University of Southern California
University of Southern California
Mrs. T.H. Chan Division of Occupational Science and Occupational Therapy
Mrs. T.H. Chan Division of Occupational Science and Occupational Therapy
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John Sideris PhD

John Sideris PhD

Professor of Research

Room: CHP 110C
(323) 442-2723
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Doctor of Philosophy (PhD) in Quantitative Psychology
2006 | University of North Carolina at Chapel Hill

Master of Arts (MA) in Quantitative Psychology
2003 | University of North Carolina at Chapel Hill

Master of Arts (MA) in Social Psychology
1993 | University of Texas at Austin

Bachelor of Arts (BA) in Psychology
1990 | University of Colorado Colorado Springs



Journal Articles

Baranek, G. T., Carlson, M., Sideris, J., Kirby, A. V., Watson, L. R., Williams, K. L., & Bulluck, J. (2019). Longitudinal assessment of stability of sensory features in children with autism spectrum disorder or other developmental disabilities. Autism Research, 12(1), 100–111. Show abstractHide abstract

Prior research on the stability of sensory processing problems in children with autism spectrum disorder (ASD) or other developmental disabilities (DD) has produced inconsistent results. We employed a longitudinal study design to assess the stability of three clinical sensory response patterns: hyporesponsiveness; hyperresponsiveness; and sensory interests, repetitions, and seeking behaviors (SIRS). Parents of children with ASD (n = 55) or DD (n = 35) responded to sensory questionnaires at two time points (T1 and T2) separated by 3.3 years on average, with the children aged 2–12 years (M = 5.69 ± 2.46) at the first assessment. For each sensory response pattern, regression analysis revealed that, for both ASD and DD groups, scores at T1 were strong predictors of scores at T2. Over the longitudinal assessment interval, there was a significant mean decline in severity for SIRS in both groups and for hyporesponsiveness in the ASD group. Parental estimates of the amount of therapy services received were positively associated with the severity of sensory features at T2, an outcome that may result from increased intervention dosages being administered to children who fail to improve over time. The results are discussed in terms of person‐centered and environmental considerations, which, in combination, have the capacity to affect stability outcomes for sensory features.


Journal Articles

Williams, K. L., Kirby, A. V., Watson, L. R., Sideris, J., Bulluck, J., & Baranek, G. T. (2018). Sensory features as predictors of adaptive behaviors: A comparative longitudinal study of children with autism spectrum disorder and other developmental disabilities. Research in Developmental Disabilities, 81, 103-112. Show abstractHide abstract

Background. Children with autism spectrum disorder (ASD) and other developmental disabilities (DD) exhibit sensory features that differ from their typically developing peers. Prior cross-sectional research has demonstrated significant associations between elevated sensory features and lower adaptive behavior scores, yet there is limited prospective research examining longitudinal associations.
Aims. To examine the longitudinal prediction of early sensory response patterns (i.e., hyperresponsiveness, hyporesponsiveness, and sensory interests, repetitions, and seeking behaviors) to later adaptive behavior outcomes in children with ASD and DD.
Methods and procedures. Children with ASD (n = 51) and DD (n = 30) were seen at two time points (Time 1: M(SD) = 5.6(2.5) years; Time 2: M(SD) = 9.0(2.2) years). We used a series of regression models with both observational and parent-report measures of sensory response patterns, and including group interactions.
Outcomes and results. All three sensory response patterns significantly predicted aspects of adaptive behaviors, with some differences based on assessment format and diagnostic group. Across groups and sensory patterns, we found some evidence that elevated sensory features early in childhood predicted lower adaptive behavior skills later in childhood.
Conclusions and implications. Sensory features may interfere with development of adaptive behaviors, suggesting a need for effective interventions addressing sensory features early in development.
Keywords. Autism; Child development disorders; Longitudinal analysis; Sensory processing; Adaptive behaviors

Boyd, B. A., Watson, L. R., Reszka, S. S., Sideris, J., Alessandri, M., Baranek, G. T., Crais, E. R., Donaldson, A., Gutierrez, A., Johnson, L., & Belardi, K. (2018). Efficacy of the ASAP intervention for preschoolers with ASD: A cluster randomized controlled trial. Journal of Autism and Developmental Disorders, 48(9), 3144–3162. Show abstractHide abstract

The advancing social-communication and play (ASAP) intervention was designed as a classroom-based intervention, in which the educational teams serving preschool-aged children with autism spectrum disorder are trained to implement the intervention in order to improve these children’s social-communication and play skills. In this 4-year, multi-site efficacy trial, classrooms were randomly assigned to ASAP or a business-as-usual control condition. A total of 78 classrooms, including 161 children, enrolled in this study. No significant group differences were found for the primary outcomes of children’s social-communication and play. However, children in the ASAP group showed increased classroom engagement. Additionally, participation in ASAP seemed to have a protective effect for one indicator of teacher burnout. Implications for future research are discussed.
Keywords. Autism spectrum disorder; ASAP; Randomized controlled trial; School interventions; Engagement; Social-communication

Costa, L.-J., Green, M., Sideris, J., & Hooper, S. R. (2018). First-grade cognitive predictors of writing disabilities in grades 2 through 4 elementary school students. Journal of Learning Disabilities, 51(4), 351-362. Show abstractHide abstract

The primary aim of this study was determining Grade 1 cognitive predictors of students at risk for writing disabilities in Grades 2 through 4. Applying cognitive measures selected to align with theoretical and empirical models of writing, tasks were administered to Grade 1 students assessing fine-motor, linguistic, and executive functions: 84 at risk (bottom quartile for age-base expectations) and 54 typically developing. A model with individual predictors was compared to a previously developed latent trait model to determine the relative predictive worth of each approach. Data analysis primarily involved stepwise logistic regression. Results revealed that the individual measures of orthographic choice, working memory, inhibitory control, visual memory recognition, and planning all were significant predictors of at risk status in Grades 2 through 4. The latent trait model also fared well but did not account for the same amount of variance as any of the individual measurement models for any of the grades. The findings lay the foundation for an empirically based approach to cognitive assessment in Grade 1 for identifying potential at-risk students in later elementary grades and suggest potential underlying neurocognitive abilities that could be employed with educational interventions for students with later-emerging writing disabilities.

Gardner-Neblett, N., & Sideris, J. (2018). Different tales: The role of gender in the oral narrative-reading link among African American children. Child Development, 89(4), 1328-1342. Show abstractHide abstract

Evidence suggests that oral narrative skills are a linguistic strength for African American children, yet few studies have examined how these skills are associated with reading for African American boys and girls. The current study uses longitudinal data of a sample of 72 African American 4-year-olds to examine how preschool oral narrative skills predict reading from first through sixth grades and explores differences by gender. Findings indicate that although girls demonstrated stronger narrative skills, their narrative skills did not moderate change in reading. For boys, narrative skills moderated change in reading over time such that as preschool narrative skills increased, their reading scores showed greater change over time. Educational implications and directions for future research are discussed.

Odom, S. L., Cox, A., Sideris, J., Hume, K. A., Hedges, S., Kucharczyk, S., Shaw, E., Boyd, B. A., Reszka, S., & Neitzel, J. (2018). Assessing quality of program environments for children and youth with autism: Autism Program Environment Rating Scale (APERS). Journal of Autism and Developmental Disorders, 48(3), 913–924. Show abstractHide abstract

The purpose of this study was to examine the psychometric properties of the Autism Program Environment Rating Scale (APERS), an instrument designed to assess quality of program environments for students with autism spectrum disorder. Data sets from two samples of public school programs that provided services to children and youth with autism spectrum disorder were utilized. Cronbach alpha analyses indicated high coefficients of internal consistency for the total APERS and moderate levels for item domains for the first data set, which was replicated with the second data set. A factor analysis of the first data set indicated that all domain scores loaded on one main factor, in alignment with the conceptual model, with this finding being replicated in the second data set. Also, the APERS was sensitive to changes resulting from a professional development program designed to promote program quality.

