Attention Deficit Hyperactivity Disorder Symptoms in Adults with Autism Spectrum Disorders
Kate Johnston, Antonia Dittner, Jessica Bramham, Clodagh Murphy, Anya Knight, and Ailsa Russell
Features of attention deficit hyperactivity disorder (ADHD) have been found in children with autism spectrum disorders (ASDs). To date, there has been a lack of research examining attention in adults with ASD. In the first study, adults with ASD completed self-report questionnaires that measure symptoms of ADHD. We compared their scores with those of adults with ADHD and a healthy control group. In the second study, adults with a diagnosis of ASD were compared with a matched group of adults with ADHD across a range of measures of attention. Study 1 showed that 36.7% of adults with ASD met formal diagnostic criteria for ADHD. The ASD group differed from the ADHD and control groups on the total and individual symptoms reported. In study 2, adults with ASD and ADHD showed comparable performance on tests of selective attention. Significant group differences were seen on measures of attentional switching; adults with ADHD were significantly faster and more inaccurate, and individuals with Asperger's syndrome showed a significantly slower and more accurate response style. Self-reported rates of ADHD among adults with ASD are significantly higher than in the general adult population and may be underdiagnosed. Adults with ASD have attentional difficulties on some measures. © 2013 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2013, 6: 225–236. DOI: 10.1002/aur.1283
The Relationship Between Attentional Bias and Anxiety in Children and Adolescents With Autism Spectrum Disorders
Matthew J. Hollocks, Ann Ozsivadjian, Claire E. Matthews, Patricia Howlin, and Emily Simonoff
Young people with an autism spectrum disorder (ASD) display higher levels of anxiety than the general population. However, there has been little research investigating the underlying the cognitive correlates of anxiety in individuals with an ASD. One cognitive feature of anxiety in the typically developing (non-ASD) population is an attentional bias toward threatening information. This study used an emotional dot-probe task to investigate attentional biases toward both emotionally salient faces and words in adolescents with an ASD. We also investigated whether any such bias was related to the severity of anxiety symptoms. In addition, we examined whether neuropsychological performance was related to performance on the dot-probe task. This study included 79 boys aged 10–16 years; 38 with an ASD and 41 typically developing controls. The ASD group had elevated levels of both parent- and child-rated anxiety and depression. However, there were no significant group differences in attentional bias to either threatening faces or threatening words. Additionally, anxiety symptom scores were not related to attentional bias score in either group. The attentional biases commonly associated with anxiety in typically developing children may not be present in those with an ASD and high levels of anxiety symptoms. This is a novel finding, which requires further replication. The limitations and potential implications of this research are discussed. © 2013 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2013, 6: 237–247. DOI: 10.1002/aur.1325
Prenatal and Early-Life Exposure to High-Level Diesel Exhaust Particles Leads to Increased Locomotor Activity and Repetitive Behaviors in Mice
Keerthi Thirtamara Rajamani, Shannon Doherty-Lyons, Crystal Bolden, Daniel Willis, Carol Hoffman, Judith Zelikoff, Lung-Chi Chen, and Howard Gu
Autism Spectrum Disorders (ASDs) are neurodevelopmental disorders. It is well known that both inheritable genetic and environmental factors contribute to the causes or to the increased risks of autism. However, we have very limited knowledge about these contributing factors. One study analyzed the living environments of pregnant women giving birth to babies that developed normally and those diagnosed with ASD later. It was observed that living closely to major highways was linked to higher incidents of autism. This suggests a possible role for pollutants from highway traffic in contributing to the etiology of ASD. We investigated whether exposure to diesel exhaust particles (DEP) negatively affected mouse development leading to autism-like phenotype later in life. Female mice and their offspring were exposed to DEP during pregnancy and nursing. Male offspring was tested for behaviors relevant to the symptoms of autism patients. We found that the DEP-exposed mice showed a moderate increase in locomotor activity, spent more time self-grooming while in the presence of an unfamiliar mouse, and stood upright on their hind legs more often compared to the control mice. However, mice exposed to DEP during early development did not exhibit deficits in social interactions or social communication which are the key features of ASD. These results suggest that exposure to environmental pollutants like DEP may have an adverse impact on mouse development leading to certain behavioral impairments that may bear some resemblance to autism spectrum disorders. © 2013 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2013, 6: 248–257. DOI: 10.1002/aur.1287
Testing the Predictive Power of Cognitive Atypicalities in Autistic Children: Evidence from a 3-Year Follow-Up Study
