Extended trajectory of spatial memory errors in typical and atypical development: The role of binding and precision.

Spatial reconstruction, a method for evaluating how individuals remember the placement of objects, has traditionally been evaluated through the aggregate estimation of placement errors. However, this approach may obscure the nature of task errors. Specifically, recent data has suggested the importance of examining the precision of responses, as well as absolute performance on item-context bindings. In contrast to traditional analysis approaches based on the distance between the target and the reconstructed item, in this study we further explored three types of errors (swap error, global error, and local distance) that may all contribute to the distance, with particular emphasis on swap errors and local distance due to their associations with item-context bindings and memory precision, respectively. We examined these errors in children aged 3-18 years, making comparisons between children with typical development (TD) and children with Down syndrome (DS), a population with known memory challenges. As expected, older children outperformed younger children in terms of overall memory accuracy. Of importance is that we measured uneven maturational trajectories of memory abilities across the various error types. Specifically, both remembered locations (irrespective of object identity) and swap errors (object-location binding errors) align with the overall memory accuracy. Memory precision, as measured by local distance in simpler set size 2 trials, mirrored overall memory accuracy. However, for more complex set size 3 trials, local distance remained stable before age 8 and showed age-related change thereafter. The group with DS showed reduced precision compared to a TD matched group, and measures of precision, and to a lesser extent binding errors, correlated with standard neuropsychological outcomes. Overall, our study contributed to a fine-grained understanding of developing spatial memory ability in a large sample of typical developing children and a memory impaired population. These findings contribute to a growing body of research examining precision as a key factor in memory performance.

The Autism Symptom Dimensions Questionnaire: Development and psychometric evaluation of a new, open-source measure of autism symptomatology.

AIM: To describe the development and initial psychometric evaluation of a new, freely available measure, the Autism Symptom Dimensions Questionnaire (ASDQ). METHOD: After development and revision of an initial 33-item version, informants completed a revised 39-item version of the ASDQ on 1467 children and adolescents (aged 2-17 years), including 104 with autism spectrum disorder (ASD). RESULTS: The initial 33-item version of the ASDQ had good reliability and construct validity. However, only four specific symptom factors were identified, potentially due to an insufficient number of items. Factor analyses of the expanded instrument identified a general ASD factor and nine specific symptom factors with good measurement invariance across demographic groups. Scales showed good-to-excellent overall and conditional reliability. Exploratory analyses of predictive validity for ASD versus neurotypical and other developmental disability diagnoses indicated good accuracy for population and at-risk contexts. INTERPRETATION: The ASDQ is a free and psychometrically sound informant report instrument with good reliability of measurement across a continuous range of scores and preliminary evidence of predictive validity. The measure may be a useful alternative to existing autism symptom measures but further studies with comparison of clinical diagnoses using criterion-standard instruments are needed. WHAT THIS PAPER ADDS: The Autism Symptom Dimensions Questionnaire (ASDQ) is a new, freely available measure of autism symptoms. The ASDQ showed reliable and accurate measurement of autism symptoms. The measure had good screening efficiency for autism spectrum disorder relative to other developmental conditions.

Preliminary psychometric properties of an inhibition task in young children with Down syndrome.

Background: Executive function (EF) skills are important treatment targets for people with Down syndrome (DS); however, few EF measures have been evaluated for use with young children in this population. Methods: The present study evaluated preliminary psychometric properties of a measure of the EF component of inhibition. Participants were 73 children with DS between 2.5 and 8.67 years old who completed an adapted ability to delay task using a desirable toy. Results: Across two separate trials, latencies to touch the toys were significantly correlated. Latencies increased overall with chronological and mental age, with caveats for the youngest and oldest participants. Conclusion: Findings suggest that an adapted prohibition task is an appropriate method of measuring inhibition for children with DS between 4 and 7 years old, though many children in this chronological age range are at early stages of acquiring this skill set.

Responsive Parenting as a Target for Telehealth Language Interventions in Fragile X Syndrome: Implications for Scalability and Best Practices.

