The Perfect Match! A Review and Tutorial on Issues Related to Matching Groups in Investigations of Children with Neurodevelopmental Conditions.

Research concerned with children and young people who have neurodevelopmental disabilities (ND) in relation to early language acquisition usually involves comparisons with matched group(s) of typically developing individuals. In these studies, several important and complex issues need to be addressed. Three major issues are related to: (1) the choice of a variables on which to carry out group matching; (2) recruiting children into the study; and (3) the statistical analysis of the data. To assist future research on this topic, we discuss each of these three issues and provide recommendations about what we believe to be the best course of action. To provide a comprehensive review of the methodological issues, we draw on research beyond the topic of early language acquisition. Our overall aim is to contribute to research that considers questions about delay or differences in development patterns of development and about identifying potentially causal variables.

A Short and Engaging Adaptive Working-Memory Intervention for Children with Developmental Language Disorder: Effects on Language and Working Memory.

Recent research has suggested that working-memory training interventions may benefit children with developmental language disorder (DLD). The current study investigated a short and engaging adaptive working-memory intervention that targeted executive skills and aimed to improve both language comprehension and working-memory abilities in children with DLD. Forty-seven 6- to 10-year-old children with DLD were randomly allocated to an executive working-memory training intervention (n = 24) or an active control group (n = 23). A pre-test/intervention/post-test/9-month-follow-up design was used. Outcome measures included assessments of language (to evaluate far transfer of the training) and working memory (to evaluate near transfer of the training). Hierarchical multiple regression analyses controlling for pre-intervention performance and age found the group to be a significant predictor of sentence comprehension and of performance on six untrained working-memory measures at post-intervention and 9-month follow-up. Children in the intervention group showed significantly higher language comprehension and working-memory scores at both time points than children in the active control group. The intervention programme showed the potential to improve working memory and language comprehension in children with DLD and demonstrated several advantages: it involved short sessions over a short period, caused little disruption in the school day, and was enjoyed by children.

Hebb repetition learning in adolescents with intellectual disabilities.

BACKGROUND: Hebb repetition learning is a form of long-term serial order learning that can occur when sequences of items in an immediate serial recall task are repeated. Repetition improves performance because of the gradual integration of serial order information from short-term memory into a more stable long-term memory trace. AIMS: The current study assessed whether adolescents with non-specific intellectual disabilities showed Hebb repetition effects, and if their magnitude was equivalent to those of children with typical development, matched for mental age. METHODS: Two immediate serial recall Hebb repetition learning tasks using verbal and visuospatial materials were presented to 47 adolescents with intellectual disabilities (11-15 years) and 47 individually mental age-matched children with typical development (4-10 years). RESULTS: Both groups showed Hebb repetition learning effects of similar magnitude, albeit with some reservations. Evidence for Hebb repetition learning was found for both verbal and visuospatial materials; for our measure of Hebb learning the effects were larger for verbal than visuospatial materials. CONCLUSIONS: The findings suggested that adolescents with intellectual disabilities may show implicit long-term serial-order learning broadly commensurate with mental age level. The benefits of using repetition in educational contexts for adolescents with intellectual disabilities are considered.

Children's Verbal, Visual and Spatial Processing and Storage Abilities: An Analysis of Verbal Comprehension, Reading, Counting and Mathematics.

The importance of working memory (WM) in reading and mathematics performance has been widely studied, with recent research examining the components of WM (i.e., storage and processing) and their roles in these educational outcomes. However, the differing relationships between these abilities and the foundational skills involved in the development of reading and mathematics have received less attention. Additionally, the separation of verbal, visual and spatial storage and processing and subsequent links with foundational skills and downstream reading and mathematics has not been widely examined. The current study investigated the separate contributions of processing and storage from verbal, visual and spatial tasks to reading and mathematics, whilst considering influences on the underlying skills of verbal comprehension and counting, respectively. Ninety-two children aged 7- to 8-years were assessed. It was found that verbal comprehension (with some caveats) was predicted by verbal storage and reading was predicted by verbal and spatial storage. Counting was predicted by visual processing and storage, whilst mathematics was related to verbal and spatial storage. We argue that resources for tasks relying on external representations of stimuli related mainly to storage, and were largely verbal and spatial in nature. When a task required internal representation, there was a draw on visual processing and storage abilities. Findings suggest a possible meaningful separability of types of processing. Further investigation of this could lead to the development of an enhanced WM model, which might better inform interventions and reasonable adjustments for children who struggle with reading and mathematics due to WM deficits.

Mock Juror Perceptions of Child Witnesses on the Autism Spectrum: The Impact of Providing Diagnostic Labels and Information About Autism.

