Selective attention and active engagement in young children.

During early development, significant changes occur in the neural regions that subserve attention and related skills. Although preschoolers typically have difficulty performing continuous performance tests, it is not clear if this is primarily due to an inability to selectively respond or an inability to maintain attention. A group of 52 children between 3.5 and 5.5 years of age performed 2 vigilance-type reaction time tasks. The tasks included short duration, continuously presented visual stimuli across several short blocks. Among the children under 4.5 years of age, 46% were unable to coordinate the necessary task demands, and those who could made significantly more omission errors than the older children. Active engagement was high during the reaction time tasks for all children. These results suggest that the skills necessary for vigilance tasks, particularly speeded response initiation and response selection, are still emerging during the preschool years but can be adequately measured after 4.5 years of age.