1. Ahmadlou M, Adeli H, Adeli A. {{Fuzzy Synchronization Likelihood-wavelet methodology for diagnosis of autism spectrum disorder}}. {J Neurosci Methods}. 2012.
This paper presents a methodology for investigation of functional connectivity in patients with autism spectrum disorder (ASD) using Fuzzy Synchronization Likelihood (Fuzzy SL). Fuzzy SLs between and within brain regions are calculated in all EEG sub-bands produced by the wavelet decomposition as well as in the full-band EEG. Then, discriminative Fuzzy SLs between and within different regions and different EEG sub-bands or full-band EEG for distinguishing autistic children from healthy control children are determined based on Analysis of Variation (ANOVA). Finally, the selected features are used as input to an Enhanced Probabilistic Neural Network classifier to make an accurate diagnosis of ASD based on the detected differences in the regional functional connectivity of autistic and healthy EEGs. The methodology is validated using EEG data obtained from 9 autistic and 9 healthy children. The ANOVA test showed high ability of the regional Fuzzy SLs in low frequency bands, delta and theta, as well as alpha band for discriminating the two groups. A high classification accuracy of 95.5% was achieved for distinguishing autistic EEGs from healthy EEGs. It is concluded that the methodology presented in this paper can be used as an effective tool for diagnosis of the autism. Further, the regional Fuzzy SLs discovered in this research can be used as reliable markers in neurofeedback treatments to improve neuronal plasticity and connectivity in autistic patients.
Lien vers le texte intégral (Open Access ou abonnement)
2. Cheung G, Trembath D, Arciuli J, Togher L. {{The impact of workplace factors on evidence-based speech-language pathology practice for children with autism spectrum disorders}}. {Int J Speech Lang Pathol}. 2012.
Although researchers have examined barriers to implementing evidence-based practice (EBP) at the level of the individual, little is known about the effects workplaces have on speech-language pathologists’ implementation of EBP. The aim of this study was to examine the impact of workplace factors on the use of EBP amongst speech-language pathologists who work with children with Autism Spectrum Disorder (ASD). This study sought to (a) explore views about EBP amongst speech-language pathologists who work with children with ASD, (b) identify workplace factors which, in the participants’ opinions, acted as barriers or enablers to their provision of evidence-based speech-language pathology services, and (c) examine whether or not speech-language pathologists’ responses to workplace factors differed based on the type of workplace or their years of experience. A total of 105 speech-language pathologists from across Australia completed an anonymous online questionnaire. The results indicate that, although the majority of speech-language pathologists agreed that EBP is necessary, they experienced barriers to their implementation of EBP including workplace culture and support, lack of time, cost of EBP, and the availability and accessibility of EBP resources. The barriers reported by speech-language pathologists were similar, regardless of their workplace (private practice vs organization) and years of experience.
Lien vers le texte intégral (Open Access ou abonnement)
3. Chomiak T, Hu B. {{Alterations of neocortical development and maturation in autism: Insight from valproic acid exposure and animal models of autism}}. {Neurotoxicol Teratol}. 2012.
Autism spectrum disorder (ASD) is a behaviourally defined brain disorder affecting approximately 1 in 88 children. Many pathological studies have shown that ASD is frequently associated with grey and white matter changes that can be described by their deviations from the normal trajectory of cortical maturation. For example, during the early (i.e. <2years) postnatal period there is marked and selective tissue overgrowth in the higher-order temporal and frontal networks involved in emotional, social, and communication functions. In this focused review we first summarize some basic principles of neocortical neural organization and how they are disrupted in ASD. We will then highlight some of the potential mechanisms by which the normal developmental trajectory and organization of neocortical networks can be altered based on animal studies of valproic acid, a teratogen widely used in animal models of ASD. We argue that the trajectory of postnatal cerebral neocortex development may be influenced by several cellular and molecular mechanisms that may all converge to produce a neuropathology characterized by premature or accelerated neuronal growth.