Research suggests that autistic children can provide accurate and forensically useful eyewitness evidence. However, members of a jury also rely on non-verbal behaviours when judging the credibility of a witness, and this could determine the verdict of a case. We presented mock jurors with videos (from an experimental study) of one of two child witnesses on the autism spectrum being interviewed about a mock minor crime. Results demonstrated that providing jurors with generic information about autism and/or informing them of the child's diagnostic label differentially affected credibility ratings, but not for both children. Implications for how to present information about child witnesses with autism to a jury-highlighting the need for approaches tailored to individual children-are discussed.

Working memory and high-level cognition in children: An analysis of timing and accuracy in complex span tasks.

This study examined working memory (WM) using complex span tasks (CSTs) to improve theoretical understanding of the relationship between WM and high-level cognition (HLC) in children. A total of 92 children aged 7 and 8 years were tested on three computer-paced CSTs and measures of nonverbal reasoning, reading, and mathematics. Processing times in the CSTs were restricted based on individually titrated processing speeds, and performance was compared with participant-led tasks with no time restrictions. Storage, processing accuracy, and both processing and recall times within the CSTs were used as performance indices to understand the effects of time restrictions at a granular level. Restricting processing times did not impair storage, challenging models that argue for a role of maintenance in WM. A task-switching account best explained the effect of time restrictions on performance indices and their interrelationships. Principal component analysis showed that a single factor with all performance indices from just one CST (counting span) was the best predictor of HLC. Storage in both the participant-led and computer-paced versions of this task explained unique and shared variance in HLC. However, the latter accounted for more variance in HLC when contributions from processing time were included in the model. Processing time in this condition also explained variance above and beyond storage. This suggests that faster processing is important to keep information active in WM; however, this is evident only when time restrictions are placed on the task and important when WM performance is applied in broader contexts that rely on this resource.

The narrative coherence of witness transcripts in children on the autism spectrum.

BACKGROUND AND AIMS: Autistic children often recall fewer details about witnessed events than typically developing children (of comparable age and ability), although the information they recall is generally no less accurate. Previous research has not examined the narrative coherence of such accounts, despite higher quality narratives potentially being perceived more favourably by criminal justice professionals and juries. This study compared the narrative coherence of witness transcripts produced by autistic and typically developing (TD) children (ages 6-11 years, IQs 70+). METHODS AND PROCEDURES: Secondary analysis was carried out on interview transcripts from a subset of 104 participants (autism = 52, TD = 52) who had taken part in a larger study of eyewitness skills in autistic and TD children. Groups were matched on chronological age, IQ and receptive language ability. Coding frameworks were adopted from existing narrative research, featuring elements of 'story grammar'. OUTCOMES AND RESULTS: Whilst fewer event details were reported by autistic children, there were no group differences in narrative coherence (number and diversity of 'story grammar' elements used), narrative length or semantic diversity. CONCLUSIONS AND IMPLICATIONS: These findings suggest that the narrative coherence of autistic children's witness accounts is equivalent to TD peers of comparable age and ability.

Do children use different forms of verbal rehearsal in serial picture recall tasks? A multi-method study.

Use of verbal rehearsal is a key issue in memory development. However, we still lack detailed and triangulated information about the early development and the circumstances in which different forms of rehearsal are used. To further understand significant factors that affect children's use of various forms of rehearsal, the present study involving 108 primary school children adopted a multi-method approach. It combined a carefully chosen word length effect method with a self-paced presentation time method to obtain behavioural indicators of verbal rehearsal. In addition, subsequent trial-by-trial self-reports were gathered. Word length effects in recall suggested that phonological recoding (converting images to names - a necessary precursor for rehearsal) took place, with evidence of more rehearsal among children with higher performance levels. According to self-paced presentation times, cumulative rehearsal was the dominant form of rehearsal only for children with higher spans on difficult trials. The combined results of self-paced times and word length effects in recall suggest that "naming" as simple form of rehearsal was dominant for most children. Self-reports were in line with these conclusions. Additionally, children used a mixture of strategies with considerable intra-individual variability, yet strategy use was nevertheless linked to age as well as performance levels.

An Exploration of the Factor Structure of Executive Functioning in Children.

There has been considerable debate and interest in the factor structure of executive functioning (EF). For children and young people, there is evidence of a progression from a single factor to a more differentiated structure, although the precise nature of these factors differs between investigations. The purpose of the current study was to look at this issue again with another sample, and try to understand possible reasons for previous differences between investigations. In addition, we examined the relationship between less central EF tasks, such as fluency and planning, to the more common tasks of updating/executive working memory (EWM), inhibition, and switching/shifting. A final aim was to carry out analyses which are relevant to the debate about whether EF is influenced by language ability, or language ability is influenced by EF. We reasoned that if language ability affects EF, a factor analysis of verbal and non-verbal EF tasks might result in the identification of a factor which predominantly contains verbal tasks and a factor that predominately contains non-verbal tasks. Our investigation involved 128 typically developing participants (mean age 10:4) who were given EF assessments that included verbal and non-verbal versions of each task: EWM; switching; inhibition; fluency; and planning. Exploratory factor analyses on EWM, switching, and inhibition produced a structure consisting of inhibition in one factor and the remaining tasks in another. It was decided to exclude verbal planning from the next analyses of all the ten tasks because of statistical considerations. Analysis of the remaining nine EF tasks produced two factors, one factor containing the two inhibition tasks, and another factor that contained all the other tasks (switching, EWM, fluency, and non-verbal planning). There was little evidence that the verbal or non-verbal elements in these tasks affected the factor structure. Both these issues are considered in the discussion, where there is a general evaluation of findings about the factor structure of EF.

