The Glasgow Sensory Questionnaire: Validation of a French Language Version and Refinement of Sensory Profiles of People with High Autism-Spectrum Quotient

International audienceSensory sensitivity peculiarities represent an important characteristic of Autism Spectrum Disorders (ASD). We first validated a French language version of the Glasgow Sensory Questionnaire (GSQ) (Robertson and Simmons 2013). The GSQ score was strongly positively correlated with the Autism-Spectrum Quotient (AQ) (r = .81, p < 10-6, n = 245). We further examined sensory profiles of groups with high versus low AQ. The high AQ group scored higher at the GSQ than the low AQ group for every sensory modality. Moreover, the high AQ group showed greater consistency in their patterns of hypersensitivity and hyposensitivity between sensory modalities, and stronger correlations between hyper and hyposensitivity. Results are discussed in the context of theories accounting for atypical sensory perception in ASD

Tactile Hypersensitivity and GABA Concentration in the Sensorimotor Cortex of Adults with Autism

International audienceSensory hypersensitivity is frequently encountered in autism spectrum disorder (ASD). Gamma-aminobutyric acid (GABA) has been hypothesized to play a role in tactile hypersensitivity. The aim of the present study was twofold. First, as a study showed that children with ASD have decreased GABA concentrations in the sensorimotor cortex, we aimed at determining whether the GABA reduction remained in adults with ASD. For this purpose, we used magnetic resonance spectroscopy to measure GABA concentration in the sensorimotor cortex of neurotypical adults (n = 19) and ASD adults (n = 18). Second, we aimed at characterizing correlations between GABA concentration and tactile hypersensitivity in ASD. GABA concentration in the sensorimotor cortex of adults with ASD was lower than in neurotypical adults (decrease by 17%). Interestingly, GABA concentrations were positively correlated with self-reported tactile hypersensitivity in adults with ASD (r = 0.50, P = 0.01), but not in neurotypical adults. In addition, GABA concentrations were negatively correlated with the intra-individual variation during threshold measurement, both in neurotypical adults (r = −0.47, P = 0.04) and in adults with ASD (r = −0.59, P = 0.01). In other words, in both groups, the higher the GABA level, the more precise the tactile sensation. These results highlight the key role of GABA in tactile sensitivity, and suggest that atypical GABA modulation contributes to tactile hypersensitivity in ASD. We discuss the hypothesis that hypersensitivity in ASD could be due to suboptimal predictions about sensations. Autism Research 2019. Lay Summary: People with autism spectrum disorder (ASD) often experience tactile hypersensitivity. Here, our goal was to highlight a link between tactile hypersensitivity and the concentration of gamma-aminobutyric acid (GABA) (an inhibitory neurotransmitter) in the brain of adults with ASD. Indeed, self-reported hypersensitivity correlated with reduced GABA levels in brain areas processing touch. Our study suggests that this neurotransmitter may play a key role in tactile hypersensitivity in autism

Adults with Autism Tend to Underestimate the Hidden Environmental Structure: Evidence from a Visual Associative Learning Task

International audienceThe learning-style theory of Autism Spectrum Disorders (ASD) (Qian and Lipkin 2011) states that individuals with ASD differ from neurotypics in the way they learn and store information about the environment and its structure. ASD would rather adopt a lookup-table strategy (LUT: memorizing each experience), while neurotypics would favor an interpolation style (INT: extracting regularities to generalize). In a series of visual behavioral tasks, we tested this hypothesis in 20 neurotypical and 20 ASD adults. ASD participants had difficulties using the INT style when instructions were hidden but not when instructions were revealed. Rather than an inability to use rules, ASD would be characterized by a disinclination to generalize and infer such rules

Disentangling sensory precision and prior expectation of change in autism during tactile discrimination