Lien vers le texte intégral (Open Access ou abonnement)
4. Cossu G, Boria S, Copioli C, Bracceschi R, Giuberti V, Santelli E, Gallese V. {{Motor representation of actions in children with autism}}. {PLoS One}. 2012; 7(9): e44779.
BACKGROUND: Children with Autistic Spectrum Disorders (ASD) are frequently hampered by motor impairment, with difficulties ranging from imitation of actions to recognition of motor intentions. Such a widespread inefficiency of the motor system is likely to interfere on the ontogeny of both motor planning and understanding of the goals of actions, thus delivering its ultimate effects on the emergence of social cognition. METHODOLOGY/PRINCIPAL FINDINGS: We investigate the organization of action representation in 15 high functioning ASD (mean age: 8.11) and in two control samples of typically developing (TD) children: the first one, from a primary school, was matched for chronological age (CA), the second one, from a kindergarten, comprised children of much younger age (CY). We used nine newly designed behavioural motor tasks, aiming at exploring three domains of motor cognition: 1) imitation of actions, 2) production of pantomimes, and 3) comprehension of pantomimes. The findings reveal that ASD children fare significantly worse than the two control samples in each of the inspected components of the motor representation of actions, be it the imitation of gestures, the self-planning of pantomimes, or the (verbal) comprehension of observed pantomimes. In the latter task, owing to its cognitive complexity, ASD children come close to the younger TD children’s level of performance; yet they fare significantly worse with respect to their age-mate controls. Overall, ASD children reveal a profound damage to the mechanisms that control both production and pre-cognitive « comprehension » of the motor representation of actions. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that many of the social cognitive impairments manifested by ASD individuals are likely rooted in their incapacity to assemble and directly grasp the intrinsic goal-related organization of motor behaviour. Such impairment of motor cognition might be partly due to an early damage of the Mirror Neuron Mechanism (MNM).
Lien vers le texte intégral (Open Access ou abonnement)
5. Fiorentini C, Gray L, Rhodes G, Jeffery L, Pellicano E. {{Reduced face identity aftereffects in relatives of children with autism}}. {Neuropsychologia}. 2012.
Autism is a pervasive developmental condition with complex aetiology. To aid the discovery of genetic mechanisms, researchers have turned towards identifying potential endophenotypes – subtle neurobiological or neurocognitive traits present in individuals with autism and their « unaffected » relatives. Previous research has shown that relatives of individuals with autism exhibit face processing atypicalities, which are similar in nature albeit of lesser degree, to those found in children and adults with autism. Yet very few studies have examined the underlying mechanisms responsible for such atypicalities. Here, we investigated whether atypicalities in adaptive norm-based coding of faces are present in relatives of children with autism, similar to those previously reported in children with autism. To test this possibility, we administered a face identity aftereffect task in which adaptation to a particular face biases perception towards the opposite identity, so that a previously neutral face (i.e., the average face) takes on the computationally opposite identity. Parents and siblings of individuals with autism showed smaller aftereffects compared to parents and siblings of typically developing children, especially so when the adapting stimuli were located further away from the average face. In addition, both groups showed stronger aftereffects for adaptors far from the average than for adaptors closer to the average. These results suggest that, in relatives of children with autism, face-coding mechanism are similar (i.e., norm-based) but less efficient than in relatives of typical children. This finding points towards the possibility that diminished adaptive mechanisms might represent a neurocognitive endophenotype for autism.
Lien vers le texte intégral (Open Access ou abonnement)
6. Hu VW. {{Is retinoic acid-related orphan receptor-alpha (RORA) a target for gene-environment interactions contributing to autism?}}. {Neurotoxicology}. 2012.
