1. Alanazi AS. {{The role of nutraceuticals in the management of autism}}. {Saudi Pharm J}. 2013; 21(3): 233-43.
Autism and related disorders are increasingly prevalent behavioral syndromes of impaired verbal and nonverbal communication and socialization owing to neurodevelopmental abnormalities. The most recent estimate for the prevalence of autistic disorders is about 1% on a global scale. Etiology of autism is multifactorial and multidimensional that makes therapeutic intervention even harder. Heterogeneity of genetic factors, oxidative stress, autoimmune mechanism, and epigenetic mechanisms complicate the nature of pathogenesis of the disease. Nutraceutical approach to treat this disease is a promising strategy, especially in some areas, it is more attractive than others. This review critically analyzes the roles of vitamins and cofactors, dietary modifications and gut abnormalities, probiotics and prebiotics, phytochemicals, and environmental factors in order to determine the state of evidence in nutraceutical-based autism management practices. This article presents a systematic review of randomized- and placebocontrolled trials to examine the evidence supports the use of autism nutraceu10.1016/j.jsps.2012.10.001ticals. The results will be discussed in the light of all relevant evidence generated from other clinical and exploratory studies.
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2. Al-Sharbati MM, Al-Farsi YM, Ouhtit A, Waly MI, Al-Shafaee M, Al-Farsi O, Al-Khaduri M, Al-Said MF, Al-Adawi S. {{Awareness about autism among school teachers in Oman: A cross-sectional study}}. {Autism}. 2013.
Children with special needs such as those with autism spectrum disorder have been recorded as ostracized and stigmatized in many parts of the world. Little is known about whether such negative views are present among mainstream teachers in Oman. A cross-sectional study was conducted to evaluate school teachers’ awareness about autism spectrum disorder in an urban region in Oman. A total of 164 teachers were randomly enrolled from five schools. Misconceptions about autism spectrum disorder were found to be common among mainstream teachers in the country. We posit that such lack of awareness was likely to be rooted with sociocultural patterning as well as conflicting views often « spun » by the scientific community and mass media. Enlightened views toward children with autism spectrum disorder should be presented to Omani teachers to overcome misconceptions and negative attitudes toward children with autism spectrum disorder.
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3. Bekhet AK, Zauszniewski JA. {{Psychometric Properties of the Resourcefulness Scale Among Caregivers of Persons With Autism Spectrum Disorder}}. {West J Nurs Res}. 2013.
Caregiving for children with autism spectrum disorder (ASD) can be very costly to caregivers’ well-being. Resourcefulness interventions have shown increases in positive health outcomes. However, before delivering the intervention, there should be a reliable and a valid measure to test resourcefulness. The psychometric properties of the Resourcefulness Scale (RS) have not been examined among ASD caregivers. This study examined the psychometrics of the 28-item RS in a convenience sample of 204 ASD caregivers. A Cronbach’s alpha of .91 showed the internal consistency of the RS. Construct validity was supported by the emergence of two dimensions of resourcefulness (personal and social) in a confirmatory factor analysis and by substantial intercorrelations between the two subscales (r = .48, p < .001). Findings suggested the reliability and validity of RS among ASD caregivers, which is a necessary step toward implementing resourcefulness interventions to help ASD caregivers to deal with their stress and improve their quality of life.
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4. Benevides TW, Lane SJ. {{A Review of Cardiac Autonomic Measures: Considerations for Examination of Physiological Response in Children with Autism Spectrum Disorder}}. {J Autism Dev Disord}. 2013.
The autonomic nervous system (ANS) is responsible for multiple physiological responses, and dysfunction of this system is often hypothesized as contributing to cognitive, affective, and behavioral responses in children. Research suggests that examination of ANS activity may provide insight into behavioral dysregulation in children with autism spectrum disorders (ASD), however, there is wide variability in samples, methods, and measures reported. The purpose of this review is to describe frequently reported cardiac ANS measures; discuss theoretical models linking ANS measures with neurological structures; and synthesize pediatric literature using ANS measures on typical and ASD samples. Such a synthesis will provide researchers with a foundation for the use of ANS cardiac methods and measures in ASD research.
