Journals

RPP25 is developmentally regulated in prefrontal cortex and expressed at decreased levels in autism spectrum disorder

Autism Research: The Journal - Wed, 07/14/2010 - 06:03
Dysfunction of cerebral cortex in autism is thought to involve alterations in inhibitory neurotransmission. Here, we screened, in prefrontal cortex (PFC) of 15 subjects diagnosed with autism and 15 matched controls the expression of 44 transcripts that are either preferentially expressed in gamma-aminobutyric acidergic interneurons of the mature cortex or important for the development of inhibitory circuitry. Significant alterations in the autism cohort included decreased expression (-45%) of RPP25 (15q24.1), which is located within the autism susceptibility locus, 15q22-26. RPP25, which encodes the 25 kDa subunit of ribonuclease P involved in tRNA and pre-ribosomal RNA processing, was developmentally regulated in cerebral cortex with peak levels of expression during late fetal development (human) or around birth (mouse). In the PFC, RPP25 chromatin showed high levels of histone H3-lysine 4 trimethylation, an epigenetic mark associated with transcriptional regulation. Unexpectedly, and in contrast to peripheral tissues, levels of RPP25 protein remained undetectable in fetal and adult cerebral cortex. Taken together, these findings suggest a potential role for the RPP25 gene transcript in the neurobiology of developmental brain disorders.
Categories: Journal Articles

White matter integrity in Asperger syndrome: a preliminary diffusion tensor magnetic resonance imaging study in adults

Autism Research: The Journal - Mon, 07/12/2010 - 07:03
Background: Autistic Spectrum Disorder (ASD), including Asperger syndrome and autism, is a highly genetic neurodevelopmental disorder. There is a consensus that ASD has a biological basis, and it has been proposed that it is a "connectivity" disorder. Diffusion Tensor Magnetic Resonance Imaging (DT-MRI) allows measurement of the microstructural integrity of white matter (a proxy measure of "connectivity"). However, nobody has investigated the microstructural integrity of whole brain white matter in people with Asperger syndrome. Methods: We measured the fractional anisotropy (FA), mean diffusivity (MD) and radial diffusivity (RD) of white matter, using DT-MRI, in 13 adults with Asperger syndrome and 13 controls. The groups did not differ significantly in overall intelligence and age. FA, MD and RD were assessed using whole brain voxel-based techniques. Results: Adults with Asperger syndrome had a significantly lower FA than controls in 13 clusters. These were largely bilateral and included white matter in the internal capsule, frontal, temporal, parietal and occipital lobes, cingulum and corpus callosum. Conclusions: Adults with Asperger syndrome have widespread significant differences from controls in white matter microstructural integrity.
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Editorial

Sage Publications: Journals - Wed, 06/30/2010 - 05:13
Categories: Journal Articles

Screening Accuracy of Level 2 Autism Spectrum Disorder Rating Scales: A Review of Selected Instruments

Sage Publications: Journals - Wed, 06/30/2010 - 05:13

The goal of this review was to examine the state of Level 2, caregiver-completed rating scales for the screening of Autism Spectrum Disorders (ASDs) in individuals above the age of three years. We focused on screening accuracy and paid particular attention to comparison groups. Inclusion criteria required that scales be developed post ICD-10, be ASD-specific, and have published evidence of diagnostic validity in peer-reviewed journals. The five scales reviewed were: the Social Communication Questionnaire (SCQ), Gilliam Autism Rating Scale/Gilliam Autism Rating Scale-Second Edition (GARS/GARS-2), Social Responsiveness Scale (SRS), Autism Spectrum Screening Questionnaire (ASSQ), and Asperger Syndrome Diagnostic Scale (ASDS). Twenty total studies were located, most examining the SCQ. Research on the other scales was limited. Comparisons between scales were few and available evidence of diagnostic validity is scarce for certain subpopulations (e.g., lower functioning individuals, PDDNOS). Overall, the SCQ performed well, the SRS and ASSQ showed promise, and the GARS/GARS-2 and ASDS demonstrated poor sensitivity. This review indicates that Level 2 ASD caregiver-completed rating scales are in need of much more scientific scrutiny.