This review highlights the ways in which telehealth procedures can be implemented to help bridge the research-to-practice gap in supporting developmental outcomes for youth with fragile X syndrome (FXS). We review how the literature to date has informed potential treatment targets in the areas of speech and language development with a focus on understanding and supporting the dyadic relationship between the child and their biological mother, who is also impacted biologically. Notably, parental responsivity is an area that is strongly related to child language outcomes, both early and into adolescence, and thus, it is an important treatment target for subsequent interventions. To date, several parent-implemented interventions have been done in FXS across a broad age range (2-17-year-olds) all showing support not only that parents are successful in learning responsive strategies but also that there are subsequent impacts to child language development. Moreover, these interventions were successfully implemented at a distance through telehealth procedures including video teleconferencing and shared recordings of parent-child interactions. This review also addresses potential moderators of treatment gains. Implications for scaling such interventions in the future as well as best practices for incorporating telehealth procedures into future research and intervention programs are also discussed.

Intellectual and developmental disabilities research centers: Fifty years of scientific accomplishments.

Progress in addressing the origins of intellectual and developmental disabilities accelerated with the establishment 50 years ago of the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health and associated Intellectual and Developmental Disabilities Research Centers. Investigators at these Centers have made seminal contributions to understanding human brain and behavioral development and defining mechanisms and treatments of disorders of the developing brain. ANN NEUROL 2019;86:332-343.

A novel eye-tracking paradigm for indexing social avoidance-related behavior in fragile X syndrome.

Fragile X syndrome (FXS) is characterized by hallmark features of gaze avoidance, reduced social approach, and social anxiety. The development of therapeutics to manage these symptoms has been hindered, in part, by the lack of sensitive outcome measures. This study investigated the utility of a novel eye-tracking paradigm for indexing social avoidance-related phenotypes. Adolescent/young adult-aged males with FXS (n = 24) and typical development (n = 23) participated in the study. Participants viewed faces displaying direct or averted gaze and the first fixation duration on the eyes was recorded as an index of initial stimulus registration. Fixation durations did not differ across the direction of gaze conditions in either group, although the control group showed longer initial fixations on the eyes relative to the FXS group. Shorter initial fixation on averted gaze in males with FXS was a robust predictor of the severity of their social avoidance behavior exhibited during a social greeting context, whereas parent-reported social avoidance symptoms were not related to performance in the semi-naturalistic context. This eye-tracking paradigm may represent a promising outcome measure for FXS clinical trials because it provides a quantitative index that closely maps onto core social avoidance phenotypes of FXS, can be completed in less than 20 min, and is suitable for use with individuals with low IQ.

Estimates of the prevalence of speech and motor speech disorders in adolescents with Down syndrome.

Although there is substantial rationale for a motor component in the speech of persons with Down syndrome (DS), there presently are no published estimates of the prevalence of subtypes of motor speech disorders in DS. The goal of this research is to provide initial estimates of the prevalence of types of speech disorders and motor speech disorders in adolescents with DS. Conversational speech samples from a convenience sample of 45 adolescents with DS, ages 10 to 20 years old, were analysed using perceptual and acoustic methods and measures in the Speech Disorders Classification System (SDCS). The SDCS cross-classified participants into five mutually exclusive speech classifications and five mutually exclusive motor speech classifications. For participants meeting criteria for Childhood Dysarthria or for Childhood Dysarthria concurrent with Childhood Apraxia of Speech, the SDCS provided information on participants' percentile status on five subtypes of dysarthria. A total of 97.8% of participants met SDCS criteria for Speech Disorders and 97.8% met criteria for Motor Speech Disorders, including Childhood Dysarthria (37.8%), Speech Motor Delay (26.7%), Childhood Dysarthria and Childhood Apraxia of Speech (22.2%), and Childhood Apraxia of Speech (11.1%). Ataxia was the most prevalent dysarthria subtype. Nearly all participants with DS in the present sample had some type of speech and motor speech disorder, with implications for theory, assessment, prediction, and treatment. Specific to treatment, the present findings are interpreted as support for motor speech disorders as a primary explanatory construct to guide the selection and sequencing of treatment targets for persons with DS. Abbreviations: CAS: Childhood Apraxia of Speech; CD: Childhood Dysarthria; DS: Down syndrome; NSA: Normal(ized) Speech Acquisition; PSD: Persistent Speech Delay; PSE: Persistent Speech Errors; SD: Speech Delay; SDCS: Speech Disorders Classification System; SE: Speech Errors; SMD: Speech Motor Delay.

