Biomedical subjects

Sally Ozonoff

Publications and source records attributed to Sally Ozonoff.

17 recordsLinked to original sources

PubMed2007

Quantitative temporal lobe differences: autism distinguished from controls using classification and regression tree analysis.

The temporal lobe is thought to be abnormal in autism, yet standard volumetric analyses are often unrevealing when age, sex, IQ, and head size are controlled. Quantification of temporal lobe structures were obtained in male subjects with autism and controls, where subjects with head circumference (HC) defined macrocephaly were excluded, so that volume differences were not just related to the higher prevalence of macrocephaly in autism. Various statistical methods were applied to the analysis including a classification and regression tree (CART) method, a non-parametric technique that helps define patterns of relationships that may be meaningful in distinguishing temporal lobe differences between subjects with autism and age and IQ matched controls. Subjects with autism were also compared to a separate control group with reading disorder (RD), with the prediction that the temporal lobe morphometric analysis of the reading disorder controls would be more similar to that of the autism group. The CART method yielded a high specificity in classifying autism subjects from controls based on the relationship between the volume of the left fusiform gyrus (LFG) gray and white matter, the right temporal stem (RTS) and the right inferior temporal gyrus gray matter (RITG-GM). Reading disordered individuals were more similar to subjects with autism. Simple size differences did not distinguish the groups. These findings demonstrate different relationships within temporal lobe structures that distinguish subjects with autism from controls. Results are discussed in terms of pathological connectivity within the temporal lobe as it relates to autism.

Adolescent↗

PubMed2006

Visual Fixation Patterns during Reciprocal Social Interaction Distinguish a Subgroup of 6-Month-Old Infants At-Risk for Autism from Comparison Infants.

Thirty-one infant siblings of children with autism and 24 comparison infants were tested at 6 months of age during social interaction with a caregiver, using a modified Still Face paradigm conducted via a closed-circuit TV-video system. In the Still Face paradigm, the mother interacts with the infant, then freezes and displays a neutral, expressionless face, then resumes interaction. Eye tracking data on infant visual fixation patterns were recorded during the three episodes of the experiment. Using a hierarchical cluster analysis, we identified a subgroup of infants demonstrating diminished gaze to the mother's eyes relative to her mouth during the Still Face episode. Ten out of the 11 infants in this subgroup had an older sibling with autism.

Affect↗

PubMed2006

Head circumference and height in autism: a study by the Collaborative Program of Excellence in Autism.

Data from 10 sites of the NICHD/NIDCD Collaborative Programs of Excellence in Autism were combined to study the distribution of head circumference and relationship to demographic and clinical variables. Three hundred thirty-eight probands with autism-spectrum disorder (ASD) including 208 probands with autism were studied along with 147 parents, 149 siblings, and typically developing controls. ASDs were diagnosed, and head circumference and clinical variables measured in a standardized manner across all sites. All subjects with autism met ADI-R, ADOS-G, DSM-IV, and ICD-10 criteria. The results show the distribution of standardized head circumference in autism is normal in shape, and the mean, variance, and rate of macrocephaly but not microcephaly are increased. Head circumference tends to be large relative to height in autism. No site, gender, age, SES, verbal, or non-verbal IQ effects were present in the autism sample. In addition to autism itself, standardized height and average parental head circumference were the most important factors predicting head circumference in individuals with autism. Mean standardized head circumference and rates of macrocephaly were similar in probands with autism and their parents. Increased head circumference was associated with a higher (more severe) ADI-R social algorithm score. Macrocephaly is associated with delayed onset of language. Although mean head circumference and rates of macrocephaly are increased in autism, a high degree of variability is present, underscoring the complex clinical heterogeneity of the disorder. The wide distribution of head circumference in autism has major implications for genetic, neuroimaging, and other neurobiological research.

Adolescent↗

PubMed2006

Autism and family home movies: a comprehensive review.