Supporting child witnesses during identification lineups: Exploring the effectiveness of registered intermediaries.

Performance at identification lineup was assessed in eighty-five 6- to 11-year-old typically developing children. Children viewed a live staged event involving 2 male actors, and were asked to identify the perpetrators from 2 separate lineups (one perpetrator-present lineup and one perpetrator-absent lineup). Half the children took part in lineups adapted by a registered intermediary (an impartial, trained professional who facilitates understanding and communication between vulnerable witnesses and members of the justice system), and half took part in "best-practice" lineups, according to the current guidance for eyewitness identification in England and Wales. Children receiving assistance from a registered intermediary (relative to children who received best-practice lineups) were more accurate in their identifications for perpetrator-present lineups, and there was some evidence that they were also more accurate for perpetrator-absent lineups. This provides the first empirical evidence for the effectiveness of registered intermediary support during identification lineups.

Autism Diagnosis in the United Kingdom: Perspectives of Autistic Adults, Parents and Professionals.

Accessing an autism diagnosis is a key milestone, both for an individual and their family. Using a qualitative methodology, the current study examined the views and experiences of ten autistic adults, ten parents of children on the autism spectrum, and ten professionals involved in autism diagnosis, all based in the United Kingdom (UK). Interviewing these 30 respondents about the diagnostic process and subsequent support options, the goal was to identify aspects of the diagnostic process that are working well, and areas in which improvements are needed. Using thematic analysis, three key themes were identified: the process of understanding and accepting autism; multiple barriers to satisfaction with the diagnostic process; and inadequate post-diagnostic support provision.

Executive functions in children with developmental coordination disorder: a 2-year follow-up study.

AIM: Executive function impairments have been identified in children with poor motor skills, with and without a diagnosis of developmental coordination disorder (DCD). However, most studies are cross-sectional. This study investigates the development of executive function in children with poor motor skills over 2 years. METHOD: Children aged 7 to 11 years (n=51) were assessed twice, 2 years apart, on verbal and nonverbal measures of executive functions: executive-loaded working memory (ELWM); fluency; response inhibition; planning; and cognitive flexibility. Typically developing children (n=17) were compared with those with a clinical diagnosis of DCD (n=17) and those with identified motor difficulties (n=17) but no formal diagnosis of DCD. RESULTS: Developmental gains in executive function were similar between groups, although a gap between children with poor motor skills and typically developing children on nonverbal executive functions persisted. Specifically, children with DCD performed significantly more poorly than typically developing children on all nonverbal executive function tasks and verbal fluency tasks at both time points; and children with motor difficulties but no diagnosis of DCD showed persistent executive function problems in nonverbal tasks of ELWM and fluency. INTERPRETATION: Children with DCD and motor difficulties demonstrated executive function difficulties over 2 years, which may affect activities of daily living and academic achievement, in addition to their motor deficit. WHAT THIS PAPER ADDS: Executive function difficulties in children with poor motor skills persist throughout middle childhood. Children with motor difficulties, without a developmental coordination disorder (DCD) diagnosis, demonstrate less pervasive executive function difficulties than those with DCD. Executive function problems in the groups with motor difficulties and DCD affect mostly nonverbal domains. All groups showed similar developmental gains in executive function.

Verbal and Non-verbal Fluency in Adults with Developmental Dyslexia: Phonological Processing or Executive Control Problems?

The executive function of fluency describes the ability to generate items according to specific rules. Production of words beginning with a certain letter (phonemic fluency) is impaired in dyslexia, while generation of words belonging to a certain semantic category (semantic fluency) is typically unimpaired. However, in dyslexia, verbal fluency has generally been studied only in terms of overall words produced. Furthermore, performance of adults with dyslexia on non-verbal design fluency tasks has not been explored but would indicate whether deficits could be explained by executive control, rather than phonological processing, difficulties. Phonemic, semantic and design fluency tasks were presented to adults with dyslexia and without dyslexia, using fine-grained performance measures and controlling for IQ. Hierarchical regressions indicated that dyslexia predicted lower phonemic fluency, but not semantic or design fluency. At the fine-grained level, dyslexia predicted a smaller number of switches between subcategories on phonemic fluency, while dyslexia did not predict the size of phonemically related clusters of items. Overall, the results suggested that phonological processing problems were at the root of dyslexia-related fluency deficits; however, executive control difficulties could not be completely ruled out as an alternative explanation. Developments in research methodology, equating executive demands across fluency tasks, may resolve this issue. Copyright © 2017 John Wiley & Sons, Ltd.