Speech and motor speech disorders and intelligibility in adolescents with Down syndrome.

The goal of this research was to assess the support for motor speech disorders as explanatory constructs to guide research and treatment of reduced intelligibility in persons with Down syndrome (DS). Participants were the 45 adolescents with DS in the prior paper who were classified into five mutually-exclusive motor speech classifications using the Speech Disorders Classification System. An ordinal index classified participants' percentage of intelligible words in conversation as High (≥ 85%), Moderate (80% - 84.9%), or Low (< 80%). Statistical analyses tested for significant differences in intelligibility status associated with demographic, intelligence, and language variables, and intelligibility status associated with motor speech classifications and speech, prosody, and voice variables. For the 10 participants who met criteria for concurrent Childhood Dysarthria and Childhood Apraxia of Speech at assessment, 80% had reduced (Moderate or Low) intelligibility and 20% had High intelligibility (significant effect size: 0.644). Proportionally more of the 32 participants who met criteria for either dysarthria or apraxia had reduced intelligibility (significant effect size: 0.318). Low intelligibility was significantly associated with across-the-board reductions in phonemic and phonetic accuracy and with inappropriate prosody and voice. Findings are interpreted as support for motor speech disorders in adolescents with DS as explanatory constructs for their reduced intelligibility. Pending cross-validation of findings in diverse samples of persons with DS, studies are needed to assess the efficacy of motor speech classification status to guide selection of treatment methods and intelligibility targets. Abbreviations: CAS: Childhood Apraxia of Speech; CD: Childhood Dysarthria; DS: Down syndrome; II: Intelligibility Index; No MSD: No Motor Speech Disorder; OII: Ordinal Intelligibility Index; PSD: Persistent Speech Delay; SDCS: Speech Disorders Classification System; SMD: Speech Motor Delay.

Cortisol profiles differentiated in adolescents and young adult males with fragile X syndrome versus autism spectrum disorder.

BACKGROUND: Fragile X syndrome (FXS) and non-syndromic autism spectrum disorder (ASD) are distinct disorders with overlapping behavioral features. Both disorders are also highly associated with anxiety with abnormal physiological regulation implied mechanistically. Some reports suggest atypical hypothalamus-pituitary-adrenal (HPA) axis function, indexed via aberrant cortisol reactivity, in both FXS and non-syndromic ASD. However, no study has compared cortisol reactivity across these two disorders, or its relationship to ASD symptom severity. METHODS: Cortisol reactivity (prior to and following a day of assessments) was measured in 54 adolescent/young adult males with FXS contrasted to 15 males with non-syndromic ASD who had low cognitive abilities. RESULTS: Greater ASD symptom severity was related to increased cortisol reactivity and higher levels at the end of the day, but only in the non-syndromic ASD group. Elevated anxiety was associated with increased HPA activation in the group with FXS alone. CONCLUSIONS: Taken together, findings suggest a unique neuroendocrine profile that distinguishes adolescent/young adult males with FXS from those with non-syndromic ASD. Severity of ASD symptoms appears to be related to cortisol reactivity in the non-syndromic ASD sample, but not in FXS; while anxiety symptoms are associated with HPA activation in the FXS sample, but not in ASD despite a high prevalence of ASD, anxiety and physiological dysregulation characteristic in both populations.

Biobehavioral composite of social aspects of anxiety in young adults with fragile X syndrome contrasted to autism spectrum disorder.

Social anxiety is a common disorder that has negative impacts across multiple domains of function. Several clinical groups are at elevated risk for social anxiety, including those with fragile X syndrome and those with autism spectrum disorder. Measuring social anxiety in these clinical subgroups is fraught with challenge, however, given the complexity of social anxiety and measurement limitations that are particularly acute in persons with neurodevelopmental disorders. The over-arching aim of this study was to contribute to our understanding of the nature of social anxiety in fragile X syndrome and its association with autism spectrum disorder. To address this aim, we created a multi-faceted composite representing behavioral and biological aspects of social anxiety and examined differences in two adolescent and young adult-aged groups: 59 males with fragile X syndrome and 18 males with autism spectrum disorder. Results indicated a lower score on the multivariate composite for the males with fragile X syndrome relative to autism spectrum disorder but with evidence that traits of autism and social anxiety overlap. We conclude that measuring anxiety and autism traits in fragile X syndrome and autism spectrum disorder is complex with features that overlap and interact in a dynamic manner.

