Genetically-Inbred Balb/c Mice Differ from Outbred Swiss Webster Mice on Discrete Measures of Sociability: Relevance to a Genetic Mouse Model of Autism Spectrum Disorders
Luis F. Jacome, Jessica A. Burket, Amy L. Herndon, and Stephen I. Deutsch
Strains of genetically-inbred or genetically-engineered mice have been shown to differ from outbred strains or their “normal” littermates, respectively, on a variety of social behaviors that are measured under standardized conditions. For example, in the presence of a social stimulus mouse, the genetically-inbred Balb/c mouse strain is less active and makes fewer social approaches toward an enclosed or freely moving stimulus mouse than an outbred Swiss Webster mouse strain. The current paper sought to characterize more fully the profile of the Balb/c mouse strain's impaired social behaviors, relative to the Swiss Webster mouse strain. Also, because the Balb/c mouse strain is used to study potential medication strategies for autism spectrum disorders, we also sought to explore differences in spontaneously observed stereotypic behaviors between the Balb/c and Swiss Webster mouse strains, and the relationships of these stereotypic behaviors to measures of sociability within each strain. The symptom domain of “restricted repetitive and stereotypic patterns of behavior” contributes to functional impairment in persons with autism spectrum disorders. Characterizing mouse strains with respect to differences in their profiles of sociability and stereotypic behaviors will facilitate medication discovery strategies that utilize mice to model dimensions of the autism spectrum. © 2011 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2011, 4: 393–400. DOI: 10.1002/aur.218
Verbal Problem-Solving in Autism Spectrum Disorders: a Problem of Plan Construction?
The way people with autism solve language-based problems can be explored using simple games like “Twenty Questions”. When people with autism play Twenty Questions, they sometimes ask questions that do not reduce the number of options in an efficient way. This study tested two explanations for this; i) that people with autism find it hard to plan the right questions to ask, and ii) that people with autism might find it hard to ignore irrelevant information when asking their questions. A sample of 22 children with an autism spectrum disorder (ASD) and 21 typically-developing children, matched for age and ability, were tested on an adapted version of Twenty Questions and two measures of planning skills. The results indicated that ASD participants were good at recognising effective questions, but when they made a plan before playing the game they tended to not select the most effective questions to ask. When playing Twenty Questions, ASD participants appeared to find it hard to track what questions they had asked, but there was no evidence to suggest that they had a problem with ignoring irrelevant information. Overall, the results suggest that people with autism may have problems combining questions in an effective way to to solve a problem. Such findings are potentially useful because they are relevant to how problem-solving skills can be assisted in school and work settings. © 2011 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2011, 4: 401–411. DOI: 10.1002/aur.222
Better Fear Conditioning is Associated with Reduced Symptom Severity in Autism Spectrum Disorders
Mikle South, Michael J. Larson, Sarah E. White, Julianne Dana, and Michael J. Crowley
The amygdala is one brain region thought to function abnormally in autism spectrum disorders (ASD). Many studies of the amygdala's role in ASD have focused on its contributions to social development. The amygdala is also critically involved in fear learning and anxiety, which are very common in ASD. The few previous studies in ASD employing classical fear conditioning, a common indicator of amygdala function, have conflicting results.. We recorded skin conductance response (SCR) during such a task in 30 children and adolescents (ages 8–18) diagnosed with high-functioning ASD and 30 typically-developing controls. Only in the ASD group, we found a correlation between anxiety symptoms and SCR response, such that ASD children with more social anxiety showed greater responsiveness to the task. We also found an association between SCR and autism symptom severity: more severe autism symptoms were correlated with reduced physiological responsiveness. We speculate that discrepancies in previous studies of fear conditioning in ASD are due to differences in the types of samples and/or the types of tasks that were used, and suggest a number of avenues for future fear conditioning studies to examine the overlap between autism and anxiety in the brain. © 2011 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2011, 4: 412–421. DOI: 10.1002/aur.221
Abstractness and Continuity in the Syntactic Development of Young Children with Autism
Letitia R. Naigles, Emma Kelty, Rose Jaffery, and Deborah Fein