Verbal, Visual, and Intermediary Support for Child Witnesses with Autism During Investigative Interviews.

Three promising investigative interview interventions were assessed in 270 children (age 6-11 years): 71 with autism spectrum disorder (ASD) and 199 who were typically developing (TD). Children received 'Verbal Labels', 'Sketch Reinstatement of Context' or 'Registered Intermediary' interviews designed to improve interview performance without decreasing accuracy. Children with ASD showed no increases in the number of correct details recalled for any of the three interview types (compared to a Best-Practice police interview), whereas TD children showed significant improvements in the Registered Intermediary and Verbal Labels interviews. Findings suggested that children with ASD can perform as well as TD children in certain types of investigative interviews, but some expected benefits (e.g., of Registered Intermediaries) were not apparent in this study.

Strategic verbal rehearsal in adolescents with mild intellectual disabilities: A multi-centre European study.

BACKGROUND: There is a long-held view that verbal short-term memory problems of individuals with intellectual disabilities (ID) might be due to a deficit in verbal rehearsal. However, the evidence is inconclusive and word length effects as indicator of rehearsal have been criticised. AIM & METHOD: The aim of this multi-site European study was to investigate verbal rehearsal in adolescents with mild ID (n=90) and a comparison group of typically developing children matched individually for mental age (MA, n=90). The investigation involved: (1) a word length experiment with non-verbal recall using pointing and (2) 'self-paced' inspection times to infer whether verbal strategies were utilised when memorising a set of pictorial items. RESULTS: The word length effect on recall did not interact with group, suggesting that adolescents with ID and MA comparisons used similar verbal strategies, possibly phonological recoding of picture names. The inspection time data suggested that high span individuals in both groups used verbal labelling or single item rehearsal on more demanding lists, as long named items had longer inspection times. CONCLUSIONS: The findings suggest that verbal strategy use is not specifically impaired in adolescents with mild ID and is mental age appropriate, supporting a developmental perspective.

The relation between executive functioning, reaction time, naming speed, and single word reading in children with typical development and language impairments.

BACKGROUND: Few investigations have examined the relationship between a comprehensive range of executive functioning (EF) abilities and reading. AIMS: Our investigation identified components of EF that independently predicted single word reading, and determined whether their predictive role remained when additional variables were included in the regression analyses. This provided information about the EF processes that are related to reading, and the unity and diversity of EF. SAMPLE: This study consisted of 160 children: 88 were typically developing with no language difficulties; 72 had language impairments. METHOD: The assessments involved decoding, 10 measures of EF, reaction time, naming speed, non-verbal and verbal age-equivalent scores. RESULTS AND CONCLUSIONS: In the first regression analysis, which only concerned the EF variables, the following verbal forms of EF had significant relationships with decoding: working memory, fluency, planning, and inhibition. Further regression analyses included additional predictor variables: reaction time, naming speed, and age-equivalent scores. These analyses indicated that most of the EF variables continued to predict decoding even when entered with competitor variables. Furthermore, after the entry of EF variables, there were no group differences in decoding (typical vs. language difficulties). We discuss the contribution of EF and other variables to reading abilities.

Executive functions in adults with developmental dyslexia.

BACKGROUND: Executive functioning (EF) deficits are well recognized in developmental dyslexia, yet the majority of studies have concerned children rather than adults, ignored the subjective experience of the individual with dyslexia (with regard to their own EFs), and have not followed current theoretical perspectives on EFs. AIMS AND METHODS: The current study addressed these shortfalls by administering a self-report measure of EF (BRIEF-A; Roth, Isquith, & Gioia, 2005) and experimental tasks to IQ-matched groups of adults with and without dyslexia. The laboratory-based tasks tested the three factors constituting the framework of EF proposed by Miyake et al. (2000). RESULTS: In comparison to the group without dyslexia, the participants with dyslexia self-reported more frequent EF problems in day-to-day life, with these difficulties centering on metacognitive processes (working memory, planning, task monitoring, and organization) rather than on the regulation of emotion and behaviour. The participants with dyslexia showed significant deficits in EF (inhibition, set shifting, and working memory). CONCLUSIONS AND IMPLICATIONS: The findings indicated that dyslexia-related problems have an impact on the daily experience of adults with the condition. Further, EF difficulties are present in adulthood across a range of laboratory-based measures, and, given the nature of the experimental tasks presented, extend beyond difficulties related solely to phonological processing.