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5. Cohen S, Masyn K, Mastergeorge A, Hessl D. {{Psychophysiological Responses to Emotional Stimuli in Children and Adolescents with Autism and Fragile X Syndrome}}. {J Clin Child Adolesc Psychol}. 2013.
Individuals with autism demonstrate atypical and variable responses to social and emotional stimuli, perhaps reflecting heterogeneity of the disorder. The goal of this study was to determine whether unique profiles of psychophysiological responses to such stimuli could be identified in individuals diagnosed with autism spectrum disorder (ASD), with fragile X syndrome (FXS), and with comorbid autism and fragile X syndrome (ASD + FXS), and in typically developing (TYP) individuals. This study included 52 boys (ages 10-17): idiopathic ASD (n = 12), FXS (n = 12), comorbid ASD + FXS (n = 17), and TYP (n = 11). Physiological responses, including potentiated startle, electrodermal response, heart rate variability, and vagal tone, were collected concurrently while participants viewed emotionally evocative pictures of human faces or nonsocial images. Although some of these measures have been utilized separately for investigations on these diagnostic groups, they have not been considered together. Results using Kruskal-Wallis one-way analysis of variance by ranks indicate statistically significant differences in distributions of autonomic regulation responses between groups. The most notable differences were between the ASD group and both the FXS groups on measures of sympathetic activity, with FXS groups evincing increased activity. Also, both the ASD and ASD + FXS groups showed significantly decreased parasympathetic activity compared with FXS and TYP groups. In addition, the ASD + FXS group demonstrated a unique distribution of startle potentiation and arousal modulation. This study provides evidence that autonomic arousal and regulation profiles could be useful for distinguishing subgroups of autism and shed light on the variability underlying emotional responsivity.
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6. Corbett BA, Swain DM, Coke C, Simon D, Newsom C, Houchins-Juarez N, Jenson A, Wang L, Song Y. {{Improvement in Social Deficits in Autism Spectrum Disorders Using a Theatre-Based, Peer-Mediated Intervention}}. {Autism Res}. 2013.
Social Emotional NeuroScience Endocrinology Theatre is a novel intervention program aimed at improving reciprocal social interaction in youth with autism spectrum disorder (ASD) using behavioral strategies and theatrical techniques in a peer-mediated model. Previous research using a 3-month model showed improvement in face perception, social interaction, and reductions in stress. The current study assessed a 2-week summer camp model. Typically developing peers were trained and paired with ASD youth (8-17 years). Social perception and interaction skills were measured before and after treatment using neuropsychological and parental measures. Behavioral coding by reliable, independent raters was conducted within the treatment context (theatre) and outside the setting (playground). Salivary cortisol levels to assess physiological arousal were measured across contexts (home, theatre, and playground). A pretest-posttest design for within-group comparisons was used, and prespecified pairwise comparisons were achieved using a nonparametric Wilcoxon signed-rank test. Significant differences were observed in face processing, social awareness, and social cognition (P < 0.05). Duration of interaction with familiar peers increased significantly over the course of treatment (P < 0.05), while engagement with novel peers outside the treatment setting remained stable. Cortisol levels rose on the first day of camp compared with home values yet declined by the end of treatment and further reduced during posttreatment play with peers. Results corroborate previous findings that the peer-mediated theatre program contributes to improvement in core social deficits in ASD using a short-term, summer camp treatment model. Future studies will explore treatment length and peer familiarity to optimize and generalize gains. Autism Res 2013,: -. (c) 2013 International Society for Autism Research, Wiley Periodicals, Inc.
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7. Deshpande G, Libero LE, Sreenivasan KR, Deshpande HD, Kana RK. {{Identification of neural connectivity signatures of autism using machine learning}}. {Front Hum Neurosci}. 2013; 7: 670.