Sentence use and understanding are frequently considered to be strengths for individuals with autism spectrum disorders (ASDs); however, few studies have investigated the extent to which this knowledge about sentences is abstract rather than tied to the use of specific words. In this study, we examine whether children with ASD can use an abstract subject-verb-object frame (“transitive”) to learn the meanings of unknown verbs. Participants in this longitudinal study (17 children with ASD averaging 41 months of age, 18 TD children averaging 28 months of age) were tested using intermodal preferential looking, in which they watched two side-by-side videos and heard speech that matched only one of the videos. Their eye movements were recorded and later coded; the expectation was that they would look longer at the video that matched the speech. They were taught two novel verbs in transitive sentences and asked whether these verbs mapped onto novel causative (e.g., a duck character makes a bunny character bend over) vs. noncausative (e.g., the duck and bunny characters both flex their arms) actions. Both groups consistently mapped the verbs onto the causative actions (i.e., they engaged in syntactic bootstrapping). Moreover, the children with ASD's performance on this task was significantly and independently predicted by both vocabulary and sentence-processing measures obtained eight months earlier. We conclude that many children with ASD are able to generalize grammatical patterns, and this ability may derive from earlier knowledge about words and sentences. © 2011 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2011, 4: 422–437. DOI: 10.1002/aur.223
Sociodemographic Risk Factors Associated with Autism Spectrum Disorders and Intellectual Disability
Judith Pinborough-Zimmerman, Deborah Bilder, Amanda Bakian, Robert Satterfield, Paul S. Carbone, Barry E. Nangle, Harper Randall, and William M. McMahon
This study tested the theory that (1) demographic and economic risk factors in young children with autism spectrum disorders (ASD) and/or intellectual disability (ID) significantly differ by disability type, and (2) measures of income (mean adjusted gross income, mean federal taxes paid, and mean tax exemptions) significantly increase between 1994 and 2002 and are lower in families with a child with ASD and/or ID compared to the general population. A multiple source public health monitoring program was used to determine the number of ASD and ID cases from a population of 26,108 8-year-old children born in 1994 and living in Utah in 2002. ASD without ID (ASD-only, n=99) cases were significantly more like to be male (P<0.01) and have mothers of White non-Hispanic background (P=0.02). ASD with ID (ASD/ID, n=33) cases were significantly more likely to be male (P<0.01) and have mothers older than 34 years (P=0.03). ID without ASD (ID-only, n=113) cases were significantly more likely to have fathers older than 34 years (P<0.01) and significantly less likely to have mothers with >13 years education (P<0.01). Measures of income for cases at birth and at age eight were not significantly lower and mean adjusted income significantly increased from birth to age eight in cases and the general population. Evaluating early demographic and economic characteristics in children with ASD and ID will help our understanding of possible risk factors for these disorders. Tax information may be a unique source of information to use in studies of large populations. © 2011 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2011, 4: 438–448. DOI: 10.1002/aur.224
Face Recognition Performance of Individuals with Asperger Syndrome on the Cambridge Face Memory Test
Darren Hedley, Neil Brewer, and Robyn Young
While face recognition deficits in individuals with Autism Spectrum Disorder (ASD), including Asperger syndrome (AS), are widely acknowledged, the empirical evidence is mixed. This in part reflects the failure to use standardized and psychometrically sound tests. We contrasted standardized face recognition scores on the Cambridge Face Memory Test (CFMT) for 34 individuals with AS with those for 42, IQ-matched non-ASD individuals. Overall, participants with AS performed significantly worse than non-ASD participants and when evaluated against standardized scores. However, many individuals with AS performed at or above the typical level for their age. There was no evidence that IQ, autistic traits, or negative affect significantly influenced face recognition performance. © 2011 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2011, 4: 449–455. DOI: 10.1002/aur.214
Are Thyroid Hormone Concentrations at Birth Associated with Subsequent Autism Diagnosis?
Sumi Hoshiko, Judith K. Grether, Gayle Windham, Daniel Smith, and Karen Fessel
Thyroid hormones help guide development of the brain during pregnancy, which suggests that disturbance of these patterns could potentially contribute to the development of autism spectrum disorders (ASD). Thyroid pathways may also provide a way for environmental factors to play a role in whether a child develops autism, as environmental contaminants known to affect the thyroid system could interfere with nervous system formation.
To search for a link between autism and thyroid hormones, we used information on two existing study groups of children with ASD (cases) compared to children without known ASD selected from birth certificate records (controls). We evaluated whether cases and controls had differences in concentrations of a thyroid hormone at birth, thyroxine (T4), which was routinely measured in newborns. One study group included children born in 1994 in the San Francisco Bay Area, with cases identified through the California Department of Developmental Services (DDS) and/or the Kaiser Permanente Medical Care Program in Northern California (244 cases, 266 controls); the other included children born in California in 1995, with cases identified through DDS (310 cases, 518 controls). This exploratory analysis suggested that newborns with very low T4 may have higher ASD risk, although this result was mainly noted in the 1995 study group. It is unknown whether this reflects a true association, chance, or is best explained by other factors. Answering the question of whether alterations in thyroid hormones contribute to risk of ASD will require further studies. © 2011 INSAR/Wiley Periodicals, Inc.
Article Citation:Autism Res2011, 4: 456–463. DOI: 10.1002/aur.219