Abstract Predictive coding theories suggest that core symptoms in autism spectrum disorders (ASD) may stem from atypical mechanisms of perceptual inference (i.e., inferring the hidden causes of sensations). Specifically, there would be an imbalance in the precision or weight ascribed to sensory inputs relative to prior expectations. Using three tactile behavioral tasks and computational modeling, we specifically targeted the implicit dynamics of sensory adaptation and perceptual learning in ASD. Participants were neurotypical and autistic adults without intellectual disability. In Experiment I, tactile detection thresholds and adaptation effects were measured to assess sensory precision. Experiments II and III relied on two-alternative forced choice tasks designed to elicit a time-order effect, where prior knowledge biases perceptual decisions. Our results suggest a subtler explanation than a simple imbalance in the prior/sensory weights, having to do with the dynamic nature of perception, that is the adjustment of precision weights to context. Compared to neurotypicals, autistic adults showed no difference in average performance and sensory sensitivity. Both groups managed to implicitly learn and adjust a prior that biased their perception. However, depending on the context, autistic participants showed no, normal or slower adaptation, a phenomenon that computational modeling of trial-to-trial responses helped us to associate with a higher expectation for sameness in ASD, and to dissociate from another observed robust difference in terms of response bias. These results point to atypical perceptual learning rather than altered perceptual inference per se, calling for further empirical and computational studies to refine the current predictive coding theories of ASD

Adaptive trajectories and early risk factors in the autism spectrum: A 15-year prospective study

International audienceLittle is known about long-term outcomes. We investigate the adaptive trajectories and their risk factors in ASD. Data were obtained from 281 children prospectively followed untill adulthood. The final sample consisted of 106 individuals. Vineland scores were collected at baseline (T1), 3 (T2), 10 (T3), and 15 (T4) years later. A group-based method was used to identify homogeneous patterns of adaptive skills trajectories. Results show that among the children initially categorized as autistic, 82.6% remained over the ADOS diagnostic threshold, 11.9% converted to atypical autism, and 5.4% fell under the ADOS threshold. Most atypical autism diagnoses were unstable. Most (81.7%) autistic participants had an ID at inclusion. At T1, 59.3% were nonverbal, but only 39% at T4. Most changes occurred between 4 and 8 years of age. Approximately 25% of participants exhibited a "high" growth trajectory, in which progress continues throughout adolescence, and 75% a "low" growth trajectory, characterized by greater autistic symptoms, intellectual disability, and lower language abilities reflected by high CARS scores, low apparent DQ, and speech difficulties, which mostly, but not always, predicted low trajectories. Our findings suggest that the adaptive prognosis of autism is mostly poor in this cohort, biased toward intellectual disability. However, changes in diagnostic, speech, and adaptive status are not uncommon, even for indivduals with low measured intelligence or apparent intellectual disability, and are sometimes difficult to predict. Autism Research 2018, 11: 1455-1467. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Most autism diagnoses given before 5 years of age are stable to adulthood, but one-fifth of individuals are no longer considered to be autistic, even in a cohort biased toward apparent intellectual disability. Conversely, atypical autism diagnoses are mostly unstable. One-third of children who are nonverbal at 5 years are verbal within 15 years, mostly before 8 years of age. Concerning adaptive behavior outcomes, only one-fourth of children exhibit a high-growth trajectory through at least 15 years

Decision-Making in a Changing World: A Study in Autism Spectrum Disorders

International audienceTo learn to deal with the unexpected is essential to adaptation to a social, therefore often unpredictable environment. Fourteen adults with Autism Spectrum Disorders (ASD) and 15 controls underwent a decision-making task aimed at investigating the influence of either a social or a non-social environment, and its interaction with either a stable (with constant probabilities) or an unstable (with changing probabilities) context on their performance. Participants with ASD presented with difficulties in accessing underlying statistical rules in an unstable context, a deficit especially enhanced in the social environment. These results point out that the difficulties people with ASD encounter in their social life might be caused by impaired social cues processing and by the unpredictability associated with the social world

Motor deficits in autism differ from that of developmental coordination disorder: Motor deficits differ in ASD and DCD

