Personality traits predict attitudes toward individuals with intellectual disability.

Background: Explaining individual differences in people's attitudes toward individuals with intellectual disability (ID) is important for increasing social inclusion of people with ID. The aim of the current study was to replicate and extend past research by formulating a single model of attitudes toward individuals with ID with several predictors: personality traits, quality and quantity of contact, perceived knowledge of ID, social desirability, and demographics. Methods: A sample of 221 undergraduate students in the United States completed several surveys in a lab setting: the Mental Retardation Attitude Inventory-Revised, the Big Five Inventory, McManus et al.'s measures of contact with and perceived knowledge of ID, and the Marlowe-Crowne Social Desirability Scale. Results: Results replicated previous findings by showing quality of contact was the strongest predictor of attitudes. Additionally, we found openness to experience and agreeableness remained significant predictors after holding all other variables constant. A follow-up mediation analysis demonstrated that quality of contact mediated the relations from openness and agreeableness to attitudes. Conclusions: Findings suggest personality factors can influence attitudes toward individuals with ID, and further emphasize the importance of quality of contact. Implications for the social inclusion of individuals with ID are discussed.

Research Note: Testing the Simple View of Reading in Adolescents and Adults With Down Syndrome.

PURPOSE: The Simple View of Reading is a well-supported framework in typical development that proposes that reading comprehension is predicted by word identification and language comprehension abilities. Although there has been some research examining relations between reading comprehension, word identification, and language comprehension, there has been little research directly testing the Simple View in individuals with Down syndrome, a population that often has difficulties with reading comprehension. Therefore, the purpose of this study was to test the Simple View model in English-speaking readers with Down syndrome and examine the contributions of word identification and language comprehension abilities to their reading comprehension success. METHOD: Twenty-one adolescent and adult readers with Down syndrome (16-36 years of age) completed standardized reading, language, and IQ assessments. RESULTS: Multiple regression assessed the contribution of word identification/phonological decoding and language comprehension skills to reading comprehension outcomes. The full model explained 59% of the variance in reading comprehension. However, language comprehension emerged as the only significant unique predictor, explaining 29% of that variance. Together then, word identification and language comprehension explained approximately 30% of the variance in reading comprehension. CONCLUSIONS: The pattern of results suggests that language comprehension is particularly important to reading comprehension success for individuals with Down syndrome, at least those who can already identify printed words. To support reading comprehension development for individuals with Down syndrome, practitioners, educators, and parents should support language comprehension processes.

Permissive parenting mediates parental stress and child emotions in families of children with Down syndrome.

BACKGROUND: Parenting styles mediate parental stress and child emotions in families of typically developing (TD) children. Our main aim was to study these relations in families of children with Down syndrome (DS), who in past research reported increased parental stress and permissive parenting. METHOD: Our sample included 100 parents of children with DS and 72 parents of TD children age 4-12 years. Parents completed online surveys of parental adjustment and emotion regulation (ER), parenting styles, and child ER and mood. RESULTS: Parents of children with DS reported more distress and permissive parenting than parents of TD children. Within parents of children with DS, there was an indirect effect of parental stress on child emotions through permissive parenting. This effect was partly conditional upon parental ER and positive adjustment. CONCLUSIONS: Results have implications for distressed parents of children with DS whose families may benefit from improved coping strategies and increased support.

Executive function in Down syndrome: A meta-analysis.

BACKGROUND: Executive function (EF) refers to a set of cognitive processes involved in goal-oriented behavior-especially inhibition, attention shifting, and working memory. EF has been identified as a probable area of difficulty in Down syndrome (DS), but the exact nature of the difficulty has not been well-established. AIMS: The meta-analysis sought to confirm or disconfirm EF as an area of difficulty in DS and elucidate an EF profile. METHODS AND PROCEDURES: A random-effects meta-analysis was conducted on 57 studies that compared a group with DS to a typically developing (TD) mental age matched group on one or more executive function tasks. Heterogeneity was examined and moderators analyzed. OUTCOMES AND RESULTS: The overall mean weighted effect size was large (d = -0.87), indicating poorer EF in groups with DS vs TD groups. Heterogeneity was significant, and moderator analysis revealed an EF profile with a very large effect for verbal WM/STM, a large effect for shifting, and moderate effects for inhibition and nonverbal WM/STM. Skewness analysis suggested that mean effect sizes might have been dampened, especially for WM/STM and shifting. CONCLUSIONS AND IMPLICATIONS: Individuals with DS display a pronounced difficulty in EFs; implications for interventions and future research are discussed.

The Acquisition of Survey Knowledge by Individuals With Down Syndrome.