It is becoming increasingly clear that gene-environment interactions are risk factors for autism. However, there is limited information regarding the susceptibility of specific autism candidate genes to dysregulation by environmental factors, and even less information on the types of environmental agents that may lead to increased risk for autism. Based on our published studies, I propose that the demonstrated responsiveness of RORA to sex hormones makes it a prime target for disruption by endocrine disrupting compounds.
Lien vers le texte intégral (Open Access ou abonnement)
7. Kana RK, Libero LE, Hu CP, Deshpande HR, Colburn JS. {{Functional Brain Networks and White Matter Underlying Theory-of-Mind in Autism}}. {Soc Cogn Affect Neurosci}. 2012.
Human beings constantly engage in attributing causal explanations to one’s own and to others’ actions, and theory-of-mind (ToM) is critical in making such inferences. Although children learn causal attribution early in development, children with autism spectrum disorders (ASD) are known to have impairments in the development of intentional causality. This fMRI and DTI study investigated the neural correlates of physical and intentional causal attribution in people with ASD. In the fMRI scanner, 15 adolescents and adults with ASD and 15 age-and-IQ-matched typically developing peers made causal judgments about comic strips presented randomly in an event-related design. All participants showed robust activation in bilateral posterior superior temporal sulcus (pSTS) at the temporoparietal junction (TPJ) in response to intentional causality. Participants with ASD showed lower activation in TPJ, right inferior frontal gyrus, and left premotor cortex. Significantly weaker functional connectivity was also found in the ASD group between TPJ and motor areas during intentional causality. DTI data revealed significantly reduced fractional anisotropy in ASD participants in white matter underlying the temporal lobe. In addition to underscoring the role of TPJ in ToM, this study found an interaction between motor simulation and mentalizing systems in intentional causal attribution and its possible discord in autism.
Lien vers le texte intégral (Open Access ou abonnement)
8. Magana S, Smith LE. {{The Use of the Autism Diagnostic Interview-Revised with a Latino Population of Adolescents and Adults with Autism}}. {J Autism Dev Disord}. 2012.
Research shows that Latinos are less likely to be diagnosed with autism than their non-Latino counterparts. One factor that may contribute to these differences is that autism diagnostic instruments have not been adapted for the Latino population. The present study compared scores from the Autism Diagnostic Interview-Revised for two groups: 48 Latino adolescents and adults with autism and a matched sample of 96 non-Latino Whites. There were no significant differences between the two groups in total impairments in social reciprocity or communication. However, lower levels of restrictive-and-repetitive behaviors were found among Latino adolescents and adults with autism compared to Whites. Findings suggest that there may be cultural equivalency in some domains, but others may warrant further exploration.
Lien vers le texte intégral (Open Access ou abonnement)
9. Nackaerts E, Wagemans J, Helsen W, Swinnen SP, Wenderoth N, Alaerts K. {{Recognizing biological motion and emotions from point-light displays in autism spectrum disorders}}. {PLoS One}. 2012; 7(9): e44473.
One of the main characteristics of Autism Spectrum Disorder (ASD) are problems with social interaction and communication. Here, we explored ASD-related alterations in ‘reading’ body language of other humans. Accuracy and reaction times were assessed from two observational tasks involving the recognition of ‘biological motion’ and ’emotions’ from point-light displays (PLDs). Eye movements were recorded during the completion of the tests. Results indicated that typically developed-participants were more accurate than ASD-subjects in recognizing biological motion or emotions from PLDs. No accuracy differences were revealed on two control-tasks (involving the indication of color-changes in the moving point-lights). Group differences in reaction times existed on all tasks, but effect sizes were higher for the biological and emotion recognition tasks. Biological motion recognition abilities were related to a person’s ability to recognize emotions from PLDs. However, ASD-related atypicalities in emotion recognition could not entirely be attributed to more basic deficits in biological motion recognition, suggesting an additional ASD-specific deficit in recognizing the emotional dimension of the point light displays. Eye movements were assessed during the completion of tasks and results indicated that ASD-participants generally produced more saccades and shorter fixation-durations compared to the control-group. However, especially for emotion recognition, these altered eye movements were associated with reductions in task-performance.
