Emi Furukawa

Along with the comparator model, the perception of action-outcome regularity is involved in the generation of sense of agency. In addition, the perception of action-outcome regularity is related to motor performance. However, no studies have examined the developmental changes in the perception of action-outcome regularity. The current study measured perceptual sensitivity to action-outcome regularity and manual dexterity in 200 children aged between 5 and 16 years. The results showed that perceptual sensitivity to action-outcome regularity was significantly lower in 5-6-year-old children than in 9-16-year-old children, and that it was significantly lower in children with low manual dexterity than in children with medium to high manual dexterity. Correlation analyses revealed significant correlations of age and perceptual sensitivity to action-outcome regularity, but no significant correlation of manual dexterity and perceptual sensitivity to action-outcome regularity, either overall or in any age band. The present study suggests that perceptual sensitivity to action-outcome regularity is immature at 5-6 years of age and that it may be impaired in 5-16-year-old children with poor manual dexterity.

BACKGROUND: Previous studies have suggested that children with developmental coordination disorder (DCD) rely heavily on vision to perform movements, which may contribute to their clumsy movements. However, few studies have objectively and quantitatively investigated the perceptual biases of children with DCD. METHODS: A visual-tactile temporal order judgment (TOJ) task was used to measure and compare the perceptual biases of 19 children with DCD and 19 age- and sex-matched typically developing children. The point of subjective equality, which demonstrates when "visual first" and "tactile first" judgment probabilities are equal (50%), obtained by analyzing the results of the visual-tactile TOJ task, was used as an indicator of perceptual biases. Further, variables (age and manual dexterity in all participants; motor function, autism spectrum disorder and attention-deficit hyperactivity disorder traits, and depressive symptoms in children with DCD) associated with perceptual biases were examined with correlation analysis. RESULTS: Children with DCD had significantly stronger visual bias than typically developing children. Overall correlation analysis showed that increased visual bias was significantly correlated with poor manual dexterity. CONCLUSION: Children with DCD had a strong visual bias, which was associated with poor manual dexterity.

Background: There is increasing evidence that the stochastic resonance (SR) phenomenon provided by subthreshold mechanical noise stimulation improves the sensory-motor system. However, the effect of SR on children with developmental coordination disorder (DCD) is unclear. The purpose of this study was to assess whether SR activated by subthreshold vibrotactile noise stimulation of the wrist influences manual dexterity in children with DCD. Methods: A double-blind interventional study was conducted. Participants were 30 children (age: 9.3 ± 1.44 years, range 6-11 years; 27 male, three female; 25 right-handed, five left-handed) meeting DCD diagnostic criteria in DSM-5. The manual dexterity test was administered the day before SR intervention (baseline-data). SR was elicited using subthreshold vibrotactile noise stimulation at 60% of the vibrotactile threshold measured at the wrist. SR was delivered two times and the manual dexterity test was administered during each SR stimulation block (SR-on condition) and after each SR stimulation block (SR-off), for a total of four measurements. Target outcomes were the component score, the standard score, and the percentile score of the manual dexterity test. Results: The manual dexterity test scores in the SR-on condition were significantly improved compared to scores at the baseline and in the SR-off condition (p < 0.001). Conclusions: The present study showed that subthreshold noise stimulation eliciting SR significantly improved manual dexterity outcomes in children with DCD during stimulation but not after stimulation. Future studies will need to investigate the carry-over effects of SR stimulation.

BACKGROUND: There is increasing evidence that children with developmental coordination disorder (DCD) have deficits in sensory-motor integration, but it is unclear whether the sense of agency (SoA) generated by sensory-motor integration is altered. AIMS: To investigate whether there is a difference in the time window for SoA between children with DCD and typically developing (TD) children. METHODS AND PROCEDURES: An agency attribution task was used to quantitatively measure and compare the time window for SoA in 15 children with DCD and 46 children in the TD group. Variables that correlated with the time window for SoA were also examined in both groups of children. OUTCOMES AND RESULTS: The time window for SoA was significantly extended in children with DCD compared to TD children. The time window for SoA in TD children was significantly associated with manual dexterity, whereas the time window for SoA in children with DCD was significantly associated with depressive tendency. CONCLUSIONS AND IMPLICATIONS: The time window for SoA is altered in children with DCD. The present results suggest that there may be a bidirectional relationship between an internal model deficit and depressive tendency and SoA in children with DCD.

