The development of separability in visual perception.

Under conditions that do not allow focused attention, reports of illusory conjunctions constitute evidence of the separate registering of features at an early processing level. The occurrence of illusory conjunctions was used to determine whether there is preattentive analysis of component dimensions and of parts of shapes in young children aged 5 to 8 years. Evidence of preattentive analysis was found, even for the youngest children, for colour and form but not for parts of shapes.