Description and predictors of self-determination in males and females with fragile X syndrome on the verge of adulthood.

BACKGROUND: Self-determination refers to setting goals and making decisions regarding one's own life with support from others as needed. Research on people with intellectual and developmental disabilities has established the importance of self-determination for quality of life outcomes, such as increased independence and life satisfaction. However, self-determination has not been characterised specifically in fragile X syndrome (FXS), the leading inherited cause of intellectual disability. Relative to youth with other forms of intellectual and developmental disabilities, youth with FXS may face exceptional barriers to the development of self-determined behaviour. In addition to intellectual disability, the FXS behavioural profile is characterised by high rates of autism and anxiety that may further limit opportunities for youth with FXS. The heritable nature of the condition can also yield a distinctive family environment, with siblings and parents also living with fragile X or its associated conditions. Considering these unique challenges, the present study examined self-determination in young adult males and females with FXS and explored whether factors such as language skills, adaptive behaviour and autism traits were associated with self-determination capacity and opportunities. METHODS: The present study included 9 females and 36 males with FXS between the ages of 17 and 25 years. Caregivers (mothers or fathers) completed the American Institute for Research Self-Determination Assessment, which is a questionnaire that yields three scores: self-determination capacity, opportunities for self-determination at home and opportunities for self-determination at school. RESULTS: Caregivers endorsed a wide range of self-determination capacity and opportunities, with ratings for opportunities at home and school exceeding ratings of capacity. Better adaptive behaviour skills were associated with more self-determination capacity, and the presence of more autism traits was associated with fewer opportunities at school. CONCLUSIONS: Results from this study contribute to our understanding of avenues to best support young adults with FXS as they transition to adulthood. Our findings also have implications for practice, such that interventions targeting adaptive behaviours and self-determination may be an effective approach for promoting autonomy and independence for young adults with FXS. Additionally, caregivers and educators should continue to provide opportunities to practise self-determination, regardless of their perception of capacity.

Characterising the social interaction style of autism in young adult males with fragile X syndrome.

BACKGROUND: The characterisation of autism in fragile X syndrome (FXS) has been a source of controversy due to the complexity of disentangling autism traits from common features of the FXS phenotype. Autism in FXS is significantly underdiagnosed in the community, which may be partly due to insufficient clinical description of the social interaction profile of autism within the FXS phenotype. In this study, we applied a classic framework for characterising social interaction styles in autism to a sample of young adult males with FXS and co-occurring autism to enhance understanding of how the social challenges associated with autism manifest within FXS. METHODS: Participants were 41 males (M age = 18 years) with FXS and co-occurring autism. Interaction samples were coded for expression of predominately 'active' (characterised by a desire to make social approaches) or 'passive' (characterised by lack of initiation of social approach towards others) interaction profiles. Differences in the expression of phenotypic features of FXS, including anxiety, attention-deficit/hyperactivity disorder, cognitive, adaptive and language impairments and autism symptom severity, were examined across those with passive and active interaction styles. RESULTS: Approximately half of the sample was classified as active and half as passive, demonstrating diversity in the social phenotype of autism associated with FXS. The two subtypes did not differ in autism severity, anxiety or attention-deficit/hyperactivity disorder symptoms or in cognitive, adaptive or language abilities. CONCLUSIONS: This study enhances understanding of FXS-associated autism by documenting phenotypic variability in the social interaction profile in this group, with active and passive social interaction styles represented. The two social interaction styles were not associated with differential expression of common phenotypic features of FXS, suggesting similar support needs.

Laboratory-based measures of executive function and daily living skills in young children with Down syndrome: informing future interventions.