Parental Responsivity and Child Communication During Mother-Child and Father-Child Interactions in Fragile X Syndrome.

PURPOSE: Past research shows that parentally responsive behavior toward the child positively influences language development in both neurotypical children and children with intellectual and developmental disabilities, including those with fragile X syndrome (FXS); however, most studies have focused exclusively on the mother-child relationship. The current study examined relationships between parent behavior (i.e., responsivity and behavior management) and child language performance in both mother-child and father-child interactions, as well as relationships between child characteristics and both parent behavior and child language. METHOD: Participants were 23 families of young boys with FXS between 3 and 7 years of age. Mothers and fathers independently completed questionnaires assessing child characteristics and separately engaged in 12-min play-based interactions with their child via telehealth. One parent also completed a comprehensive interview assessing child adaptive behavior. Video recordings of the parent-child interactions were transcribed and coded for parent and child behavior, and measures of parent and child language were obtained from the transcripts. RESULTS: Mothers and fathers used similar rates of responsive behaviors during parent-child interactions, and parental responsivity was positively associated with some aspects of child language performance (i.e., talkativeness and lexical diversity). Parental behavior, however, was not associated with syntactic complexity. Older children and children with higher levels of adaptive behavior had parents who used higher rates of responsive behaviors. Fathers used higher rates of behavior management strategies compared to mothers, and this type of parent behavior was not associated with child language. CONCLUSION: Overall, this study provides evidence that interventions focused on increasing parental responsiveness would be beneficial for families of children with FXS and that these interventions should be delivered early given the association between responsivity and child age. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25229939.

The impact of social-environmental factors on IQ in syndromic intellectual developmental disabilities.

Despite having the same underlying genetic etiology, individuals with the same syndromic form of intellectual developmental disability (IDD) show a large degree of interindividual differences in cognition and IQ. Research indicates that up to 80% of the variation in IQ scores among individuals with syndromic IDDs is attributable to nongenetic effects, including social-environmental factors. In this narrative review, we summarize evidence of the influence that factors related to economic stability (focused on due to its prevalence in existing literature) have on IQ in individuals with syndromic IDDs. We also highlight the pathways through which economic stability is hypothesized to impact cognitive development and drive individual differences in IQ among individuals with syndromic IDDs. We also identify broader social-environmental factors (e.g., social determinants of health) that warrant consideration in future research, but that have not yet been explored in syndromic IDDs. We conclude by making recommendations to address the urgent need for further research into other salient factors associated with heterogeneity in IQ. These recommendations ultimately may shape individual- and community-level interventions and may inform systems-level public policy efforts to promote the cognitive development of and improve the lived experiences of individuals with syndromic IDDs.

Longitudinal follow-up of metformin treatment in Fragile X Syndrome.

Introduction: Metformin has been used as a targeted treatment to potentially improve cognition and slow the typical IQ decline that occurs during development among individuals with fragile X syndrome (FXS). In this follow-up study, we are following the trajectory of IQ and adaptive behavior changes over 1 to 3 years in individuals with FXS who are clinically treated with metformin in an open label trial. Method: Individuals with FXS ages 6 to 25 years (mean 13.15 ± 5.50) and nonverbal IQ mean 57.69 (±15.46) were treated for 1-3 years (1.88 ± 0.63). They all had a baseline IQ test using the Leiter-III non-verbal cognitive assessment and the Vineland-III adaptive behavior assessment before the start of metformin. Repeat Leiter-III and Vineland-III were completed after at least 1 year of metformin (500-1,000 mg/dose given twice a day). Result: There were no significant changes in non-verbal IQ or in the adaptive behavior measurements at FDR < 0.05. The findings thus far indicate that both IQ and adaptive behavior are stable over time, and we did not see a significant decline in either measure. Conclusion: Overall, the small sample size and short follow-up duration limit the interpretation of the effects of metformin on cognitive development and adaptive functioning. There is individual variability but overall for the group there was no significant decline in IQ or adaptive behavior.