Schertz, H. H., Odom, S. L., Baggett, K. M., & Sideris, J. H. (2018). Mediating parent learning to promote social communication for toddlers with autism: Effects from a randomized controlled trial. Journal of Autism and Developmental Disorders, 48(3), 853–867. Show abstractHide abstract

A randomized controlled trial was conducted to evaluate effects of the Joint Attention Mediated Learning (JAML) intervention. Toddlers with autism spectrum disorders (ASD) aged 16–30 months (n = 144) were randomized to intervention and community control conditions. Parents, who participated in 32 weekly home-based sessions, followed a mediated learning process to target preverbal social communication outcomes (social visual synchrony, reciprocity, and responding and initiating forms of joint attention) throughout daily interactions. The analysis found post-intervention effects for all outcomes, with all except initiating joint attention sustaining 6 months post-intervention. Findings support the value of very early intervention targeting explicitly social functions of preverbal communication and of promoting active engagement in the learning process for both toddlers and parents.

Hume, K., Dykstra Steinbrenner, J., Sideris, J., Smith, L., Kucharczyk, S., & Szidon, K. (2018). Multi-informant assessment of transition-related skills and skill importance in adolescents with autism spectrum disorder. Autism, 22(1), 40-50. Show abstractHide abstract

Adolescents with autism spectrum disorder have limited participation in the transition planning process, despite the link between active participation and an improvement in postsecondary education and employment outcomes. The Secondary School Success Checklist was designed to support transition planning for adolescents with autism spectrum disorder by incorporating their own assessments of strengths, skill deficits, and prioritization for instruction along with those of their parents and teachers across multiple skill domains. Findings from more than 500 adolescents with autism spectrum disorder across the United States indicate discrepancies between adolescent, teacher, and parent ratings of skills highlighting the importance of the inclusion of multiple perspectives in transition planning. Although ratings varied, agreement between adolescents with autism spectrum disorder, parents, and teachers across the highest and lowest rated skills suggests the need to broaden the focus on critical transition skills to include problem-solving, planning for life after high school, and self-advocacy.


Journal Articles

Watson, L. R., Crais, E. R., Baranek, G. T., Turner-Brown, L., Sideris, J., Wakeford, L., Kinard, J., Reznick, J. S., Martin, K. L., & Nowell, S. W. (2017). Parent-mediated intervention for one-year-olds screened as at-risk for autism spectrum disorder: A randomized controlled trial. Journal of Autism and Developmental Disorders, 47(11), 3520-3540. Show abstractHide abstract

Theoretically, interventions initiated with at-risk infants prior to the point in time a definitive autism spectrum disorder (ASD) diagnosis can be made will improve outcomes. Pursuing this idea, we tested the efficacy of a parent-mediated early intervention called Adapted Responsive Teaching (ART) via a randomized controlled trial with 87 one-year-olds identified by community screening with the First Year Inventory as at-risk of later ASD diagnoses. We found minimal evidence for main effects of ART on child outcomes. However, ART group parents showed significantly greater increases in responsiveness to their infants than control group parents. Further, significant indirect (mediation) effects of assignment group on multiple child outcomes through changes in parent responsiveness supported our theory of change.

Losh, M., Martin, G. E., Lee, M., Klusek, J., Sideris, J., Barron, S., & Wassink, T. (2017). Developmental markers of genetic liability to autism in parents: A longitudinal, multigenerational study. Journal of Autism and Developmental Disorders, 47(3), 834-845. Show abstractHide abstract

Genetic liability to autism spectrum disorder (ASD) can be expressed in unaffected relatives through subclinical, genetically meaningful traits, or endophenotypes. This study aimed to identify developmental endophenotypes in parents of individuals with ASD by examining parents' childhood academic development over the school-age period. A cohort of 139 parents of individuals with ASD were studied, along with their children with ASD and 28 controls. Parents' childhood records in the domains of language, reading, and math were studied from grades K-12. Results indicated that relatively lower performance and slower development of skills (particularly language related skills), and an uneven rate of development across domains predicted ASD endophenotypes in adulthood for parents, and the severity of clinical symptoms in children with ASD. These findings may mark childhood indicators of genetic liability to ASD in parents, that could inform understanding of the subclinical expression of ASD genetic liability.

Kinard, J. L., Sideris, J., Watson, L. R., Baranek, G. T., Crais, E. R., Wakeford, L., & Turner-Brown, L. (2017). Predictors of parent responsiveness to 1-year-olds at-risk for autism spectrum disorder. Journal of Autism and Developmental Disorders, 47(1), 172-186. Show abstractHide abstract

Parent responsiveness is critical for child development of cognition, social-communication, and self-regulation. Parents tend to respond more frequently when children at-risk for autism spectrum disorder (ASD) demonstrate stronger social-communication; however, it is unclear how responsiveness is associated with sensory characteristics of children at-risk for ASD. To address this issue, we examined the extent to which child social-communication and sensory reactivity patterns (i.e., hyper- and hypo-reactivity) predicted parent responsiveness to 1-year-olds at-risk for ASD in a community sample of 97 parent-infant pairs. A combination of child social-communication and sensory hypo-reactivity consistently predicted how parents played and talked with their 1-year-old at-risk for ASD. Parents tended to talk less and use more play actions when infants communicated less and demonstrated stronger hypo-reactivity.


Journal Articles

Ausderau, K. K., Sideris, J., Little, L. M., Furlong, M., Bulluck, J. C., & Baranek, G. T. (2016). Sensory subtypes and associated outcomes in children with autism spectrum disorders. Autism Research, 9(12), 1316-1327. Show abstractHide abstract

Sensory features are prevalent and heterogeneous across children with ASD and these features have been associated with child outcomes. Identification of clinically defined sensory subtypes may enhance our understanding of unique phenotypes that have implications for etiology, prognosis, and intervention. This longitudinal study used a national online survey aimed to identify associations of previously validated sensory subtypes to specific child and family characteristics and functional outcomes [Vineland Adaptive Behavior Scale-II (VABS) and Parenting Stress Index short form (PSI)]. The sensory experiences questionnaire-3.0 was collected from caregivers with children with ASD, ages 2-12, at two time points (Time 1, n = 1307, Time 2, n = 884), 1 year apart. Functional outcomes assessments were collected at the second time point. A latent profile transition analysis (LPTA) was used to test associations, and results indicated that the attenuated-preoccupied subtype presented with the significantly lowest levels of VABS adaptive behavior composite scores compared to the other three sensory subtypes. Both the VABS maladaptive behavior index and the total PSI score were significantly highest in the extreme-mixed subtype. These results underscore the clinical utility of this subtyping approach for differentiating characteristics and functional outcomes associated with clinically defined sensory phenotypes. These findings may have implications for better understanding etiology, prognosis, and more precise targets for interventions designed to ameliorate sensory difficulties, and ultimately mitigate negative developmental consequences and parenting stress.

Wheeler, A. C., Sideris, J., Hagerman, R., Berry-Kravis, E., Tassone, F., & Bailey Jr, D. B. (2016). Developmental profiles of infants with an FMR1 premutation. Journal of Neurodevelopmental Disorders, 8, 40. Show abstractHide abstract

Background. Emerging evidence suggests that a subset of FMR1 premutation carriers is at an increased risk for cognitive, emotional, and medical conditions. However, because the premutation is rarely diagnosed at birth, the early developmental trajectories of children with a premutation are not known.
Methods. This exploratory study examined the cognitive, communication, and social-behavioral profiles of 26 infants with a premutation who were identified through participation in a newborn screening for fragile X syndrome pilot study. In this study, families whose newborn screened positive for an FMR1 premutation were invited to participate in a longitudinal study of early development. Twenty-six infants with the premutation and 21 matched, screen-negative comparison babies were assessed using validated standardized measures at 6-month intervals starting as young as 3 months of age. The babies were assessed up to seven times over a 4-year period.
Results. The premutation group was not statistically different from the comparison group on measures of cognitive development, adaptive behavior, temperament, or overall communication. However, the babies with the premutation had a significantly different developmental trajectory on measures of nonverbal communication and hyperresponsivity to sensory experiences. They also were significantly more hyporesponsive at all ages than the comparison group. Cytosine-guanine-guanine repeat length was linearly associated with overall cognitive development.
Conclusions. These results suggest that infants with a premutation may present with subtle developmental differences as young as 12 months of age that may be early markers of later anxiety, social deficits, or other challenges thought to be experienced by a subset of carriers.

