VISUAL PERCEPTION AND SENSE-MAKING IN INTELLECTUAL DISABILITY, AUTISM SPECTRUM DISORDER, AND DEAFNESS

Background: The standardization study of the ComFor  (Forerunners in Communication – Verpoorten, Noens, & Van Berckelaer-Onnes, 2004) - a clinical instrument measuring visual perception and sense-making at the levels of presentation and representation – has shown that individuals with an intellectual disability (ID) and an autism spectrum disorder (ASD) exhibit a higher discrepancy between presentation and representation scores than individuals with an intellectual disability only. Items with meaningless materials provided the best discrimination between the two samples (Noens & Van Berckelaer-Onnes, 2007).

Objectives: To examine the influence of co-morbid deafness on visual perception and sense-making in individuals with an intellectual disability and an autism spectrum disorder.

Methods: The ComFor was administered from a sample of 200 children and adults with an adaptive level between 24 and 54 months measured with the Vineland Screener 0-6yrs-NL (Scholte et al., in press). The total sample consists of four subgroups: (1) individuals with an ID (n=78), (2) individuals with an ID and an ASD (n=84), (3) individuals with an ID and deafness (n=22), and (4) individuals with an ID, an ASD, and deafness (n=16).

Results: Preliminary results indicate that individuals with deafness also show a significantly higher discrepancy between presentation and representation scores compared to hearing individuals with an ID, but not specifically for items with meaningless materials.

Conclusions: Deaf individuals and individuals with ASD both exhibit a higher discrepancy between presentation and representation scores. In ASD, the discrepancy can be understood within the framework of the central coherence theory, whereas in deafness, it might be due to a more generally enhanced visual perception.