Discriminating Down Syndrome and Fragile X syndrome based on language ability.

ABSTRACT This study compared the receptive and expressive language profiles of verbally expressive children and adolescents with Down Syndrome (DS) and those with Fragile X syndrome (FXS) and examined the extent to which these profiles reliably differentiate the diagnostic groups. A total of twenty-four verbal participants with DS (mean age: 12 years), twenty-two verbal participants with FXS (mean age: 12 years), and twenty-seven participants with typical development (TD; mean age = 4 years) completed standardized measures of receptive and expressive vocabulary and grammar, as well as a conversational language sample. Study results indicate that there are distinct DS and FXS language profiles, which are characterized by differences in grammatical ability. The diagnostic groups were not differentiated based on vocabulary performance. This study supports the existence of unique language profiles associated with DS and FXS.

Exploring the feasibility of collecting multimodal multiperson assessment data via distance in families affected by fragile X syndrome.

INTRODUCTION: Telehealth is an important tool in helping to provide services for hard-to-reach populations. One population that might benefit from telehealth are individuals with fragile X syndrome (FXS). Although FXS is the leading inherited cause of intellectual disability, it is nonetheless a low incidence disorder. Individuals with FXS and their families are involved in research studies, clinical trials and receive interventions - many of which are only offered in a few locations in the United States and thus, not easily accessible to many families. The current project explored the feasibility of using telehealth procedures to collect multimodal behavioural and psychological assessment data from these families. METHODS: Participation in the current study involved online surveys, measures of physiological indices of stress, live interviews and observations of mother-child interactions conducted via distance videoconferencing using the family's own technology when possible. Across all modes of data collection, we obtained information regarding the feasibility of participating entirely via distance by documenting missing data as well as each mother's overall impression of participating via distance. RESULTS: Our telehealth procedures were successfully implemented across a wide range of technology platforms with limited difficulty, and we documented little missing data due to technology-related challenges. Perhaps most importantly, however, our sample of mothers reported high satisfaction with participating via distance. DISCUSSION: These findings suggest that a wide range of services and types of assessments may be amenable to telehealth procedures. Further, the findings have immediate applications as the field shifts towards telehealth due to the coronavirus disease 2019 (COVID-19) pandemic.

The Work Ahead for Intellectual and Developmental Disabilities Research.

In "Toward Equity in Research on Intellectual and Developmental Disabilities," we sought to make entrenched assumptions and practices of intellectual and developmental disabilities research visible by explicitly describing the status quo in terms of models of disability, participant and researcher identities, research priorities, and biases in measurement and treatment approaches. We then curated individual- and systems-level actions drawn from disability justice and broader social justice lenses to offer a way forward. We focused on three major areas (i.e., intersectionality and person-centered approaches, participatory research, and interprofessional collaboration), depicting influences, methods, and actions in a framework of disability, identity, and culture. In this Author Response, we address five commentaries that critique and extend that synthesis.

Toward Equity in Research on Intellectual and Developmental Disabilities.

Lack of diversity in IDD research is typically conceptualized only in terms of (1) recruitment of samples that do not appropriately represent the sociodemographics of the population, or (2) the limited number of researchers from historically marginalized backgrounds. Critically, the field also suffers from over-reliance on perspectives and social systems of dominant culture-both in how disability is regarded and in relation to other dimensions of identity and culture. These lenses lead to research findings that reinforce, rather than reduce, social inequities. We propose a framework that minimizes reliance on diagnostic categories, shifts from deficit- to person-centered models, acknowledges people's multiple identities, and includes self-advocates and diverse communities as partners in the research enterprise. The systems change necessary to support this framework is described.

Parental Survey on Spanish­English Bilingualism in Neurotypical Development and Neurodevelopmental Disabilities in the United States.

