Autism and dimensionality: differences between copying and drawing tasks.

Previous research suggests individuals with autism may be less influenced by a three-dimensional interpretation when copying line drawings (Sheppard et al. J Autism Dev Disord 37:1913-1924, 2007). The current research aimed to determine whether this reduced dimensionality effect extends to drawings of an actual object. Twenty-four children and adolescents with autism and 24 comparison participants copied one line drawing with no depth cues, line drawings with a three-dimensional interpretation, and drew a actual three-dimensional object. Participants with autism were less influenced by three-dimensionality on the copying tasks but were equally affected when drawing the actual object. This suggests that any advantage for three-dimensional drawing in non-savant individuals with autism is confined to situations when the individual copies a line drawing with depth cues.