Are people with autism and Asperger syndrome faster than normal on the Embedded Figures Test?

Previous work suggests children with autism show superior performance (in relation to their general mental age) on the Embedded Figures Test (EFT). Frith interprets this as showing that they have "weak central coherence". In Experiment 1, using an adult level version of this task, we aimed to replicate and extend this finding, first, by collecting response time (RT) data; second, by testing adults with autism of normal intelligence; and third, by testing a group of adults with Asperger syndrome, in order to test for differences between autism and Asperger syndrome. Both clinical groups were significantly faster on the EFT. In Experiment 2, we investigated if this difference was due to a preference for local over global processing, using a novel drawing task based on the classical Rey Figure. The clinical groups did not differ significantly on this test, but there was a trend towards such a difference. Alternative explanations for the EFT superiority in autism and Asperger syndrome are considered.