Schertz, H. H., Odom, S. L., Baggett, K. M., & Sideris, J. H. (2016). Parent-reported repetitive behavior in toddlers on the autism spectrum. Journal of Neurodevelopmental Disorders, 46(10), 3308-3316. Show abstractHide abstract

Toddlers with autism spectrum disorder (ASD) were assessed on the Repetitive Behavior Scale-Revised (RBS-R), which we found to have acceptable internal consistency. Stereotypical subscale scores showed a negligible association with cognitive level, but correlated more strongly with adaptive and social indicators. Relative to earlier reported RBS-R scores for older age groups, toddlers' scores trended toward higher stereotyped behavior and lower ritualistic/sameness behavior. Our findings on associations with developmental indicators align with those of researchers who used more resource-intensive repetitive behavior measures. The convergence of these findings with those derived from other measurement methods suggests that the RBS-R, a cost effective parent-report measure, is a viable means of assessing repetitive behavior in toddlers with autism.


Journal Articles

Little, L. M., Ausderau, K., Sideris, J., & Baranek, G. T. (2015). Activity participation and sensory features among children with autism spectrum disorders. Journal of Autism and Developmental Disorders, 45(9), 2981-2990. Show abstractHide abstract

Sensory features are highly prevalent among children with autism spectrum disorders (ASD) and have been shown to cluster into four patterns of response, including hyperresponsiveness, hyporesponsiveness, enhanced perception, and sensory interests, repetitions and seeking behaviors. Given the lack of large-scale research on the differential effects of sensory response patterns on children's participation in specific activities, this study investigated the extent to which sensory response patterns impacted six dimensions of children's activity participation as measured by the Home and Community Activities Scale among a large, national sample of school aged children with ASD (n = 674). Using mixed model regression, results showed that sensory response patterns differentially impacted dimensions of activity participation, and associations were moderated by a number of child characteristics.

Bailey Jr, D. B., Wheeler, A., Berry-Kravis, E., Hagerman, R., Tassone, F., Powell, C. M., Roche, M., Gane, L. W., & Sideris, J. (2015). Maternal consequences of the detection of Fragile X carriers in newborn screening. Pediatrics, 136(2), e433-e440. Show abstractHide abstract

Objectives. The possibility of newborn screening for fragile X syndrome is complicated by the potential for identifying premutation carriers. Although knowing the child's carrier status has potential benefits, the possibility of late-onset disorders in carrier children and their parents raises concerns about whether such information would be distressing to parents and potentially more harmful than helpful. This study sought to answer this question by offering voluntary fragile X screening to new parents and returning results for both the full mutation and premutation FMR1 gene expansions. We tested the assumption that such information could lead to adverse mental health outcomes or decision regret. We also wanted to know if child age and spousal support were associated with the outcomes of interest.
Methods. Eighteen mothers of screen-positive infants with the premutation and 15 comparison mothers completed a battery of assessments of maternal anxiety, postpartum depression, stress, family quality of life, decision regret, and spousal support. The study was longitudinal, with an average of 3 assessments per mother.
Results. The premutation group was not statistically different from the comparison group on measures of anxiety, depression, stress, or quality of life. A subset of mothers experienced clinically significant anxiety and decision regret, but factors associated with these outcomes could not be identified. Greater spousal support was generally associated with more positive outcomes.
Conclusions. Although we did not find evidence of significant adverse events, disclosure of newborn carrier status remains an important consideration in newborn screening policy.

Crowther, A., Smoski, M. J., Minkel, J., Moore, T., Gibbs, D., Petty, C., Bizzell, J., Schiller, C. E., Sideris, J., Carl, H., & Dichter, G. S. (2015). Resting-state connectivity predictors of response to psychotherapy in major depressive disorder. Neuropsychopharmacology, 40, 1659-1673. Show abstractHide abstract

Despite the heterogeneous symptom presentation and complex etiology of major depressive disorder (MDD), functional neuroimaging studies have shown with remarkable consistency that dysfunction in mesocorticolimbic brain systems are central to the disorder. Relatively less research has focused on the identification of biological markers of response to antidepressant treatment that would serve to improve the personalized delivery of empirically supported antidepressant interventions. In the present study, we investigated whether resting-state functional brain connectivity (rs-fcMRI) predicted response to Behavioral Activation Treatment for Depression, an empirically validated psychotherapy modality designed to increase engagement with rewarding stimuli and reduce avoidance behaviors. Twenty-three unmedicated outpatients with MDD and 20 matched nondepressed controls completed rs-fcMRI scans after which the MDD group received an average of 12 sessions of psychotherapy. The mean change in Beck Depression Inventory-II scores after psychotherapy was 12.04 points, a clinically meaningful response. Resting-state neuroimaging data were analyzed with a seed-based approach to investigate functional connectivity with four canonical resting-state networks: the default mode network, the dorsal attention network, the executive control network, and the salience network. At baseline, the MDD group was characterized by relative hyperconnectivity of multiple regions with precuneus, anterior insula, dorsal anterior cingulate cortex (dACC), and left dorsolateral prefrontal cortex seeds and by relative hypoconnectivity with intraparietal sulcus, anterior insula, and dACC seeds. Additionally, connectivity of the precuneus with the left middle temporal gyrus and connectivity of the dACC with the parahippocampal gyrus predicted the magnitude of pretreatment MDD symptoms. Hierarchical linear modeling revealed that response to psychotherapy in the MDD group was predicted by pretreatment connectivity of the right insula with the right middle temporal gyrus and the left intraparietal sulcus with the orbital frontal cortex. These results add to the nascent body of literature investigating pretreatment rs-fcMRI predictors of antidepressant treatment response and is the first study to examine rs-fcMRI predictors of response to psychotherapy.

Damiano, C. R., Cockrell, D. C., Dunlap, K., Hanna, E. K., Miller, S., Bizzell, J., Kovac, M., Turner-Brown, L., Sideris, J., Kinard, J., & Dichter, G. S. (2015). Neural mechanisms of negative reinforcement in children and adolescents with autism spectrum disorders. Neuropsychopharmacology, 7, 12. Show abstractHide abstract

Background. Previous research has found accumulating evidence for atypical reward processing in autism spectrum disorders (ASD), particularly in the context of social rewards. Yet, this line of research has focused largely on positive social reinforcement, while little is known about the processing of negative reinforcement in individuals with ASD.
Methods. The present study examined neural responses to social negative reinforcement (a face displaying negative affect) and non-social negative reinforcement (monetary loss) in children with ASD relative to typically developing children, using functional magnetic resonance imaging (fMRI).
Results. We found that children with ASD demonstrated hypoactivation of the right caudate nucleus while anticipating non-social negative reinforcement and hypoactivation of a network of frontostriatal regions (including the nucleus accumbens, caudate nucleus, and putamen) while anticipating social negative reinforcement. In addition, activation of the right caudate nucleus during non-social negative reinforcement was associated with individual differences in social motivation.
Conclusions. These results suggest that atypical responding to negative reinforcement in children with ASD may contribute to social motivational deficits in this population.


Journal Articles

Ausderau, K. K., Furlong, M., Sideris, J., Bulluck, J., Little, L. M., Watson, L. R., Boyd, B. A., Belger, A., Dickie, V. A., & Baranek, G. T. (2014). Sensory subtypes in children with autism spectrum disorder: Latent profile transition analysis using a national survey of sensory features. Journal of Child Psychology and Psychiatry, and Allied Disciplines, 55(8), 935-944. Show abstractHide abstract

Background. Sensory features are highly prevalent and heterogeneous among children with ASD. There is a need to identify homogenous groups of children with ASD based on sensory features (i.e., sensory subtypes) to inform research and treatment.
Methods. Sensory subtypes and their stability over 1 year were identified through latent profile transition analysis (LPTA) among a national sample of children with ASD. Data were collected from caregivers of children with ASD ages 2-12 years at two time points (Time 1 N = 1294; Time 2 N = 884).
Results. Four sensory subtypes (Mild; Sensitive-Distressed; Attenuated-Preoccupied; Extreme-Mixed) were identified, which were supported by fit indices from the LPTA as well as current theoretical models that inform clinical practice. The Mild and Extreme-Mixed subtypes reflected quantitatively different sensory profiles, while the Sensitive-Distressed and Attenuated-Preoccupied subtypes reflected qualitatively different profiles. Further, subtypes reflected differential child (i.e., gender, developmental age, chronological age, autism severity) and family (i.e., income, mother's education) characteristics. Ninety-one percent of participants remained stable in their subtypes over 1 year.
Conclusions. Characterizing the nature of homogenous sensory subtypes may facilitate assessment and intervention, as well as potentially inform biological mechanisms.

