1. Brosnan MJ, Gwilliam LR, Walker I. {{Brief Report: The Relationship Between Visual Acuity, the Embedded Figures Test and Systemizing in Autism Spectrum Disorders}}. {J Autism Dev Disord};2012 (Mar 27)
Enhanced performance upon the Embedded Figures Test (EFT) in individuals with autism spectrum disorder (ASD) has informed psychological theories of the non-social aspects that characterise ASD. The Extreme Male Brain theory of autism proposes that enhanced visual acuity underpins greater attention to detail (assessed by the EFT) which is a prerequisite for Systemizing. To date, however, no study has empirically examined these relationships. 13 males with ASD and 13 male controls were assessed upon tasks argued to reflect these levels of processing. The ASD group were found to have significantly greater visual acuity, EFT performance and Systemizing ability than the control group. However, regression analysis revealed that the strongest relationship was between visual acuity and EFT performance.
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2. Cascio CJ, Moana-Filho EJ, Guest S, Nebel MB, Weisner J, Baranek GT, Essick GK. {{Perceptual and Neural Response to Affective Tactile Texture Stimulation in Adults with Autism Spectrum Disorders}}. {Autism Res};2012 (Mar 23)
Autism spectrum disorders (ASD) are associated with differences in sensory sensitivity and affective response to sensory stimuli, the neural basis of which is still largely unknown. We used psychophysics and functional magnetic resonance imaging (fMRI) to investigate responses to somatosensory stimulation with three textured surfaces that spanned a range of roughness and pleasantness in a sample of adults with ASD and a control group. While psychophysical ratings of roughness and pleasantness were largely similar across the two groups, the ASD group gave pleasant and unpleasant textures more extreme average ratings than did controls. In addition, their ratings for a neutral texture were more variable than controls, indicating they are less consistent in evaluating a stimulus that is affectively ambiguous. Changes in brain blood oxygenation level-dependent (BOLD) signal in response to stimulation with these textures differed substantially between the groups, with the ASD group exhibiting diminished responses compared to the control group, particularly for pleasant and neutral textures. For the most unpleasant texture, the ASD group exhibited greater BOLD response than controls in affective somatosensory processing areas such as the posterior cingulate cortex and the insula. The amplitude of response in the insula in response to the unpleasant texture was positively correlated with social impairment as measured by the Autism Diagnostic Interview-Revised (ADI-R). These results suggest that people with ASD tend to show diminished response to pleasant and neutral stimuli, and exaggerated limbic responses to unpleasant stimuli, which may contribute to diminished social reward associated with touch, perpetuating social withdrawal, and aberrant social development. Autism Res 2012,**:**-**. (c) 2012 International Society for Autism Research, Wiley Periodicals, Inc.
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3. Hudson M, Nijboer TC, Jellema T. {{Implicit Social Learning in Relation to Autistic-Like Traits}}. {J Autism Dev Disord};2012 (Mar 24)
We investigated if variation in autistic traits in the typically-developed population (using the Autism-spectrum Quotient, AQ) influenced implicit learning of social information. In the learning phase, participants repeatedly observed two identities whose gaze and expression conveyed either a pro- or antisocial disposition. These identities were then employed in a gaze-cueing paradigm. Participants made speeded responses to a peripheral target that was spatially pre-cued by a non-predictive gaze direction. The low AQ group (n = 50) showed a smaller gaze-cueing effect for the antisocial than for the prosocial identity. The high AQ group (n = 48) showed equivalent gaze-cueing for both identities. Others’ intentions/dispositions can be learned implicitly and affect subsequent responses to their behavior. This ability is impaired with increasing levels of autistic traits.
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4. Irie F, Badie-Mahdavi H, Yamaguchi Y. {{Autism-like socio-communicative deficits and stereotypies in mice lacking heparan sulfate}}. {Proc Natl Acad Sci U S A};2012 (Mar 27);109(13):5052-5056.
Heparan sulfate regulates diverse cell-surface signaling events, and its roles in the development of the nervous system recently have been increasingly uncovered by studies using genetic models carrying mutations of genes encoding enzymes for its synthesis. On the other hand, the role of heparan sulfate in the physiological function of the adult brain has been poorly characterized, despite several pieces of evidence suggesting its role in the regulation of synaptic function. To address this issue, we eliminated heparan sulfate from postnatal neurons by conditionally inactivating Ext1, the gene encoding an enzyme essential for heparan sulfate synthesis. Resultant conditional mutant mice show no detectable morphological defects in the cytoarchitecture of the brain. Remarkably, these mutant mice recapitulate almost the full range of autistic symptoms, including impairments in social interaction, expression of stereotyped, repetitive behavior, and impairments in ultrasonic vocalization, as well as some associated features. Mapping of neuronal activation by c-Fos immunohistochemistry demonstrates that neuronal activation in response to social stimulation is attenuated in the amygdala in these mice. Electrophysiology in amygdala pyramidal neurons shows an attenuation of excitatory synaptic transmission, presumably because of the reduction in the level of synaptically localized AMPA-type glutamate receptors. Our results demonstrate that heparan sulfate is critical for normal functioning of glutamatergic synapses and that its deficiency mediates socio-communicative deficits and stereotypies characteristic for autism.
