Blog Archives

Decreased Interhemispheric Functional Connectivity in Autism

The cortical underconnectivity theory asserts that reduced long-range functional connectivity might contribute to a neural mechanism for autism. We examined resting-state blood oxygen level–dependent interhemispheric correlation in 53 males with high-functioning autism and 39 typically developing males from late childhood through early adulthood. By constructing spatial maps of correlation between homologous voxels in each hemisphere, we found significantly reduced interhemispheric correlation specific to regions with functional relevance to autism: sensorimotor cortex, anterior insula, fusiform gyrus, superior temporal gyrus, and superior parietal lobule. Observed interhemispheric connectivity differences were better explained by diagnosis of autism than by potentially confounding neuropsychological metrics of language, IQ, or handedness. Although both corpus callosal volume and gray matter interhemispheric connectivity were significantly reduced in autism, no direct relationship was observed between them, suggesting that structural and functional metrics measure different aspects of interhemispheric connectivity. In the control but not the autism sample, there was decreasing interhemispheric correlation with subject age. Greater differences in interhemispheric correlation were seen for more lateral regions in the brain. These findings suggest that long-range connectivity abnormalities in autism are spatially heterogeneous and that transcallosal connectivity is decreased most in regions with functions associated with behavioral abnormalities in autism. Autism subjects continue to show developmental differences in interhemispheric connectivity into early adulthood.

from Cerebral Cortex


Diagnostic Differentiation of Autism Spectrum Disorders and Pragmatic Language Impairment

The present study examined diagnostic differentiation between school-aged children with autism spectrum disorders (ASD) and children with pragmatic language impairment (PLI). Standardized diagnostic instruments were used to investigate the relationship between severity of ‘autism triad’ impairments and group membership. The Autism Diagnostic Observation Schedule was administered to 19 children with PLI and 22 children with ASD. Parents completed the Social Communication Questionnaire. There was a significant difference between diagnostic groups in the level of the severity of behaviors represented by the Communication and Reciprocal Social Interaction sub-domains on both diagnostic measures. Currently displayed Repetitive and Restricted Behaviors and Interests were not found to be useful for differentiating between groups. The similarities found between groups have important implications for intervention.

from the Journal of Autism and Developmental Disorders

New Autism Diagnostic Interview-Revised Algorithms for Toddlers and Young Preschoolers from 12 to 47 Months of Age

Autism Diagnostic Interview-Revised (Rutter et al. in Autism diagnostic interview-revised. Western Psychological Services, Los Angeles, 2003) diagnostic algorithms specific to toddlers and young preschoolers were created using 829 assessments of children aged from 12 to 47 months with ASD, nonspectrum disorders, and typical development. The participants were divided into three more homogeneous groups by language level and age. Items that best differentiated the diagnostic groups were selected and arranged into domains based on multifactor item-response analyses. Using the new algorithms for toddlers and preschool children, we were able to improve sensitivity and specificity compared to the previously developed algorithm.

from the European Archives of Oto-Rhino-Laryngology

A Meta-Analysis of Single Case Research Studies on Aided Augmentative and Alternative Communication Systems with Individuals with Autism Spectrum Disorders

Many individuals with autism cannot speak or cannot speak intelligibly. A variety of aided augmentative and alternative communication (AAC) approaches have been investigated. Most of the research on these approaches has been single-case research, with small numbers of participants. The purpose of this investigation was to meta-analyze the single case research on the use of aided AAC with individuals with autism spectrum disorders (ASD). Twenty-four single-case studies were analyzed via an effect size measure, the Improvement Rate Difference (IRD). Three research questions were investigated concerning the overall impact of AAC interventions on targeted behavioral outcomes, effects of AAC interventions on individual targeted behavioral outcomes, and effects of three types of AAC interventions. Results indicated that, overall, aided AAC interventions had large effects on targeted behavioral outcomes in individuals with ASD. AAC interventions had positive effects on all of the targeted behavioral outcome; however, effects were greater for communication skills than other categories of skills. Effects of the Picture Exchange Communication System and speech-generating devices were larger than those for other picture-based systems, though picture-based systems did have small effects.