In this article, we focus on the early development of autism studied through family home movies. We review all investigations published in English that met specific methodological standards, including the use of comparison samples, coding blind to group membership, and adequate levels of interrater reliability. After discussing in detail the pros and cons of the home-movie methodology, we review the results of all empirical studies conducted to date. We then present a summary of the features found consistently across studies that differentiate autism from typical development and mental retardation in the first 2 years of life. How family home movies can contribute to our understanding of the regression phenomenon is also addressed. Finally, the results are interpreted from both a theoretical and clinical point of view.

Autistic Disorder↗

PubMed2005

Repetitive behavior profiles in Asperger syndrome and high-functioning autism.

Although repetitive behaviors are a core diagnostic domain for autism spectrum disorders, research in this area has been neglected. This study had two major aims: (1) to provide a detailed characterization of repetitive behaviors in individuals with Asperger Syndrome (AS), high-functioning autism (HFA), and typically developing controls (TD); and (2) to examine whether differences in repetitive behavior profiles could provide evidence for the external validity of AS separate from HFA. Specifically, it was hypothesized that circumscribed interests would be more prevalent and cause more impairment in the AS group than the HFA group, while the reverse would be true for other categories of repetitive behavior. The parent(s) of 61 children and adolescents (19 with AS, 21 with HFA, and 21 TD) completed two interviews focused specifically on lifetime and current repetitive behavior symptoms. No reliable differences in repetitive behavior between AS and HFA children were found. Results suggested that circumscribed interests differ in developmental course from the three other DSM-IV-TR categories of repetitive behavior. Internal consistency among the four DSM-IV-TR categories of repetitive behavior was high, alpha = .84, providing evidence for a unitary repetitive behaviors factor. The importance of expanding research in the repetitive behavior domain is highlighted as part of the necessary integration of behavioral and neurobiological approaches to understanding the etiology of autism.

Adolescent↗

PubMed2005

Examining the relationship between executive functions and restricted, repetitive symptoms of Autistic Disorder.

The executive function theory was utilized to examine the relationship between cognitive process and the restricted, repetitive symptoms of Autistic Disorder (AD). Seventeen adults with AD were compared to 17 nonautistic controls on a new executive function battery (Delis-Kaplin Executive Function Scales). Restricted, repetitive symptoms were measured by a variety of instruments (i.e., the Autism Diagnostic Observation Schedule, Autism Diagnostic Interview-Revised, Gilliam Autism Rating Scale, and the Aberrant Behavior Checklist). The study replicated the executive function profile that has been reported in adults with AD. In addition to the replication findings, the study found several executive processes (i.e., cognitive flexibility, working memory, and response inhibition) were highly related to the restrictive, repetitive symptoms of AD; whereas, other executive process (i.e., planning and fluency) were not found to be significantly correlated with restricted, repetitive symptoms. Similarly, we found an executive function model consisting of relative strengths and deficits was the best predictor of restricted, repetitive symptoms of autism. The implications for the executive function theory and how the theory predicts core symptoms of autism are discussed.

Adolescent↗

PubMed2005

Annotation: what do we know about sensory dysfunction in autism? A critical review of the empirical evidence.

BACKGROUND: Unusual responses to sensory stimuli are seen in many children with autism. Their presence was highlighted both in early accounts of autism and in more recent first-person descriptions. There is a widespread belief that sensory symptoms characterize autism and differentiate it from other disorders. This paper examines the empirical evidence for this assumption. METHOD: All controlled experimental laboratory investigations published since 1960 were identified through systematic searches using Medline/PubMed and PsycInfo search engines. A total of 48 empirical papers and 27 theoretical or conceptual papers were reviewed. RESULTS: Sensory symptoms are more frequent and prominent in children with autism than in typically developing children, but there is not good evidence that these symptoms differentiate autism from other developmental disorders. Certain groups, including children with fragile X syndrome and those who are deaf-blind, appear to demonstrate higher rates of sensory symptoms than children with autism. In reviewing the evidence relevant to two theories of sensory dysfunction in autism, over- and under-arousal theory, we find that there is very little support for hyper-arousal and failure of habituation in autism. There is more evidence that children with autism, as a group, are hypo-responsive to sensory stimuli, but there are also multiple failures to replicate findings and studies that demonstrate lack of group differences. CONCLUSIONS: The use of different methods, the study of different sensory modalities, and the changing scientific standards across decades complicate interpretation of this body of work. We close with suggestions for future research in this area.