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Recognising 'social' and 'non-social' emotions in self and others: A study of autism

Sage Publications: Journals - Wed, 06/30/2010 - 05:13

Studies of emotion processing in autism have produced mixed results, with fewer studies observing autism-specific deficits than might be imagined. In the current study, 21 individuals with autism and 21 age- and ability-matched, learning disabled comparison participants were tested for their ability to (a) recognise, in others, expressions of ‘social’ emotions (e.g., embarrassment) and ‘non-social’ emotions (e.g., happiness) and; (b) report their own previous experiences of each of these emotions.

In line with predictions, amongst both groups of participants, social emotions were more difficult to recognise and report than non-social emotions. Also amongst both groups, the ability to report social emotion-experience was significantly associated with the ability to recognise social emotions in others, independent of age and verbal ability. However, contrary to predictions, no between-group differences in levels or patterns of performance on the experimental tasks were observed.

In light of previous research, these results suggest either that emotion-processing is not as specifically impaired in autism as is traditionally thought to be the case, or that individuals with autism are implementing compensatory strategies to succeed on experimental tasks in the absence of emotion-processing competence.

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Visual influences on speech perception in children with autism

Sage Publications: Journals - Wed, 06/30/2010 - 05:13

The bimodal perception of speech sounds was examined in children with autism as compared to mental age—matched typically developing (TD) children. A computer task was employed wherein only the mouth region of the face was displayed and children reported what they heard or saw when presented with consonant-vowel sounds in unimodal auditory condition, unimodal visual condition, and a bimodal condition. Children with autism showed less visual influence and more auditory influence on their bimodal speech perception as compared to their TD peers, largely due to significantly worse performance in the unimodal visual condition (lip reading). Children with autism may not benefit to the same extent as TD children from visual cues such as lip reading that typically support the processing of speech sounds. The disadvantage in lip reading may be detrimental when auditory input is degraded, for example in school settings, whereby speakers are communicating in frequently noisy environments.

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Increasing social responsiveness in a child with autism: A comparison of music and non-music interventions

Sage Publications: Journals - Wed, 06/30/2010 - 05:13

This study sought to determine the effects of using music and non-music interventions on the social responsive and avoidant behaviours of a preschool child with autism. A single-subject alternating treatment design was used in which two interventions were presented in a similar fashion except for the addition of music during the music condition. Four phases took place: baseline (Phase A), alternating treatments (Phase B), a second treatment phase (Phase C) using the condition that proved to be more effective in Phase B, and follow-up (Phase D). Data were collected over a total of 12 treatment sessions for various social responsive and avoidant behaviours. Results indicated that the music intervention was more effective than the non-music intervention in increasing all three social responsive behaviours in both Phases B and C. Furthermore, no avoidant behaviours were observed during the music condition. It is suggested that the music condition was more motivating for the participant than the non-music condition, resulting in more social responsive behaviours.

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Brief report: Electroconvulsive therapy for malignant catatonia in an autistic adolescent

Sage Publications: Journals - Wed, 06/30/2010 - 05:13

A 14-year-old male with autism and mild mental retardation developed malignant catatonia characterized by classic symptoms of catatonia, bradycardia and hypothermia. Bilateral electroconvulsive therapy and lorazepam were required for resolution. The case expands the occurrence of catatonia in autism into its malignant variant.

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How Parents Perceive and Feel about Participation in Community Activities: The Comparison between Parents of Preschoolers with and without Autism Spectrum Disorders

Sage Publications: Journals - Wed, 06/30/2010 - 05:13

The present study compared how parents of preschoolers with and without Autism Spectrum Disorders (ASD) perceived and felt about participation in community activities. A questionnaire survey was conducted with 380 Hong Kong parents of preschoolers with ASD and 214 Hong Kong parents of preschoolers without ASD. The two groups were not different in their willingness and frequency of participation in community activities. However, the psychological processes underneath their willingness were very different. Among the parents of preschoolers with ASD, their willingness was associated with how they perceived the difficulty and importance of the participation and what emotions they experienced during the activities. This pattern of association was not evident among the parents of preschoolers without ASD.