Alterations in interregional neural connectivity have been suggested as a signature of the pathobiology of autism. There have been many reports of functional and anatomical connectivity being altered while individuals with autism are engaged in complex cognitive and social tasks. Although disrupted instantaneous correlation between cortical regions observed from functional MRI is considered to be an explanatory model for autism, the causal influence of a brain area on another (effective connectivity) is a vital link missing in these studies. The current study focuses on addressing this in an fMRI study of Theory-of-Mind (ToM) in 15 high-functioning adolescents and adults with autism and 15 typically developing control participants. Participants viewed a series of comic strip vignettes in the MRI scanner and were asked to choose the most logical end to the story from three alternatives, separately for trials involving physical and intentional causality. The mean time series, extracted from 18 activated regions of interest, were processed using a multivariate autoregressive model (MVAR) to obtain the causality matrices for each of the 30 participants. These causal connectivity weights, along with assessment scores, functional connectivity values, and fractional anisotropy obtained from DTI data for each participant, were submitted to a recursive cluster elimination based support vector machine classifier to determine the accuracy with which the classifier can predict a novel participant’s group membership (autism or control). We found a maximum classification accuracy of 95.9% with 19 features which had the highest discriminative ability between the groups. All of the 19 features were effective connectivity paths, indicating that causal information may be critical in discriminating between autism and control groups. These effective connectivity paths were also found to be significantly greater in controls as compared to ASD participants and consisted predominantly of outputs from the fusiform face area and middle temporal gyrus indicating impaired connectivity in ASD participants, particularly in the social brain areas. These findings collectively point toward the fact that alterations in causal connectivity in the brain in ASD could serve as a potential non-invasive neuroimaging signature for autism.
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8. Fong BM, Tam S, Leung KS. {{Determination of plasma cholesterol sulfate by LC-APCI-MS/MS in the context of pediatric autism}}. {Talanta}. 2013; 116: 115-21.
Cholesterol sulfate (CS) has various biological functions. Previously, plasma CS was measured primarily as a means to diagnose X-linked ichthyosis; however, a recent hypothesis suggests that CS deficiency might be related to autism. As such, an assay capable of measuring both very high (in the case of X-linked ichthyosis) and very low (in the case of autism) plasma CS levels is required. Here we describe a novel LC-APCI-MS/MS method for the determination of CS in human plasma, and we propose normal CS ranges for children, based on studies of a local population of normal Chinese children between the ages of 2 and 10. In addition, we have used this method to measure plasma CS in autistic children. CS was isolated by solid-phase extraction, and quantified by isotope-dilution LC-APCI-MS/MS in negative ion mode monitoring 465.3>97.1m/z (CS) and 472.3>97.1m/z (CS-d7). Mean recovery of the assay ranged from 88.1 to 112.7%; within- and between-run imprecisions have CVs less than 7.2 and 8.1%, respectively. The assay was linear up to at least 100micromolL(-1). The reference interval of plasma CS in males (range: 1.16-4.23micromolL(-1)) was found to be higher than in females (range: 0.86-3.20micromolL(-1)). Comparison of normal and autistic children showed no statistically significant difference in the plasma CS level. In conclusion, a robust LC-APCI-MS/MS method for plasma CS was developed, and a pediatric reference interval was derived from applying the method to normal and autistic children.
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9. Gadad BS, Hewitson L, Young KA, German DC. {{Neuropathology and Animal Models of Autism: Genetic and Environmental Factors}}. {Autism Res Treat}. 2013; 2013: 731935.
Autism is a heterogeneous behaviorally defined neurodevelopmental disorder. It is defined by the presence of marked social deficits, specific language abnormalities, and stereotyped repetitive patterns of behavior. Because of the variability in the behavioral phenotype of the disorder among patients, the term autism spectrum disorder has been established. In the first part of this review, we provide an overview of neuropathological findings from studies of autism postmortem brains and identify the cerebellum as one of the key brain regions that can play a role in the autism phenotype. We review research findings that indicate possible links between the environment and autism including the role of mercury and immune-related factors. Because both genes and environment can alter the structure of the developing brain in different ways, it is not surprising that there is heterogeneity in the behavioral and neuropathological phenotypes of autism spectrum disorders. Finally, we describe animal models of autism that occur following insertion of different autism-related genes and exposure to environmental factors, highlighting those models which exhibit both autism-like behavior and neuropathology.
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10. Happe F. {{International society for autism research news}}. {Autism Res}. 2013; 6(5): 460.
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11. Hasegawa N, Kitamura H, Murakami H, Kameyama S, Sasagawa M, Egawa J, Tamura R, Endo T, Someya T. {{Altered Activity of the Primary Visual Area during Gaze Processing in Individuals with High-Functioning Autistic Spectrum Disorder: A Magnetoencephalography Study}}. {Neuropsychobiology}. 2013; 68(3): 181-8.