Objectives: The cognitive and social benefits of bilingualism for children, including those with neurodevelopmental disabilities (NDDs), have been documented. The present study was designed to characterize and compare English and Spanish use in Hispanic families with and without NDDs residing in the U.S. as well as to understand parental perceptions of their child's bilingualism and of community and professional support. Methods: We conducted an online survey of 84 Spanish-speaking parents of 4- to 24-year-olds with (n = 44) and without NDDs (n = 40) who were born in and living in the U.S. Results: We found that bilingualism was a desired goal for 95% of our families. We also found, however, that 17.1% of parents of children with NDDs have raised them as monolinguals English-speakers, as they thought there were reasons for that, while all families from the NT group raised their children in both languages. In addition, nearly 40% of the NDD children only speak English, compared to a 5% in the NT group. Finally, parents of children with NDDs cite a lack of support for bilingualism in the community (47.6% do not feel supported, compared to a 7.9% in the NT group) and recommendation from professionals as major factors for not raising their children as bilingual. Conclusions: The results suggest a need to educate professionals from many disciplines about the benefits of bilingualism for children with NDDs and for implementation of inclusion policies that provide access to dual-language programs.

Predictors, Parental Views, and Concordance Across Diagnostic Sources of Autism in Male Youth with Fragile X Syndrome: Clinical Best Estimate and Community Diagnoses.

Persons with fragile X syndrome (FXS) with cooccurring autism spectrum disorder (ASD) are at risk for poorer educational, medical, employment, and independent living outcomes. Thus, the identification of ASD in those with FXS is fundamental to ensuring access to appropriate supports to achieve good quality of life. Yet, optimal diagnostic methods and the exact rate of ASD comorbidity remains controversial, and description of ASD identification in the community in FXS has been limited. This study characterized ASD in a sample of 49 male youth with FXS across multiple diagnostic sources: parent-reported community diagnoses, classification derived from ADOS-2 and ADI-R thresholds, and clinical best-estimate classifications from an expert multidisciplinary team. High concordance was found between ADOS-2/ADI-R and clinical best estimate classifications, with both methods supporting ASD in ~ 75% of male youth with FXS. In contrast, 31% had a community diagnosis. Findings supported gross under-identification of ASD in male youth with FXS in community settings; 60% of those who met clinical best estimate criteria for ASD had not received a diagnosis in the community. Moreover, community diagnoses were poorly aligned with the presence of ASD symptoms as perceived by parents and professionals and, unlike clinical best estimate diagnoses, were not associated with cognitive, behavioral, or language features. Findings highlight under-identification of ASD in community settings as a significant barrier to service access for male youth with FXS. Clinical recommendations should emphasize the benefits of seeking a professional ASD evaluation for children with FXS who are noted to display key ASD symptoms.

Examining indicators of psychosocial risk and resilience in parents of autistic children.

Background: Parents of autistic children experience increased levels of caregiver strain and adverse mental health outcomes, even in comparison to parents of children with other neurodevelopmental disabilities. Previous studies have largely attributed these increased levels of mental health concerns to their child behavioral concerns and autism symptomatology, but less attention has been given to other potential child factors, such as child adaptive functioning. Additionally, little is known about potential protective factors, such as parents' emotion regulation (ER) abilities, that may ameliorate the experience of caregiver strain, anxiety, and depression. Objective: The current study examined the impact of child characteristics (restricted and repetitive behaviors, adaptive functioning and behavioral concerns) on parent mental health outcomes (caregiver strain, anxiety, depression and wellbeing). Additionally, we explore parents' ER abilities as a moderator of the impact of child characteristic on parents' mental health outcomes. Results: Results of linear mixed effect models indicated a significant relationship between parents' ER abilities and all four parent outcomes. Additionally, children's adaptive functioning abilities and repetitive behaviors (RRBs) were significant predictors of caregiving strain. Parents' ER abilities were a significant moderator of the effect of children's repetitive behaviors and adaptive functioning challenges on caregiver strain, such that better ER abilities mitigated the impact of child clinical factors on caregiver strain. Finally, a significant difference was detected for mothers' and fathers' mental health, with mothers reporting higher caregiver strain, and more symptoms of anxiety and depression than did fathers. Conclusion: This study leveraged a large sample of autistic children and their biological parents to examine the relationship between children's clinical characteristics and parents' psychological wellbeing. Results indicate that, although parents of autistic children do experience high rates of internalizing mental health concerns that relate to child adaptive functioning and RRBs, parent ER abilities act as a protective factor against parents' adverse mental health outcomes. Further, mothers in our sample reported significantly higher rates of depression, anxiety, and caregiver strain, as compared with fathers.