Interpretation of ambiguous pronouns in adults with intellectual disabilities

Background — Pronouns are referentially ambiguous (e.g. she could refer to any female), yet they are common in everyday conversations. Individuals with typical development (TD) employ several strategies to avoid pronoun interpretation errors, including the subject bias — an assumption that a pronoun typically refers to the subject (or, with the closely related order-of-mention bias, the first-mentioned character) of the previous sentence. However, it is unknown if adults with intellectual disability (ID) share this strategy or the extent to which the subject bias is associated with non-verbal abilities or receptive vocabulary. Methods — We tested 22 adults with mixed-aetiology ID on their interpretation of ambiguous pronouns using the visual world eye-tracking paradigm and by asking a follow-up pronoun interpretation question. A group of TD adults was also tested to establish the strength of the subject bias with our materials and task. Results — Adults with ID did demonstrate the subject bias, but it was significantly less robust than that seen in TD. For participants with ID, the subject bias was influenced by non-verbal IQ and receptive vocabulary at different stages of processing. Conclusions — Given the frequency of pronouns in conversation, strengthening the subject bias may help alleviate discourse and reading comprehension challenges for individuals with ID, particularly those with lower non-verbal and/or vocabulary skills

Home-literacy environments and language development in toddlers with Down syndrome

Introduction: The present study aimed to (1) characterize the home-literacy environments (HLE) of toddlers with Down syndrome (DS) and (2) examine if richness of the HLE, child engagement during shared storybook reading activities, quality of a caregiver-child shared storybook reading activity, and exposure to language in the home environment predicted child receptive vocabulary concurrently (Time 1) and 6 months later (Time 2). Methods: Participants were toddlers with DS (n = 13 at Time 1, 11–29 months of age; n = 10 at Time 2) and their mothers. Mothers completed a Home Literacy Environment Questionnaire at Time 1, which was used to characterize the HLE and to calculate two composite variables: richness of the HLE and child engagement in shared storybook reading. Also at Time 1, the home language environment was measured using adult word count from the LENA Recorder DLP©. The LENA was also used to audio-record and capture the quality of a caregiver-child storybook reading task in the child’s home using the book Dear Zoo. At both time points, mothers completed the MacArthur-Bates Communicative Development Inventories, and the number of words understood variable was used to measure receptive vocabulary. Results/Discussion: Results indicated that toddlers with DS experience rich HLEs and interactive shared storybook reading encounters with their mothers. A multiple linear regression revealed that child engagement and the home language environment correlated with both toddlers’ concurrent and later receptive vocabularies, while the richness of the HLE and the shared storybook reading task emerged as moderate predictors of receptive vocabulary 6 months later

Inclusion of Individuals With Neurodevelopmental Disorders in Norm-Referenced Language Assessments

Standardized, norm-referenced language assessment tools are used for a variety of purposes, including in education, clinical practice, and research. Unfortunately, normreferenced language assessment tools can demonstrate floor effects (i.e., a large percentage of individuals scoring at or near the lowest limit of the assessment tool) when used with some groups with neurodevelopmental disorders (NDDs), such as individuals with intellectual disability and neurogenetic syndromes. Without variability at the lower end of these assessment tools, professionals cannot accurately measure language strengths and difficulties within or across individuals. This lack of variability may be tied to poor representation of individuals with NDDs in normative samples. Therefore, the purpose of this study was to identify and examine common standardized, norm-referenced language assessment tools to report the representation of individuals with NDDs in normative samples and the range of standard/index scores provided. A systematic search identified 57 assessment tools that met inclusion criteria. Coding of the assessment manuals identified that most assessment tools included a “disability” or “exceptionality” group in their normative sample. However, the total number of individuals in these groups and the number of individuals with specific NDDs was small. Further, the characteristics of these groups (e.g., demographic information; disability type) were often poorly defined. The floor standard/index scores of most assessment tools were in the 40s or 50s. Only four assessment tools provided a standard score lower than 40. Findings of this study can assist clinicians, educators, and researchers in their selections of norm-referenced assessment tools when working with individuals with NDDs

Matching Variables for Research Involving Youth with Down Syndrome: Leiter-R versus PPVT-4

Much of what is known about the cognitive profile of Down syndrome (DS) is based on using either receptive vocabulary (e.g., PPTV-4) or nonverbal ability (e.g., Leiter-R) as a baseline to represent cognitive developmental level. In the present study, we examined the relation between these two measures in youth with DS, with non-DS intellectual disability (ID) and with typical development (TD). We also examined the degree to which these two measures produce similar results when used as a group matching variable. In a cross-sectional developmental trajectory analysis, we found that the relation between PPVT-4 and Leiter-R was largely similar across groups. However, when contrasting PPVT-4 and Leiter-R as alternate matching variables, the pattern of results was not always the same. When matched on Leiter-R or PPVT-4, the group with DS performed below that of the groups with ID and TD on receptive grammar and below the group with TD on category learning. When matched on the PPVT-4, the group with ID performed below that of the group with TD on receptive grammar and category learning, but these differences between the groups with ID and TD were not found when matched on the Leiter-R. The results of the study suggest that the PPVT-4 and Leiter-R are interchangeable at least for some outcome measures for comparing youth with DS and TD, but they may produce different results when comparing youth with ID and TD

