ABSTRACT
It has long been observed that individuals with autism exhibit peculiar attentional and perceptual abnormalities. For example, individuals with autism frequently notice minor changes in their environments. In one of the earliest studies of autism, Kanner noted the following statement made by the mother of a child with autism: “On one of the bookshelves, we had three pieces in a certain arrangement. When this was changed, he always rearranged it in the old pattern” (Kanner, 1943; 1973, p. 9). This sort of behavior is consistent with many anecdotal and clinical reports that individuals with autism notice features about a situation or event that to others seem small and insignificant. Another example of this exquisite perception of detail has been observed when children with autism tackle jigsaw puzzles-the solution appears to be derived from the shapes of the pieces rather than the printed picture, so that the child with autism, unlike a normal child, could as easily complete a jigsaw puzzle with the picture facedown as when it is faceup (Frith & Hermelin, 1969). This ability to pick out individual features from some larger entity has also been observed using the Embedded Figures Task and the block design subtest of the Weschler intelligence scales. Several studies have established that both children and adults with autism show superior performance on these tasks compared with normal individuals and individuals with learning disabilities, matched for mental age (Shah & Frith, 1983; Shah & Frith, 1993; Jolliffe & Baron-Cohen, 1997).