Ausderau, K., Sideris, J., Furlong, M., Little, L. M., Bulluck, J., & Baranek, G. T. (2014). National survey of sensory features in children with ASD: Factor structure of the sensory experience questionnaire (3.0). Journal of Autism and Developmental Disorders, 44(4), 915-925. Show abstractHide abstract

This national online survey study characterized sensory features in 1,307 children with autism spectrum disorder (ASD) ages 2-12 years using the Sensory Experiences Questionnaire Version 3.0 (SEQ-3.0). Using the SEQ-3.0, a confirmatory factor analytic model with four substantive factors of hypothesized sensory response patterns (i.e., hyporesponsiveness; hyperresponsiveness; sensory interests, repetitions and seeking behaviors; enhanced perception), five method factors of sensory modalities (i.e., auditory, visual, tactile, gustatory/olfactory, vestibular/proprioceptive), and one of social context were tested with good model fit. Child and family characteristics associated with the sensory response patterns were explored. The effect of sensory response patterns on autism severity was tested, controlling for key child and family characteristics. The SEQ-3.0 demonstrates an empirically valid factor structure specific to ASD that considers sensory response patterns, modalities, and social context.

Little, L. M., Sideris, J., Ausderau, K., & Baranek, G. T. (2014). Activity participation among children with autism spectrum disorder. American Journal of Occupational Therapy, 68(2), 177-185. Show abstractHide abstract

Objective. The purpose of this study was to empirically derive dimensions of activity participation among a sample of school-age children with autism spectrum disorder (ASD; n = 713). Additionally, we examined the associations between dimensions of activity participation and child characteristics (i.e., chronological age, autism severity, gender) and family demographics (i.e., maternal education).
Methods. Exploratory factor analysis was used to determine the factors on the Home and Community Activities Scale (HCAS). Multiple regression was used to examine the extent to which child characteristics and family demographics were related to HCAS dimensions.
Results. A six-factor model best characterized activity participation among the school-age children with ASD, and child characteristics and family demographics were differentially associated with HCAS dimensions.
Conclusion. The findings have implications for how activities may be categorized for children with ASD and suggest that the frequency of specific activities is affected by child characteristics and maternal education.


Journal Articles

Martin, G. E., Losh, M., Estigarribia, B., Sideris, J., & Roberts, J. (2013). Longitudinal profiles of expressive vocabulary, syntax and pragmatic language in boys with fragile X syndrome or Down syndrome. International Journal of Language & Communication Disorders, 48(4), 432-443. Show abstractHide abstract

Background. Fragile X syndrome (FXS) and Down syndrome (DS) are the two leading genetic causes of intellectual disability, and FXS is the most common known genetic condition associated with autism. Both FXS and DS are associated with significant language impairment, but little is known about expressive language across domains over time or the role of autism in language development in FXS.
Aims. To compare three domains of language production (vocabulary, syntax, pragmatics) over time within and across groups of boys with FXS with and without autism spectrum disorder (FXS-ASD, FXS-O), boys with DS, and typically developing (TD) boys.
Methods & Proceures. Twenty-nine boys with FXS-O, 40 boys with FXS-ASD, 34 boys with DS, and 48 younger TD boys of similar non-verbal mental age living in the United States participated in the study. The Antonyms, Syntax Construction and Pragmatic Judgment subtests of the Comprehensive Assessment of Spoken Language were administered annually over 3 years.
Outcomes & Results. TD boys scored higher than all other groups on all three subtests; boys with FXS-O and FXS-ASD scored higher than boys with DS in Syntax Construction; and boys with FXS-O scored higher than boys with FXS-ASD in Pragmatic Judgment. Within-group patterns varied between groups. Overall, the TD group showed significantly more change over time than all other groups.
Conclusions & Implications. Findings suggest that expressive language skills and growth across various domains are more impaired in boys with FXS and DS than would be expected based on non-verbal mental age, that for boys with DS syntax is more impaired than would be expected based on intellectual disability, and that autism status affects pragmatic language in boys with FXS. Findings suggest that language production across domains should be addressed during assessment and intervention for boys with FXS and boys with DS, with differing group profiles also suggesting potentially different areas of focus.

Nelson, D. K., Skinner, D., Guarda, S., Choudhury, S., Sideris, J., Barnum, L., Ten Haagen, K., Heyward, Q., & Bailey Jr, D. B. (2013). Obtaining consent from both parents for pediatric research: What does "reasonably available" mean? Pediatrics, 131(1), e223-e229. Show abstractHide abstract

Objective. Circumstances surrounding parental availability and decision-making were examined in the setting of a research protocol involving newborn screening (NBS) for fragile X syndrome, in which the institutional review board (IRB) had determined that consent (permission) was required from both parents.
Methods. A survey was conducted with 3001 families who were approached to participate in optional NBS. In addition to basic demographics, observational notes detailed the reasons why fathers were not present or deemed "not reasonably available" (per IRB regulations), and content analysis identified the factors for this lack of availability. Logistic regression models estimated the likelihood that both parents would agree to enroll their infant in the screening project.
Results. Fathers were not present in 589 cases, including 158 in which fathers were ultimately determined to be not reasonably available. Primary reasons for father's unavailability were deployment with the military, incarceration, living out of state, or not involved in the mother's life. In cases in which both parents were available, 64% agreed to enroll in the NBS study. Criteria to guide researchers in making required determinations were developed from consultations with IRB officials and legal counsel.
Conclusions. In a large-scale population-based study, 19.6% of fathers were absent for the consent process. Scenarios encountered underscore the complexity of parental relations and their implications for obtaining consent for research involving children. The algorithm developed may serve as a useful tool for others in applying the regulatory requirements for dual parental permission.


Journal Articles

Martin, G. E., Roberts, J. E., Helm-Estabrooks, N., Sideris, J., Vanderbilt, J., & Moskowitz, L. (2012). Perseveration in the connected speech of boys with Fragile X syndrome with and without autism spectrum disorder. American Journal on Intellectual and Developmental Disabilities, 117(5), 384-399. Show abstractHide abstract

Verbal perseveration is a frequently reported language characteristic of males with Fragile X syndrome and may be a defining feature or hallmark of the syndrome. We compared the verbal perseveration of boys with Fragile X syndrome with (n = 29) and without (n = 30) autism spectrum disorder, boys with Down syndrome (n = 27), and typically developing boys (n = 25) at similar nonverbal mental ages. During a social interaction, boys with both Fragile X syndrome and autism spectrum disorder produced significantly more topic perseveration than all other groups. In social interaction as compared to narration, boys with Fragile X syndrome (regardless of autism status) produced significantly more topic perseveration. These findings suggest that autism status, as well as language sampling context, affect perseveration in boys with Fragile X syndrome.

Losh, M., Klusek, J., Martin, G. E., Sideris, J., Parlier, M., & Piven, J. (2012). Defining genetically meaningful language and personality traits in relatives of individuals with fragile X syndrome and relatives of individuals with autism. American Journal of Medical Genetics: Part B, Neuropsychiatric Genetics, 159B(6), 660-668. Show abstractHide abstract

Substantial phenotypic overlap exists between fragile X syndrome (FXS) and autism, suggesting that FMR1 (the gene causing FXS) poses a significant risk for autism. Cross-population comparisons of FXS and autism therefore offer a potentially valuable method for refining the range of phenotypes associated with variation in FMR1. This study adopted a broader phenotype approach, focusing on parents who are at increased genetic liability for autism or FXS. Women who were carriers of FMR1 in its premutation state were compared with mothers of individuals with autism, and controls in an attempt to determine whether subtle features of the broad autism phenotype may express at elevated rates among FMR1 premutation carriers. The principal personality and language features comprising the broad autism phenotype (i.e., rigid and aloof personality, and particular patterns of pragmatic language use) were assessed among 49 premutation carriers who were mothers of individuals with FXS, 89 mothers of individuals with autism, and 23 mothers of typically developing individuals. Relative to controls, the autism and premutation parent groups showed elevated rates of certain personality and language characteristics of the broad autism phenotype. Findings suggest partially overlapping personality and language profiles among autism and premutation parent groups, with rigid personality style and patterns of pragmatic language use emerging as features most clearly shared between groups. These results provide further evidence for the overlap of autism and FXS, and may implicate FMR1 in some of the subtle features comprising the broad autism phenotype.