地域における里親・養親支援に資するべく、小児科医の里子・養子の診療経験ならびに里親・養親支援に関する意識について質問紙調査を行った。対象は一般社団法人大阪小児科医会会員715名である。方法は大阪小児科医会事務局から質問紙を郵送し、料金後納郵便で返送を求めた(返送率17.6%)。結果は(1)回答者の小児科医経験は平均28.8年、里子・養子の診療経験があるのは81名(65.3%)であった。(2)「里親・養親が受診したとき困った経験」は、養子縁組の成立前には「医療券(受診券)の使用について」6.5%、「子の姓が違う」12.1%、「子どもの既往歴がわからない」21.8%、「子どもの実家族の病歴がわからない」18.5%、「母子手帳の記載に関すること」17.7%、「手術の同意書に関すること」1.6%であった。医療者が困ったことの内容は、子どもの既往歴で予防接種歴やアレルギーがわからないこと、発達障害の相談で子どもや実親の発達歴がわからないことであった。(3)「里親・養親からの相談に乗ることができると思うこと」は、「子どもの病気」90.3%、「身体発育」89.5%、「心の成長」72.6%、「育てにくさ」69.3%、「思春期の問題」66.1%であった。(4)里親・養親の支援に関する自由記述は28件あり、「里親・養親を支援したい」、「里子制度に関する研修を求める」というものが多かった。小児科医がかかりつけ医としてかかわる中で、子どもの心の問題や思春期の相談に乗ることが里親・養親支援につながると考えられた。(著者抄録)

Is there a difference in sense of agency between children and adults? This study investigated the difference in the time window of sense of agency between school-age children (N = 94, aged 6-12 years) and young adults (N = 30, aged 21-23 years) by using an agency attribution task and international standardized manual dexterity test. The results showed that the time window for sense of agency was significantly shorter in children compared to young adults. In addition, there was a significant correlation between the time window for sense of agency and manual dexterity only in children. The present results suggested that sensory-motor function greatly contributes to sense of agency in school-age children.

Although the media can have both negative and positive effects on children's cognitive and motor functions, its influence on their perceptual bias and manual dexterity is unclear. Thus, we investigated the association between media viewing time, media preference level, perceptual bias, and manual dexterity in 100 school-aged children. Questionnaires completed by children and their parents were used to ascertain media viewing time and preference levels. Perceptual bias and manual dexterity were measured using the visual-tactile temporal order judgment task and Movement Assessment Battery for Children-2nd edition, respectively. There were significant positive correlations between age and media viewing time and between media viewing time and media preference level. There was also a significant negative correlation between visual bias and manual dexterity. Hierarchical multiple regression analysis revealed that increasing visual bias was a significant predictor of decreasing manual dexterity. Further, children with low manual dexterity showed significant visual bias compared to those with high manual dexterity, when matched for age and gender. The present results demonstrated that, in school-aged children, although viewing media was not associated with perceptual bias and manual dexterity, there was a significant association between perceptual bias and manual dexterity.

Developmental coordination disorder (DCD) is the most common childhood movement disorder. It is characterized by clumsiness of fine and gross motor skills in developing children. Children with DCD have low ability to effectively use tactile information for movements, instead relying on visual information. In addition, children with DCD have deficits in visuo-motor temporal integration, which is important in motor control. These traits subsequently lead to clumsiness of movements. Conversely, however, imperceptible vibrotactile noise stimulation (at 60%-intensity of the sensory threshold) to the wrist provides stochastic resonance (SR) phenomenon to the body, improving the sensory and motor systems. However, the effects of SR have not yet been validated in children with DCD. Thus, we conducted a single case study of a 10-year-old boy with a diagnosis of DCD to investigate the effect of SR on visual dependence, visuo-motor temporal integration, and manual dexterity. SR was provided by vibrotactile noise stimulation (at an intensity of 60% of the sensory threshold) to the wrist. Changes in manual dexterity (during the SR on- and off-conditions) were measured using the manual dexterity test of the Movement Assessment Battery for Children-2nd edition. The point of subjective equality measured by visual or tactile temporal order judgment task served as a quantitative indicator reflecting specific sensory dependence. The delay detection threshold and steepness of delay detection probability curve, which were measured using the delayed visual feedback detection task, were used as quantitative indicators of visuo-motor temporal integration. The results demonstrated alleviated visual dependence and improved visuo-motor temporal integration during the SR on-conditions rather than the SR off-conditions. Most importantly, manual dexterity during the SR on-conditions was significantly improved compared to that during the SR off-conditions. Thus, the present results highlighted that SR could contribute to improving poor movement in children with DCD. However, since this was a single case study, a future interventional study with a large sample size is needed to determine the effectiveness of SR for children with DCD.