People with Down syndrome often exhibit deficiencies in wayfinding activities, particularly route learning (e.g., Courbois et al., 2013; Davis et al., 2014; Farran et al., 2015). Evidence concerning more sophisticated survey learning has been sparse. In the research reported here, two experiments are reported that evaluated survey learning of youth with DS and typically developing children (TD) matched on mental age. In Experiment 1, participants learned two overlapping routes consisting of three turns each through a virtual environment depicting 9 square city blocks. Following acquisition, they were tested on multiple measures of survey knowledge: finding a shortcut, identifying the direction of landmarks not currently visible from their location in the environment, and recognizing a bird's-eye representation of the overall environment. Under these conditions, which should provide relatively optimal opportunities for survey learning, the participants with DS performed comparably to TD participants matched on non-verbal ability on all of our measures of survey learning. Hence, we concluded that people with DS can acquire some survey knowledge when tasked with learning a small environment and given the opportunity to do so. In Experiment 2, the experimenter navigated participants through a large, relatively complex, virtual environment along a circuitous path, beginning and ending at a target landmark. Then, the participants were placed at a pre-specified location in the environment that they had viewed previously and instructed to navigate to the same target (a door) using the shortest possible path from their current location. They completed the task three times: once after being shown the environment one time, once after three exposures, and once after five exposures. Results indicated that the participants with DS exhibited significantly less skill at identifying the shortcut than did the TD participants, with differences emerging as the number of exposures increased. Participants with DS were also less able to recall landmarks at the end of the experiment. Overall, however, the performance of both groups was relatively poor in both experiments - with the performance of participants with DS being worse as conditions became less optimal. These results were discussed in terms of underlying mechanisms that may account for variations in survey learning as environmental complexity increases.

Peer Victimization and Communication Skills in Adolescents with Down Syndrome: Preliminary Findings.

In this preliminary study, we examined peer victimization in adolescents with Down syndrome (DS) and how it relates to language and communication skills. We modified the Childrens' Social Experience Questionnaire (Crick and Grotpeter in Dev Psychopathol 8:367-380, 1996) to better suit adolescents with DS by simplifying vocabulary and syntax, using two step interview response format. Internal reliability was adequate, and all peer victimization measures were significantly elevated compared to a typically developing sample. Further, peer victimization (especially relational victimization) correlated with speech intelligibility, pragmatic judgment, conversational behavior, and receptive vocabulary. These preliminary data suggest that having DS may put adolescents at risk for peer victimization, but having relatively good language/communication skills may be a protective factor. Further research is warranted on this topic.

Modeling the Relations Among Sustained Attention, Short-Term Memory, and Language in Down Syndrome.

Sustained attention (SA) and short-term memory (STM) contribute to language function in Down syndrome (DS). We proposed models in which relations of SA to language in DS are mediated by STM. Thirty-seven youth with DS aged 10-22 years (M = 15.59) completed SA, STM, and language tasks. Cross-sectional mediation analyses were run with the bootstrapping method. We found significant indirect effects of SA separately on vocabulary and syntax through auditory STM with point estimates of -.30 and -.31, respectively. Results suggest lapses in SA compromise auditory STM, which in turn impacts vocabulary and syntax in youth with DS; however, further research is needed to confirm causality. Addressing SA and STM in language therapy with youth with DS could lead to improved outcomes.

Verb production by individuals with Down syndrome during narration.

BACKGROUND: Despite 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. AIMS: The 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 PROCEDURES: Thirty-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 RESULTS: Examining 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 IMPLICATIONS: The 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.

Growth and Decline in Language and Phonological Memory Over Two Years Among Adolescents With Down Syndrome.

Forty-two adolescents with Down syndrome (DS) ages 10 to 21 years completed a battery of language and phonological memory measures twice, 2 years apart. Individual differences were highly stable across two years. Receptive vocabulary scores improved, there was no change in receptive or expressive grammar scores, and nonword repetition scores declined. Digit memory and expressive vocabulary scores improved among younger adolescents, but generally held steady among older adolescents. These patterns may reveal key points in development at which interventions may be best applied. Further research is needed to understand specific processes in tasks that appear to be slowing or declining during adolescence. They may be important for understanding early aging and dementia in DS.

Narrative Language Sampling in Typical Development: Implications for Clinical Trials.

Purpose: This study examined cross-sectional age-related trajectories of expressive language variables (syntactic complexity, lexical diversity, unintelligibility, dysfluency, and talkativeness) derived from a narrative language sampling procedure. Method: Narrative samples were analyzed from 103 typically developing individuals, ages 4-21 years. Results: Results showed that this procedure was effective for the entire age range, with participants producing an utterance on virtually every page of the wordless picture books used to prompt the narrative. Importantly, the cross-sectional trajectories for syntactic complexity and lexical diversity showed age-related increases through the age of 18 years, although measures of other dimensions of language showed different relationships with age. Conclusions: These data inform developmental work and document the extent to which the narrative procedure can be used to characterize expressive language over a wide age range. This procedure has been proposed as an outcome measure for clinical trials and interventions involving individuals with intellectual and developmental disabilities. The present data document the developmental levels for which the procedure and metrics derived are appropriate.