BACKGROUND: Adaptive behaviour refers to the practical skills necessary for independence and is considered a high-priority intervention target for children with neurogenetic conditions associated with intellectual disability, like Down syndrome (DS). Daily living skills (DLS) are a critical aspect of adaptive behaviour, but they have received little intervention attention, possibly because they involve a wide variety of skills across many settings. The present study aimed to advance DLS intervention science by examining the concurrent and longitudinal association between DLS performances and a cognitive skillset hypothesised to support DLS skill acquisition, executive function (EF). METHODS: Participants were 71 children with DS between the ages of 2.5 and 8.7 years (M = 5.23 years; standard deviation = 1.65) who completed a battery of adapted EF tasks and a primary caregiver who completed the Vineland Adaptive Behavior Scales 3rd Edition Parent/Caregiver Comprehensive Report Form. A subset of caregivers also provided 6- and 12-month follow-up adaptive behaviour information. RESULTS: Results demonstrated a positive association between EF task performance and DLS standard scores and v-scores both concurrently and longitudinally. CONCLUSIONS: The findings have implications for potential future intervention approaches that aim to strengthen DLS performances by advancing EF skills in this population.

Evaluating an adapted reverse categorisation task to assess cognitive flexibility in young children with Down syndrome.

BACKGROUND: Accurate measurement of cognitive skills is necessary to advance both developmental and intervention science for individuals with Down syndrome (DS). This study evaluated the feasibility, developmental sensitivity and preliminary reliability of a reverse categorisation measure designed to assess cognitive flexibility in young children with DS. METHODS: Seventy-two children with DS ages 2.5-8 years completed an adapted version of a reverse categorisation task. Twenty-eight of the participants were assessed again 2 weeks later for retest reliability. RESULTS: This adapted measure demonstrated adequate feasibility and developmental sensitivity, and preliminary evidence for test-retest reliability when administered to children with DS in this age range. CONCLUSIONS: This adapted reverse categorisation measure may be useful for future developmental and treatment studies that target early foundations of cognitive flexibility in young children with DS. Additional recommendations for use of this measure are discussed.

Co-occurring medical and behavioural conditions in children with Down syndrome with or without ADHD symptom presentation.

BACKGROUND: Co-occurring attention deficit hyperactivity disorder (ADHD) is a challenge to characterise in the presence of other medical conditions commonly present in children with Down syndrome (DS). The current study examined differences among children with DS with or without ADHD symptomatology in terms of demographics, developmental level, co-occurring medical conditions, and parent and teacher ratings of behaviour and executive functioning. METHODS: Parents and teachers of 108 school-age children with DS provided ratings of ADHD symptoms, behaviour problems and executive functioning skills. Children with DS and ADHD symptom presentation, as identified by a scoring algorithm, were compared with those without ADHD symptom presentation on demographic characteristics, developmental level, co-occurring medical conditions and parent-report and teacher-report measures of behaviours and executive functioning. RESULTS: Sleep disorders, disruptive behaviour disorder, allergies and seizures were more common in children with DS and ADHD symptom presentation than in children without ADHD symptom presentation. After controlling for ADHD medication use, children with DS and ADHD symptom presentation had poorer performance than those without ADHD symptom presentation on parent behaviour ratings, teacher behaviour ratings and parent but not teacher ratings of executive functioning. No significant group differences in demographic characteristics or developmental level were identified. CONCLUSIONS: Higher rates of co-occurring medical conditions present in children with DS and ADHD symptom presentation support the need for thorough differential diagnoses. The different pattern of group differences between parent-report and teacher-report has implications for diagnostic practices across settings as well as for treatment.

Latent profiles of autism symptoms in children and adolescents with Down syndrome.

BACKGROUND: Down syndrome (DS) is associated with elevated rates of autism spectrum disorder (ASD) and autism symptomatology. To better characterise heterogeneity in ASD symptomatology in DS, profiles of caregiver-reported ASD symptoms were modelled for children and adolescents with DS. METHODS: Participants (n = 125) were recruited through several multi-site research studies on cognition and language in DS. Using the Social Responsiveness Scale-2 (SRS-2; Constantino and Gruber 2012), two latent profile analyses (LPA) were performed, one on the broad composite scores of social communication and interaction and restricted interests and repetitive behaviour, and a second on the four social dimensions of social communication, social motivation, social awareness, and social cognition. RESULTS: A three-profile model was the best fit for both analyses, with each analysis yielding a low ASD symptom profile, an elevated or mixed ASD symptom profile and a high ASD symptom profile. Associations were observed between profile probability scores and IQ, the number of co-occurring biomedical conditions reported, sex, and SRS-2 form. CONCLUSIONS: Characterising heterogeneity in ASD symptom profiles can inform more personalised supports in this population, and implications for potential therapeutic approaches for individuals with DS are discussed.

