Entity

Time filter

Source Type


Galle S.A.,Center Dexcellence En Troubles Envahissants Du Developpement Of Luniversite Of Montreal Cetedum | Galle S.A.,University of Amsterdam | Courchesne V.,University of Montreal | Mottron L.,Center Dexcellence En Troubles Envahissants Du Developpement Of Luniversite Of Montreal Cetedum | Frasnelli J.,University of Montreal
Perception | Year: 2013

The autism spectrum (AS) is characterized by enhanced perception in vision and audition, described by the enhanced perceptual functioning (EPF) model. This model predicts enhanced low-level (discrimination of psychophysical dimensions), and mid- and high-level (pattern detection and identification) perception. The EPF model is here tested for olfaction by investigating olfactory function in autistic and Asperger participants. Experiment 1 targeted higher-order olfactory processing by assessing olfactory identification in nine Asperger, ten autistic, and eleven typically developed individuals. Experiment 2 focused on low-level olfactory processing; we assessed odour detection thresholds and odour discrimination in five Asperger, five autistic, and five typically developed males. Olfactory identification was impaired in autistic participants relative to control and Asperger participants. Typical performance in low-level olfactory processing suggests that neural mechanisms involved in the perceptual phenotype of AS do not affect structures implicated in olfactory processing. Reduced olfactory identification is limited to autistic participants who displayed speech delay and may be due to a reduced facility to use verbal labels. The apparent absence of enhanced olfactory perception of AS participants distinguishes the olfactory system from the other sensory modalities and might be caused by the absence of an obligatory thalamic relay. Source


Mitchell P.,University of Nottingham | Mottron L.,Center Dexcellence En Troubles Envahissants Du Developpement Of Luniversite Of Montreal Cetedum | Mottron L.,University of Montreal | Soulieres I.,Center Dexcellence En Troubles Envahissants Du Developpement Of Luniversite Of Montreal Cetedum | And 2 more authors.
Autism Research | Year: 2010

Previous research [Ropar & Mitchell, 2002] has shown that autistic individuals are somewhat immune to biases induced by top-down processes, particularly the influence of previous knowledge on perception. In order to test this hypothesis within perception, 18 participants with autism who had measured intelligence in the normal range were compared against 18 matched controls in their susceptibility to the Shepard illusion. The illusion consists in misperceiving the shape of a parallelogram in the presence of depth cues. It is attributed [Mitchell, Ropar, Ackroyd, & Rajendran, 2005] to the effect of top-down constraints within perception. The task involved adjusting a stimulus to the dimensions of a template on a computer screen. Both groups were susceptible to the illusion and the illusion effect was stronger when three-dimensional perspective cues were prominent. Notably, participants with autism were less susceptible to the illusion than typically developing individuals. The findings raise the possibility that in some instances top-down influences are attenuated in individuals with autism. © 2010 International Society for Autism Research, Wiley Periodicals, Inc. Source


Courchesne V.,Center Dexcellence En Troubles Envahissants Du Developpement Of Luniversite Of Montreal Cetedum | Meilleur A.-A.S.,Center Dexcellence En Troubles Envahissants Du Developpement Of Luniversite Of Montreal Cetedum | Poulin-Lord M.-P.,Center Dexcellence En Troubles Envahissants Du Developpement Of Luniversite Of Montreal Cetedum | Dawson M.,Center Dexcellence En Troubles Envahissants Du Developpement Of Luniversite Of Montreal Cetedum | Soulieres I.,University of Quebec at Montreal
Molecular Autism | Year: 2015

