1. Bernier R, Aaronson B, McPartland J. {{The role of imitation in the observed heterogeneity in EEG mu rhythm in autism and typical development}}. {Brain Cogn};2013 (Mar 16);82(1):69-75.
Dysfunction in an execution/observation matching system, or mirror neuron system, has been proposed to contribute to the social deficits observed in Autism Spectrum Disorder (ASD). Atypical activity in this system, as reflected in attenuation of the EEG mu rhythm, has been demonstrated in several studies; however, normative patterns of activity have been evident in other ASD samples. The current study sought to investigate this poorly understood heterogeneity in social perceptual brain function in ASD. EEG mu rhythm was recorded in a well-characterized sample of 19 children with ASD (mean age=6.4; 1 female) and 19 age-matched typically developing peers (mean age=6.9; 2 females) during execution and observation of goal-directed hand actions. Children were assessed on variables theoretically related to mirror neuron system function (MNS), such as ASD symptoms and imitation ability. Results indicated that MNS activity was associated with facial imitation ability, but not hand imitation ability, in children with ASD and typically developing individuals. Groups were comparable in terms of average MNS activity during both action observation and execution, but, in both groups, a subset of children showed absent or significantly reduced MNS activity during observation of action in conjunction with greater difficulty in imitation. These results emphasize the relationship between EEG indices of MNS function and imitative skill and suggest that dysfunction of the MNS is related to imitation ability in both clinical and typical populations, rather than representing a core deficit or universal impairment in ASD.
Lien vers le texte intégral (Open Access ou abonnement)
2. Domes G, Heinrichs M, Kumbier E, Grossmann A, Hauenstein K, Herpertz SC. {{Effects of Intranasal Oxytocin on the Neural Basis of Face Processing in Autism Spectrum Disorder}}. {Biol Psychiatry};2013 (Mar 16)
BACKGROUND: Autism spectrum disorder (ASD) is associated with altered face processing and decreased activity in brain regions involved in face processing. The neuropeptide oxytocin has been shown to promote face processing and modulate brain activity in healthy adults. The present study examined the effects of oxytocin on the neural basis of face processing in adults with Asperger syndrome (AS). METHODS: A group of 14 individuals with AS and a group of 14 neurotypical control participants performed a face-matching and a house-matching task during functional magnetic resonance imaging. The effects of a single dose of 24 IU intranasally administered oxytocin were tested in a randomized, placebo-controlled, within-subject, cross-over design. RESULTS: Under placebo, the AS group showed decreased activity in the right amygdala, fusiform gyrus, and inferior occipital gyrus compared with the control group during face processing. After oxytocin treatment, right amygdala activity to facial stimuli increased in the AS group. CONCLUSIONS: These findings indicate that oxytocin increases the saliency of social stimuli and in ASD and suggest that oxytocin might promote face processing and eye contact in individuals with ASD as prerequisites for neurotypical social interaction.
Lien vers le texte intégral (Open Access ou abonnement)
3. Elison JT, Paterson SJ, Wolff JJ, Reznick JS, Sasson NJ, Gu H, Botteron KN, Dager SR, Estes AM, Evans AC, Gerig G, Hazlett HC, Schultz RT, Styner M, Zwaigenbaum L, Piven J. {{White Matter Microstructure and Atypical Visual Orienting in 7-Month-Olds at Risk for Autism}}. {Am J Psychiatry};2013 (Mar 20)
OBJECTIVE The authors sought to determine whether specific patterns of oculomotor functioning and visual orienting characterize 7-month-old infants who later meet criteria for an autism spectrum disorder (ASD) and to identify the neural correlates of these behaviors. METHOD Data were collected from 97 infants, of whom 16 were high-familial-risk infants later classified as having an ASD, 40 were high-familial-risk infants who did not later meet ASD criteria (high-risk negative), and 41 were low-risk infants. All infants underwent an eye-tracking task at a mean age of 7 months and a clinical assessment at a mean age of 25 months. Diffusion-weighted imaging data were acquired for 84 of the infants at 7 months. Primary outcome measures included average saccadic reaction time in a visually guided saccade procedure and radial diffusivity (an index of white matter organization) in fiber tracts that included corticospinal pathways and the splenium and genu of the corpus callosum. RESULTS Visual orienting latencies were longer in 7-month-old infants who expressed ASD symptoms at 25 months compared with both high-risk negative infants and low-risk infants. Visual orienting latencies were uniquely associated with the microstructural organization of the splenium of the corpus callosum in low-risk infants, but this association was not apparent in infants later classified as having an ASD. CONCLUSIONS Flexibly and efficiently orienting to salient information in the environment is critical for subsequent cognitive and social-cognitive development. Atypical visual orienting may represent an early prodromal feature of an ASD, and abnormal functional specialization of posterior cortical circuits directly informs a novel model of ASD pathogenesis.