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A single case design evaluation of a software and tutor intervention addressing emotion recognition and social interaction in four boys with ASD

Sage Publications: Journals - Wed, 06/30/2010 - 05:12

Many students with Autism Spectrum Disorders (ASD) have delays learning to recognize emotions. Social behavior is also challenging, including initiating interactions, responding to others, developing peer relationships, and so forth. In this single case design study we investigated the relationship between use of computer software (Mind Reading: The Interactive Guide to Emotions) and emotion recognition (ER) and social behavior change. After using Mind Reading for 7 to 10 weeks with a tutor, four boys with ASD improved ER scores and social interactions with peers. However, observed behavior changes were not strong enough to claim a causal relationship between variables. Findings, practice implications, and future research are discussed.

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Efficacy of TeachTown: Basics computer-assisted intervention for the Intensive Comprehensive Autism Program in Los Angeles Unified School District

Sage Publications: Journals - Wed, 06/30/2010 - 05:12

Computer Assisted Instruction (CAI) has shown increased popularity recently and there are many studies showing promise for this approach for children with Autism Spectrum Disorders (ASD). However, there are no between-subject studies to date assessing the efficacy of CAI with this population. In this study, 47 preschool and K-1 students in ASD classrooms participated from Los Angeles Unified School District. TeachTown: Basics, a CAI program which also includes supplementary off-computer activities, was implemented over 3 months for approximately 20 minutes per day on the computer and 20 minutes per day in supplementary TeachTown: Basics activities. Compared to the students in the control group, the TeachTown: Basics students showed more improvement overall on language and cognitive outcome measures. In addition, students who used TeachTown: Basics demonstrated significant progress overall in the software and those students who used the program for more time demonstrated larger gains within the software and in outcome measures. Although not conclusive, these findings offer possibilities for the use of CAI for remediating many deficits for children with ASD and other special needs. In addition, CAI may offer solutions to schools and parents with insufficient funds for more expensive treatments.

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Sense of presence and atypical social judgments in immersive virtual environments: Responses of adolescents with Autism Spectrum Disorders

Sage Publications: Journals - Wed, 06/30/2010 - 05:12

Immersive virtual environments (IVEs) are potentially powerful educational resources but their application for children with Autism Spectrum Disorder (ASD) is under researched. This study aimed to answer two research questions: (1) Do children with ASD experience IVEs in different ways to typically developing children given their cognitive, perceptual and sensory differences? and (2) Can an IVE accurately simulate ecologically valid social situations? Ten children with ASD and 14 typically developing (TD) adolescents all aged 12—16 years experienced three different IVEs. They completed self-report questionnaires on their sense of ‘presence’ in the IVEs and rated ‘social attractiveness’ of a virtual character in socially desirable and undesirable scenarios. The children with ASD reported similar levels of presence to their TD peers and no negative sensory experiences. Although TD adolescents rated the socially desirable character as more socially attractive than the undesirable character, adolescents with ASD rated the two characters as equally socially attractive. These findings suggest that children with ASD do not experience IVEs in different ways to their TD counterparts and that the IVEs are realistic enough to simulate authentic social situations. This study paints a very encouraging picture for the potential uses of IVEs in assessing and educating individuals with ASD.