Losh, M., Martin, G. E., Klusek, J., Hogan-Brown, A. L., & Sideris, J. (2012). Social communication and theory of mind in boys with autism and fragile x syndrome. Frontiers in Psychology, 3, 266. Show abstractHide abstract

Impairments in the social use of language, or pragmatics, constitute a core characteristic of autism. Problems with pragmatic language have also been documented in fragile X syndrome (FXS), a monogenic condition that is the most common known genetic cause of autism. Evidence suggests that social cognitive ability, or theory of mind, may also be impaired in both conditions, and in autism, may importantly relate to pragmatic language ability. Given the substantial overlap observed in autism and FXS, this study aimed to better define those social-communicative phenotypes that overlap in these two conditions by comparing pragmatic language ability and theory of mind in children with idiopathic autism and children with FXS, with and without autism, as well as children with Down syndrome and typically developing controls. We further examined correlations between these cognitive-behavioral phenotypes and molecular genetic variation related to the Fragile X Mental Retardation-1 gene (FMR1) in the FXS group. Results indicated that children with idiopathic autism and those with FXS and autism performed comparably on direct-assessment measures of pragmatic language and theory of mind, whereas those with FXS only did not differ from controls. Theory of mind was related to pragmatic language ability in all groups. Pragmatic language and theory of mind also correlated with genetic variation at the FMR1 locus (Cytosine-Guanine-Guanine repeats and percent methylation). These results point toward substantial overlap in the social and language phenotypes in autism and FXS and suggest a molecular genetic basis to these phenotypic profiles.


Journal Articles

Skinner, D., Choudhury, S., Sideris, J., Guarda, S., Buansi, A., Roche, M., Powell, C., & Bailey Jr, D. B. (2011). Parents' decisions to screen newborns for FMR1 gene expansions in a pilot research project. Pediatrics, 127(6), e1455-1463. Show abstractHide abstract

Objective. The goal of this study was to document rates of parental consent in a pilot study of newborn screening for FMR1 gene expansions, examine demographic characteristics of mothers who consented or declined, describe the reasons for their decision, and discuss ethical and social aspects of the consent process.
Methods. A brief survey was used to record basic demographic data from mothers and an open-ended question was used to elicit parents' reasons for accepting or declining screening. A descriptive analysis was conducted on the number of mothers who consented to or declined screening, and a logistic regression model predicted mothers' likelihood to agree to screening based on demographic characteristics. Reasons for decisions were analyzed using content analysis. The study was conducted at University of North Carolina Hospitals. A total of 2137 mothers were approached.
Results. The uptake rate for couples was 63%. Acceptance rates varied by race/ethnicity, with black respondents being less likely to accept screening. Primary reasons for accepting were "to know," "belief in research," and "the test was minimal/no risk." Reasons for declining included not wanting to know or worry, not being a good time, and issues with testing children or with genetic tests.
Conclusions. Findings demonstrate that a majority of parents accepted newborn screening for FMR1 gene expansions, but decision rates and reasons for accepting or declining varied in part as a function of race/ethnicity and in part as a function of what parents most valued or feared in their assessment of risks and benefits.

Estigarribia, B., Martin, G. E., Roberts, J. E., Spencer, A., Gucwa, A., & Sideris, J. (2011). Narrative skill in boys with fragile X syndrome with and without autism spectrum disorder. Applied Psycholinguistics, 32(2), 359-388. Show abstractHide abstract

We examined recalled narratives of boys with fragile X syndrome with autism spectrum disorder (FXS-ASD; N=28) and without ASD (FXS-O; N=29), and compared them to those of boys with Down syndrome (DS; N=33) and typically developing boys (TD; N=39). Narratives were scored for mentions of macrostructural Story Grammar elements (Introduction, Relationship, Initiating Events, Internal Response, Attempts/Actions, and Ending). We found that narrative recall is predicted by short-term memory and nonverbal mental age levels in almost all groups (except TD), but not by expressive syntax or caregiver education. After adjusting for these covariates, there were no differences between the three groups with intellectual disability (ID). The FXS-ASD group, however, had significantly poorer performance than the TD group on the overall Story Grammar score, and both the FXS-O and FXS-ASD groups had lower Attempts/Actions scores than the TD group. We conclude that some form of narrative impairment may be associated with FXS, that this impairment may be shared by other forms of ID, and that the presence of ASD has a significantly detrimental effect on narrative recall.

Estigarribia, B., Roberts, J. E., Sideris, J., & Price, J. (2011). Expressive morphosyntax in boys with Fragile X syndrome with and without autism spectrum disorder. International Journal of Language & Communication Disorders, 46(2), 216-230. Show abstractHide abstract

Background. Fragile X syndrome (FXS) is the most common inherited cause of intellectual disability, and the most common single gene disorder associated with autism. Language impairments in this disorder are well documented, but the nature and extent of syntactic impairments are still unclear.
Aims. To compare the performance of boys with FXS with and without autism spectrum disorder on measures of verb (VM) and noun (NM) morphosyntax with that of typically developing boys of similar non-verbal mental ages.
Methods & Procedures. Conversational samples were obtained from 33 boys with FXS with autism spectrum disorder (FXS-ASD), 35 boys with FXS and no ASD (FXS-O), and 46 typically developing boys (TD). Production of verbal and nominal morphosyntax was assessed separately in these two subdomains. A hierarchical linear model compared morphosyntactic scores in all groups after adjusting for non-verbal cognition, articulatory skill, and caregiver education. The model also tested interactions between group and morphosyntactic subdomain.
Outcomes & Results. Boys with FXS in both groups scored lower than the TD boys on both measures. The FXS-O and the FXS-ASD groups did not differ on either composite measure. All covariates were significantly related to morphosyntactic scores.
Conclusions & Implications. Part of the morphosyntactic impairment in FXS may be attributable to cognitive, environmental, and speech factors. However, it is clear that boys with FXS perform at levels lower than expected from differences in these extra-linguistic factors alone, across both the verb and the noun domains. Clinical interventions should therefore seek to address specific syntactic targets.


Journal Articles

Hooper, S. R., Roberts, J., Sideris, J., Burchinal, M., & Zeisel, S. (2010). Longitudinal predictors of reading and math trajectories through middle school for African American versus Caucasian students across two samples. Developmental Psychology, 46(5), 1018-1029. Show abstractHide abstract

This study's primary purpose was to examine the relative contribution of social-behavioral predictors to reading and math skills. The study expands on Duncan et al.'s (2007) work by using longitudinal methodology from the National Institute of Child Health and Human Development's Study of Child Care and Youth Development (SECCYD) and the Early Childhood Longitudinal Study, Kindergarten Class of 1998-1999 (ECLS-K) databases, and by focusing on potential differences in patterns of early predictors of later reading and math trajectories for African American versus Caucasian students. Predictor measures were selected at kindergarten, and the outcomes included standardized reading and math scores obtained from Grades 1, 3, 5, and 9 for the SECCYD sample, and Grades 3, 5, and 8 for the ECLS-K sample. Consistent with Duncan et al.'s findings, results reflect the relative contributions of early reading and math skills to later functioning in these respective academic domains for both samples, and there are indications for the importance of early expressive language skills to both reading and math in the SECCYD sample. Findings related to the power of social-behavioral predictors, however, are not consistent across samples. Although the SECCYD sample evidenced no such predictors, several interactions in the ECLS-K sample suggested the moderating effects of early ratings of aggressive behaviors and internalizing behaviors on later reading and math for African American students. The moderating effects of early teacher ratings of attention and internalizing behaviors for African American students as compared with Caucasian students in later math growth also were noted. The importance of early social-behavioral functions as related to later academic skills remains an important area of inquiry.

