Distance perception in autism and typical development.

Children with autism and typically developing children walked blindfolded to a previously seen target (blindwalking task) and matched the frontal to the sagittal extent of a pattern formed by ropes on the ground (L-matching task). All participants were accurate in the blindwalking task. Children with autism were also very accurate in the matching task. By contrast, in the matching task typically developing children made substantial underestimations that were inversely correlated with age. These findings support models that posit independent representations for the egocentric distance to a target location and for the spatial extent to a target object relative to the other spatial extents. These latter representations involve a form of large-scale pattern perception that may mature more slowly than representations of egocentric distance and develop atypically in autism.