Pubmed du 17/07/17

Pubmed du jour

2017-07-17 12:03:50

1. Alaerts K, Swinnen SP, Wenderoth N. {{Neural processing of biological motion in autism: An investigation of brain activity and effective connectivity}}. {Sci Rep};2017 (Jul 17);7(1):5612.

The superior temporal sulcus (STS) forms a key region for social information processing and disruptions of its function have been associated with socio-communicative impairments characteristic of autism spectrum disorders (ASD). Task-based fMRI was applied in 15 adults with ASD and 15 matched typical-controls (TC) to explore differences in activity and effective connectivity of STS while discriminating either ‘intact’ versus ‘scrambled’ biological motion point light displays (explicit processing) or responding to a color-change while the ‘intact’ versus ‘scrambled’ nature of the stimulus was irrelevant for the task (implicit processing). STS responded stronger to ‘intact’ than ‘scrambled’ stimuli in both groups, indicating that the basic encoding of ‘biological’ versus ‘non-biological’ motion seems to be intact in ASD. Only in the TC-group however, explicit attention to the biological motion content induced an augmentation of STS-activity, which was not observed in the ASD-group. Overall, these findings suggest an inadequacy to recruit STS upon task demand in ASD, rather than a generalized alteration in STS neural processing. The importance of attention orienting for recruiting relevant neural resources was further underlined by the observation that connectivity between STS and medial prefrontal cortex (mPFC), a key region in attention regulation, effectively modulated STS-recruitment in the ASD-group.

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2. Craig AB, Grossman E, Krichmar JL. {{Investigation of autistic traits through strategic decision-making in games with adaptive agents}}. {Sci Rep};2017 (Jul 17);7(1):5533.

Autism Spectrum Disorders are characterized by difficulties in communicating and cooperating with other people. Impairment in Theory of Mind (ToM), the ability to infer what another person is thinking, may contribute to these social deficits. The present study assesses the relationship between autistic traits and decision-making in a socioeconomic game environment that measures ToM and cooperation. We quantified participant strategy during game play with computer agents that simulated aspects of ToM or fixed strategy agents with static behaviors or heuristics. Individuals with higher Autism Quotient (AQ) scores cooperated less than subjects with low AQ scores with the ToM agents. In contrast, subjects with higher AQ scores cooperated more with fixed strategy agents. Additionally, subjects with higher AQ scores spent more time than low AQ subjects signaling cooperative intent in games with fixed strategy agents while spending less time signaling cooperation with adaptive agents, indicating a preference toward systemizing behaviors in the face of uncertainty. We conclude that individuals with high levels of autistic traits are less likely to utilize ToM as a cognitive strategy, even when it is beneficial, to achieve a desired outcome.

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3. Guivarch J, Murdymootoo V, Elissalde SN, Salle-Collemiche X, Tardieu S, Jouve E, Poinso F. {{Impact of an implicit social skills training group in children with autism spectrum disorder without intellectual disability: A before-and-after study}}. {PLoS One};2017;12(7):e0181159.

INTRODUCTION: Children with Autism Spectrum Disorders (ASDs) have problems with social skills. Social skills training groups are among the proposed therapeutic strategies, but their efficacy still needs to be evaluated. OBJECTIVE: To evaluate the efficacy of an implicit social skills training group in children with ASDs without intellectual disability. METHODS: A before-and-after study of children with ASD without intellectual disability was conducted in a child psychiatry day hospital, where they participated in an implicit group with cooperative games. Their social skills were assessed using the Social-Emotional Profile (SEP), the Childhood Autism Rating Scale (CARS), and the empathy quotient (EQ) before and after 22 weeks. RESULTS: Six patients aged 9 to 10 years old were evaluated. A significant increase in overall adaptation and social skills (median 8 and 7.7 points) in the SEP was demonstrated in addition to a significant reduction in the CARS score (median: 4 points), including in the field of social relationships. The EQ increased two-fold. DISCUSSION-CONCLUSION: This implicit group improved the children’s social skills. It would be interesting to evaluate the maintenance of these skills over time, examine more widespread results, and compare implicit and explicit groups.

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4. Lim ET, Uddin M, De Rubeis S, Chan Y, Kamumbu AS, Zhang X, D’Gama AM, Kim SN, Hill RS, Goldberg AP, Poultney C, Minshew NJ, Kushima I, Aleksic B, Ozaki N, Parellada M, Arango C, Penzol MJ, Carracedo A, Kolevzon A, Hultman CM, Weiss LA, Fromer M, Chiocchetti AG, Freitag CM, Church GM, Scherer SW, Buxbaum JD, Walsh CA. {{Rates, distribution and implications of postzygotic mosaic mutations in autism spectrum disorder}}. {Nat Neurosci};2017 (Jul 17)