Autistic people are thought to show a specific profile of cognitive strengths and weaknesses. These include difficulties appreciating others' thoughts and feelings (“theory of mind”) and problems regulating and controlling behavior (“executive function”) combined with an aptitude for detecting parts of objects or small details (“weak central coherence”). These cognitive skills vary widely within individuals on the autism spectrum. Some researchers believe that this variation might map on to individuals' behavior—the extent to which they show difficulties interacting and communicating with others and have repetitive behaviors and interests. The current study tested this possibility. We expected that children's difficulties in theory of mind should be strongly related to their difficulties in social communication; problems in executive function should best capture children's repetitive behaviors and interest; and children's excellent local processing skills should account for their resistance to change. Thirty-seven autistic children were first seen when they were around 5–6 years old and given tasks assessing each cognitive skill. These children were followed and reassessed 3 years later with regards to their social communication and repetitive behaviors and interests. Children's executive function—but not theory of mind or central coherence—was found to be specifically linked to their behavior at follow-up. Children who were better able to plan, regulate, and control their thoughts and actions showed fewer social difficulties and fewer repetitive behaviors. These findings stress the important role that early executive function plays in autistic children's subsequent development. © 2013 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2013, 6: 258–267. DOI: 10.1002/aur.1286
The Interstitial Duplication 15q11.2-q13 Syndrome Includes Autism, Mild Facial Anomalies and a Characteristic EEG Signature
Nora Urraca, Julie Cleary, Victoria Brewer, Eniko K. Pivnick, Kathryn McVicar, Ronald L. Thibert, N. Carolyn Schanen, Carmen Esmer, Dustin Lamport, and Lawrence T. Reiter
New DNA testing methods have made it easier to detect the loss (deletion) or gain (duplication) of segments of human chromosomes, sometimes quite small segments. These copy number variants, or CNVs, are the most common DNA changes found in autism. In fact, duplications of chromosome 15 (15q) are the second most common CNV found in autism. Although many individuals with 15q duplication are new cases in a family, some 15q duplications can also be inherited. We performed an in-depth analysis of individuals with small 15q duplications to determine if 15q duplication increases autism risk, thus implicating a gene in the duplicated region. We analyzed the duplication size and parental origin for fourteen 15q duplication individuals: ten maternal and four paternal cases. Most of the individuals in the study were duplicated on their mother's chromosome, most likely because maternal duplications are often coincident with autism. The size of the duplication did not correlate with the severity of the disease, but we did identify characteristics not described before in this syndrome including mild facial features, sleep problems and an unusual brain wave pattern that was not associated with seizures and did not depend on the parental origin of the duplication. Our results are consistent with the theory that a maternally expressed gene named ubiquitin protein ligase E3A is primarily responsible for the autism phenotype because all of the maternal duplication cases were on the autism spectrum. © 2013 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2013, 6: 268–279. DOI: 10.1002/aur.1284
The Role of Gaze Direction in Face Memory in Autism Spectrum Disorder
Safa R. Zaki and Shannon A. Johnson
We tested the hypothesis that the direction of gaze of target faces may play a role in reported face recognition deficits in those with an autism spectrum disorder (ASD). In previous studies, typically developing children and adults better remembered faces in which the eyes were gazing directly at them compared with faces in which the eyes were averted. In the current study, high-functioning children and adolescents with an ASD and age- and IQ-matched typically developing controls were shown a series of pictures of faces in a study phase. These pictures were of individuals whose gaze was either directed straight ahead or whose gaze was averted to one side. We tested the memory for these study faces in a recognition task in which the faces were shown with their eyes closed. The typically developing group better remembered the direct-gaze faces, whereas the ASD participants did not show this effect. These results imply that there may be an important link between gaze direction and face recognition abilities in ASD. © 2013 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2013, 6: 280–287. DOI: 10.1002/aur.1292
Brain Function Differences in Language Processing in Children and Adults with Autism
Diane L. Williams, Vladimir L. Cherkassky, Robert A. Mason, Timothy A. Keller, Nancy J. Minshew, and Marcel Adam Just
Previous research with adults with autism has shown that the way the areas of the brain are used and the way these areas are coordinated during language comprehension differs from adult controls. Using the same language task with children and adults allowed us to examine the group differences at two ages, an important comparison because autism is a developmental disorder which may present differently at different ages. We used functional imaging (functional magnetic resonance imaging) to assess brain functioning during reading of texts with literal or ironic meaning. Fifteen children with autism, 14 child controls, 13 adults with autism, and 12 adult controls participated. During irony comprehension, the children and adults with autism had lower functional connectivity (less synchronization of activation among brain areas that were doing work) than both control groups, and neither autism group had an increase in left hemisphere language network functional connectivity in response to the increased task demands. The children and adults with autism differed from each other in the use of some brain regions during the irony task, with the adults with autism having changes similar to those of the control groups. Overall, the adults and children with autism differed from the adult and child controls in (a) the degree of network coordination, (b) the distribution of the workload among the parts of the network, and (c) in the active recruitment of key brain regions for the processing of the ironic texts. Moreover, differences between the two autism age groups occurred, potentially representing positive effects in language development. © 2013 INSAR/Wiley Periodicals, Inc.
Article citation: Autism Res 2013, 6: 288–302. DOI: 10.1002/aur.1291