Hideyuki Okuzumi

GAIT DISTURBANCE OF PATIENTS WITH VASCULAR AND ALZHEIMER-TYPE DEMENTIAS

The gaits of 15 patients with senile dementia of the Alzheimer type and 15 with vascular dementia were compared with those of 15 healthy control subjects. Patients with senile dementia showed significantly slower velocity and shorter step length than the healthy controls, and those with vascular dementia exhibited a reduction on these two variables relative to patients with senile dementia of the Alzheimer type.

Discrepancy Between Mental Rotation and Perspective-Taking Abilities in Normal Aging Assessed by Piaget's Three-Mountain Task

In a cross-sectional study, we examined age-related differences in visuo-spatial ability associated with image rotation, using two variants of Piagets ‘Three-Mountain Task.’ The object-mental rotation (OMR) task detects the ability to mentally rotate an image, whereas the subject-mental rotation (SMR) task reveals the ability to mentally change ones perspective. A group of 33 young adults, 26 middle-aged adults, and 31 elderly normal adults were studied. Both tasks revealed age-related differences in performance but a larger difference between middle-aged and elderly group was observed for SMR than OMR performance. Age-related increases in the ‘egocentric’ type of error were found only on the SMR task. The results suggest that the ability to mentally change ones perspective declines with age, perhaps more than the ability to mentally rotate objects.

Longitudinal Change in the Physical Performance of Older Adults in the Community

The primary purposes of this study were 1) to confirm age-related deterioration of physical performance in older adults longitudinally, and 2) to predict future functional status and mortality by initial level of physical performances. The subjects were 517 older adults examined both in 1992 and 1996 in the Tokyo Metropolitan Institute of Gerontology, Longitudinal Interdisciplinary Study on Aging. The same battery consisting of muscle strength, balance, walking, and manual speed was administered to the subjects in the baseline and follow-up examinations. A significant longitudinal decline was observed in all physical performances except for grip strength. The age-related decline accelerated with aging for preferred walking velocity. Inter-subject variability in walking velocity significantly increased for 4 years period. Maximum walking velocity was a common predictor for functional status and mortality. The results suggest that physical performance measures, especially maximum walking velocity, is a valid means for physical therapy to evaluate physical functioning of community-living older persons.

COMPARISON OF POSTURAL CONTROL OF CHILDREN WITH DOWN SYNDROME AND THOSE WITH OTHER FORMS OF MENTAL RETARDATION

To confirm the 1994 findings of Okuzumi, Haishi, and Kokubun, the displacement of the center of foot pressure, one-foot balance and bead 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 bodys sway which might be related to postural control.

Age-Related Trends of Interference Control in School-Age Children and Young Adults in the Stroop Color–Word Test:

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.

Features of Stroop and Reverse-Stroop Interference: Analysis by Response Modality and Evaluation:

Stroop interference (the Stroop effect) is the phenomenon observed when naming the color of an incongruent stimulus, such as the word “red” printed in blue ink; typically, this color incongruence causes slower naming compared to a neutral stimulus, such as a blue square patch. Reverse-Stroop interference occurs when reading the stimulus takes longer than reading the neutral stimulus. Features of Stroop and reverse-Stroop interference were examined, focusing on the difference between the response modalities — oral response and manual response — and the difference between methods of evaluating performance (time or correct responses) and the interference score. Participants were 47 students (30 women, 17 men; M age = 20.8 yr., range = 19–29). The results were as follows: (1) the performance of the reverse-Stroop condition was higher than that of the Stroop condition for both oral and manual responses; (2) the Stroop interference score was significantly greater with the oral response than with the manual response; and (3) the reverse-Stroop interference score was constant regardless of the response modality. The results were discussed with respect to differences in processing speeds of verbal and sensory information.

Stroop/reverse-Stroop interference in typical development and its relation to symptoms of ADHD.

This study examined prepotent response inhibition among 376 children and young adults divided into five age groups: 23 5-6-year-olds, 80 7-8-year-olds, 72 9-10-year-olds, 98 11-12-year-olds, and 70 young adults (19-24-year-olds). The Stroop/reverse-Stroop test was administered with a manual response. This test measured Stroop interference, which occurred when naming the ink color of the incongruent color word stimuli (for instance the word red printed in blue ink), and the reverse-Stroop interference, which occurred when reading the stimuli. This study also examined the relation between performance on the Stroop/reverse-Stroop test and scores on the ADHD Rating Scale-IV. Results indicated that the Stroop interference decreased with age, whereas the reverse-Stroop interference increased with age. Results also showed that all three scores in the ADHD Rating Scale-IV, two subscale scores of inattentive and hyperactive-impulsive symptoms and a total score, correlated with the Stroop interference, but not with the reverse-Stroop interference in typically developing children. These results indicated the difference in mechanism between the Stroop interference and the reverse-Stoop interference, and suggested that the Stroop interference is strongly correlated with ADHD symptoms in typically developing children.

Age-related trends of stroop-like interference in animal size tests in 5- to 12-year-old children and young adults

Few studies have examined the development of Prepotent Response Inhibition (Niggs interference control) from childhood to adulthood. This cross-sectional study examined differences in Prepotent Response Inhibition among children of 5 age groups: twenty 5- to 6-year-olds, twenty-one 7- to 8-year-olds, twenty-two 9- to 10-year-olds, eighteen 11- to 12-year-olds, and 24 young adults (18- to 24-year-olds). Participants were administered two Stroop-like tasks: the Real Animal Size Test described in 2009 by Catale and Meulemans, which requires that participants decide the real size of animals (big vs. small) displayed in a mismatching pictorial size; and the Pictorial Animal Size Test (an original test), which requires that participants report the pictorial size of the animals. Results showed clear differences between the tests. The Pictorial Animal Size Test elicited robust interference whereas the Real Animal Size Test elicited no interference. The Pictorial Animal Size Test also revealed the development of Prepotent Response Inhibition in children of 5–12 years and between children and young adults. These results were discussed with respect to differences in strengths of processing. The Pictorial Animal Size Test can be a useful tool for assessment of Prepotent Response Inhibition in children older than 5 years of age.

Factors Affecting Age of Walking by Children with Mental Retardation

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.

Age-related trends of inhibitory control in Stroop-like big-small task in 3 to 12-year-old children and young adults.

Inhibitory control is the ability to suppress competing, dominant, automatic, or prepotent cognitive processing at perceptual, intermediate, and output stages. Inhibitory control is a key cognitive function of typical and atypical child development. This study examined age-related trends of Stroop-like interference in 3 to 12-year-old children and young adults by administration of a computerized Stroop-like big–small task with reduced working memory demand. This task used a set of pictures displaying a big and small circle in black and included the same condition and the opposite condition. In the same condition, each participant was instructed to say “big” when viewing the big circle and to say “small” when viewing the small circle. In the opposite condition, each participant was instructed to say “small” when viewing the big circle and to say “big” when viewing the small circle. The opposite condition required participants to inhibit the prepotent response of saying the same, a familiar response to a perceptual stimulus. The results of this study showed that Stroop-like interference decreased markedly in children in terms of error rates and correct response time. There was no deterioration of performance occurring between the early trials and the late trials in the sessions of the day–night task. Moreover, pretest failure rate was relatively low in this study. The Stroop-like big–small task is a useful tool to assess the development of inhibitory control in young children in that the task is easy to understand and has small working memory demand.