Categories: Journal Articles

Computational prosodic markers for autism

Sage Publications: Journals - Wed, 06/30/2010 - 05:12

We present results obtained with new instrumental methods for the acoustic analysis of prosody to evaluate prosody production by children with Autism Spectrum Disorder (ASD) and Typical Development (TD). Two tasks elicit focal stress — one in a vocal imitation paradigm, the other in a picture-description paradigm; a third task also uses a vocal imitation paradigm, and requires repeating stress patterns of two-syllable nonsense words. The instrumental methods differentiated significantly between the ASD and TD groups in all but the focal stress imitation task. The methods also showed smaller differences in the two vocal imitation tasks than in the picture-description task, as was predicted. In fact, in the nonsense word stress repetition task, the instrumental methods showed better performance for the ASD group. The methods also revealed that the acoustic features that predict auditory-perceptual judgment are not the same as those that differentiate between groups. Specifically, a key difference between the groups appears to be a difference in the balance between the various prosodic cues, such as pitch, amplitude, and duration, and not necessarily a difference in the strength or clarity with which prosodic contrasts are expressed.

Categories: Journal Articles

Social benefits of a tangible user interface for children with Autistic Spectrum Conditions

Sage Publications: Journals - Wed, 06/30/2010 - 05:12

Tangible user interfaces (TUIs) embed computer technology in graspable objects. This study assessed the potential of Topobo, a construction toy with programmable movement, to support social interaction in children with Autistic Spectrum Conditions (ASC). Groups of either typically developing (TD) children or those with ASC had group play sessions with Topobo and with LEGOTM. We recorded the extent and sequence of different categories of play during these sessions. For both participant groups, there were more social forms of play with Topobo than with LEGOTM. More solitary play occurred for LEGOTM and more parallel play occurred with Topobo. Topobo was also associated with more time in onlooker and cooperative play in TD. Finally, we observed differences in play sequences between TD and ASC children, and discuss how different play materials might produce specific patterns of play in these two groups.

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Is there a role for routinely screening children with autism spectrum disorder for creatine deficiency syndrome?

Autism Research: The Journal - Tue, 06/29/2010 - 06:25
Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that presents in the first three years of life. Currently, diagnosis of ASD is based on its behavioural manifestations, as laboratory diagnostic tests do not exist. Creatine deficiency syndrome (CDS) is one form of inborn error of metabolism where affected individuals have similar clinical features to individuals with ASD. Abnormal urinary creatine (CR) and guanidinoacetate (GAA) levels have been reported as biomarkers of CDS. We hypothesized that screening for abnormal levels of urinary CR and GAA in children with ASD may assist in identifying a subgroup of ASD individuals who can be managed with dietary interventions. Morning urine samples were collected from children with and without autism and analyzed for CR and GAA levels. Results showed there was no statistically significant difference in urinary CR:creatinine and GAA:creatinine between the children with ASD and sibling or unrelated controls. In conclusion, routine screening for abnormal urinary CR and GAA could be considered in ASD diagnostic protocols; however, individuals positive for CDS are likely to be rare in an ASD cohort.
Categories: Journal Articles

Restricted and repetitive behaviors in toddlers and preschoolers with autism spectrum disorders based on the Autism Diagnostic Observation Schedule (ADOS)

Autism Research: The Journal - Tue, 06/29/2010 - 04:38
Restricted and repetitive behaviors (RRBs) observed during the Autism Diagnostic Observation Schedule [ADOS: Lord et al., 2000] were examined in a longitudinal data set of 455 toddlers and preschoolers (age 8-56 months) with clinical diagnosis of Autism Spectrum Disorders (ASD; autism, n=121 and pervasive developmental disorders - not otherwise specified (PDD-NOS), n=71), a nonspectrum disorder (NS; n=90), or typical development (TD; n=173). Even in the relatively brief semi-structured observations, GEE analyses of the severity and prevalence of RRBs differentiated children with ASD from those with NS and TD across all ages. RRB total scores on the ADOS were stable over time for children with ASD and NS; however, typically developing preschoolers showed lower RRB scores than typically developing toddlers. Nonverbal IQ (NVIQ) was more strongly related to the prevalence of RRBs in older children with PDD-NOS, NS, and TD than younger children under 2 years and those with autism. Item analyses revealed different relationships between individual items and NVIQ, age, diagnosis, and gender. These findings are discussed in terms of their implications for the etiology and treatment of RRBs as well as for the framework of ASD diagnostic criteria in future diagnostic systems.
Categories: Journal Articles

