Résumé
The present research was conducted to compare the executive functions among the children with attention deficit hyperactivity disorder [ADHD], learning disability [LD] and normal children. Samples of this comparative study were students of 3rd to 6th grades of normal elementary schools and schools for mentally disabled children in 2005 in Ardabil city, north western part of Iran. Sixty subjects [20 ADHD boys, 20 LD and 20 normal children] were selected by multi-stage cluster sampling method. Data gathering was done by Conners' questionnaire for ADHD, hearts and flowers test, Simons 1 and 2, visual search and Raven intelligence scales. The multiple analysis of variance [MANOVA] and least significant difference [LSD] post hoc tests were used to analyze data. The results revealed that there is a significant difference in executive functions among three groups [P<0.00]. ADHD children obtained higher scores in working memory in comparison with LD group [P<0.05], but had not a significant difference in inhibition [P>0.05]. Children of LD group obtained lower scores in both inhibition and working memory in comparison with normal group. Children suffering from LD are more impaired in executive functions in comparison with normal and ADHD groups