Arousal↗

PubMed2005

Macrocephaly, corpus callosum morphology, and autism.

Although the cause of autism is undetermined, a general consensus has been that some type of early aberrant neural development underlies the disorder. Given the increased prevalence of macrocephaly in autism, one theory of abnormal neural development implicates early brain growth resulting in larger brain and head size in autism. Surface area measurements of the midsagittal section of the corpus callosum can be used as an index of neural development and white-matter integrity because the corpus callosum is the major white-matter structure that interconnects the two cerebral hemispheres. The purpose of this study was to obtain corpus callosum surface area, shape, and contour in a sample of non-mentally retarded autistic subjects with macrocephaly (n = 12) and compare them with those of matched (n = 8), typically developing control subjects with benign macrocephaly. No significant differences were found in surface area, shape, or contour between groups, nor did corpus callosum surface area relate to measures of IQ or picture vocabulary. These findings suggest no unique difference in overall regional corpus callosum surface area in autism with macrocephaly.

Adolescent↗

PubMed2005

MMPI-2 personality profiles of high-functioning adults with autism spectrum disorders.

The Minnesota Multiphasic Personality Inventory-Second Edition was administered to 20 adults with autism spectrum disorders (ASD) who fell in the average to above average range of intelligence and 24 age-, intelligence-, and gender-matched college students. Large group differences, with the ASD group scoring higher, were found on the L validity scale, Clinical Scales 2 (D) and 0 (Si), Content scale Social Discomfort (SOD), Supplementary scale Repression (R), and Personality Psychopathology Five (PSY-5) scale INTR (Introversion). The proportion of ASD adults scoring in the clinical range on these scales was between 25% and 35%. High scores on these scales are consistent with the clinical picture of Asperger syndrome and high-functioning autism in adulthood. Future directions and implications for identifying adults in need of a specialized autism assessment are discussed.

Adolescent↗

PubMed2005

Parental report of the early development of children with regressive autism: the delays-plus-regression phenotype.

Most children with autism demonstrate developmental abnormalities in their first year, whereas others display regression after mostly normal development. Few studies have examined the early development of the latter group. This study developed a retrospective measure, the Early Development Questionnaire (EDQ), to collect specific, parent-reported information about development in the first 18 months. Based on their EDQ scores, 60 children with autism between the ages of 3 and 9 were divided into three groups: an early onset group (n = 29), a definite regression group (n = 23), and a heterogeneous mixed group (n = 8). Significant differences in early social development were found between the early onset and regression groups. However, over 50 percent of the children who experienced a regression demonstrated some early social deficits during the first year of life, long before regression and the apparent onset of autism. This group, tentatively labeled 'delays-plus-regression', deserves further study.

Autistic Disorder↗

PubMed2005

Evidence-based assessment of autism spectrum disorders in children and adolescents.

This article reviews evidence-based criteria that can guide practitioners in the selection, use, and interpretation of assessment tools for autism spectrum disorders (ASD). As Mash and Hunsley (2005) discuss in this special section, evidence-based assessment tools not only demonstrate adequate psychometric qualities, but also have relevance to the delivery of services to individuals with the disorder (see also Hayes, Nelson, & Jarrett, 1987). Thus, we use what is known about the symptoms, etiologies, developmental course, and outcome of ASD to evaluate the utility of particular assessment strategies and instruments for diagnosis, treatment planning and monitoring, and evaluation of outcome. The article begins with a review of relevant research on ASD. Next we provide an overview of the assessment process and some important issues that must be considered. We then describe the components of a core (minimum) assessment battery, followed by additional domains that might be considered in a more comprehensive assessment. Domains covered include core autism symptomatology, intelligence, language, adaptive behavior, neuropsychological functions, comorbid psychiatric illnesses, and contextual factors (e.g., parent well-being, family functioning, quality of life). We end with a discussion of how well the extant literature meets criteria for evidence-based assessments.