Background: Individuals with autistic spectrum disorder (ASD) demonstrate an impaired ability to infer the mental states of others from their gaze. Thus, investigating the relationship between ASD and eye gaze processing is crucial for understanding the neural basis of social impairments seen in individuals with ASD. In addition, characteristics of ASD are observed in more comprehensive visual perception tasks. These visual characteristics of ASD have been well-explained in terms of the atypical relationship between high- and low-level gaze processing in ASD. Method: We studied neural activity during gaze processing in individuals with ASD using magnetoencephalography, with a focus on the relationship between high- and low-level gaze processing both temporally and spatially. Minimum Current Estimate analysis was applied to perform source analysis of magnetic responses to gaze stimuli. Results: The source analysis showed that later activity in the primary visual area (V1) was affected by gaze direction only in the ASD group. Conversely, the right posterior superior temporal sulcus, which is a brain region that processes gaze as a social signal, in the typically developed group showed a tendency toward greater activation during direct compared with averted gaze processing. Conclusion: These results suggest that later activity in V1 relating to gaze processing is altered or possibly enhanced in high-functioning individuals with ASD, which may underpin the social cognitive impairments in these individuals. (c) 2013 S. Karger AG, Basel.
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12. Hobson RP. {{The coherence of autism}}. {Autism}. 2013.
There is a growing body of opinion that we should view autism as fractionable into different, largely independent sets of clinical features. The alternative view is that autism is a coherent syndrome in which principal features of the disorder stand in intimate developmental relationship with each other. Studies of congenitally blind children offer support for the latter position and suggest that a source of coherence in autism is restriction in certain forms of perceptually dependent social experience.
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13. Lopez B. {{Beyond Modularisation: The Need of a Socio-Neuro-Constructionist Model of Autism}}. {J Autism Dev Disord}. 2013.
Autism is a developmental disorder defined by social and communication impairments. Current theoretical approaches and research studies however conceptualise autism as both static and independent from the social context in which it develops. Two lines of research stand out from this general trend. First, research from the neuroconstructivist approach of Karmiloff-Smith (Hum Brain Mapp 31:934-941, 2010) aims to establish developmental trajectories of cognitive impairments in autism over time. Second, studies from intersubjective approaches such as that of Hobson (The cradle of thought, Macmillan, London, 2002) focus on the influence of emotional engagement in cognitive impairments. Although these two lines of research have made an invaluable contribution towards our understanding of autism, both offer only partial explanations: Intersubjective approaches fail to provide a developmental perspective and the neuroconstructivist model neglects the role of the social context. This paper argues that the nature of autism demands the theoretical and methodological integration of these two approaches so that developmental and social aspects are investigated in tandem.
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14. Mbadiwe T, Millis RM. {{Epigenetics and Autism}}. {Autism Res Treat}. 2013; 2013: 826156.
This review identifies mechanisms for altering DNA-histone interactions of cell chromatin to upregulate or downregulate gene expression that could serve as epigenetic targets for therapeutic interventions in autism. DNA methyltransferases (DNMTs) can phosphorylate histone H3 at T6. Aided by protein kinase C beta 1, the DNMT lysine-specific demethylase-1 prevents demethylation of H3 at K4. During androgen-receptor-(AR-) dependent gene activation, this sequence may produce AR-dependent gene overactivation which may partly explain the male predominance of autism. AR-dependent gene overactivation in conjunction with a DNMT mechanism for methylating oxytocin receptors could produce high arousal inputs to the amygdala resulting in aberrant socialization, a prime characteristic of autism. Dysregulation of histone methyltransferases and histone deacetylases (HDACs) associated with low activity of methyl CpG binding protein-2 at cytosine-guanine sites in genes may reduce the capacity for condensing chromatin and silencing genes in frontal cortex, a site characterized by decreased cortical interconnectivity in autistic subjects. HDAC1 inhibition can overactivate mRNA transcription, a putative mechanism for the increased number of cerebral cortical columns and local frontal cortex hyperactivity in autistic individuals. These epigenetic mechanisms underlying male predominance, aberrant social interaction, and low functioning frontal cortex may be novel targets for autism prevention and treatment strategies.