Lien vers le texte intégral (Open Access ou abonnement)
4. Feuk L. {{Copy number variation in the autism genome}}. {Expert Opin Med Diagn};2008 (Apr);2(4):417-428.
Background: Autism spectrum disorders (ASDs) are among the most heritable of all neurodevelopmental disorders. Despite intense research there has been limited success in deciphering the etiology of ASDs. Objective: It has been shown that chromosomal rearrangements play an important role in ASDs. The recent development of techniques to screen the genome for genetic variation at ever-higher resolution has led to some crucial discoveries over the last year. This progress is described and discussed. Methods: This review provides an overview of genetic variation studies in ASD, with a focus on structural genetic variation. Results/conclusion: Screening for copy number variation is an important approach in ASD research. With the introduction of next-generation sequencing, the pace of ASD genetics will increase in the near future.
Lien vers le texte intégral (Open Access ou abonnement)
5. Firth I, Dryer R. {{The predictors of distress in parents of children with autism spectrum disorder}}. {J Intellect Dev Disabil};2013 (Mar 19)
Background It is well recognised that parents of children with autism spectrum disorder (ASD) often experience clinically significant levels of stress and depression. This study examined which ASD characteristic best predicted parental distress. Method Parents of 109 children aged between 4 and 12 (M age = 7.89, SD = 2.43) completed self-report measures of anxiety, depression, stress, and parenting-specific stress. They also completed rating scales regarding their child’s ASD characteristics. Results This study found that the child’s behavioural and emotional impairments predicted the parents’ overall levels of distress (i.e., stress/tension, anxiety, and depression), but not the stress associated with parenting. Instead, the child’s social impairment severity was found to predict parenting-specific stress. Conclusion This study highlights the pervasive influence of ASD symptomatology on the mental wellbeing of the parents and the importance of assisting parents to cope with the behavioural and social impairments of their child.
Lien vers le texte intégral (Open Access ou abonnement)
6. Rojahn J, Schroeder SR, Mayo-Ortega L, Oyama-Ganiko R, Leblanc J, Marquis J, Berke E. {{Validity and reliability of the Behavior Problems Inventory, the Aberrant Behavior Checklist, and the Repetitive Behavior Scale – Revised among infants and toddlers at risk for intellectual or developmental disabilities: A multi-method assessment approach}}. {Res Dev Disabil};2013 (Mar 16);34(5):1804-1814.
Reliable and valid assessment of aberrant behaviors is essential in empirically verifying prevention and intervention for individuals with intellectual or developmental disabilities (IDD). Few instruments exist which assess behavior problems in infants. The current longitudinal study examined the performance of three behavior-rating scales for individuals with IDD that have been proven psychometrically sound in older populations: the Aberrant Behavior Checklist (ABC), the Behavior Problems Inventory (BPI-01), and the Repetitive Behavior Scale – Revised (RBS-R). Data were analyzed for 180 between six and 36 months old children at risk for IDD. Internal consistency (Cronbach’s alpha) across the subscales of the three instruments was variable. Test-retest reliability of the three BPI-01 subscales ranged from .68 to .77 for frequency ratings and from .65 to .80 for severity ratings (intraclass correlation coefficients). Using a multitrait-multimethod matrix approach high levels of convergent and discriminant validity across the three instruments was found. As anticipated, there was considerable overlap in the information produced by the three instruments; however, each behavior-rating instrument also contributed unique information. Our findings support using all three scales in conjunction if possible.
Lien vers le texte intégral (Open Access ou abonnement)
7. Xue J, Ooh J, Magiati I. {{Family functioning in Asian families raising children with autism spectrum disorders: the role of capabilities and positive meanings}}. {J Intellect Disabil Res};2013 (Mar 19)
BACKGROUND: There has been increasing interest in exploring the factors contributing to successful adaptation and family functioning in ethnically and culturally diverse families who raise children with autism spectrum disorders (ASD), in order to inform more appropriate strength-based family support services. This pilot study used the Family Adjustment and Adaptation Response (FAAR) model as a theoretical framework to investigate the role of families’ capabilities (coping strategies and resources of support) and positive meanings in raising a child with ASD in family functioning in an Asian context. METHODS: Sixty-five Singaporean parents of 3- to 11-year-old children with ASD completed a series of questionnaires on demands, coping strategies, social support, positive meanings and family functioning. RESULTS: Families reported a number of helpful coping strategies. Coping through family integration/optimism was most helpful, followed by understanding the condition and by developing esteem and psychological stability. Reported capabilities, but not positive meanings, mediated the relationship between demands and family functioning. CONCLUSION: The findings are discussed in relation to existing literature, possible specific cultural issues, and the strengths and limitations of the study. Implications for supporting families of children with ASD in different social and cultural contexts are also discussed.
Lien vers le texte intégral (Open Access ou abonnement)
8. Zaki SR, Johnson SA. {{The Role of Gaze Direction in Face Memory in Autism Spectrum Disorder}}. {Autism Res};2013 (Mar 19)
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. Autism Res 2013, : -. (c) 2013 International Society for Autism Research, Wiley Periodicals, Inc.
