference (neonatal); lower maternal responsivity (maternal mental health); lower intelligence, visual-motor skill and higher behavioral disturbance scores (early childhood).

CONCLUSIONS

Sequential early childhood risk factors in premature and LBW children lead to a cumulative risk for academic difficulties and can be used for early identification.

Are abilities abnormally interdependent in children with autism?

We propose that stronger than usual correlations between abilities indicate which cognitive processes are impaired in autism. Study 1 compared partial correlations (controlling age) between intelligence and social cognition in children with autism (n = 18), mental retardation (MR; n = 34), or no psychological disorder (n = 37). Correlations were stronger in the autism group. Study 2 compared correlations between measures of perceptual organization and verbal comprehension, receptive and expressive language, fine and gross motor coordination, and theory of mind, emotion recognition, and emotion understanding abilities in children with autism (n = 30) or MR (n = 24) and in a large representative sample of children (n = 449). Results indicate that autism is marked by stronger correlations between all ability domains, and MR is marked by stronger correlations between motor coordination tasks and other ability measures.

The relationship between fine and gross motor ability, self-perceptions and self-worth in children and adolescents

The present study examined the impact of fine and gross motor ability on self-perceptions of male and female children and adolescents. Participants were compared across age group, sex, and level of motor ability. When intercorrelations between self-perceptions were taken into account, the level of movement ability was found to impact upon perceived athletic competence and scholastic competence. When movement was considered in terms of fine and gross motor ability, it was found that those with higher perceived scholastic competence were in the younger group and had better fine motor skills. Furthermore, those with greater perceived athletic competence were also in the younger group, were predominantly male and had better gross motor skills. The types of self-perceptions that influenced self-worth were dependent on the level of motor ability of the participants and varied according to their sex. The implications of these findings are discussed with reference to the necessity to assess specific types of motor deficit when tailoring intervention strategies for children with motor disorders, particularly within the academic setting.

Sensory-motor deficits in children with developmental coordination disorder, attention deficit hyperactivity disorder and autistic disorder

Children who have been diagnosed with any one developmental disorder are very likely to meet diagnostic criteria for some other developmental disorder. Although comorbidity has long been acknowledged in childhood disorders, little is understood about the mechanisms that are responsible for the high level of comorbidity. In a series of studies, we have investigated the link between sensory-motor deficits and developmental disorders. Poor sensory-motor integration has long been implicated as a cause of motor problems in developmental disorders such as developmental coordination disorder (DCD), and our recent research has also investigated sensory-motor deficits in children with attention deficit hyperactivity disorder (ADHD) and autistic disorder. Based on a critical examination of relevant literature and some of our recent research findings, we argue that the importance of poor sensory-motor functioning in discriminating children with different disorders has been underestimated. Poor sensory-motor coordination appears to be linked to DCD, but not ADHD. Also, sensory-motor deficits in children with DCD and autistic disorder may provide insight into some of the social difficulties found in these groups of children. This research will increase our understanding of why children with one developmental disorder typically also have problems in other areas.