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15. Moyal WN, Lord C, Walkup JT. {{Quality of Life in Children and Adolescents with Autism Spectrum Disorders: What Is Known About the Effects of Pharmacotherapy?}}. {Paediatr Drugs}. 2013.
A diagnosis of autistic spectrum disorder (ASD), now estimated to affect one in 88 children, requires deficits in social communication and interactions, and restricted interests and/or repetitive behaviors. Almost all children with ASD have deficits in adaptive skills, many have intellectual disability, and others have co-occurring psychiatric disorders or symptoms. Thus, this complex disorder has shown to have a substantial impact on patients’ quality of life (QoL) and that of their families. Medication treatment is considered by clinicians and families to address problems with functioning due to psychiatric problems, and, as such, one-third of children and adolescents with ASD take at least one psychotropic medication and many use complementary and alternative medicine. This paper reviews what is known about the benefits and risks of psychotropic medications on the QoL of children with ASD. Although scarce, there are studies of psychiatric medications in autistic patients that include QoL measures, such as the pediatric studies of aripiprazole for irritability and one adult study of oxytocin. The aripiprazole study showed a positive effect on QoL in treated patients, as did the oxytocin study. Several other psychotropic medications are used in the treatment of children with ASD, and although information is available on the risks and benefits of each, we do not have specific data on the QoL impact of these medications. The aripiprazole and oxytocin studies exemplify how researchers can include QoL measures and use this information to guide clinicians. Additionally, we will recommend areas of further study in pharmacotherapy and QoL research in the context of treating children with ASD.
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16. O’Haire ME, McKenzie SJ, McCune S, Slaughter V. {{Effects of Classroom Animal-Assisted Activities on Social Functioning in Children with Autism Spectrum Disorder}}. {J Altern Complement Med}. 2013.
Abstract Objective: The objective of this study was to implement and evaluate a classroom-based Animal-Assisted Activities (AAA) program on social functioning in children with autism spectrum disorder (ASD). Design: This was a multisite, control-to-intervention design study. Settings/location: The study was conducted in 41 classrooms in 15 schools in Brisbane, Australia. Subjects: Sixty-four (64) 5- to 12-year-old children diagnosed with ASD comprised the study group. Intervention: The AAA program consisted of 8 weeks of animal exposure in the school classroom in addition to 16 20-minute animal-interaction sessions. Outcome measures: Teacher- and parent-reported child behavior and social functioning were assessed through standardized instruments at three time points: upon study entry (Time 1), after an 8-week waiting period during the week prior to the AAA program (Time 2), and during the week following the 8-week AAA program (Time 3). Results: Significant improvements were identified in social functioning, including increases in social approach behaviors and social skills, and decreases in social withdrawal behaviors, from before to after the AAA program, but not during the waitlist period. Over half of parents also reported that participants demonstrated an increased interest in attending school during the program. Conclusions: Results demonstrate the feasibility and potential efficacy of a new classroom-based Animal-Assisted Activities model, which may provide a relatively simple and cost-effective means of helping educators and families to improve the social functioning of children with ASD.
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17. Pallett PM, Cohen SJ, Dobkins KR. {{Face and Object Discrimination in Autism, and Relationship to IQ and Age}}. {J Autism Dev Disord}. 2013.
The current study tested fine discrimination of upright and inverted faces and objects in adolescents with Autism Spectrum Disorder (ASD) as compared to age- and IQ-matched controls. Discrimination sensitivity was tested using morphed faces and morphed objects, and all stimuli were equated in low-level visual characteristics (luminance, contrast, spatial frequency make-up). Participants with ASD exhibited slight, non-significant impairments in discrimination sensitivity for faces, yet significantly enhanced discrimination sensitivity for objects. The ASD group also showed a protracted development of face and object inversion effects. Finally, for ASD participants, face sensitivity improved with increasing IQ while object sensitivity improved with age. By contrast, for controls, face sensitivity improved with age, but neither face nor object sensitivity was influenced by IQ. These findings suggest that individuals with ASD follow a qualitatively different path in the development of face and object processing abilities.
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18. Plummer JT, Evgrafov OV, Bergman MY, Friez M, Haiman CA, Levitt P, Aldinger KA. {{Transcriptional regulation of the MET receptor tyrosine kinase gene by MeCP2 and sex-specific expression in autism and Rett syndrome}}. {Transl Psychiatry}. 2013; 3: e316.