Achievement↗

PubMed2004

Performance on Cambridge Neuropsychological Test Automated Battery subtests sensitive to frontal lobe function in people with autistic disorder: evidence from the Collaborative Programs of Excellence in Autism network.

Recent structural and functional imaging work, as well as neuropathology and neuropsychology studies, provide strong empirical support for the involvement of frontal cortex in autism. The Cambridge Neuropsychological Test Automated Battery (CANTAB) is a computer-administered set of neuropsychological tests developed to examine specific components of cognition. Previous studies document the role of frontal cortex in performance of two CANTAB subtests: the Stockings of Cambridge, a planning task, and the Intradimensional/Extradimensional Shift task, a measure of cognitive set shifting. To examine the integrity of frontal functions, these subtests were administered to 79 participants with autism and 70 typical controls recruited from seven universities who are part of the Collaborative Programs of Excellence in Autism network. The two groups were matched on age, sex, and full-scale IQ. Significant group differences were found in performance on both subtests, with the autism group showing deficits in planning efficiency and extradimensional shifting relative to controls. Deficits were found in both lower- and higher-IQ individuals with autism across the age range of 6 to 47 years. Impairment on the CANTAB executive function subtests did not predict autism severity or specific autism symptoms (as measured by the ADI-R and ADOS), but it was correlated with adaptive behavior. If these CANTAB subtests do indeed measure prefrontal function, as suggested by previous research with animals and lesion patients, this adds to the accumulating evidence of frontal involvement in autism and indicates that this brain region should remain an active area of investigation.

Adolescent↗

PubMed2003

Social skills interventions for the autism spectrum: essential ingredients and a model curriculum.

This article outlines the ingredients the authors feel are critical to making social skills interventions successful for children with autism spectrum disorders. The authors described basic principles for teaching social skills that capitalize on the strengths of such children, while specifically addressing their deficits. The authors applied these widely used principles to group social skills intervention. In particular, social skills groups for children with ASD need to break down complex social behaviors into concrete steps and rules that can be memorized and practiced in a variety of settings. Abstract concepts must be made concrete through a variety of visual, tangible, "hands-on" activities that make socialization fun. Visual structure and predictable routines are essential. Also critical to the success of social skills intervention are instruction and activities that provide necessary support for the language abilities of the participants. A variety of learning opportunities must be used to teach the goals and skills most relevant to children with ASD. These skills must be integrated as intervention progresses. Furthermore, interactions that require the children to focus on peers create a positive social group culture. Within this culture and environment, self-awareness and positive self-esteem can be fostered. A behavior plan that specifies individual goals for group members and a specific system for delivering rewards should be included. Other important ingredients include generalization, which is encouraged through community outings, skill practice in more naturalistic settings, and collaboration with parents and teachers to work on skills outside the group intervention. Weekly therapy does little to change basic deficits of ASD unless there is daily practice and reinforcement of the skills being learned in more natural situations. The authors hope that outlining these principles and specific techniques will encourage more clinicians to offer social skills groups and thus increase their availability around the nation and world. Continued research and treatment for social skills is necessary to provide much needed empiric evidence to determine effectiveness of such interventions.

Adolescent↗

PubMed2003

Brief report: pitocin induction in autistic and nonautistic individuals.

