In this cross-sectional study, differences in interference control, one component of executive function, were investigated among three age groups, 15 early childhood (7- to 8-yr.-olds), 25 middle childhood (9- to 12-yr.-olds), and 20 young adults (21- to 30-yr.-olds). Participants were administered a computer version of the Stroop color-word test with an oral response; correct responses, response time (RT), and the interference ratio were examined. The data indicated that (1) most of the participants showed no errors in word reading, color-naming, and incongruent color-naming tasks; (2) in word-reading and color-naming tasks, RT for 7- to 8-yr.-olds was longer than that for 9- to 12-yr.-olds, while RT of 9- to 12-yr.-olds and young adults were comparable; (3) in an incongruent color-naming task, RT for 7- to 8-yr.-olds was longer than RT for 9- to 12-yr.-olds, which was longer than RT for young adults; and (4) the interference ratio was higher in 7- to 8-yr.-olds than in 9- to 12-yr.-olds, which was higher than in young adults. These results suggested the difference in interference control between early and middle childhood reported on the go/no-go task and the stop-signal procedure would be observed in the Stroop color-word paradigm as well. The utility of this modified Stroop color-word test for those with intellectual and developmental disabilities was discussed.

To confirm the 1994 findings of Okuzumi, Haishi, and Kokubun, the displacement of the center of foot pressure, one-foot balance and head sway were measured in children with Down syndrome (n = 11) compared to those with other types of mental retardation (n = 17). The magnitudes of the displacement of the center of foot pressure and head sway were not significantly different between the Down group and other forms of mental retardation, whereas the performance of one-foot balance was significantly lower in the Down group. The mean frequencies of sway waves were generally higher in the Down group, and the differences between the two groups were significant except for sagittal head sway. The results generally supported the prior findings. We proposed that it was not the magnitude of the displacement of the center of foot pressure but rather the manner of the whole body's sway which might be related to postural control.

No abstract

The relationship between age of walking and two factors of severity of intellectual disability and clinical types (autism, Down syndrome, epilepsy, and "residual") in children with mental retardation was investigated. Subjects were 118 children whose disabilities ranged from severe to mild. Measures by clinical type were significant, and the differences of any two clinical types except between children with epilepsy and the "residual" group were significant, but severity of intellectual disability was not significant. Most children with autism (27 subjects, 93%) walked by the normal time limit of 18 months. Only 3 children (11%) with Down syndrome began to walk within that limit, and 9 of them (33%) walked after 2 years of age. In the "residual" group (including children with epilepsy), 37 children (60%) walked within the normal limit but 15 (25%) only after 2 years of age.

This study examined Stroop-like interference in the fruit Stroop test among 271 5 -12-year-old children and young adults divided into five age groups: 64 5 -6-year-olds, 65 7 -8-year-olds, 60 9 -10-year-olds, 46 11 -12-year-olds, and 36 young adults (18 -23-year-olds). Participants were administered a paper-and-pencil version of the fruit Stroop test, which includes the canonical color task, the superficial color task, and the fruit name task. In these tasks, participants were presented with line-drawings of fruits having strongly associated colors (e.g., yellow banana) and were asked to name the ink colors of the fruits, name the colors the fruit "should be", or read the fruit name. The results indicated robust interference in the canonical color task of the fruit Stroop test, suggesting that this task is useful to assess individual differences of inhibitory control in typical development.