Background: An important minority of school-aged autistic children, often characterized as 'nonverbal' or 'minimally verbal,' displays little or no spoken language. These children are at risk of being judged 'low-functioning' or 'untestable' via conventional cognitive testing practices. One neglected avenue for assessing autistic children so situated is to engage current knowledge of autistic cognitive strengths. Our aim was thus to pilot a strength-informed assessment of autistic children whose poor performance on conventional instruments suggests their cognitive potential is very limited. Methods: Thirty autistic children (6 to 12 years) with little or no spoken language, attending specialized schools for autistic children with the highest levels of impairment, were assessed using Wechsler Intelligence Scale for Children (WISC-IV), Raven's Colored Progressive Matrices board form (RCPM), Children's Embedded Figures Test (CEFT), and a visual search task. An age-matched control group of 27 typical children was also assessed. Results: None of the autistic children could complete WISC-IV; only six completed any subtest. In contrast, 26 autistic children could complete RCPM, with 17 scoring between the 5th and 90th percentile. Twenty-seven autistic children completed the visual search task, while 26 completed CEFT, on which autistic children were faster than RCPM-matched typical children. Autistic performance on RCPM, CEFT, and visual search were correlated. Conclusion: These results indicate that 'minimally verbal' or 'nonverbal' school-aged autistic children may be at risk of being underestimated: they may be wrongly regarded as having little cognitive potential. Our findings support the usefulness of strength-informed approaches to autism and have important implications for the assessment and education of autistic children. © 2015 Courchesne et al.; licensee BioMed Central. Source


Collignon O.,University of Montreal | Collignon O.,University of Trento | Charbonneau G.,University of Montreal | Peters F.,University of Montreal | And 6 more authors.
Cortex | Year: 2013

Although the literature concerning auditory and visual perceptual capabilities in the autism spectrum is growing, our understanding of multisensory integration (MSI) is rather limited. In the present study, we assessed MSI in autism by measuring whether participants benefited from an auditory cue presented in synchrony with the color change of a target during a complex visual search task. The synchronous auditory pip typically increases search efficacy (pip and pop effect), indicative of the beneficial use of sensory input from both modalities. We found that for conditions without auditory information, autistic participants were better at visual search compared to neurotypical participants. Importantly, search efficiency was increased by the presence of auditory pip for neurotypical participants only. The simultaneous occurrence of superior unimodal performance with altered audio-visual integration in autism suggests autonomous sensory processing in this population. © 2012 Elsevier Ltd. Source


Soulieres I.,Center Dexcellence En Troubles Envahissants Du Developpement Of Luniversite Of Montreal Cetedum | Soulieres I.,Harvard University | Dawson M.,Center Dexcellence En Troubles Envahissants Du Developpement Of Luniversite Of Montreal Cetedum | Gernsbacher M.A.,University of Wisconsin - Madison | Mottron L.,Center Dexcellence En Troubles Envahissants Du Developpement Of Luniversite Of Montreal Cetedum
PLoS ONE | Year: 2011

A distinctively uneven profile of intelligence is a feature of the autistic spectrum. Within the spectrum, individuals with Asperger syndrome differ from patients with autism in their early speech development and in being less likely to be characterized by visuospatial peaks. While different specific strengths characterize different autistic spectrum subgroups, all such peaks of ability have been interpreted as deficits: isolated, aberrant, and irreconcilable with real human intelligence. This view has recently been challenged by findings of autistic strengths in performance on Raven's Progressive Matrices (RPM), an important marker of general and fluid intelligence. We investigated whether these findings extend to Asperger syndrome, an autistic spectrum subgroup characterized by verbal peaks of ability, and whether the cognitive mechanisms underlying autistic and Asperger RPM performance differ. Thirty-two adults with Asperger syndrome displayed a significant advantage on RPM over Wechsler Full-Scale and Performance scores relative to their typical controls, while in 25 children with Asperger syndrome, an RPM advantage was found over Wechsler Performance scores only. As previously found with patients with autism, children and adults with Asperger syndrome achieved RPM scores at a level reflecting their Wechsler peaks of ability. Therefore, strengths in RPM performance span the autistic spectrum and imply a common mechanism advantageously applied to different facets of cognition. Autistic spectrum intelligence is atypical, but also genuine, general, and underestimated. © 2011 Soulières et al. Source

Discover hidden collaborations