from the Journal of Autism and Developmental Disorders

Phonology and vocal behavior in toddlers with autism spectrum disorders

The purpose of this study is to examine the phonological and other vocal productions of children, 18–36 months, with autism spectrum disorder (ASD) and to compare these productions to those of age-matched and language-matched controls. Speech samples were obtained from 30 toddlers with ASD, 11 age-matched toddlers and 23 language-matched toddlers during either parent–child or clinician–child play sessions. Samples were coded for a variety of speech-like and nonspeech vocalization productions. Toddlers with ASD produced speech-like vocalizations similar to those of language-matched peers, but produced significantly more atypical nonspeech vocalizations when compared to both control groups. Toddlers with ASD show speech-like sound production that is linked to their language level, in a manner similar to that seen in typical development. The main area of difference in vocal development in this population is in the production of atypical vocalizations. Findings suggest that toddlers with ASDs do not tune into the language model of their environment. Failure to attend to the ambient language environment negatively impacts the ability to acquire spoken language.

from Autism Research

Emotion Perception in Music in High-Functioning Adolescents With Autism Spectrum Disorders

Individuals with Autism Spectrum Disorders (ASD) succeed at a range of musical tasks. The ability to recognize musical emotion as belonging to one of four categories (happy, sad, scared or peaceful) was assessed in high-functioning adolescents with ASD (N = 26) and adolescents with typical development (TD, N = 26) with comparable performance IQ, auditory working memory, and musical training and experience. When verbal IQ was controlled for, there was no significant effect of diagnostic group. Adolescents with ASD rated the intensity of the emotions similarly to adolescents with TD and reported greater confidence in their responses when they had correctly (vs. incorrectly) recognized the emotions. These findings are reviewed within the context of the amygdala theory of autism.

from the Journal of Autism and Developmental Disorders

What’s in a voice? Prosody as a test case for the Theory of Mind account of autism

The human voice conveys a variety of information about people’s feelings, emotions and mental states. Some of this information relies on sophisticated Theory of Mind (ToM) skills, while others are more simple and do not require ToM. This variety provides an interesting test case for the ToM account of autism, which would predict greater impairment as ToM requirements increase. In this paper, we draw on psychological and pragmatic theories to classify vocal cues according to the amount of mindreading required to identify them. Children with a high functioning Autism Spectrum Disorder and matched controls were tested in three experiments where the speakers’ state had to be extracted from their vocalizations. Although our results confirm that people with autism have subtle difficulties dealing with vocal cues, they show a pattern of performance that is inconsistent with the view that atypical recognition of vocal cues is caused by impaired ToM.

from Neuropsychologia

Behavioral and Physiological Responses to Child-Directed Speech as Predictors of Communication Outcomes in Children With Autism Spectrum Disorders

Conclusions: Behavioral and physiological responses to CDS are significantly related to concurrent and later communication skills of children with ASD. Furthermore, higher vagal activity during CDS predicts better communication outcomes 12 months later, after initial communication skills are accounted for. Further research is needed to better understand the physiological mechanisms underlying variable responses to CDS among children with ASD.

from the Journal of Speech, Language, and Hearing Research

Measuring Pragmatic Language in Speakers With Autism Spectrum Disorders: Comparing the Children’s Communication Checklist—2 and the Test of Pragmatic Language

Conclusions: In these children with ASD, who displayed age-appropriate structural language skills, the CCC–2 identified pragmatic language impairment better than the TOPL. Clinically, this can be useful in documenting the presence of language dysfunction when traditional standardized language assessments would not reveal communication problems.

from American Journal of Speech Language Pathology

‘Everyday Memory’ Impairments in Autism Spectrum Disorders

‘Everyday memory’ is conceptualised as memory within the context of day-to-day life and, despite its functional relevance, has been little studied in individuals with autism spectrum disorders (ASDs). In the first study of its kind, 94 adolescents with an ASD and 55 without an ASD completed measures of everyday memory from the Rivermead Behavioural Memory Test (RBMT) and a standard word recall task (Children’s Auditory Verbal Learning Test-2: CAVLT-2). The ASD group showed significant impairments on the RBMT, including in prospective memory, alongside impaired performance on the CAVLT-2. Social and communication ability was significantly associated with prospective remembering in an everyday memory context but not with the CAVLT-2. The complex nature of everyday memory and its relevance to ASD is discussed.

from the Journal of Autism and Developmental Disorders

Moebius sequence and autism spectrum disorders—Less frequently associated than formerly thought

