Validation of the repetitive and restricted behaviour scale in autism spectrum disorders

Repetitive and restricted behaviours represent a common problem for various psychiatric syndromes, especially in autistic spectrum disorders, and they include a wide range of heterogeneous behavioural manifestations. An accurate and standardized description of these behaviours is needed to advance the understanding of this complex and heterogeneous clinical dimension of autism. The present article reports the reliability and validity studies of a new assessment scale: the repetitive and restricted behaviour scale. 145 subjects with autism spectrum disorders were assessed using the RRB scale. The RRB scale has good interrater reliability, internal consistency and content validity. Factorial analysis produced four clinically meaningful factors, i.e. “sensorimotor stereotypies”, “reaction to change”, “restricted behaviours” and “modulation insufficiency”. The RRB scale has good psychometric qualities and constitutes a real breakthrough towards a neurofunctional approach to autistic disorders. It should be valuable for research and treatment, and in clinical practice

Neural repetition suppression to vocal and non-vocal sounds

Adaptation to the sensory environment is essential in everyday life, to anticipate future events and quickly detect and respond to changes; and to distinguish vocal variations in congeners, for communication. The aim of the current study was to explore the effects of the nature (vocal/non-vocal) of the information to be encoded, on the establishment of auditory regularities. In electrophysiology, neural adaptation is measured by the ‘Repetition Positivity’ (RP), which refers to an increase in positive potential, with the increasing number of repetitions of a same stimulus. The RP results from the combined variation of several ERP components; the P1, the first positivity (∼100 ms) may reflect the onset of repetition effects. We recorded auditory evoked potentials during a roving paradigm in which trains of 4, 8 or 16 repetitions of the same stimulus were presented. Sequences of vocal and non-vocal complex stimuli were delivered, to study the influence of the type of stimulation on the characteristics of the brain responses. The P1 to each train length, and the RP responses were recorded between 90 and 200 ms, reflecting adaptation for both vocal and non-vocal stimuli. RP was not different between vocal and non-vocal sequences (in latency, amplitude and spatial organization) and was found to be similar to that found in previous studies using pure tones, suggesting that the repetition suppression phenomena is somehow independent of the nature of the stimulus. However, results showed faster stabilization of the P1 amplitude for non vocal stimuli than for vocal stimuli, which require more repetitions. This revealed different dynamics for the establishment of regularity encoding for non-vocal and vocal stimuli, indicating that the richness of vocal sounds may require further processing before full neural adaptation occurs

Attitudes of the autism community to early autism research

Investigation into the earliest signs of autism in infants has become a significant sub-field of autism research. This work invokes specific ethical concerns such as: use of ‘at-risk’ language; communicating study findings to parents; and the future perspective of enrolled infants when they reach adulthood. The current study aimed to ground this research field in an understanding of the perspectives of members of the autism community. Following focus groups to identify topics, an online survey was distributed to autistic adults, parents of children with autism, and practitioners in health and education settings across eleven European countries. Survey respondents (n=2317) were positively disposed towards early autism research and there was significant overlap in their priorities for the field, and preferred language to describe infant research participants. However there were also differences including overall less favourable endorsement of early autism research by autistic adults relative to other groups and a dislike of the phrase ‘at-risk’ to describe infant participants, in all groups except healthcare practitioners. The findings overall indicate that the autism community in Europe is supportive of early autism research. Researchers should endeavour to maintain this by continuing to take community perspectives into account

Les stades de l'organogenèse et la cytodifférenciation de la glande à albumen de l'escargot Helix aspersa Müller

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Le développement des processus de remémoration et de familiarité : données comportementales et électrophysiologiques

International audienceThis article examines studies that have used behavioral and electrophysiological measures to look at the development of recollection and familiarity processes during childhood and adolescence. Behavioral data show different developmental trajectories for these two processes. Indeed, recollection and familiarity both develop during early childhood, but familiarity stabilizes from the age of eight while recollection increases throughout childhood and adolescence. Unexpectedly, event-related potential studies detailed the presence of an old/new parietal effect in children, associated with recollection, while most studies failed to highlight the early frontal old/new effect that is supposed to reflect familiarity in adults. Avenues for reflection are discussed in order to explain the discrepancy between behavioral and electrophysiological data on children’s use of the familiarity process.Cet article présente une synthèse des études qui se sont intéressées au développement des processus de remémoration et de familiarité au cours de l’enfance et de l’adolescence en utilisant les approches comportementale et électrophysiologique. Les données comportementales révèlent que ces deux processus présentent des trajectoires développementales différentes. En effet, les processus de remémoration et de familiarité se développent au cours de la petite enfance mais la familiarité se stabilise dès l’âge de 8 ans alors que la remémoration augmente tout au long de l’enfance et de l’adolescence. De façon inattendue, les études en potentiels évoqués ont décrit chez l’enfant un effet old/new pariétal, associé à la remémoration, et, dans la majorité des travaux, une absence d’effet old/new frontal précoce, supposé refléter la familiarité chez l’adulte. Des pistes de réflexion sont discutées afin d’expliquer cette discordance entre données comportementales et électrophysiologiques sur le recours à la familiarité chez l’enfant

Practical guidelines for studying young children with autism spectrum disorder in psychophysiological experiments

Understanding neurocognitive mechanisms in children with autism spectrum disorder (ASD) is an essential goal of autism research. Studying young children with ASD or other neurodevelopmental conditions in demanding experimental settings, however, can pose many practical and ethical challenges. In this article, we present practical strategies that facilitate data acquisition from psychophysiological experiments involving young children with ASD. We focus on a range of common, non-invasive technologies including EEG, MEG, eye tracking as well as some common measures of physiological arousal. Topics have been divided according to the chronological order of the experimental procedure: (a) design, (b) preparing for the measurement visit, (c) conducting the experiment and (d) the data handling. A key theme in the proposed guidelines is the difficulty in balancing the procedural adaptations necessary to facilitate participation of children with ASD, and maintaining standardisation for all participating children

Emotional expression visual mismatch negativity in children

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Is the cadmium uptake from soil important in bioaccumulation and toxic effects for snails?

International audienceTo evaluate the contribution of digestive and epithelial transfer of Cd from soil to snail, Helix aspersa was exposed to an artificial substrate contaminated with 0,100,500, and 1000 microg Cd.g(-1) for 4 weeks under laboratory conditions. Two modes of exposure were used: (1) the snails were in direct contact with the substrate (DC) or (2) were separated from substrate with a perforated plate (no contact (NC)) which allowed ingestion of substrate but avoided epithelial contact. Cd concentrations in DC snails were twice as high as in NC snails. The bioaccumulation factors were 0.51+/-0.13 in DC snails and 0.26+/-0.04 in NC snails. Dose-dependent growth inhibition was noted in DC snails (50

Candidate Electrophysiological Endophenotypes of Hyper-Reactivity to Change in Autism.

International audienceAlthough resistance to change is a main feature of autism, the brain processes underlying this aspect of the disorder remain poorly understood. The aims of this study were to examine neural basis of auditory change-detection in children with autism spectrum disorders (ASD; N = 27) through electrophysiological patterns (MMN, P3a) and to test whether these are quantitatively related to intolerance of change (using the BSE-R scale). ASD displayed significantly shorter MMN latency and larger P3a than controls, indicating a greater tendency to switch attention to deviant events. These electrophysiological abnormalities were significantly more marked in children who displayed greater difficulties in tolerating change. The atypical neurophysiological mechanism of change perception identified might thus be associated with one of the hallmark behavioural manifestations of autism