[Children with attention deficit/hyperactivity disorder and pervasive developmental disorder:attention and response inhibition in the kiddie continuous performance test].

Continuous Performance Test (CPT) is widely used to assess the attention function and response inhibition in both children and adults. This study attempts to examine the performances of boys with attention deficit/hyperactivity disorder (AD/HD) and pervasive developmental disorder (PDD) with and without comorbid AD/HD using a CPT. Among the various versions of the CPT available, we used the Kiddie CPT (K-CPT) modified for younger children. The K-CPT was administered to children with AD/HD (n=22), those with PDD (n=19), and typically developing children (n=41) from 7 to 12 years of age. All children were drug free at the time of examination. The performances were examined in 6 measures:total number of omission errors (OE), total number of commission errors (CE), mean hit reaction time (HRT), hit reaction time standard error (HRTSE), perceptual sensitivity (d'), and response style (beta). Significantly lower scores in d' and a tendency to more errors in CE were found in the AD/HD group compared with the control group. Significantly lower scores in d' and significantly more errors in CE were also found in the PDD group with AD/HD symptoms compared with the control group. Moreover the AD/HD group showed significantly more errors in OE and higher scores in HRTSE compared with the control group. There were no significant group differences between the PDD group without AD/HD symptoms and the control group on all measures. Less favorable scores in AD/HD suggest inadequate selective attention, sustained attention and/or response inhibition. Results of the PDD group with comorbid AD/HD may reflect a basis of AD/HD impairment. Our findings may provide an understanding of neuropsychological characteristics underlying developmental disorders.

[Clinical application of the modified Stroop test to children with attention deficit/hyperactivity disorder].

The Stroop test has been already applied to many children with attention deficit/hyperactivity disorder (AD/HD). There are, however, differences in the measurement of the Stroop test, and also in the background conditions of the patients, such as the status of comorbidity with learning disorder (LD), medication and the level of Intelligence Quotient (IQ), and presumably as a result, the outcome of the Stroop test shows a diversity. This study was undertaken to compare the performances of children with AD/HD to normal controls using the modified Stroop test according to the subtypes of AD/HD. Subjects in this study were 23 unmedicated children with AD/HD, ranging from 6 to 14 years of age, and 69 normal controls who were matched on sex and age. Children with AD/HD whose verbal IQ and performance IQ were above 80 showed significant differences in such indices as Incongruent Color Naming time (ICN) and the resulting index of subtracting Color Naming time (CN) from ICN (ICN-CN). As to the analysis according to the subtypes excluding 8 cases with comorbid LD, both the predominantly inattentive type and the group putting together the predominantly hyperactive-impulsive type and the combined type showed significant differences in ICN--CN compared with the normal controls. These results suggest that the inattentiveness relevant factor affects the performance of the interference task in children with AD/HD.

[Developmental changes in the kiddie continuous performance test and its appropriate age for application].

The Kiddie Continuous Performance Test (K-CPT) was produced by Conners for children in age from 4 to 5 years. This study attempted to examine the developmental changes and gender differences of this test in children from preschool to adolescence, to verify its appropriate age range for application, and also to obtain a norm for clinical applications. K-CPT was administered to 327 healthy participants from 4 to 18 years of age. Participants were divided into 7 age groups. The performances were examined in 6 measures: the total number of omission errors (OE), the total number of commission errors (CE), the mean hit reaction time (HRT), the hit reaction time standard error (HRTSE), perceptual sensitivity (d') and response style (beta). All measures showed significant developmental changes. OE and beta showed floor effects around 10 years. Such measures as CE, HRT, HRTSE and d' showed significant developmental changes until adolescence. The effect of gender was found in performances in OE, CE, d' and beta. Male participants made more errors and showed less favorable perceptual sensitivity than did female participants. Results suggested that K-CPT would be appropriate for use with preschoolers and school-aged children. Findings also suggested that it is a potential diagnostic tool in children with developmental disorders.

[Standard value and developmental changes in the indices of interference effect in the modified Stroop test].

The Stroop test was originally invented by Stroop to measure selective attention and cognitive flexibility and various versions of this test have been developed by many other researchers. Since the Stroop test requires the examinee's sustained efforts, it is not readily applicable to children with developmental disorders. In order to overcome this weakness, a modified Stroop test by reducing the total number of stimulations from 300 to 72 was proposed for clinical use. This study was performed to obtain the standard value of the modified Stroop test, and also to clarify the developmental changes in indices of interference effect. Two hundred eighty one normal children and adults, ranging from 6 to 20 years of age were examined. A simple regression analysis was performed to examine the relation between age and the score of indices such as Incongruent Color Naming (ICN), ICN--Color Naming (CN), ICN/CN. The results from this analysis showed significant age-related changes. Subjects between sixteen and seventeen showed the best score in each index. These findings suggest that a brain region and/or functional system of late maturation might participate in the execution of the interference task.