Children with and without autism were compared on two visual
search tasks in which a letter
target appeared among two sets of letter distracters. In one task, the
target shared colour
with one set of distracters but was unique in shape — the feature search
task. In the other, the
conjunctive search task, the target shared colour with one set and shape
with another set of
distracters. Although search was slower in the conjunctive task than the
feature task in
normally developing control children, children with autism showed no significant
slowing in
reaction time in the conjunctive task and were faster than
control children in this task. This
result is discussed in the light of theories of visual search which state
that rate of search is
determined by the degree of similarity between target and distracters.