E-ISSN : 2733-4538
With a perceptual task of which difficulty was varied by the ambiguity of stimulus, a new diagnostic technique for testing the Attention Deficit Hyperactivity Disorder(ADHD) children was developed and tested for its validity. As the stimuli of the new diagnostic tool, a pair of simple target and nontarget figures were administered across three different levels of task difficulty. The task difficulty was controled by the vividness of the stimuli made of random dots. The target and nontarget were, respectively, a square of 3×3 cm and a triangle of 3.5cm base and 3.5cm height presented in the middle of a 6×6 cm background square. The target and nontarget stimuli appeared on a computer screen in a random order. The clinical group consisted of 22 ADHD children and the control group 22 normal children who were matched to the clinical subjects in terms of sex and age. When a target appeared on the screen, a subject had to press the space bar. If the stimulus was a nontarget, a subject must not respond. The data of this study were analyzed on correct responses, commission error, omission error, mean response time, standard diviation of response time, multiple responses, anticipatory responses, d', β based on signal detection theory. The result showed that the inattention and impulsivity, the two distinctive characteristics of ADHD, were effectively captured by the new diagnostic test. Especially, it was found that the clinical subjects who did not show difference with the control group at the lower levels of task difficulty showed a differential response tendency as the level of task difficulty went up. This result suggests that the new test could make up the weak points of the existing continuous performance tests(CPT) by allowing the assessment of the degrees of ADHD symptoms.