Differences in visuospatial processing in individuals with nonverbal learning disability or autism spectrum disorder without intellectual disability

Objective: Although previous reports produced converging empirical evidence of a core deficit on visuospatial processing in children with a nonverbal learning disability (NLD), few studies compared the visuospatial profile of individuals with an autism spectrum disorder (ASD) or NLD in visuoconstructive and visuospatial working memory tasks. Nor did any of these studies investigate the role of the local bias, typically observed in ASD, when comparing these clinical groups. The present study aimed to analyze whether NLD and ASD share any characteristics. Method: A group of participants with NLD (n 17) was compared with another group who had ASD (n 17) without intellectual disability (ID), and without a peak in visuospatial intelligence, and with a control group (n 17). Participants aged from 8 to 18 years performed a visuoconstructive and a visuospatial working memory task in which global–local processing styles were manipulated. Results: The analysis of their visuospatial processing clearly distinguished between the neuropsychological profiles of the group with ASD without ID and the group with NLD: the latter performed less well than the former in all domains. The participants with ASD without ID had a more heterogeneous visuospatial profile, showing a diminished sensitivity to perceptual cohesiveness only in the visuoconstructive task. Conclusions: Examining different visuospatial domains and manipulating the cohesiveness of the stimuli might be useful for better discriminating between NLD and ASD without ID.