Processus de catégorisation perceptive dans l'autisme de haut-niveau

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

The Level and Nature of Autistic Intelligence II: What about Asperger Syndrome?

A distinctively uneven profile of intelligence is a feature of the autistic spectrum. Within the spectrum, Asperger individuals differ from autistics 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 Asperger adults displayed a significant advantage on RPM over Wechsler Full-Scale and Performance scores relative to their typical controls, while in 25 Asperger children an RPM advantage was found over Wechsler Performance scores only. As previously found with autistics, Asperger children and adults 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

Mimetic desire in autism spectrum disorder

International audienceMimetic desire (MD), the spontaneous propensity to pursue goals that others pursue, is a case of social influence that is believed to shape preferences. Autism spectrum disorder (ASD) is defined by both atypical interests and altered social interaction. We investigated whether MD is lower in adults with ASD compared to typically developed adults and whether MD correlates with social anhedonia and social judgment, two aspects of atypical social functioning in autism. Contrary to our hypotheses, MD was similarly present in both ASD and control groups. Anhedonia and social judgment differed between the ASD and control groups but did not correlate with MD. These results extend previous findings by suggesting that basic mechanisms of social influence are preserved in autism. The finding of intact MD in ASD stands against the intuitive idea that atypical interests stem from reduced social influence and indirectly favors the possibility that special interests might be selected for their intrinsic properties

Discrepancy between WISC-III and WISC-IV Cognitive Profile in Autism Spectrum: What Does It Reveal about Autistic Cognition?

The cognitive profile and measured intellectual level vary according to assessment tools in children on the autism spectrum, much more so than in typically developing children. The recent inclusion of intellectual functioning in the diagnostic process for autism spectrum disorders leads to the crucial question on how to assess intelligence in autism, especially as some tests and subtests seem more sensitive to certain neurodevelopmental conditions. Our first aim was to examine the cognitive profile on the current version of the most widely used test, the Wechsler Intelligence Scales for Children (WISC-IV), for a homogenous subgroup of children on the autism spectrum, i.e. corresponding to DSM-IV diagnosis of "autism". The second aim was to compare cognitive profiles obtained on the third edition versus 4th edition of WISC, in order to verify whether the WISC-IV yields a more distinctive cognitive profile in autistic children. The third aim was to examine the impact of the WISC-IV on the cognitive profile of another subgroup, children with Asperger's Syndrome. 51 autistic, 15 Asperger and 42 typically developing children completed the WISC-IV and were individually matched to children who completed the WISC-III. Divergent WISC-IV profiles were observed despite no significant intelligence quotient difference between groups. Autistic children scored significantly higher on the Perceptual Reasoning Index than on the Verbal Comprehension Index, a discrepancy that nearly tripled in comparison to WISC-III results. Asperger children scored higher on the VCI than on other indexes, with the lowest score found on the Processing Speed Index. WISC-IV cognitive profiles were consistent with, but more pronounced than WISC-III profiles. Cognitive profiles are a valuable diagnostic tool for differential diagnosis, keeping in mind that children on the autism spectrum might be more sensitive to the choice of subtests used to assess intelligence

Cognition sociale et sens de l’agentivité en autisme : de l’action à l’interaction

Le sens de l’agentivité (SdA) consiste à détecter que l’on est la cause d’une action (Gallagher, 2000). Il est lié au contrôle moteur, mais également à la conscience de soi et pourrait jouer un rôle important dans l’interaction sociale. Le trouble du spectre de l’autisme (TSA) est caractérisé par une altération des interactions sociales et de la communication (DSM-5 ; APA, 2013), et est souvent perçu comme relevant d’un déficit primaire de fonctions spécifiques à la cognition sociale. Pourtant, le contrôle moteur est également altéré dans le TSA. Nous faisons l’hypothèse que les symptômes moteurs et l’atteinte de l’interaction sociale pourraient relever d’une même atteinte du SdA. Nous présentons d’abord les modèles explicatifs généraux et les bases neurofonctionnelles du SdA implicite et explicite (Synofzik et al., 2008), puis les manifestations de ses perturbations dans d’autres troubles neuropsychiatriques comme la schizophrénie. Dans le TSA, la formation atypique des modèles internes de l’action lors de l’apprentissage moteur (Haswell et al., 2009) pourrait être à l’origine de l’altération du SdA implicite. Le manque de fidélité des indices d’agentivité sensorimoteurs (Zalla et al., 2015) pourrait de façon concomitante entraîner l’altération du SdA explicite. Nous discutons les principales manifestations cliniques du TSA qui seraient reliées aux altérations du SdA (difficultés dans la théorie de l’esprit et l’imitation, déficits de la coordination et des praxies, etc.)The sense of agency (SoA) refers to the ability for one to detect that she is the cause of an action (Gallagher, 2000). The SoA is linked to motor control but also to self-awareness and could play an important role in social interactions. Autism spectrum disorder (ASD) is characterized by an alteration of social interactions and communication (DSM-5; APA, 2013) and is often seen as a primary deficit of functions specific to social cognition. However, motor control is also altered in ASD. We hypothesize that motor symptoms and social impairments could both arise from the same alteration of SoA. We first introduce theoretical models of implicit and explicit SoA (Synofzik et al., 2008) and present their neurofunctional basis. Then, we assess the clinical expressions of a disrupted SoA in different neuropsychiatric disorders such as schizophrenia. In ASD, the atypical formation of internal models of action during motor acquisition (Haswell et al., 2009) could be at the source of an altered implicit SoA. A lack of fidelity of sensorimotor agency cues (Zalla et al., 2015) could also entail an alteration of explicit SoA. We discuss the main clinical expressions of ASD that may ensue from a disrupted SoA (difficulties in theory of mind and imitation, deficits in motor coordination and praxis, etc.

Autistic fluid intelligence: Increased reliance on visual functional connectivity with diminished modulation of coupling by task difficulty

Different test types lead to different intelligence estimates in autism, as illustrated by the fact that autistic individuals obtain higher scores on the Raven's Progressive Matrices (RSPM) test than they do on the Wechsler IQ, in contrast to relatively similar performance on both tests in non-autistic individuals. However, the cerebral processes underlying these differences are not well understood. This study investigated whether activity in the fluid “reasoning” network, which includes frontal, parietal, temporal and occipital regions, is differently modulated by task complexity in autistic and non-autistic individuals during the RSPM. In this purpose, we used fMRI to study autistic and non-autistic participants solving the 60 RSPM problems focussing on regions and networks involved in reasoning complexity. As complexity increased, activity in the left superior occipital gyrus and the left middle occipital gyrus increased for autistic participants, whereas non-autistic participants showed increased activity in the left middle frontal gyrus and bilateral precuneus. Using psychophysiological interaction analyses (PPI), we then verified in which regions did functional connectivity increase as a function of reasoning complexity. PPI analyses revealed greater connectivity in autistic, compared to non-autistic participants, between the left inferior occipital gyrus and areas in the left superior frontal gyrus, right superior parietal lobe, right middle occipital gyrus and right inferior temporal gyrus. We also observed generally less modulation of the reasoning network as complexity increased in autistic participants. These results suggest that autistic individuals, when confronted with increasing task complexity, rely mainly on visuospatial processes when solving more complex matrices. In addition to the now well-established enhanced activity observed in visual areas in a range of tasks, these results suggest that the enhanced reliance on visual perception has a central role in autistic cognition

Style cognitif et style d'apprentissage dans l'autisme, une étude en oculométrie

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