Visual abilities and exploration behaviors as predictors of intelligence in autistic children from preschool to school age

Abstract

The current prospective cohort study investigated whether early perceptual abilities, measured at preschool age, could predict later intellectual abilities at school age in a group of 41 autistic (9 girls, 32 boys) and 57 neurotypical children (29 girls, 28 boys). More than 80% of the autistic children were considered minimally verbal. Participants were assessed at three time points between the age of 2 and 8 years using the Wechsler Preschool and Primary Scales of Intelligence–Fourth Edition as a measure of full-scale IQ and the Raven’s Colored Progressive Matrices as a measure of fluid reasoning abilities (Gf). The performance on two perceptual tests (Visual Search and Children Embedded Figures Test) and the frequency of early non-verbal behaviors served as predictors of later intellectual abilities. Early performance on perceptual tests measured at preschool age was positively related to later full-scale IQ in both autistic and neurotypical children. Furthermore, both early non-verbal behaviors and performance on perceptual tests measured at preschool age were associated with later Gf in the autistic group. In contrast, only the performance on Children Embedded Figures Test was associated with later Gf in the neurotypical group. Early perceptual abilities\and non-verbal behaviors may be indicators of general intelligence and Gf abilities.Lay AbstractAt the time of diagnosis, parents of autistic children frequently wonder what the future holds for their children in terms of intellectual development. It remains however difficult to answer this question at such a young age. Indeed, while early precursors of intelligence are well known for children following a typical development, these precursors remain to be identified for autistic children. Some theoretical models of intelligence suggest that perceptual abilities or behaviors, as seen early in autistic cognitive development, could be early indicators of intelligence. However, research examining the relation between early perceptual predictors and autistic intelligence over time is needed. This article is the first to consider a variety of early perceptual abilities and behaviors as precursors/predictors of intelligence at school age in autistic children. We showed that better performance in perceptual tasks at preschool age predicted better intellectual abilities measured later in autistic children. Importantly, our sample of autistic children represented the whole spectrum, including children with few to no spoken words, who are an important proportion of autistic preschoolers. While early perceptual abilities and behaviors may not substitute for a formal intellectual assessment, our results support that these indices may help estimate later intellectual level in autistic children. Perceptual abilities have the advantage to be easy to observe at preschool age and seem to fit the cognitive style of autistic children. Assessment methods could probably gain from including and focusing more on the perceptual strengths of autistic children.