Lien vers le texte intégral (Open Access ou abonnement)
10. Ozonoff S. {{Editorial Perspective: Autism Spectrum Disorders in DSM-5 – An historical perspective and the need for change}}. {J Child Psychol Psychiatry}. 2012.
Lien vers le texte intégral (Open Access ou abonnement)
11. Silverman JL, Babineau BA, Oliver CF, Karras MN, Crawley JN. {{Influence of stimulant-induced hyperactivity on social approach in the BTBR mouse model of autism}}. {Neuropharmacology}. 2012.
Translational research is needed to discover pharmacological targets and treatments for the diagnostic behavioral domains of autism spectrum disorders. Animal models with phenotypic relevance to diagnostic criteria offer clear experimental strategies to test the efficacy and safety of novel treatments. Antagonists of mGluR5 receptors are in clinical trials for Fragile X syndrome and under investigation for the treatment of autism spectrum disorders. However, in preclinical studies of mGluR5 compounds tested in our laboratory and others, increased locomotion following mGluR5 modulation has been observed. Understanding the influence of general activity on sociability and repetitive behaviors will increase the accuracy of interpretations of positive outcomes measured from pharmacological treatment that produces locomotor activating or sedating effects. In the present studies, dose-response curves for d-amphetamine (AMPH)-induced hyperlocomotion were similar in standard B6 mice and in the BTBR mouse model of autism. AMPH produced significant, robust reductions in the high level of repetitive self-grooming that characterizes BTBR, and also reduced the low baseline grooming in B6, indicating that AMPH-induced hyperlocomotion competes with time spent engaged in self-grooming. We then tested AMPH in B6 and BTBR on the 3-chambered social approach task. One component of sociability, the time spent in the chamber with the novel mouse, in B6 mice was reduced, while the sniffing time component of sociability in BTBR mice was enhanced. This finding replicated across multiple cohorts treated with AMPH and saline vehicle. In-depth analysis revealed that AMPH increased the number and decreased the duration of sniffing bouts in BTBR, suggesting BTBR treated with AMPH mostly engaged in brief sniffs rather than true social interactions with the novel mouse during the social approach task. Our data suggest that compounds with stimulant properties may have some direct benefits on reducing repetitive behaviors in autism spectrum disorders, particularly in the subset of autistic individuals with hyperactivity. This article is part of a Special Issue entitled ‘Neurodevelopment Disorder’.
Lien vers le texte intégral (Open Access ou abonnement)
12. Wang J, Hu Y, Wang Y, Qin X, Xia W, Sun C, Wu L. {{Parenting stress in Chinese mothers of children with autism spectrum disorders}}. {Soc Psychiatry Psychiatr Epidemiol}. 2012.
OBJECTIVE: Elevated parenting stress has been observed among mothers of children with autism spectrum disorders (ASDs) in western countries, but little is known about mothers of Han Chinese children. The aim of the current study was to further the knowledge about stress experienced by Chinese mothers of children with ASD by examining maternal parenting stress in Heilongjiang province of China. METHODS: In this cross-sectional study, data about participants’ demographic characteristics, parenting stress, anxiety, depression, child’s behavioral problems, coping strategies, and social support were collected though a questionnaire survey. The participants included 150 families with ASD children, who were consecutively admitted to the clinics of the Children Development and Behavior Research Center in Harbin Medical University, Heilongjiang Disabled Persons Federation, and Mudanjiang Child Welfare Home. RESULTS: The participants reported elevated parenting stress. Mothers’ parenting stress was associated with levels of depression and anxiety, and child’s behavioral symptoms. Child’s behavioral symptoms, maternal anxiety, maternal depressive symptoms, and lack of governmental financial support were associated with overall parenting stress. CONCLUSIONS: Government support may play an important role in reducing parenting stress in this population.