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5. Segura Benedicto A. {{[The putative link between the MMR vaccine and autism and refusal to vaccinate.]}}. {Gac Sanit};2012 (Mar 23)
The paper of Wakefield et al. in The Lancet, triggered a negative reaction to the MMR vaccine, even though it was just a series of cases and the association between vaccination and autism could well be anecdotal. However, it was found that this association was spurious, not only because of hidden biases but also to alterations of the data and other improper behavior of the two authors that they were expelled from medical council. Finally, the article was removed from the magazine. This episode invites to think about the credibility and trust in the authorities and professionals to the population, as well as the suspicions that may arise when there are potential conflicts of interest among professionals, industry magazines and the population. A special area of interest is on the distorted expectations of health interventions, including vaccination, particularly with regard to both individual and collective prevention.
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6. Teunisse JP, Roelofs RL, Verhoeven EW, Cuppen L, Mol J, Berger HJ. {{Flexibility in children with autism spectrum disorders (ASD): Inconsistency between neuropsychological tests and parent-based rating scales}}. {J Clin Exp Neuropsychol};2012 (Mar 26)
In this study, we compared neuropsychological tests and parent-based ratings of flexibility in a sample of children with autism spectrum disorders (ASD). We investigated the discriminant validity of the domain-specific flexibility measures by comparison with the domain general measures, general behavioral problems, general ASD-related traits, and general intelligence. Tests and parent-based ratings of flexibility were not significantly correlated. Parent-based ratings were strongly related with the three broadband measures, whereas the discriminant validity indices of the neuropsychological tests were satisfactory. These findings suggest that parent-based ratings do not reflect the specific executive construct of flexibility, but instead reflect a broad spectrum of general child characteristics.
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7. The Simons Vip C. {{Simons Variation in Individuals Project (Simons VIP): A Genetics-First Approach to Studying Autism Spectrum and Related Neurodevelopmental Disorders}}. {Neuron};2012 (Mar 22);73(6):1063-1067.
We describe a project aimed at studying a large number of individuals (>200) with specific recurrent genetic variations (deletion or duplication of segment 16p11.2) that increase the risk of developing autism spectrum (ASD) and other developmental disorders. The genetics-first approach augmented by web-based recruitment, multisite collaboration and calibration, and robust data-sharing policies could be adopted by other groups studying neuropsychiatric disorders to accelerate the pace of research.
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8. Varni JW, Handen BL, Corey-Lisle PK, Guo Z, Manos G, Ammerman DK, Marcus RN, Owen R, McQuade RD, Carson WH, Mathew S, Mankoski R. {{Effect of Aripiprazole 2 to 15 mg/d on Health-Related Quality of Life in the Treatment of Irritability Associated with Autistic Disorder in Children: A Post Hoc Analysis of Two Controlled Trials}}. {Clin Ther};2012 (Mar 21)
Background: There are limited published data on the impact of treatment on the health-related quality of life (HRQOL) in individuals with autistic disorder. OBJECTIVE: The aim of this study was to evaluate the impact of aripiprazole on HRQOL in the treatment of irritability in pediatric patients (aged 6-17 years) with autistic disorder. METHODS: This post hoc analysis assessed data from two 8-week, double-blind, randomized, placebo-controlled studies that compared the efficacy of aripiprazole (fixed-dose study, 5, 10, and 15 mg/d; flexible-dose study, 2-15 mg/d) with placebo in the treatment of irritability associated with autistic disorder. HRQOL was assessed at baseline and week 8 using 3 Pediatric Quality of Life Inventory (PedsQL) scales. Clinically relevant improvement in HRQOL was determined using an accepted distribution-based criterion-1 standard error of measurement. RESULTS: In total, 316 patients were randomly assigned to receive treatment with aripiprazole (fixed-dose study, 166; flexible-dose study, 47) or placebo (fixed-dose study, 52; flexible-dose study, 51). Aripiprazole was associated with significantly greater improvement than placebo in PedsQL combined-scales total score (difference, 7.8; 95% CI, 3.8-11.8; P < 0.001) and in 3 PedsQL scale scores (differences [95% CI]: Emotional Functioning, 7.8 [3.4-12.2]; Social Functioning, 6.2 [0.7-11.8]; Cognitive Functioning, 9.3 [3.8-14.9]; all, P < 0.05). Patients who received aripiprazole were significantly more likely than those who received placebo to have a clinically meaningful improvement on the combined-scales total score (odds ratio [OR] = 1.9; 95% CI, 1.0-3.3; P < 0.05), Emotional Functioning scale (OR = 2.2; 95% CI, 1.2-4.0; P < 0.05) and Social Functioning scale (OR = 2.2; 95% CI, 1.2-4.1; P < 0.05), and were significantly less likely to experience deterioration (OR: 0.3, 95% CI: 0.1-0.8; P < 0.05) when « Stable » was used as the reference group. CONCLUSIONS: The findings from the present post hoc analysis suggest that aripiprazole was associated with improved HRQOL, as assessed using 3 PedsQL scales, in pediatric patients with irritability associated with autistic disorder.