Wheeler, A. C., Hatton, D., Holloway, V. T., Sideris, J., Neebe, E. C., Roberts, J. E., & Reznick, J. S. (2010). Maternal responses to child frustration and requests for help in dyads with fragile X syndrome. Journal of Intellectual Disability Research, 54(6), 501-515. Show abstractHide abstract

Background. Variability in behaviour displayed by children with fragile X syndrome (FXS) may be partially attributable to environmental factors such as maternal responsivity. The purpose of this study was to explore variables associated with maternal behaviour during a task designed to elicit frustration in their children with FXS.
Methods. Forty-six mother-child dyads, in which the child had full-mutation FXS, were observed in their homes during a task designed to elicit frustration in the child. Each child was given a wrong set of keys and asked to open a box to retrieve a desired toy. Mothers were provided with the correct set of keys and instructed to intervene when they perceived their child was getting too frustrated. Child-expressed frustration and requests for help and maternal behaviours (comforting, negative control, and encouraging/directing) were observed and coded. Maternal variables (e.g. depression, stress, education levels), child variables (e.g. autistic behaviours, age, medication use) and child behaviours (frustration, requests for help) were explored as predictors of maternal behaviour.
Results. Almost all mothers intervened to help their children and most used encouraging/directing behaviours, whereas very few used comforting or negative control. Child age and child behaviours during the frustrating event were significant predictors of encouraging/directing behaviours in the mothers. Children whose mothers reported higher depressive symptomology used fewer requests for help, and mothers of children with more autistic behaviours used more negative control.
Conclusions. The results of this study suggest that child age and immediate behaviours are more strongly related to maternal responsivity than maternal traits such as depression and stress.

Boyd, B. A., Baranek, G. T., Sideris, J., Poe, M. D., Watson, L. R., Patten, E., & Miller, H. (2010). Sensory features and repetitive behaviors in children with autism and developmental delays. Autism Research, 3(2), 78-87. Show abstractHide abstract

This study combined parent and observational measures to examine the association between aberrant sensory features and restricted, repetitive behaviors in children with autism (N=67) and those with developmental delays (N=42). Confirmatory factor analysis was used to empirically validate three sensory constructs of interest: hyperresponsiveness, hyporesponsiveness, and sensory seeking. Examining the association between the three derived sensory factor scores and scores on the Repetitive Behavior Scales—Revised revealed the co-occurrence of these behaviors in both clinical groups. Specifically, high levels of hyperresponsive behaviors predicted high levels of repetitive behaviors, and the relationship between these variables remained the same controlling for mental age. We primarily found non-significant associations between hyporesponsiveness or sensory seeking and repetitive behaviors, with the exception that sensory seeking was associated with ritualistic/sameness behaviors. These findings suggest that shared neurobiological mechanisms may underlie hyperresponsive sensory symptoms and repetitive behaviors and have implications for diagnostic classification as well as intervention.


Journal Articles

Roberts, J. E., Mankowski, J. B., Sideris, J., Goldman, B. D., Hatton, D. D., Mirrett, P. L., Baranek, G. T., Reznick, J. S., Long, A. C., & Bailey Jr, D. B. (2009). Trajectories and predictors of the development of very young boys with fragile X syndrome. Journal of Pediatric Psychology, 34(8), 827-836. Show abstractHide abstract

Objective. To describe the development of young boys with fragile X syndrome (FXS).
Methods. Fifty-five boys (aged 8-48 months at study entry) with the full mutation FXS received multiple developmental assessments.
Results. As expected, the boys' rate of development was significantly lower than chronological age expectations. No evidence of slowing in the rate of development was found. Autistic behavior was negatively associated with development, but maternal IQ was not. Developmental delays were evident in some domains as early as 9 months; however, initial detection of delays is complicated by measures and criteria used. Developmental age scores at 31 months of age were related to scores obtained at 61 months of age only in the global composite and visual reception domain.
Conclusions. Developmental delays are evident in some infants with FXS as young as 9 months of age. Pediatric psychologists need to be informed about the developmental profiles in young children with FXS to accurately diagnose, treat, and support these children and their families.

Barnes, E., Roberts, J., Long, S. H., Martin, G. E., Berni, M. C., Mandulak, K. C., & Sideris, J. (2009). Phonological accuracy and intelligibility in connected speech of boys with fragile X syndrome or Down syndrome. Journal of Speech, Language, and Hearing Research, 52, 1048-1061. Show abstractHide abstract

Purpose. To compare the phonological accuracy and speech intelligibility of boys with fragile X syndrome with autism spectrum disorder (FXS-ASD), fragile X syndrome only (FXS-O), Down syndrome (DS), and typically developing (TD) boys.
Method. Participants were 32 boys with FXS-O (3-14 years), 31 with FXS-ASD (5-15 years), 34 with DS (4-16 years), and 45 TD boys of similar nonverbal mental age. We used connected speech samples to compute measures of phonological accuracy, phonological process occurrence, and intelligibility.
Results. The boys with FXS, regardless of autism status, did not differ from TD boys on phonological accuracy and phonological process occurrence but produced fewer intelligible words than did TD boys. The boys with DS scored lower on measures of phonological accuracy and occurrence of phonological processes than all other groups and used fewer intelligible words than did TD boys. The boys with FXS and the boys with DS did not differ on measures of intelligibility.
Conclusions. Boys with FXS, regardless of autism status, exhibited phonological characteristics similar to those of younger TD children but were less intelligible in connected speech. Boys with DS showed greater delays in all phonological measures than the boys with FXS and the TD boys.

Hatton, D. D., Wheeler, A., Sideris, J., Sullivan, K., Reichardt, A., Roberts, J., Clark, R., & Bailey Jr, D. B. (2009). Developmental trajectories of young girls with fragile X syndrome. American Journal on Intellectural and Developmental Disabilities, 114(3), 161-171. Show abstractHide abstract

To describe the early phenotype of girls with full mutation fragile X, we used 54 observations of 15 girls between the ages of 6 months and 9 years to examine developmental trajectories as measured by the Battelle Development Inventory. In this sample, autistic behavior was associated with poorer developmental outcomes, primarily due to interactions of age with autistic behavior, even though autistic behavior, measured continuously, was relatively mild. Although this small sample, ascertained primarily through male relatives with fragile X syndrome, limits generalizability, considerable variability in developmental outcome in young girls was documented. In addition, findings support previous research suggesting that even mild autistic behaviors in girls can be associated with developmental outcomes.

Roberts, J. E., Bailey Jr, D. B., Mankowski, J., Ford, A., Sideris, J., Weisenfeld, L. A., Heath, T. M., & Golden, R. N. (2009). Mood and anxiety disorders in females with the FMR1 premutation. American Journal of Medical Genetics: Part B, Neuropsychiatric Genetics, 150B(1), 130-139. Show abstractHide abstract

Fragile X syndrome (FXS) is a model for studying the relative contributions of genetic and environmental factors to psychiatric disorders in mothers of children with disabilities. Here, we examine the frequency and predictors of mood and anxiety disorders in mothers with the FMR1 premutation. Ninety-three females with the FMR1 premutation were in the study and were compared to 2,159 women from the National Comorbidity Survey Replication (NCS-R) dataset. Mood and anxiety disorders were assessed using the SCID-I. Our data reflect elevated lifetime major depressive disorder (MDD), lifetime panic disorder without agoraphobia and current agoraphobia without panic disorder in the FMR1 premutation sample. Also, we found a low frequency of lifetime social phobia, specific phobia, and post-traumatic stress disorders and current specific phobia in the FMR1 premutation sample. The profile of MDD in the FMR1 premutation sample was not episodic or comorbid with an anxiety disorder, as in the NCS-R dataset. Never having been married and smaller CGG repeat length were associated with increased likelihood of MDD while increased children with FXS in the family and greater child problem behaviors were associated with increased likelihood of an anxiety disorder in the FMR 1 premutation group. Major depression in females with the FMR1 premutation may not be characterized as an episodically chronic recurrent disorder as it is in community samples and may have a genetic basis given the relationship with CGG repeat length and lack of association with all child and most demographic factors.


Journal Articles

Bailey Jr, D. B., Sideris, J., Roberts, J., & Hatton, D. (2008). Child and genetic variables associated with maternal adaptation to fragile X syndrome: A multidimensional analysis. American Journal of Medical Genetics: Part A, 146A(6), 720-729. Show abstractHide abstract

One hundred eight carrier mothers (95 premutation, 13 full mutation) of children with the full mutation fragile X syndrome completed seven scales to assess maternal stress, depressive symptoms, anger, anxiety, quality of life, hope, and optimism. A wide range of responses was found on each measure, with most mothers scoring in the non-clinical range on any individual measure. However, nearly half of the mothers scored in the clinically significant range on at least one measure and 25% on two or more measures. High stress and low quality of life were the most common domains of concern. Mothers with the full mutation generally did not differ from mothers with the premutation. CGG repeat length was not associated with responses on any of the measures completed by mothers with the premutation. Severity of the child's delay was not associated with any of the outcome measures, but child behavior problems accounted for significant variance in stress, depressive symptoms, anxiety, anger, and quality of life. Maternal adaptation appears to be a multidimensional phenomenon experienced in unique ways by each mother. Most mothers experienced positive adaptation, but a subset appear to be more vulnerable, especially those with children who have significant behavior problems. Future research needs to identify family, child, and support factors associated with maternal vulnerability and how adaptation changes over time in response to these factors.

