About 3 in every 1000 US children in large metropolitan areas may have autism or related developmental disorders.
Explore the source record for details and available documents.
Comment↗
Biomedical subjects
Susan E Bryson
Publications and source records attributed to Susan E Bryson.
The development of exogenous orienting: mechanisms of control.
The present study examined exogenous orienting in children ages 6 years (n=14), 10 years (n=13), 14 years (n=14), and adults (n=13). The main purpose was to identify which of the attentional operations underlying exogenous orienting (disengaging, shifting, and/or engaging) improves with age. A simple detection task was used in which single targets were correctly (80%) or incorrectly (20%) cued. The main finding was that disengaging attention alone distinguished the performance of younger children from that of older children and adults, regardless of whether attention alone (covert attention) or attention and associated sensory and motor systems (overt attention) were involved. In addition, our data, in contrast to those reported previously, raise the possibility that even the youngest children tested were able to use the predictability of the cue to enhance their performance. These and related neuroanatomical findings are taken as evidence for the development with age of more flexible control in orienting visual attention.
Adolescent↗
Quantifying dimensions in autism: a factor-analytic study.
OBJECTIVE: The objective of this study was to determine whether the phenotypic variation in autism and the related pervasive developmental disorders (PDDs) is a unitary construct or whether it is composed of distinct dimensions of autistic symptoms and measures of level of functioning. METHOD: One hundred twenty-nine children with autism and other forms of PDD from two samples with different inclusion criteria were assessed with the Vineland Adaptive Behavior Scales to measure level of functioning and the Autism Diagnostic Interview to measure severity of autistic behaviors. A factor analysis with varimax rotation was performed on each sample, separately and combined. RESULTS: Two factors emerged; one representing autistic symptoms and another representing level of functioning. The factor structure was remarkably similar and robust to variations in ascertainment and inclusion criteria between the samples. The validity of the distinction was supported by differences between males and females on the symptom factor, but not on the level of functioning factor. IQ was modestly correlated with level of functioning, but not with symptoms. CONCLUSIONS: The phenotypic variation seen in autism/PDD is composed of at least two different dimensions of autistic symptoms and level of functioning. The implications of this dimensional heterogeneity for research, classification, and clinical practice are discussed.
Adolescent↗
Pregnancy and birth complications in autism and liability to the broader autism phenotype.
OBJECTIVE: To understand better the relationship between pregnancy and birth complications and genetic factors in autism. METHOD: The sample included 78 children with an autism spectrum disorder and 88 unaffected siblings. A standardized interview was used to ask mothers about the pregnancy and birth of each child, and an overall index reflecting freedom from complications (termed "optimality") was determined. The presence of autism-like traits (termed the "broader autism phenotype") in second- and third-degree relatives was ascertained by reports from multiple informants. The pro-. portion of relatives with the broader autism phenotype, corrected for degree of relation, was used as an index of family loading. RESULTS: Children with autism spectrum disorders have lower optimality (higher rates of complications) than unaffected siblings. High family loading for the broader autism phenotype is associated with higher rates of complications in unaffected siblings. Family loading was not significantly associated with complications in affected siblings in this sample. Overall, these findings argue against complications being a direct cause of autism, as one would expect to find the most complications in sporadic cases (i.e., in children without a positive family history). CONCLUSION: Increased rates of birth and pregnancy complications are likely secondary to familial factors associated with autism.
Autistic Disorder↗
Mental retardation in teenagers: prevalence data from the Niagara region, Ontario.
OBJECTIVES: There are few Canadian prevalence studies of mental retardation (MR); those that do exist were conducted prior to the era of community integration. We undertook a population-based study to explore mental health disturbances in young persons with MR. The first requirement was to identify a population with MR and to establish its prevalence. Here, we report data on the prevalence of MR in a population aged 14 to 20 years. METHOD: We conducted the study in the Niagara Region of Ontario, which has a population base of around 400,000. Researchers worked closely with schools and with agencies providing services to persons with MR to identify the study group. We confirmed the functioning level of participants through standard tests of nonverbal intelligence and receptive language; teachers and other service personnel provided information relevant to the estimation of nonparticipants' functioning level. RESULTS: We identified 255 individuals as having MR (IQ < or = 75). Of these, 171 chose to participate (defined as "participants with MR"; the remaining 84 were "nonparticipants with MR"). Thus, the participation rate was 67% (171/255). Participants and nonparticipants with MR did not differ on age, sex, or IQ, although there were more nonparticipants in the lower social strata. Overall prevalence for MR was 7.18/1000. For mild mental retardation (MMR; that is, IQ = 50 to 75), prevalence was 3.54/1000, and for severe mental retardation (SMR; that is, IQ < 50), it was 3.64/1000. CONCLUSIONS: Our prevalence estimate for SMR is similar to rates from previous studies conducted worldwide. Our estimate for MMR parallels the lower rates found in Scandinavian countries and contrasts with the higher rates generally reported in the US.
Adolescent↗