Vision Research Literature May Not Represent the Full Intellectual Range of Autism Spectrum Disorder

Abstract

Sensory, in particular visual processing is recognized as often perturbed in individuals with Autism Spectrum Disorder (ASD). However, in terms of the literature pertaining to visual processing, individuals in the normal intelligence range (IQ = 90–110) and above, are more frequently represented in study samples than individuals who score below normal in the borderline intellectual disability (ID) (IQ = 71–85) to ID (IQ < 70) ranges. This raises concerns as to whether or not current research is generalizable to a disorder that is often co-morbid with ID. Thus, the aim of this review is to better understand to what extent the current ASD visual processing literature is representative of the entire ASD population as either diagnosed or recognized under DSM-5. Our recalculation of ASD prevalence figures, using the criteria of DSM-5, indicates approximately 40% of the ASD population are likely to be ID although searching of the visual processing literature in ASD up to July 2016 showed that only 20% of papers included the ASD with-ID population. In the published literature, the mean IQ sampled was found to be 104, with about 80% of studies sampling from the 96–115 of the IQ range, highlighting the marked under-representation of the ID and borderline ID sections of the ASD population. We conclude that current understanding of visual processing and perception in ASD is not based on the mean IQ profile of the DSM-5 defined ASD population that now appears to lie within the borderline ID to ID range. Give the importance of the role of vision for the social and cognitive processing in ASD, we recommend accurately representing ASD via greater inclusion of individuals with IQ below 80, in future ASD research.

Autistic Children Show a Surprising Relationship between Global Visual Perception, Non-Verbal Intelligence and Visual Parvocellular Function, Not Seen in Typically Developing Children

“…The literature is supportive of a relationship between visual processing and mental ability in ASD (Brown et al, 2017 ). The report of correlations between full-scale WAIS scores and performance on biological (Koldewyn et al, 2010 ; Rutherford and Troje, 2012 ) and coherent (Jones et al, 2011 ) motion tasks (associated with ASD populations but not TD groups), appears qualitatively similar.…”

“…One of the fundamental tenets of general intelligence—speed of processing, appears not to contribute to low intelligence for those with ASD (Anderson, 2008 ). A review by Brown et al ( 2017 ) extends these deviations from the normal relation between ASD and IQ to visual processing. For example inspection time (IT) has a well-studied relationship with intelligence in typically developing (TD) individuals, established since the late 1970’s (Nettelbeck, 1982 ).…”

“…While ASD has been recognized as being associated with generally lower IQ, the nature of the intellectual disability in ASD is not classically subnormal (Frith, 2003 ; Brown et al, 2017 ). This understanding is based on the profile of subtest scores that individuals with ASD receive on the Wechsler Intelligence Scale for Children (WISC), for example, high performance on the Block Design task even as general IQ decreases (Lincoln et al, 1988 ; Allen et al, 1991 ; Shah and Frith, 1993 ; Happé, 1994 ).…”

Seeing a Page in a Flipbook: Shorter Visual Temporal Integration Windows in 2‐Year‐Old Toddlers with Autism Spectrum Disorder

“…Here we investigate the development of temporal processing in toddlers diagnosed with ASD, and age‐matched TD toddlers, at 18–36 months, the youngest age at which an ASD diagnosis can be reliably made, in a paradigm where, importantly, both integration and segmentation skills are measured. Since at this very young age, one of the main concerns that lead families to see a specialist is language and cognitive delays, this means a large portion of our ASD sample will have low mental age (the mean mental age of our sample is a full 2 SD below the mean of the TD group), whereas most autism research is conducted with samples with less substantial intellectual impairment [Brown, Chouinard, & Crewther, 2017; Russell et al, 2019]. Using an eye‐tracking task with no verbal instructions, we measured how often a child is able to find a visual target hidden in a cluttered display of other items, as the pace of a sequence of displays was varied to facilitate (or hinder) the visibility of the target.…”

Heterogeneities in Cognitive and Socio-Emotional Development in Children With Autism Spectrum Disorder and Severe Intellectual Disability as a Comorbidity

“…Intellectual disability (IQ less than 70), previously referred to as “mental retardation” (2) and with a wide variability in profiles (3) affects more than half of the children with autism (4, 5) but Christensen et al (6) showed that the percentage of children with an intellectual disability (ID) varied widely across 9 out of 11 geographic areas, ranging from 20 to 50%, and significantly more girls had ASD associated with ID (37%) than boys (30%). Using the criteria of DSM-5, Brown et al (7) reported IQ prevalence and indicated that about 40% of the ASD population are likely to present ID. In the present study, differences and similarities in the cognitive and socio-emotional developmental profiles of children with ASD and comorbid ID as compared with those of typical children were examined across three countries (France, Brazil, and Algeria).…”