Abstract

The purpose of this study is that how the children's ability of sustained attention changes with age and how the interval of letter-presentation and period of trial influence the sustained attention. In the study, a spilt-plot design was used, theat is, 3 (grade: 2, 4, 6) X 2 (interval of letter-presentation: 1, 3 sec) X 2 (period of trial: the first half, the second half) was done. And for the period of trial, repeated design was used. The Continuous Performance Task(CPT) viewed through a computer was presented to them. In a result of the study, the ability of sustained attention was decresed with age being lower, with the interval of letter-presentation being longer, and with trial being longer. The children of the lowest year, i.e. 2nd grade showed a significant decrease of performance with the interval of letter-presentation and the period of trial, while the children of 4, 6 grade had no change in their performance, it is conceivable that the more 2nd grade of children was required with sustained attention and passed with time, the more the ability of sustained attention is decreased. The decrease of performance appeared in condition of the interval of letter-presentation being 3 seconds, while the decrease of performance did not appear in the condition of 1 second. Therefore sustained attention ability is considered to be decreased in the tasks which require more sustained attention.