Moebius sequence is a rare congenital disorder usually defined as a combination of facial weakness with impairment of ocular abduction. It is questionable, whether there is a strong association of the sequence with autism spectrum disorders (ASDs) as suggested in some earlier case reports and studies. Twenty-two participants with Möbius sequence aged 6–16 years followed a request of the German Moebius foundation to participate in a nationwide study. All patients had a physical examination and intelligence testing. Primary caregivers were asked to complete two screening measures of ASD (Behaviour and Communication Questionnaire, VSK; Marburger Asperger’s Syndrome Rating Scale, MBAS). For those who reached the cut-off for ASD and/or showed behavioural aspects indicative of ASDs during IQ testing and/or physical examination, well standardized diagnostic instruments (Autism Diagnostic Interview-Revised, Autism Diagnostic Observation Schedule, and Kinder-DIPS) were administered. Minimal diagnostic criteria for Möbius sequence were congenital facial weakness (uni- or bilateral) and impairment of ocular abduction (uni- or bilateral). Three boys (one of them mentally retarded) out of 22 participants (12 males and 10 females) were found suspicious of ASD by screening, but none of them fulfilled diagnostic criteria of ASD on a clinical consensus conference. Therefore, ASDs seem to be not as frequent as reported in previous studies on patients with Möbius sequence.

from Research in Developmental Disabilities

Screening Accuracy of Level 2 Autism Spectrum Disorder Rating Scales

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.

from Autism

Patterns of language and discourse comprehension skills in school-aged children with autism spectrum disorders

The present study examined patterns of language and discourse comprehension skills in Swedish school-aged children with autism spectrum disorders (ASD) (n = 16) as compared to a slightly younger group of typically developing children (n = 16) matched for non-verbal cognitive ability. Results suggested significantly lower abilities in narrative discourse comprehension for the ASD group, but not in oral receptive vocabulary or reception of grammar. This difficulty with discourse-level comprehension appeared to be of a general nature, as no evidence was found for the hypothesis that participants with ASD would find comprehension of inferential discourse information disproportionally more difficult than stated information, or for the hypothesis that discourse processing in ASD would be characterized by an elevated processing of explicitly stated narrative details. The study has clinical and educational implications, as the findings suggest that children with ASD would benefit from being offered specific support for discourse-level comprehension.

from Scandinavian Journal of Psychology

Relationships Between Early Gestures and Later Language in Children With Fragile X Syndrome

Conclusions: These outcomes did not support the authors’ initial hypotheses. It was concluded that extensive use of developmentally early gestures by children with FXS who also have many symptoms of autism may not be a positive indicator of later language.

from the American Journal of Speech-Language Pathology

Enhanced Pure-Tone Pitch Discrimination among Persons with Autism but not Asperger Syndrome

Persons with Autism Spectrum Disorders (ASD) display atypical perceptual processing in visual and auditory tasks. In vision, Bertone et al. (2005) found that enhanced and diminished visual processing is linked to the level of neural complexity required to process stimuli, as proposed in the neural complexity hypothesis. Based on these findings, Samson et al. (2006) proposed to extend the neural complexity hypothesis to the auditory modality. They hypothesized that persons with ASD should display enhanced performance for simple tones that are processed in primary auditory cortical regions, but diminished performance for complex tones that require additional processing in associative auditory regions, in comparison to typically developing individuals. To assess this hypothesis, we designed four auditory discrimination experiments targeting pitch, non-vocal and vocal timbre, and loudness. Stimuli consisted of spectro-temporally simple and complex tones. The participants were adolescents and young adults with autism, Asperger syndrome, and typical developmental histories, all with IQs in the normal range. Consistent with the neural complexity hypothesis and enhanced perceptual functioning model of ASD (Mottron et al., 2006), the participants with autism, but not with Asperger syndrome, displayed enhanced pitch discrimination for simple tones. However, no discrimination-thresholds differences were found between the participants with ASD and the typically developing persons across spectrally and temporally complex conditions. These findings indicate that enhanced pure-tone pitch discrimination may be a cognitive correlate of speech-delay among persons with ASD. However, auditory discrimination among this group does not appear to be directly contingent on the spectro-temporal complexity of the stimuli.

from Neuropsychologia