1. Chouinard PA, Unwin KL, Landry O, Sperandio I. {{Susceptibility to Optical Illusions Varies as a Function of the Autism-Spectrum Quotient but not in Ways Predicted by Local-Global Biases}}. {J Autism Dev Disord};2016 (Feb 25)
Individuals with autism spectrum disorder and those with autistic tendencies in non-clinical groups are thought to have a perceptual style privileging local details over global integration. We used 13 illusions to investigate this perceptual style in typically developing adults with various levels of autistic traits. Illusory susceptibility was entered into a principal-component analysis. Only one factor, consisting of the Shepard’s tabletops and Square-diamond illusions, was found to have reduced susceptibility as a function of autistic traits. Given that only two illusions were affected and that these illusions depend mostly on the processing of within-object relational properties, we conclude there is something distinct about autistic-like perceptual functioning but not in ways predicted by a preference of local over global elements.
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2. Guillon Q, Roge B, Afzali MH, Baduel S, Kruck J, Hadjikhani N. {{Intact perception but abnormal orientation towards face-like objects in young children with ASD}}. {Sci Rep};2016;6:22119.
There is ample behavioral evidence of diminished orientation towards faces as well as the presence of face perception impairments in autism spectrum disorder (ASD), but the underlying mechanisms of these deficits are still unclear. We used face-like object stimuli that have been shown to evoke pareidolia in typically developing (TD) individuals to test the effect of a global face-like configuration on orientation and perceptual processes in young children with ASD and age-matched TD controls. We show that TD children were more likely to look first towards upright face-like objects than children with ASD, showing that a global face-like configuration elicit a stronger orientation bias in TD children as compared to children with ASD. However, once they were looking at the stimuli, both groups spent more time exploring the upright face-like object, suggesting that they both perceived it as a face. Our results are in agreement with abnormal social orienting in ASD, possibly due to an abnormal tuning of the subcortical pathway, leading to poor orienting and attention towards faces. Our results also indicate that young children with ASD can perceive a generic face holistically, such as face-like objects, further demonstrating holistic processing of faces in ASD.
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3. Heaton TJ, Freeth M. {{Reduced Visual Exploration When Viewing Photographic Scenes in Individuals With Autism Spectrum Disorder}}. {J Abnorm Psychol};2016 (Feb 25)
Individuals with autism spectrum disorder (ASD) often display enhanced attention to detail and exhibit restricted behavior. However, due to a lack of comprehensive eye-movement modeling techniques, it is currently unknown whether these behavioral effects are also evident during scene viewing (i.e., detailed visual inspection and restricted visual exploration). Free-viewing eye-tracking data from observation of everyday photographic scenes were recorded during 2 experiments involving high-functioning adolescents with ASD and matched typically developing (TD) controls (Experiment 1, ASD n = 14; TD n = 22; Experiment 2, ASD n = 16; TD n = 23). Data from both experiments were combined and analyzed using 5 novel methods of eye-tracking, time-course analysis, enabling detailed characterization of viewing strategies. Participants’ verbal descriptions of scenes were also assessed. Scenes either contained a centrally positioned person whose face was in full view or contained no centrally positioned face. For both types of scene, ASD participants displayed significantly less exploration of new areas over time compared with their TD peers. Analyses of scan-path length and recursion suggested a greater tendency to explore areas close to the current fixation in the ASD group, termed visual persistence. Differences were not accounted for by fixation rate. Significantly more areas within the scenes were also missing from the verbal descriptions in the ASD group. Differences were observed for both scene types, suggesting a domain-general difference rather than a specific impairment related to face processing. The observed characteristic viewing patterns may explain relative superior processing of local level information in individuals with ASD. (PsycINFO Database Record
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4. Mei Y, Monteiro P, Zhou Y, Kim JA, Gao X, Fu Z, Feng G. {{Adult restoration of Shank3 expression rescues selective autistic-like phenotypes}}. {Nature};2016 (Feb 25);530(7591):481-484.
Because autism spectrum disorders are neurodevelopmental disorders and patients typically display symptoms before the age of three, one of the key questions in autism research is whether the pathology is reversible in adults. Here we investigate the developmental requirement of Shank3 in mice, a prominent monogenic autism gene that is estimated to contribute to approximately 1% of all autism spectrum disorder cases. SHANK3 is a postsynaptic scaffold protein that regulates synaptic development, function and plasticity by orchestrating the assembly of postsynaptic density macromolecular signalling complex. Disruptions of the Shank3 gene in mouse models have resulted in synaptic defects and autistic-like behaviours including anxiety, social interaction deficits, and repetitive behaviour. We generated a novel Shank3 conditional knock-in mouse model, and show that re-expression of the Shank3 gene in adult mice led to improvements in synaptic protein composition, spine density and neural function in the striatum. We also provide behavioural evidence that certain behavioural abnormalities including social interaction deficit and repetitive grooming behaviour could be rescued, while anxiety and motor coordination deficit could not be recovered in adulthood. Together, these results reveal the profound effect of post-developmental activation of Shank3 expression on neural function, and demonstrate a certain degree of continued plasticity in the adult diseased brain.