Characterising repetitive behaviours in young boys with fragile X syndrome.

BACKGROUND: Repetitive behaviours are frequently observed in individuals with intellectual disability (ID). The present study examined the profile, inter-correlations and predictive correlates of repetitive behaviours in boys with fragile X syndrome (FXS), the leading inherited cause of ID. Specific child characteristics examined as predictors included anxiety, nonverbal cognition and autism social-affective symptomatology. METHOD: Participants were 39 boys with FXS (aged 6-10 years). Repetitive behaviours were measured using the Repetitive Behavior Scale - Revised (RBS-R) - a 43-item caregiver-report measure normed on individuals with ID. RESULTS: Restricted Interests and Sensory Motor behaviours were reported as most problematic for this sample of boys, whereas Self-injurious behaviours were less problematic. All subscales of the RBS-R were significantly inter-correlated. Nonverbal IQ was negatively related, whereas anxiety and social affective symptoms of autism spectrum disorder were positively related, to scores for Restricted Interests. Anxiety was also positively related to scores for Compulsive behaviours and Ritualistic Sameness behaviours. CONCLUSIONS: This study provides a preliminary description of repetitive behaviours in boys with FXS, which may form the groundwork for future research.

Language development in school-age girls with fragile X syndrome.

BACKGROUND: Girls with fragile X syndrome (FXS) have a wide range of cognitive and language abilities. The range of language outcomes experienced by girls with FXS, however, has been relatively unexplored. The purpose of this exploratory study was to examine receptive and expressive language, with a focus on vocabulary and syntax, in a group of school-age girls with FXS. METHOD: Twenty-one girls with FXS aged 7-15 years participated in the study. The girls completed a receptive vocabulary test, non-verbal IQ test and an expressive language sample. RESULTS: The mean IQ for this group of girls was at the cut-off for intellectual disability. Vocabulary was an area of strength relative to non-verbal cognition. Age and non-verbal IQ were significant predictors of vocabulary performance. CONCLUSIONS: The data suggest that a substantial portion of the sample would qualify for speech and language services. This study highlights the need for continued research in the area of language and cognitive development in girls with the full mutation of fragile X.

Expressive language in male adolescents with fragile X syndrome with and without comorbid autism.

BACKGROUND: Approximately one-quarter of individuals with fragile X syndrome (FXS) meet diagnostic criteria for autism; however, it is unclear whether individuals with comorbid FXS and autism are simply more severely affected than their peers with only FXS or whether they have qualitatively different profiles of behavioural impairments. To address this issue, variation in the FXS linguistic phenotype was examined in males with FXS with and without autism. The syndrome-specificity of the expressive language impairment of both groups of those with FXS was assessed in relation to Down syndrome. The extent to which different language sampling contexts affected expressive language in each diagnostic group was also examined. METHOD: Spontaneous language samples were collected from male adolescents with FXS without autism (n = 20), comorbid FXS and autism (n = 8), and Down syndrome (n = 16). Syntactic complexity (indexed by mean length of utterance), expressive vocabulary (indexed by lexical diversity), talkativeness, fluency and intelligibility were assessed in two contexts: conversation and narration. Groups were matched on non-verbal IQ, non-verbal mental age and chronological age to allow the assessment of relative strengths and weaknesses across language variables. RESULTS: Males with comorbid FXS and autism were less intelligible than males with only FXS; no other differences between these two groups were found. Participants' performance differed across contexts for syntactic complexity, lexical diversity, talkativeness and fluency. CONCLUSIONS: These findings contribute to existing research on the behavioural profiles of individuals with FXS or FXS with autism who have low cognitive abilities. Although individuals with comorbid FXS and autism may be, as a group, more impaired than those with only FXS, data from this small sample of males with comorbid FXS and autism with low IQs suggest that their relative strengths and weaknesses in spontaneous expressive language are largely comparable and not differentially affected by the context in which their talk occurs.