International audienceAutism spectrum disorders and developmental coordination disorders are both associated with sensorimotor impairments, yet their nature and specificity remain unknown. In order to clearly distinguish the specificity between the two disorders, children with autism spectrum disorder or developmental coordination disorder presenting the same degree of motor impairment, thus homogeneous profiles, were examined in a reach-to-displace paradigm, which allows the integrity of two main aspects of motor control (anticipation/feedforward control and movement correction/feedback control) to be separately interrogated. We manipulated children’s previous knowledge of the weight of the object they were to displace: when known, participants could anticipate the consequences of the weight when reaching for the object, prior to contact with it, thus allowing for feedforward control. Conversely, when unknown prior to contact, participants had to cope with the object weight in the displacing phase of the movement, and use feedback control. Results revealed a preserved feedforward control, but an impaired movement execution (atypical slowness) in children with developmental coordination disorder, while children with autism spectrum disorder displayed the opposite pattern with an impaired feedforward control, but a preserved feedback one. These findings shed light on how specific motor impairments might differently characterize developmental disorders and call for motor rehabilitation programmes adapted to each population. Lay abstract A vast majority of individuals with autism spectrum disorder experience impairments in motor skills. Those are often labelled as additional developmental coordination disorder despite the lack of studies comparing both disorders. Consequently, motor skills rehabilitation programmes in autism are often not specific but rather consist in standard programmes for developmental coordination disorder. Here, we compared motor performance in three groups of children: a control group, an autism spectrum disorder group and a developmental coordination disorder group. Despite similar level of motor skills evaluated by the standard movement assessment battery for children, in a Reach-to-Displace Task, children with autism spectrum disorder and developmental coordination disorder showed specific motor control deficits. Children with autism spectrum disorder failed to anticipate the object properties, but could correct their movement as well as typically developing children. In contrast, children with developmental coordination disorder were atypically slow, but showed a spared anticipation. Our study has important clinical implications as motor skills rehabilitations are crucial to both populations. Specifically, our findings suggest that individuals with autism spectrum disorder would benefit from therapies aiming at improving their anticipation, maybe through the support of their preserved representations and use of sensory information. Conversely, individuals with developmental coordination disorder would benefit from a focus on the use of sensory information in a timely fashion

A de novo frameshift pathogenic variant in TBR1 identified in autism without intellectual disability

International audienceBackground: In order to be able to provide accurate genetic counseling to patients with Autism Spectrum Disorder (ASD), it is crucial to identify correlations between heterogeneous phenotypes and genetic alterations. Among the hundreds of de novo pathogenic variants reported in ASD, single-nucleotide variations and small insertions/deletions were reported in TBR1. This gene encodes a transcription factor that plays a key role in brain development. Pathogenic variants in TBR1 are often associated with severe forms of ASD, including intellectual disability and language impairment. Methods: Adults diagnosed with ASD but without intellectual disability (diagnosis of Asperger syndrome, according to the DSM-IV) took part in a genetic consultation encompassing metabolic assessments, a molecular karyotype and the screening of a panel of 268 genes involved in intellectual disability, ASD and epilepsy. In addition, the patient reported here went through a neuropsychological assessment, structural magnetic resonance imaging and magnetic resonance spectroscopy measurements. Results: Here, we report the case of a young adult male who presents with a typical form of ASD. Importantly, this patient presents with no intellectual disability or language impairment, despite a de novo heterozygous frameshift pathogenic variant in TBR1, leading to an early premature termination codon (c.26del, p.(Pro9Leufs*12)). Conclusion: Based on this case report, we discuss the role of TBR1 in general brain development, language development, intellectual disability and other symptoms of ASD. Providing a detailed clinical description of the individuals with such pathogenic variants should help to understand the genotype-phenotype relationships in ASD

Investigating the natural history and prognostic factors of ASD in children: the multicEntric Longitudinal study of childrEN with ASD - the ELENA study protocol

International audienceThere is global concern about the increasing prevalence of autism spectrum disorders (ASDs), which are early-onset and long-lasting disorders. Although ASDs are considered to comprise a unique syndrome, their clinical presentation and outcome vary widely. Large-scale and long-term cohort studies of well-phenotyped samples are needed to better understand the course of ASDs and their determinants. The primary objective of the multicEntric Longitudinal study of childrEN with ASD (ELENA) study is to understand the natural history of ASD in children and identify the risk and prognostic factors that affect their health and development