The neurological basis of developmental coordination disorder (DCD) is thought to be deficits in the internal model and mirror-neuron system (MNS) in the parietal lobe and cerebellum. However, it is not clear if the visuo-motor temporal integration in the internal model and automatic-imitation function in the MNS differs between children with DCD and those with typical development (TD). The current study aimed to investigate these differences. Using the manual dexterity test of the Movement Assessment Battery for Children (second edition), the participants were either assigned to the probable DCD (pDCD) group or TD group. The former was comprised of 29 children with clumsy manual dexterity, while the latter consisted of 42 children with normal manual dexterity. Visuo-motor temporal integration ability and automatic-imitation function were measured using the delayed visual feedback detection task and motor interference task, respectively. Further, the current study investigated whether autism-spectrum disorder (ASD) traits, attention-deficit hyperactivity disorder (ADHD) traits, and depressive symptoms differed among the two groups, since these symptoms are frequent comorbidities of DCD. In addition, correlation and multiple regression analyses were performed to extract factors affecting clumsy manual dexterity. In the results, the delay-detection threshold (DDT) and steepness of the delay-detection probability curve, which indicated visuo-motor temporal integration ability, were significantly prolonged and decreased, respectively, in children with pDCD. The interference effect, which indicated automatic-imitation function, was also significantly reduced in this group. These results highlighted that children with clumsy manual dexterity have deficits in visuo-motor temporal integration and automatic-imitation function. There was a significant correlation between manual dexterity, and measures of visuo-motor temporal integration, and ASD traits and ADHD traits and ASD. Multiple regression analysis revealed that the DDT, which indicated visuo-motor temporal integration, was the greatest predictor of poor manual dexterity. The current results supported and provided further evidence for the internal model deficit hypothesis. Further, they suggested a neurorehabilitation technique that improved visuo-motor temporal integration could be therapeutically effective for children with DCD.

Although visuo-motor temporal integration in children is suggested to be related to motor control and motor learning, its relevance is still unclear. On the other hand, visuo-motor temporal integration ability undergoes developmental changes with age. In the current correlational study, we measured manual dexterity and visuo-motor temporal integration ability in 132 children with typical development (age, 4-15 years) and investigated the relationship between the two functions. The Movement Assessment Battery for Children-2nd edition was used as an indicator of manual dexterity. The delay detection threshold (DDT) and steepness of the probability curve for delay detection, which was measured by the delayed visual feedback detection task for self-generated movement, were used as indices of the visuo-motor temporal integration ability. The results indicated significant correlations between manual dexterity/age and DDT/steepness of the probability curve for delay detection. In addition, hierarchical multiple regression analysis showed that both manual dexterity and age significantly contributed to visuo-motor temporal integration, indicating a better fit than when only age was employed as an independent variable. Importantly, there was no interaction effect between age and manual dexterity. These findings were the first to suggest that manual dexterity is a significant predictor of visuo-motor temporal integration ability in children, regardless of age. The present study validated the important relationship between visuo-motor temporal integration and manual dexterity in children. Considering the limitations of the current study, including the non-homogeneous sample, further studies are still warranted to validate the results.

The purpose of this study is to examine the nature of the anxiety felt by parents raising high school students with developmental disorders. Self-reported questionnaires were distributed and 199 parents returned the completed form. The respondents were raising high school students with learning disabilities (LD), attention-deficit hyperactivity disorder (ADHD), pervasive developmental disorder (PDD), and mental retardation (MR). The results found that some students had a plural number of disorders: singular LD, 46; LD with ADHD, 24; LD with PDD, 13; LD with MR, 3; LD with ADHD and PDD, 6; LD with ADHD and MR, 3; LD with PDD and MR, 1; for a total of 97. The other 102 persons did not have LD, but rather ADHD, PDD, or MR singularly or in a plural number of disorders. Most parents feel anxiety when the student's problematic behaviors are shown. Their anxiety is associated with the problems of judging circumstances, communicating with others, expressing their own feelings, acting clumsily and not knowing tacit rules. Our conclusions show that anxiety is common among the respondents. Parents make contact only with their child's teacher at school. However, it is important for parents and high school students to be given careful consideration by both the homeroom teachers and the yogo teachers involved. Thus, the most important thing for high school students with developmental disorders is that their parents, healthcare providers, homeroom teachers and school nurses establish a network.