Relation between receptive language and cognitive maturity in persons with mental retardation.

We examined the correlations between receptive language level and performance on indices of nonverbal cognitive functioning for 20 persons with mental retardation and for 20 children without mental retardation matched to them on nonverbal MA. The correlations suggested that the retarded group focused on the formal, sequential properties of language. The correlations also suggested that the nondisabled group placed less emphasis on the formal, sequential properties of language and more on semantic, conceptual properties. These differences in approach may explain why the persons with mental retardation did poorly on the task of understanding spoken language compared to the children without mental retardation.

Relation between the receptive language and mental age of persons with mental retardation.

The purpose of this study was to determine whether the development of receptive language lags behind nonverbal cognitive development in school age persons with mental retardation. The relation between receptive language and nonverbal MA was examined as a function of MA level and the linguistic form to be understood. Individual differences in the receptive language-MA relation were also investigated. Results indicated that the relation between receptive language and MA varied across MA levels, linguistic forms, and individuals at the same MA for listeners with mental retardation.

Identifying the referents of spoken messages: use of context and clarification requests by children with and without mental retardation.

The ability of children with mental retardation and of children without mental retardation matched to them on nonverbal MA to use (a) contextual information and (b) clarification requests to resolve referential ambiguity was evaluated. Each child pretended to be a storekeeper and responded to an adult customer's ambiguous requests. The context disambiguated the request in some cases, but not in others. Both groups of children selected the appropriate referent when the context was informative. Only the children without mental retardation appropriately requested clarification when the context was uninformative. Referential performance was not related to their receptive language level or nonverbal MAs.

Development of a theory of mind in individuals with mental retardation.

The ability of adolescents with mental retardation to reason about other people's mental states was examined. Subjects were asked questions about the knowledge and beliefs of characters in stories that they heard and saw enacted with props. The adolescents with mental retardation performed worse than did children without mental retardation matched for MA. The adolescents with mental retardation did better on questions requiring first-order reasoning than on those involving second-order reasoning; this pattern is similar to that found previously for children without mental retardation.

Signaling of noncomprehension by children and adolescents with mental retardation: effects of problem type and speaker identity.

Previous research has demonstrated considerable within-individual and within-group variability in the signaling of noncomprehension by persons with mental retardation. The first purpose of this study was to determine whether within-individual variability in such signaling was related to differences in the nature of the inadequate message and the identity of the speaker. The second purpose was to evaluate the relationship between within-group variability in noncomprehension signaling and measures of cognition, receptive and excessive language ability, speech intelligibility, and social cognition. Participants were school-age individuals with mild mental retardation and typically developing children matched to them on nonverbal MA. Noncomprehension signaling was examined in a direction-following task in which inadequate message type and speaker were manipulated. It was found that message type, but not speaker, influenced noncomprehension signaling, with no difference between the two groups. We also found that performance on a test of receptive language ability was the best predictor of noncomprehension signaling for persons with mental retardation.

Understanding referential expressions in context: use of common ground by children and adolescents with mental retardation.