Price, J. R., Roberts, J. E., Hennon, E. A., Berni, M. C., Anderson, K. L., & Sideris, J. (2008). Syntactic complexity during conversation of boys with fragile X syndrome and Down syndrome. Journal of Speech, Language, and Hearing Research, 51, 3-15. Show abstractHide abstract

Purpose. This study compared the syntax of boys who have fragile X syndrome (FXS) with and without autism spectrum disorder (ASD) with that of (a) boys who have Down syndrome (DS) and (b) typically developing (TD) boys.
Method. Thirty-five boys with FXS only, 36 boys with FXS with ASD, 31 boys with DS, and 46 TD boys participated. Conversational language samples were evaluated for utterance length and syntactic complexity (i.e., Index of Productive Syntax; H. S. Scarborough, 1990).
Results. After controlling for nonverbal mental age and maternal education levels, the 2 FXS groups did not differ in utterance length or syntactic complexity. The FXS groups and the DS group produced shorter, less complex utterances overall and less complex noun phrases, verb phrases, and sentence structures than did the TD boys. The FXS with ASD group and the DS group, but not the FXS-only group, produced less complex questions/negations than did the TD group. Compared with the DS group, both FXS groups produced longer, more complex utterances overall, but on the specific complexity measures, they scored higher only on questions/negations.
Conclusion. Boys with FXS and DS have distinctive language profiles. Although both groups demonstrated syntactic delays, boys with DS showed greater delays.

Hooper, S. R., Hatton, D., Sideris, J., Sullivan, K., Hammer, J., Schaaf, J., Mirrett, P., Ornstein, P. A., & Bailey Jr, D. B. (2008). Executive functions in young males with fragile X syndrome in comparison to mental age-matched controls: Baseline findings from a longitudinal study. Neuropsychology, 22(1), 36-47. Show abstractHide abstract

The performance of 54 boys with fragile X syndrome (FXS), ages 7 to 13 years, was compared to that of a group of typically developing boys who were matched on mental age (MA) and ethnicity across multiple measures of executive function (EF). Boys with FXS varied in their ability to complete EF measures, with only 25.9% being able to complete a set-shifting task and 94.4% being able to complete a memory for word span task. When compared to the control group, and controlling for MA and maternal education, boys with FXS showed significant deficits in inhibition, working memory, cognitive flexibility/set-shifting, and planning. No group differences were observed in processing speed. Mental age significantly impacted performance on working memory, set-shifting, planning, and processing speed tasks for both groups. In boys with FXS, MA significantly predicted performance on working memory and set-shifting tasks. Our findings suggest that deficits in EF in boys with FXS are not solely attributable to developmental delays but, rather, present as a true array of neurocognitive deficits.

Baranek, G. T., Roberts, J. E., David, F. J., Sideris, J., Mirrett, P. L., Hatton, D. D., & Bailey Jr, D. B. (2008). Developmental trajectories and correlates of sensory processing in young boys with fragile X syndrome. Physical & Occupational Therapy in Pediatrics, 28(1), 79-98. Show abstractHide abstract

Background and Purpose. No longitudinal study on sensory processing in children with fragile X syndrome (FXS) exists. This study examined developmental trajectories and correlates of sensory processing from infancy through preschool years in 13 boys with FXS.
Method. Participants were assessed using observational and parent-report measures 2-6 times between 9 and 54 months of age.
Results. Over time, an increasing proportion of boys displayed sensory processing that differed significantly from test norms. Observational measures were more sensitive than parent-reports early in infancy. Age and developmental quotient significantly predicted levels of hyporesponsiveness; there was a trend for hyperresponsiveness to increase with age. Baseline physiological and biological measures were not predictive.
Conclusions. Sensory processing problems are observable early and grow increasingly problematic from infancy through the preschool ages. Early identification and intervention may attenuate long-term difficulties for children with FXS.


Journal Articles

Sullivan, K., Hatton, D. D., Hammer, J., Sideris, J., Hooper, S., Ornstein, P. A., & Bailey Jr, D. B. (2007). Sustained attention and response inhibition in boys with fragile X syndrome: Measures of continuous performance. American Journal of Medical Genetics: Part B, Neuropsychiatric Genetics, 144B(4), 517-532. Show abstractHide abstract

Sustained attention and response inhibition were examined in boys with full mutation fragile X syndrome (FXS) using adapted visual and auditory continuous performance tests (CPTs). Only 61% of 56 boys with visual CPT data and 54% of 52 boys with auditory data were able to demonstrate sufficient understanding to complete the visual and auditory CPTs, respectively. Mental age (MA) predicted whether boys with FXS were able to demonstrate understanding of the CPTs. The performance of boys with FXS who were able to complete the CPTs was compared to a sample of boys without disabilities matched on MA. Boys with FXS demonstrated similar or smaller declines in sustained attention over task time than their MA-matched peers on the visual and auditory CPTs, respectively, but consistently demonstrated greater declines in response inhibition over task time than their MA-matched peers. There were no differences between groups for response time of hits. Higher MAs consistently predicted better sustained attention and response inhibition over task time on the visual and auditory CPTs. Furthermore, boys taking psychotropic medication performed better at the beginning of most tasks, although their performance deteriorated at a faster rate over time, and boys rated as meeting diagnostic criteria for ADHD-hyperactive type had more difficulty over task time with response inhibition on the auditory CPT. For both boys with FXS and their MA matches, performance was better on the visual CPT than on the auditory CPT though this effect may be attributable to a number of factors other than the modality.


Journal Articles

Sullivan, K., Hatton, D., Hammer, J., Sideris, J., Hooper, S., Ornstein, P., & Bailey Jr, D. (2006). ADHD symptoms in children with FXS. American Journal of Medical Genetics: Part A, 140A(21), 2275-2288. Show abstractHide abstract

Parent- and teacher-report of attention-deficit/hyperactivity disorder (ADHD) symptoms were examined using problem behavior and DSM-IV symptom inventory questionnaires for 63 children with full mutation fragile X syndrome (FXS) and 56 children without disabilities matched on mental age (MA). Prevalence rates of ADHD symptoms varied depending on type of measure (problem behavior or DSM-IV criteria), subscale (ADHD-inattentive or ADHD-hyperactive), scoring method (continuous T-scores or categorical scores based on DSM-IV algorithm), and rater (parent or teacher). Overall, 54-59% of boys with FXS met diagnostic behavioral criteria for either ADHD-inattentive type only, ADHD-hyperactive type only, or ADHD-combined type based on parent or teacher report. Boys with FXS were rated as having clinically high scores or met diagnostic criteria at higher rates than expected for the general population and had higher raw scores than their MA-matched peers. Parent ratings of boys with FXS resulted in higher ADHD-inattentive type and ADHD-hyperactive type T-scores than teachers. Boys who were rated as meeting DSM-IV criteria were more likely to be taking psychotropic medication and to have younger mental ages. Parents were substantially more likely than teachers to rate boys as meeting DSM-IV criteria for ADHD-inattentive type, while teachers were only slightly more likely than parents to rate boys as meeting DSM-IV criteria for ADHD-hyperactive type. Teachers were more likely than parents to rate boys as meeting DSM-IV criteria for ADHD when boys had lower levels of FMRP.

Hatton, D. D., Sideris, J., Skinner, M., Mankowski, J., Bailey Jr, D. B., Roberts, J., & Mirrett, P. (2006). Autistic behavior in children with fragile X syndrome: Prevalence, stability, and the impact of FMRP. American Journal of Medical Genetics: Part A, 140A(17), 1804-1813. Show abstractHide abstract

We examined autistic behavior in a cross-sectional sample of 179 children with fragile X syndrome (FXS) and a longitudinal subset of 116 children using the Childhood Autism Rating Scale (CARS) to (a) determine a prevalence of autistic behavior in FXS, (b) examine the stability of autistic ratings over time, and (c) assess the association between the fragile X mental retardation protein (FMRP) and autistic behavior. Approximately 21% of the sample of 129 children (25.9% of boys) scored at or above the cutoff for autism. CARS scores increased slowly, yet significantly, over time, and low levels of FMRP were associated with higher mean levels of autistic behavior as measured by the CARS.