Patterns of autism spectrum symptomatology in individuals with Down syndrome without comorbid autism spectrum disorder

Background Prevalence estimates of autism spectrum disorder (ASD) in Down syndrome (DS) are highly varied. This variation is partly due to the difficulty of screening for and diagnosing comorbid ASD in individuals with a syndrome that carries its own set of social communicative and behavioral difficulties that are not well documented. The aim of this study was to identify the typical range of social communicative impairments observed in children, adolescents, and young adults with DS who do not have comorbid ASD. Methods We examined patterns of scores from the five subscales of the Social Responsiveness Scale (SRS) in 46 individuals with DS (ages 10–21 years) without comorbid ASD relative to the published normative sample. We also explored the correlations between SRS symptomatology and age, nonverbal cognition, and receptive language. Results SRS scores were elevated (i.e., more ASD symptoms endorsed), with mean scores falling into the clinically significant range. Analysis by subscale revealed a specific pattern, with Autistic Mannerisms and Social Cognition scores significantly more elevated than Social Communication scores, which were significantly more elevated than Social Awareness and Social Motivation scores. Correlations between SRS scores and the other measures varied by subscale. Conclusions General elevated ASD symptomatology on the SRS indicates the need for developing population-based norms specific to DS. The pattern of scores across subscales should inform clinicians of the typical range of behaviors observed in DS so that individuals with atypical patterns of behavior can be more easily identified and considered for a full ASD evaluation

Peer Review of Teaching Portfolio - SPED 990: Intervention Design lll

This portfolio documents the development of SPED 990: Intervention Design III, a doctoral course being taught for the first time in the Spring of 2021 in the Department of Special Education and Communication Disorders. The primary goals motivating my creation of this benchmark portfolio included: 1) deciding what to teach and how to teach it for the course’s first iteration, 2) understanding how this course fits into my department’s broader curriculum and doctoral training program, 3) upon completion of the course, reflecting on what worked and what didn’t to improve the course for future semesters, and 4) continuing my professional growth as an instructor. Since this was a very small doctoral level course, I qualitatively analyzed students’ written feedback of the course to evaluate their learning. I also reviewed students’ progress in their development of a research proposal from the beginning of the semester to the end. Both suggest that the course was effective but also identified areas for improvement. Lastly, I reflect on my experience in PRTP and how it has improved my teaching skills, particularly in the development of course assignments and in how I evaluate course effectiveness

Perspectives on adaptive functioning and intellectual functioning measures for intellectual disabilities behavioral research

Introduction: Intellectual disability (ID) is a significant limitation in both intellectual ability and adaptive functioning, but many studies of participants with ID only include a measure of overall intellectual functioning when describing their samples. The purpose of this perspective article was to provide a starting point for future research regarding the utility of including measures of both intellectual and adaptive functioning in research focused on ID. In this article, we discuss the differences and similarities between the constructs of intellectual and adaptive functioning, how they are measured, and the benefits of using both measures to describe participant abilities. Data are presented to demonstrate that intellectual and adaptive functioning measures capture separate but related skills in a sample of individuals with ID (i.e., children with Down syndrome [DS]; the leading genetic cause of ID). Methods: Thirty children with DS (7–31 months) were administered the Mullen Scales of Early Learning and their mothers were interviewed using the Vineland Adaptive Behavior Scales. Results: At the group level, Vineland and Mullen composite scores were relatively normally distributed and positively correlated. At the individual level, a concordance correlation coefficient indicated moderate agreement between Vineland and Mullen composite scores. Discussion: Although many children showed consistency between measures, others did not. Our discussion and findings, though preliminary, highlight that intellectual and adaptive functioning are separate but related skills and that there are benefits to including both measures when describing samples with ID. We discuss considerations for including adaptive functioning measures to enhance future research on individuals with ID

Verb production by individuals with Down syndrome during narration

BackgroundDespite research identifying verb knowledge as a strong predictor of later syntactic skills in typical development, virtually no research has examined verb development in Down syndrome.AimsThe purpose of this study was to examine verb production (density, diversity, and type-token ratios) by individuals with Down syndrome in the context of story generation relative to two comparison groups - nonverbal cognitive ability level matches with typical development and chronological age matches with mixed-etiology intellectual disability.Methods and proceduresThirty-five participants with Down syndrome (11-21 years), 27 participants with intellectual disability (13-20 years), and 29 participants with typical development (4-6 years) completed a narrative story generation task. Transcripts were coded and analyzed for verb production.Outcomes and resultsExamining overall verb production, participants with Down syndrome produced narratives with less verb density than participants with typical development and had smaller verb type-token ratios than participants with intellectual disability. Upon examining lexical verb production, participants with Down syndrome produced narratives with less lexical verb density than participants with typical development.Conclusions and implicationsThe results indicate that individuals with Down syndrome have a developmentally appropriate diversity of verbs in their lexicon but are not using verbs as frequently as comparison groups