Listeners interpret utterances against the common ground, or network of presuppositions shared with the speaker. The first purpose of the study was to determine whether individuals with mental retardation use the major sources of common ground (i.e., physical copresence, linguistic copresence, and community membership) to resolve referential ambiguity. The second purpose was to determine whether they seek confirmation of their referent choices in accordance with the certainty of interpretation afforded by the common ground. The third purpose was to determine whether they signal noncomprehension when faced with ambiguity and common ground that is not informative. The final purpose was to evaluate the relationship between within-group variability in common ground use and measures of nonverbal cognition, receptive and expressive language, and social cognition. Participants were school-age individuals with mental retardation and typically developing children matched to them on nonverbal MA. Common ground use was examined in a role-playing task in which the participant responded to ambiguous utterances. Common ground was manipulated within participants. We determined whether referent selections were appropriate for the common ground, whether they were accompanied by confirmation requests, and whether noncomprehension was signaled. Both groups used all sources of common ground to resolve referential ambiguity at better than chance levels but were less successful in using community membership. Both groups also requested confirmation of their referent choices most often when the common ground was based on community membership. Both groups signaled noncomprehension when the common ground was not informative. Different aspects of common ground use were related to different predictors for the group with mental retardation.

Identifying speech acts from contextual and linguistic information.

We conducted an experiment to examine the comprehension of interrogatives such as Could you make the pencil roll?, which can be intended as yes-no questions, as directives to perform an action, or as both. Clark (1979) has claimed that the comprehension of such sentences is governed by, among other things, the answer obviousness rule; that is, listeners are more likely to interpret such a sentence as a question if the question posed is nonobvious to the speaker. One purpose of the present experiment was to test Clark's claim. A second purpose was to begin identifying the types of contextual information listeners use in comprehending speech acts. The final purpose was to provide data relevant to the controversy about whether listeners evaluate the syntactically direct, literal meaning of a sentence in the course of arriving at a syntactically indirect interpretation. We found that listeners follow an answer obviousness rule, utilize their knowledge of objects and the actions they allow as context for sentence interpretation, and do sometimes evaluate the syntactically direct reading of a sentence before arriving at an indirect speech act.

The linguistic and cognitive profile of Down syndrome: evidence from a comparison with fragile X syndrome.

In this paper, we report on the results of our research, which is designed to address two broad questions about the cognitive and linguistic profile of Down syndrome: (1) Which domains of functioning are especially impaired in individuals with Down syndrome? and (2) Which aspects of the language and cognitive profile of Down syndrome are syndrome specific? To address these questions, we focused on three dimensions of the Down syndrome profile--receptive language, expressive language, and theory of mind--and made comparisons to individuals with fragile X syndrome, which is an X-linked form of intellectual disability. We identified Down syndrome impairments on all three dimensions that were substantially greater than those seen in nonverbal cognition and that were not shared by individuals with fragile X syndrome. Clinical implications of these findings are considered.

Gender differences in repetitive language in fragile X syndrome.

BACKGROUND: Verbal perseveration (i.e. excessive self-repetition) is a characteristic of male individuals with fragile X syndrome; however, little is known about its occurrence among females or its underlying causes. This project examined the relationship between perseveration and (1) gender, (2) cognitive and linguistic ability, and (3) language sampling context, among youth with fragile X syndrome. METHOD: Language transcripts were obtained from adolescent male (n = 16) and female participants (n = 8) with fragile X syndrome in two language contexts (i.e. narration and conversation) designed to elicit spontaneous language samples. Transcripts were coded for utterance-level repetition (i.e. repetition of words, phrases, dependent clauses or whole utterances), topic repetition and conversational device repetition (i.e. repetition of rote phrases or expressions). RESULTS: Male participants produced more conversational device repetition than did female participants. Gender differences in conversational device repetition were not explained by differences in non-verbal cognitive or expressive language ability. Context influenced the type of repetition observed; for example, more topic repetition occurred in conversation than in narration regardless of gender. CONCLUSIONS: The observed gender differences in conversational device repetition among adolescents with fragile X syndrome suggest that, relative to females, male participants may rely more heavily on rote phrases or expressions in their expressive language. Further, results suggest that this gender difference is not simply the result of the correlation between gender and cognitive or linguistic ability in fragile X syndrome; rather, gender may make an independent contribution to conversational device repetition. Repetition type also varied as a function of expressive language context, suggesting the importance of assessing language characteristics in multiple contexts.