Single nucleotide variants (SNV) in the gene encoding the MET receptor tyrosine kinase have been associated with an increased risk for autism spectrum disorders (ASD). The MET promoter SNV rs1858830 C ‘low activity’ allele is enriched in ASD, associated with reduced protein expression, and impacts functional and structural circuit connectivity in humans. To gain insight into the transcriptional regulation of MET on ASD-risk etiology, we examined an interaction between the methyl CpG-binding protein 2 (MeCP2) and the MET 5′ promoter region. Mutations in MeCP2 cause Rett syndrome (RTT), a predominantly female neurodevelopmental disorder sharing some ASD clinical symptoms. MeCP2 binds to a region of the MET promoter containing the ASD-risk SNV, and displays rs1858830 genotype-specific binding in human neural progenitor cells derived from the olfactory neuroepithelium. MeCP2 binding enhances MET expression in the presence of the rs1858830 C allele, but MET transcription is attenuated by RTT-specific mutations in MeCP2. In the postmortem temporal cortex, a region normally enriched in MET, gene expression is reduced dramatically in females with RTT, although not due to enrichment of the rs1858830 C ‘low activity’ allele. We newly identified a sex-based reduction in MET expression, with male ASD cases, but not female ASD cases compared with sex-matched controls. The experimental data reveal a prominent allele-specific regulation of MET transcription by MeCP2. The mechanisms underlying the pronounced reduction of MET in ASD and RTT temporal cortex are distinct and likely related to factors unique to each disorder, including a noted sex bias.
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19. Steadman PE, Ellegood J, Szulc KU, Turnbull DH, Joyner AL, Henkelman RM, Lerch JP. {{Genetic Effects on Cerebellar Structure Across Mouse Models of Autism Using a Magnetic Resonance Imaging Atlas}}. {Autism Res}. 2013.
Magnetic resonance imaging (MRI) of autism populations is confounded by the inherent heterogeneity in the individuals’ genetics and environment, two factors difficult to control for. Imaging genetic animal models that recapitulate a mutation associated with autism quantify the impact of genetics on brain morphology and mitigate the confounding factors in human studies. Here, we used MRI to image three genetic mouse models with single mutations implicated in autism: Neuroligin-3 R451C knock-in, Methyl-CpG binding protein-2 (MECP2) 308-truncation and integrin beta3 homozygous knockout. This study identified the morphological differences specific to the cerebellum, a structure repeatedly linked to autism in human neuroimaging and postmortem studies. To accomplish a comparative analysis, a segmented cerebellum template was created and used to segment each study image. This template delineated 39 different cerebellar structures. For Neuroligin-3 R451C male mutants, the gray (effect size (ES) = 1.94, FDR q = 0.03) and white (ES = 1.84, q = 0.037) matter of crus II lobule and the gray matter of the paraflocculus (ES = 1.45, q = 0.045) were larger in volume. The MECP2 mutant mice had cerebellar volume changes that increased in scope depending on the genotype: hemizygous males to homozygous females. The integrin beta3 mutant mouse had a drastically smaller cerebellum than controls with 28 out of 39 cerebellar structures smaller. These imaging results are discussed in relation to repetitive behaviors, sociability, and learning in the context of autism. This work further illuminates the cerebellum’s role in autism. Autism Res 2013, : -. (c) 2013 International Society for Autism Research, Wiley Periodicals, Inc.
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20. Tanaka JW, Sung A. {{The « Eye Avoidance » Hypothesis of Autism Face Processing}}. {J Autism Dev Disord}. 2013.
Although a growing body of research indicates that children with autism spectrum disorder (ASD) exhibit selective deficits in their ability to recognize facial identities and expressions, the source of their face impairment is, as yet, undetermined. In this paper, we consider three possible accounts of the autism face deficit: (1) the holistic hypothesis, (2) the local perceptual bias hypothesis and (3) the eye avoidance hypothesis. A review of the literature indicates that contrary to the holistic hypothesis, there is little evidence to suggest that individuals with autism do perceive faces holistically. The local perceptual bias account also fails to explain the selective advantage that ASD individuals demonstrate for objects and their selective disadvantage for faces. The eye avoidance hypothesis provides a plausible explanation of face recognition deficits where individuals with ASD avoid the eye region because it is perceived as socially threatening. Direct eye contact elicits a increased physiological response as indicated by heightened skin conductance and amygdala activity. For individuals with autism, avoiding the eyes is an adaptive strategy, however, this approach interferes with the ability to process facial cues of identity, expressions and intentions, exacerbating the social challenges for persons with ASD.