We systematically analyzed postzygotic mutations (PZMs) in whole-exome sequences from the largest collection of trios (5,947) with autism spectrum disorder (ASD) available, including 282 unpublished trios, and performed resequencing using multiple independent technologies. We identified 7.5% of de novo mutations as PZMs, 83.3% of which were not described in previous studies. Damaging, nonsynonymous PZMs within critical exons of prenatally expressed genes were more common in ASD probands than controls (P < 1 x 10-6), and genes carrying these PZMs were enriched for expression in the amygdala (P = 5.4 x 10-3). Two genes (KLF16 and MSANTD2) were significantly enriched for PZMs genome-wide, and other PZMs involved genes (SCN2A, HNRNPU and SMARCA4) whose mutation is known to cause ASD or other neurodevelopmental disorders. PZMs constitute a significant proportion of de novo mutations and contribute importantly to ASD risk. Lien vers le texte intégral (Open Access ou abonnement)

5. Melogno S, Pinto MA, Di Filippo G. {{Sensory and Physico-Psychological Metaphor Comprehension in Children with ASD: A Preliminary Study on the Outcomes of a Treatment}}. {Brain Sci};2017 (Jul 17);7(7)

Recent research into difficulties in figurative language in children with ASD highlighted that it is possible to devise training interventions to overcome these difficulties by teaching specific strategies. This study describes how children with ASD can improve their capability to explain metaphors with a treatment. Two types of metaphors, in the « X is Y » form, were addressed: sensory and physico-psychological. To face the difficulties posed by these metaphors, the adult taught two strategies: inserting the connective « is like » between « X » and « Y », which transforms the metaphor into a simile; comparing « X » and « Y » by means of thinking maps. Two tests of metaphor comprehension were used, one based on sensory and the other on physico-psychological metaphors. Sixteen 10 year-old children participated into the study, including an experimental group formed by 8 children with ASD (n = 4) which had received the treatment, and a control group (n = 4) which had not, and 8 typically-developing (TD) children. At the post-test, the experimental group significantly outperformed the controls in explaining both types of metaphors, but only in the sensory metaphors did their performances reach TD children’s levels. These results illuminate how clinical treatment can positively influence the developmental trajectories of metaphor comprehension.

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6. Smith IC, Swain D, Murphy HG, Ollendick TH, White SW. {{The Under- and Over-Identification of Autism: Factors Associated With Diagnostic Referral}}. {J Clin Child Adolesc Psychol};2017 (Jul 17):1-7.

As reported prevalence and public awareness of Autism Spectrum Disorder (ASD) have grown in recent years, clinicians will likely see increased referrals for suspected ASD. The current study sought to elucidate factors associated with referral for possible ASD, as well as diagnostic outcome among youth referred for suspected ASD. Youth referred for psychological evaluations at an outpatient clinic (N = 69, 6-18 years, 48 male) were categorized into four groups: referred for suspected ASD and diagnosed as such, referred for ASD and not diagnosed as such, not referred for ASD but diagnosed as such, and neither referred for nor diagnosed with ASD. Approximately half of cases referred for suspected ASD did not meet diagnostic criteria. A significant effect of group was found for cognitive ability and anxiety. Youth receiving ASD diagnoses, regardless of whether they were referred for suspected ASD, demonstrated lower cognitive ability than children not receiving ASD diagnoses. Youth neither referred for nor diagnosed with ASD demonstrated lower anxiety than those who were referred and diagnosed. Maternal education significantly differed among the four groups. Although group differences are seen for youth cognitive ability, anxiety, and maternal education, we found no clear indicators differentiating referrals that were « accurate » (i.e., those diagnosed with ASD) and those that were not (i.e., those who did not receive ASD diagnosis). Comorbidity was high in all groups, including those referred primarily for ASD assessment, underscoring the importance of comprehensive assessment regardless of specificity of the referral.

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7. Strathearn L, Kim S, Bastian DA, Jung J, Iyengar U, Martinez S, Goin-Kochel RP, Fonagy P. {{Visual systemizing preference in children with autism: A randomized controlled trial of intranasal oxytocin}}. {Dev Psychopathol};2017 (Jul 17):1-11.

Several studies have suggested that the neuropeptide oxytocin may enhance aspects of social communication in autism. Little is known, however, about its effects on nonsocial manifestations, such as restricted interests and repetitive behaviors. In the empathizing-systemizing theory of autism, social deficits are described along the continuum of empathizing ability, whereas nonsocial aspects are characterized in terms of an increased preference for patterned or rule-based systems, called systemizing. We therefore developed an automated eye-tracking task to test whether children and adolescents with autism spectrum disorder (ASD) compared to matched controls display a visual preference for more highly organized and structured (systemized) real-life images. Then, as part of a randomized, double-blind, placebo-controlled crossover study, we examined the effect of intranasal oxytocin on systemizing preferences in 16 male children with ASD, compared with 16 matched controls. Participants viewed 14 slides, each containing four related pictures (e.g., of people, animals, scenes, or objects) that differed primarily on the degree of systemizing. Visual systemizing preference was defined in terms of the fixation time and count for each image. Unlike control subjects who showed no gaze preference, individuals with ASD preferred to fixate on more highly systemized pictures. Intranasal oxytocin eliminated this preference in ASD participants, who now showed a similar response to control subjects on placebo. In contrast, control participants increased their visual preference for more systemized images after receiving oxytocin versus placebo. These results suggest that, in addition to its effects on social communication, oxytocin may play a role in some of the nonsocial manifestations of autism.

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