Motor Learning in children with ADHD and Normal Children: Comparison of Implicit and Explicit Motor Sequence

Introduction: Children with Attention Deficit Hyperactivity Disorder (ADHD) face many academic and training problems and also impose some problems on their teachers and classmates. Motor learning can be categorized into two main types: implicit and explicit. The main goal of the present study was to investigate the possible differences between implicit and explicit motor sequence learning in children with ADHD and normal children by using serial reaction time task. Materials and Methods: The sample consisted of 24 children with ADHD, who were equally assigned to explicit and implicit learning groups, and 24 normal children, also equally assigned to implicit and explicit learning groups. Each group, therefore, consisted of 12 participants. Repetitive Measure ANOVA was run to compare reaction time and error in different blocks, and squared t-test was used to compare regular and irregular blocks. Results: Comparison of implicit and explicit learning for accuracy (the number of reaction errors) and speed (response time) revealed the accuracy to be P=0.012 and speed P=0.012 in ADHD explicit group, and accuracy P=0.094 and speed P=0.954, in ADHD implicit group. Normal explicit group indicated accuracy of (P=0.008) and speed of (P=0.05) and normal implicit group indicated accuracy of (P=0.011) and speed of (P=0.442). Conclusion: The results of the present study indicated that explanation and description of the task was more effective in motor sequence learning in ADHD children. It is, therefore, recommended that pre-exercise training be included in the programs provided to these children.Keywords: Motor Sequence, Explicit Learning, Implicit Learning, ADH

Inter-Intra Rater Reliability, Construct and Discriminative Validity of Iranian Typically Developing Children Handwriting Speed Test (I-CHST)

Objectives: The purpose of this study was to develop an Iranian Hand writing Speed Test (I-CHST) for testing of Iranian students aged 8-12. To date, no  norms of handwriting speed have been published for hand-writing speed of the Iranian students. Methods: A sample of 400 typically developing Iranian students across four age cohorts was recruited. Among those 400 students 50% were girls and 50%  were boys. 73% were studding at government schools and 27% were from the private schools. 79% were right handed and 11% were left handed. The results showed that the handwriting speed assessment test has excellent inter-rater reliability (r=1, P=0.000) and construct validity (r=0.798, P=0.000). Results: The findings showed that handwriting speed increases with age and the rate of increase was found to be greatest among Iranian children aged 8-12. It is also found that the girls aged 11-12 wrote faster than boys of the same age. Discussion: Based on this research, I-CHST was a valid and reliable test for testing the hand writing speed in Iranian children and it could be used for testing or intervention purposes by the therapists at clinics