Outcome Measures for Clinical Trials in Down Syndrome.

Increasingly individuals with intellectual and developmental disabilities, including Down syndrome, are being targeted for clinical trials. However, a challenge exists in effectively evaluating the outcomes of these new pharmacological interventions. Few empirically evaluated, psychometrically sound outcome measures appropriate for use in clinical trials with individuals with Down syndrome have been identified. To address this challenge, the National Institutes of Health (NIH) assembled leading clinicians and scientists to review existing measures and identify those that currently are appropriate for trials; those that may be appropriate after expansion of age range addition of easier items, and/or downward extension of psychometric norms; and areas where new measures need to be developed. This article focuses on measures in the areas of cognition and behavior.

Addressing phonological memory in language therapy with clients who have Down syndrome: Perspectives of speech-language pathologists.

BACKGROUND: Phonological memory (PM) plays a significant role in language development but is impaired in individuals with Down syndrome (DS). Without formal recommendations on how to address PM limitations in clients with DS, it is possible speech-language pathologists (SLPs) find ways to do so in their practices. AIMS: This study asked if and how SLPs address PM in language therapy with clients who have DS. It also asked about SLPs' opinions of the importance, practicality and difficulty of addressing PM in clients with DS. METHODS & PROCEDURES: SLPs participated in an online survey that asked if they address PM in clients with DS and, if so, how often and with which techniques. The survey also asked SLPs to rate their opinions of addressing PM in clients with DS with Likert scales. To contrast clients with DS, SLPs were asked about their practices and opinions with clients who have specific language impairment (SLI) and autism spectrum disorders (ASD). SLPs were recruited through e-mails sent from state organizations and researchers. To compare SLPs' practices and opinions across client types, frequency analyses and analyses of variance (ANOVAs) were run. OUTCOMES & RESULTS: In all, 290 SLPs from 28 states completed the survey. Nearly all SLPs were currently practising at the time data were collected, and all worked with at least one of the three client types. Findings indicated SLPs less often addressed PM and used less variety when addressing PM with clients who have DS compared with clients who have SLI or ASD. Further, SLPs considered it less important, less practical and more difficult to address PM in clients who have DS when compared with clients who have SLI, whereas a similar pattern was found with clients who have ASD. CONCLUSIONS & IMPLICATIONS: SLPs' opinions could be one reason they under-address PM with clients who have DS. Other reasons include there are no evidence-based practice (EBP) guidelines on this topic, and there is not enough familiarity with the DS phenotype among SLPs. Future research on ways to address PM in clients with DS successfully are essential so that EBP guidelines can be established and language therapy can be made more effective.

Receptive vocabulary analysis in Down syndrome.

The present study is an in-depth examination of receptive vocabulary in individuals with Down syndrome (DS) in comparison to control groups of individuals of similar nonverbal ability with typical development (TD) and non-specific etiology intellectual disability (ID). Verb knowledge was of particular interest, as it is known to be a predictor of later syntactic development. Fifty participants with DS, aged 10-21 years, 29 participants with ID, 10-21 years, and 29 participants with TD, 4-9 years, completed measures of receptive vocabulary (PPVT-4), nonverbal ability (Leiter-R), and phonological memory (Nonword Repetition subtest of the CTOPP). Groups were compared on percentage correct of noun, verb and attribute items on the PPVT-4. Results revealed that on verb items, the participants with ID performed significantly better than both participants with DS and TD, even when overall receptive vocabulary ability and phonological memory were held constant. Groups with DS and TD showed the same pattern of lexical knowledge, performing better on nouns than both verbs and attributes. In contrast, the group with ID performed similarly on nouns and verbs, but worse on attributes.

Reading Skills in Down Syndrome: An Examination of Orthographic Knowledge.

The primary goal of this study was to examine the word identification domain of the Simple View of Reading in participants with Down syndrome (DS) by comparing them to participants with typical development (TD) matched on word identification ability. Two subskills, phonological recoding and orthographic knowledge, were measured. Results revealed that individuals with DS performed similarly to controls on 2 measures of orthographic knowledge, but more poorly on phonological recoding and a third measure of orthographic knowledge. The first two orthographic tasks included real words as stimuli; the third task used letter patterns, not real words. These results suggest that individuals with DS may have a relative strength in word-specific orthographic knowledge but not in general orthographic knowledge.

Auditory and visual sustained attention in Down syndrome.