Role for antibodies in altering behavior and movement

Autism Research: The Journal - Tue, 06/29/2010 - 04:38
At the past meeting of INSAR, the role of autoimmunity was discussed in an educational session. This article summarizes this discussion. In immune-mediated diseases, antibodies can contribute to the pathogenesis of the disease and are sometimes the force that drives the disease process. This concept has not been established for autism. In autoimmune diseases, such as systemic lupus erythematosus (SLE), antibodies are found to react with double-stranded DNA. These antibodies also cross-react with N-methyl-D aspartate receptors. Many SLE patients suffer neurologic syndromes of the central nervous system (CNS). Similarly individuals infected with Group A streptococcus (GAS) have antibodies against the GAS carbohydrate, which cross-react with tubulin and lysoganglioside GM1 on neurons. During the acute stage of infection, GAS-infected patients develop Syndenham chorea where the disease process is driven in part by these cross-reactive antibodies. As the antibody levels decrease, the clinical features of Syndenham chorea resolve. In these two immune-mediated diseases, antibodies clearly play a role in the pathogenesis of the diseases. There are reports that mothers of individuals with autism have antibodies that react with brain proteins and when these antibodies are passively transferred to pregnant non-human primates or rodents the offspring has behavioral and nervous system changes. It is still not clear whether the antibodies found in mothers of individuals with autism actually play a role in the disease. More studies need to be performed to identify the proteins recognized by the antibodies and to determine how these could affect development, behavior and changes within the CNS.
Categories: Journal Articles

More than maths and mindreading: Sex differences in empathizing/systemizing covariance

Autism Research: The Journal - Tue, 06/29/2010 - 04:38
Empathizing-Systemizing theory posits a continuum of cognitive traits extending from autism into normal cognitive variation. Covariance data on empathizing and systemizing traits have alternately suggested inversely dependent, independent, and sex-dependent (one sex dependent, the other independent) structures. A total of 144 normal undergraduates (65 men, 79 women) completed the Reading the Mind in the Eyes, Embedded Figures, and Benton face recognition tests, the Autism Spectrum Quotient, and measures of digit length ratio and field of study; some also completed tests of motion coherence threshold (64) and go/no-go motor inhibition (128). Empathizing and systemizing traits were independent in women, but largely dependent in men. In men, level of systemizing skill required by field of study was directly related to social interactive and mindreading deficits; men's social impairments correlated with prolonged go/no-go response times, and men tended to apply systemizing strategies to solve problems of empathizing or global processing: rapid perceptual disembedding predicted heightened sensitivity to facial emotion. In women, level of systemizing in field was related to male-typical digit ratios and autistic superiorities in detail orientation, but not to autistic social and communicative impairments; and perceptual disembedding was related to social interactive skills but independent of facial emotion and visual motion perception.
Categories: Journal Articles

Comparison of visual sensitivity to human and object motion in autism spectrum disorder

Autism Research: The Journal - Tue, 06/08/2010 - 05:40
Successful social behavior requires the accurate detection of other people's movements. Consistent with this, typical observers demonstrate enhanced visual sensitivity to human movement relative to equally complex, nonhuman movement [e.g., Pinto & Shiffrar, ]. A psychophysical study investigated visual sensitivity to human motion relative to object motion in observers with autism spectrum disorder (ASD). Participants viewed point-light depictions of a moving person and, for comparison, a moving tractor and discriminated between coherent and scrambled versions of these stimuli in unmasked and masked displays. There were three groups of participants: young adults with ASD, typically developing young adults, and typically developing children. Across masking conditions, typical observers showed enhanced visual sensitivity to human movement while observers in the ASD group did not. Because the human body is an inherently social stimulus, this result is consistent with social brain theories [e.g., Pelphrey & Carter, ; Schultz, ] and suggests that the visual systems of individuals with ASD may not be tuned for the detection of socially relevant information such as the presence of another person. Reduced visual sensitivity to human movements could compromise important social behaviors including, for example, gesture comprehension.
Categories: Journal Articles
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