Barnes, E. F., Roberts, J., Mirrett, P., Sideris, J., & Misenheimer, J. (2006). A comparison of oral structure and oral-motor function in young males with fragile X syndrome and Down syndrome. Journal of Speech, Language, and Hearing Research, 49, 903-917. Show abstractHide abstract

This study compared the oral structure and oral-motor skills of 59 boys with fragile X syndrome (FXS), 34 boys with Down syndrome (DS), and 36 developmentally similar typically developing (TD) boys. An adaptation of the J. Robbins and T. Klee (1987) Oral Speech Motor Protocol was administered to participants and their scores on measures of oral structure and accuracy on speech motor and oral-motor tasks were analyzed. Boys with FXS scored lower than TD boys on oral structure, most oral function tasks, and all speech function tasks. Boys with DS scored lower than boys with FXS and TD boys on oral structure, and lower than TD boys on 1 oral function task and all speech function tasks. Boys with FXS and TD boys scored higher on speech function than oral function tasks, while boys with DS scored higher on oral function than speech function tasks. Boys with FXS and boys with DS repeated single syllable words with greater accuracy than multiple syllable words, while the TD boys produced both types of words with equal accuracy. These results suggest that boys with FXS and boys with DS exhibit atypical oral structure and motor function, yet differ in specific oral-motor patterns.

Roberts, J. E., Boccia, M. L., Hatton, D. D., Skinner, M. L., & Sideris, J. (2006). Temperament and vagal tone in boys with fragile X syndrome. Journal of Developmental & Behavioral Pediatrics, 27(3), 193-201. Full text Show abstractHide abstract

Physiological hyperarousal, an elevated state of physiological arousal and poor modulation, has been postulated to be a significant source of behavior problems in children with fragile X syndrome (FXS). Temperament has been associated with behavior problems and may also reflect biological reactivity. Young boys with FXS display poorly modulated and low levels of vagal tone (Roberts, Dev Psychobiol 2001;39:107-123) and high activity, poor attention, low adaptability, poor persistence, and low intensity when compared with a reference sample of typically developing (Hatton, Dev Med Child Neurol 1991;41:625-632). In this study, we integrated physiological indices of vagal tone with temperament ratings and compared a sample of 29 young boys with FXS to 31 typically developing boys matched on chronological age and ethnicity. Boys with FXS were more active, less adaptable, and less persistent than the comparison group. Boys with FXS also showed lower baseline levels and less suppression of vagal tone in response to changing task demands. A relationship between baseline vagal tone and persistence was shown across both groups. However, group differences in temperament dimensions did not appear to be mediated or moderated by vagal tone.


Research Reports

McWilliam, R. A., Tocci, L., Sideris, J., & Harbin, G. L. (1998, March). Using and providing services: Case studies in early intervention [Early Childhood Research Institute on Service Utilization] (ED 417 509). Chapel Hill, NC: Frank Porter Graham Child Development Center. Full text Show abstractHide abstract

A case study approach was used to examine the complexities of service utilization in early intervention with infants, toddlers, and young children with disabilities. Seventy-two families of children (ages birth to 4) participating in nine early intervention programs in three states (Colorado, North Carolina, and Pennsylvania) and their service providers completed a self-report questionnaire and were interviewed. In addition, documents (the Individualized Family Service Plan or the Individualized Education Program and the latest assessment report) were analyzed. Results are reported in terms of families' service use and professionals' provision of services, including family characteristics, family-service provider relationships, African American mothers, support families received, families' reflections, and service providers' reflections. Overall, findings suggest that professionals' provision of services reflects: (1) a predominant child versus family orientation; (2) a generally positive approach to families; (3) a disjointed and segregated way of working with other professionals; (4) reasonably effective coordination of existing services; (5) poor provision of information about resources outside the formal early intervention/preschool programs; (6) a heavy reliance on therapists; and (7) dependence on direct, hands-on treatment for short periods.

Harbin, G. L., McWilliam, R. A., Shaw, D., Buka, S. L., Sideris, J., Kochaek, T. T., Gallagher, J. J., Tocci, L., West, T., & Clark, K. (1998, March). Implementing federal policy for young children with disabilities: How are we doing? [Early Childhood Research Institute on Service Utilization] (ED 417 527). Chapel Hill, NC: Frank Porter Graham Child Development Center. Full text Show abstractHide abstract

This report presents the findings of a study that investigated the scope and nature of early childhood service delivery systems in three states (Pennsylvania, North Carolina, and Colorado). The study followed 75 children with disabilities for 18 months and surveyed 170 service providers of infants and toddlers and 186 service providers of preschool children. Findings from the study indicate: (1) utilization of infant and toddler and preschool services is high, particularly in comparison to the utilization rates of other federal entitlement programs; (2) percentages of children served indicate that not all eligible children are being served; (3) the average amount of specialized intervention services provided to infants and toddlers is 1.7 hours a week, while preschool children receive an average of 18 hours if they are in segregated settings, and 11 hours if they are in inclusive settings; (4) most systems have failed to put together a sufficient array of services to address the diverse needs of both the child and the family; (5) a significant proportion of the services occur in inclusive settings; and (6) better service outcomes for children and their families occurred in the more comprehensive and coordinated service delivery models.


Research Reports

Tocci, L., McWilliam, R. A., Sideris, J., & Melton, S. (1997, September). Families' reflections on their experiences with early intervention services [Early Childhood Research Institute: Service utilization findings] (ED 412 671). Chapel Hill, NC: Frank Porter Graham Child Development Center. Full text Show abstractHide abstract

Seventy-five families of children with special needs were interviewed after one year's experience with early intervention services and 69 of these families were then re-interviewed a year later after two years of such services. Five themes were identified in the families' views of "what works well." These were: (1) consistency of staff, (2) home visits, (3) programs providing financial support, (4) professionals who support parents and respond to their needs, and (5) professionals who show parents how developmental play stimulates the child's development. Suggestions from parents for other parents and service providers stressed the following: parents need to fight for services and advocate for their child; parents should get involved in an early intervention program as soon as possible; parents want information; parents value support from and connection with other parents; and parents need to take care of themselves emotionally. Other findings indicated that parents experience a somewhat fragmented service system, which requires that they learn different rules for dealing with different subsystems (e.g., social services, education).


Journal Articles

Pyszczynski, T., Greenberg, J., Solomon, S., Cather, C., Gat, I., & Sideris, J. (1995). Defensive distancing from victims of serious illness: The role of delay. Personality and Social Psychology Bulletin, 21(1), 13-20. Show abstractHide abstract

Defensive distancing from victims of serious illness was investigated by providing subjects with personality profiles of a target person who had either a serious life-threatening illness (stomach cancer) or a less serious health problem (sprained ankle). Either immediately after learning of the target person's illness or after a 3-min delay, subjects rated themselves on the same set of personality traits. A significant Illness x Delay interaction was found on a composite measure of distancing from the victim. Subjects distanced themselves from the cancer victim by rating their own personalities as discrepant from this person in the delay but not in the immediate condition. Immediate but not delay subjects indicated greater liking for the cancer victim than the sprained ankle victim. Theoretical and practical implications are discussed.


Journal Articles

Pyszczynski, T., Greenberg, J., Solomon, S., Sideris, J., & Stubing, M. J. (1993). Emotional expression and the reduction of motivated cognitive bias: Evidence from cognitive dissonance and distancing from victims' paradigms. Journal of Personality and Social Psychology, 64(2), 177-186. Full text Show abstractHide abstract

Two experiments tested whether expression of emotions from which motivated cognitive biases presumably provide protection would reduce the extent of such biases. In Study I, we hypothesized that expressing any tension produced by writing a counterattitudinal essay would reduce the extent of dissonance-reducing attitude change. To test this hypothesis, Ss were induced to write an essay arguing for higher tuition. High-choice Ss were either encouraged to express their emotions, to suppress them, or to do neither. As expected, high-choice-express Ss exhibited the least attitude change. Study 2 tested the hypothesis that expressing fear of cancer would reduce the extent of defensive distancing from cancer patients, but expressing sympathy would not. Although control Ss clearly distanced from cancer patients, fear-expression Ss did not. Implications for understanding the role of affect in defense are discussed.