BACKGROUND: Sustained attention (SA) is important to task performance and development of higher functions. It emerges as a separable component of attention during preschool and shows incremental improvements during this stage of development. AIMS: The current study investigated if auditory and visual SA match developmental level or are particular challenges for youth with DS. Further, we sought to determine if there were modality effects in SA that could predict those seen in short-term memory (STM). METHODS AND PROCEDURES: We compared youth with DS to typically developing youth matched for nonverbal mental age and receptive vocabulary. Groups completed auditory and visual sustained attention to response tests (SARTs) and STM tasks. OUTCOMES AND RESULTS: Results indicated groups performed similarly on both SARTs, even over varying cognitive ability. Further, within groups participants performed similarly on auditory and visual SARTs, thus SA could not predict modality effects in STM. However, SA did generally predict a significant portion of unique variance in groups' STM. CONCLUSIONS AND IMPLICATIONS: Ultimately, results suggested both auditory and visual SA match developmental level in DS. Further, SA generally predicts STM, though SA does not necessarily predict the pattern of poor auditory relative to visual STM characteristic of DS.

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.

Emotion knowledge in children and adolescents with Down syndrome: a new methodological approach.

Emotion knowledge was examined in 19 youth with Down syndrome (DS) and compared to typically developing (TD) children of similar developmental levels. This project expanded upon prior research on emotion knowledge in DS by utilizing a measure that minimized the need for linguistic skills, presented emotion expressions dynamically, and included social context cues. In Study 1, participants with DS were as accurate as TD participants when judging emotions from static or dynamic expression stimuli and from facial or contextual cues. In Study 2, participants with DS and TD participants showed similar cross-sectional developmental trajectories of emotion knowledge across mental age. This project highlights the importance of measure selection when examining emotion knowledge in samples with intellectual and developmental disabilities.

The acquisition of contextual cueing effects by persons with and without intellectual disability.

Two experiments were conducted to compare the acquisition of contextual cueing effects of adolescents and young adults with intellectual disabilities (ID) relative to typically developing children and young adults. Contextual cueing reflects an implicit, memory based attention guidance mechanism that results in faster search for target locations that have been previously experienced in a predictable context. In the study, participants located a target stimulus embedded in a context of numerous distracter stimuli. During a learning phase, the location of the target was predictable from the location of the distracters in the search displays. We then compared response times to locating predictable relative to unpredictable targets presented in a test phase. In Experiment 1, all of the distracters predicted the location of the target. In Experiment 2, half of the distracters predicted the location of the target while the other half varied randomly. The participants with ID exhibited significant contextual facilitation in both experiments, with the magnitude of facilitation being similar to that of the typically developing (TD) children and adults. We concluded that deficiencies in contextual cueing are not necessarily associated with low measured intelligence that results in a classification of ID.

Rule-based category learning in Down syndrome.

Rule-based category learning was examined in youths with Down syndrome (DS), youths with intellectual disability (ID), and typically developing (TD) youths. Two tasks measured category learning: the Modified Card Sort task (MCST) and the Concept Formation test of the Woodcock-Johnson-III ( Woodock, McGrew, & Mather, 2001 ). In regression-based analyses, DS and ID groups performed below the level expected for their nonverbal ability. In cross-sectional developmental trajectory analyses, results depended on the task. On the MCST, the DS and ID groups were similar to the TD group. On the Concept Formation test, the DS group had slower cross-sectional change than the other 2 groups. Category learning may be an area of difficulty for those with ID, but task-related factors may affect trajectories for youths with DS.

Visuo-spatial ability in individuals with Down syndrome: is it really a strength?

Down syndrome (DS) is associated with extreme difficulty in verbal skills and relatively better visuo-spatial skills. Indeed, visuo-spatial ability is often considered a strength in DS. However, it is not clear whether this strength is only relative to the poor verbal skills, or, more impressively, relative to cognitive ability in general. To answer this question, we conducted an extensive literature review of studies on visuo-spatial abilities in people with Down syndrome from January 1987 to May 2013. Based on a general taxonomy of spatial abilities patterned after Lohman, Pellegrino, Alderton, and Regian (1987) and Carroll (1993) and existing studies of DS, we included five different domains of spatial abilities - visuo-spatial memory, visuo-spatial construction, mental rotation, closure, and wayfinding. We evaluated a total of 49 studies including 127 different comparisons. Most comparisons involved a group with DS vs. a group with typical development matched on mental age and compared on a task measuring one of the five visuo-spatial abilities. Although further research is needed for firm conclusions on some visuo-spatial abilities, there was no evidence that visuo-spatial ability is a strength in DS relative to general cognitive ability. Rather, the review suggests an uneven profile of visuo-spatial abilities in DS in which some abilities are commensurate with general cognitive ability level, and others are below.