Oxytocin plays an important role in social-affiliative behaviors. It has been proposed that exposure to high levels of exogenous oxytocin at birth, via pitocin induction of delivery, might increase susceptibility to autism by causing a downregulation of oxytocin receptors in the developing brain. This study examined the rates of labor induction using pitocin in children with autism and matched controls with either typical development or mental retardation. Birth histories of 41 boys meeting the criteria for autistic disorder were compared to 25 age- and IQ-matched boys without autism (15 typically developing and 10 with mental retardation). There were no differences in pitocin induction rates as a function of either diagnostic group (autism vs. control) or IQ level (average vs. subaverage range), failing to support an association between exogenous exposure to oxytocin and neurodevelopmental abnormalities.

Adolescent↗

PubMed2002

Autism, regression, and the broader autism phenotype.

The broader autism phenotype (BAP) is a subclinical set of personality and other features that is thought to index familiality and/or genetic liability to autism. Eighteen parents of autistic probands with a history of language regression and 70 parents of autistic probands without regression were assessed for features of the BAP and compared with published rates in parents of nonautistic subjects. Parents of probands with regressive and nonregressive autism demonstrated similar rates of the BAP (27.8% vs. 32.9%; P = 0.33). The rate of the BAP was significantly higher in both groups of autism parents than in parents of nonautistic subjects (P < or = 0.01). Thus, this measure of genetic liability is increased equally in families with both forms of autism when compared with controls. Environmental events are therefore unlikely to be the sole cause of regressive autism in our sample. Environmental events, however, may act in an additive or "second-hit" fashion in individuals with a genetic vulnerability to autism.

Adult↗

PubMed2002

Utility of the Gilliam Autism Rating Scale in research and clinical populations.

The Gilliam Autism Rating Scale (GARS) was developed as a relatively easy, inexpensive aid in the surveillance and diagnosis of autism. This study examined the validity of the GARS when used with a sample of 119 children with strict DSM-IV diagnoses of autism, ascertained from both clinical and research settings. The GARS consistently underestimated the likelihood that autistic children in this sample would be classified as having autism. The sample mean for the Autism Quotient, a hypothesized index of the likelihood of having autism, was 90.10, significantly below the reference mean of 100. Diagnostic classification according to criteria specified by the GARS resulted in a sensitivity of only .48. Limitations of rating scales in general and of the GARS specifically are discussed. It is recommended that clinicians and researchers using or considering using the GARS for autism diagnosis or ratings of autism severity recognize the need for further research regarding its use.

Autistic Disorder↗

PubMedDate not supplied

Temporal lobe, autism, and macrocephaly.

BACKGROUND AND PURPOSE: Because of increased prevalence of macrocephaly in autism, head size must be controlled for in studies that examine volumetric findings of the temporal lobe in autistic subjects. We prospectively examined temporal lobe structures in individuals with autism who were normocephalic or macrocephalic (head circumference > 97th percentile) and in control subjects who were normocephalic or macrocephalic or who had a reading disorder (unselected for head size). The rationale for the reading disorder group was to have control subjects with potential temporal lobe anomalies, but who were not autistic. METHODS: In individuals aged 7-31 years, autism was diagnosed on the basis of standardized interview and diagnostic criteria. Control subjects ranged in age from 7 to 22 years. All subjects were male. MR morphometrics of the major temporal lobe structures were based on ANALYZE segmentation routines, in which total brain volume and total intracranial volume (TICV) were calculated. Both group comparisons and developmental analyses were performed. RESULTS: No distinct temporal lobe abnormalities of volume were observed once head size (TICV) was controlled for. In autistic and control subjects, robust growth patterns were observed in white and gray matter that differed little between the groups. Although subtle differences were observed in some structures (ie, less white matter volume in the region of the temporal stem and overall temporal lobe), none was statistically significant. CONCLUSION: No major volumetric anomalies of the temporal lobe were found in cases of autism when IQ, TICV, and age were controlled. Temporal lobe abnormalities that may be associated with autism are likely to be more related to functional organization within the temporal lobe than to any gross volumetric difference.

Adolescent↗