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21. Visser E, Zwiers MP, Kan CC, Hoekstra L, van Opstal AJ, Buitelaar JK. {{Atypical vertical sound localization and sound-onset sensitivity in people with autism spectrum disorders}}. {J Psychiatry Neurosci}. 2013; 38(6): 398-406.
BACKGROUND: Autism spectrum disorders (ASDs) are associated with auditory hyper- or hyposensitivity; atypicalities in central auditory processes, such as speech-processing and selective auditory attention; and neural connectivity deficits. We sought to investigate whether the low-level integrative processes underlying sound localization and spatial discrimination are affected in ASDs. METHODS: We performed 3 behavioural experiments to probe different connecting neural pathways: 1) horizontal and vertical localization of auditory stimuli in a noisy background, 2) vertical localization of repetitive frequency sweeps and 3) discrimination of horizontally separated sound stimuli with a short onset difference (precedence effect). RESULTS: Ten adult participants with ASDs and 10 healthy control listeners participated in experiments 1 and 3; sample sizes for experiment 2 were 18 adults with ASDs and 19 controls. Horizontal localization was unaffected, but vertical localization performance was significantly worse in participants with ASDs. The temporal window for the precedence effect was shorter in participants with ASDs than in controls. LIMITATIONS: The study was performed with adult participants and hence does not provide insight into the developmental aspects of auditory processing in individuals with ASDs. CONCLUSION: Changes in low-level auditory processing could underlie degraded performance in vertical localization, which would be in agreement with recently reported changes in the neuroanatomy of the auditory brainstem in individuals with ASDs. The results are further discussed in the context of theories about abnormal brain connectivity in individuals with ASDs.
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22. Wang HZ, Qin HD, Guo W, Samuels J, Shugart YY. {{New insights into the genetic mechanism of IQ in autism spectrum disorders}}. {Front Genet}. 2013; 4: 195.
Autism spectrum disorders (ASD) comprise a number of underlying sub-types with various symptoms and presumably different genetic causes. One important difference between these sub-phenotypes is IQ. Some forms of ASD such as Asperger’s have relatively intact intelligence while the majority does not. In this study, we explored the role of genetic factors that might account for this difference. Using a case-control study based on IQ status in 1657 ASD probands, we analyzed both common and rare variants provided by the Autism Genome Project (AGP) consortium via dbGaP (database of Genotypes and Phenotypes). We identified a set of genes, among them HLA-DRB1 and KIAA0319L, which are strongly associated with IQ within a population of ASD patients.
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23. Wojcik DZ, Waterman AH, Lestie C, Moulin CJ, Souchay C. {{Metacognitive judgments-of-learning in adolescents with autism spectrum disorder}}. {Autism}. 2013.
This study investigated metacognitive monitoring abilities in adolescents with autism spectrum disorder in two experiments using the judgment-of-learning paradigm. Participants were asked to predict their future recall of unrelated word pairs during the learning phase. Experiment 1 compared judgments-of-learning made immediately after learning and judgments-of-learning made after a delay. We found that both groups overestimated their memory performance but that overall there were no group differences in judgment-of-learning accuracy. Additionally, both groups displayed the standard delayed judgment-of-learning effect (yielding greater judgment accuracy in delayed compared to immediate judgments), suggesting that both groups were able to use appropriate information in making their judgments-of-learning. Experiment 2 assessed whether adolescents with autism spectrum disorder could regulate their study time according to their judgments-of-learning using a self-paced learning procedure. Results showed that both groups spent more time learning items given lower judgments-of-learning. Finally, Experiment 2 showed that judgments-of-learning and study time varied according to item difficulty in both groups. As a whole, these findings demonstrate that adolescents with autism spectrum disorder can accurately gauge their memory performance while learning new word associations and use these skills to control their study time at learning.
