رابطه بین حافظه ی کاری و استدلال سیال کودکان نارساخوان: نقش میانجی کنش های جرایی

هدف: پژوهش حاضر با هدف شناسایی نقش میانجی عملکرد اجرایی در رابطه‌ی بین حافظه‌ی کاری و استدلال سیال کودکان نارساخوان انجام شد.روش: این پژوهش توصیفی- همبستگی از نوع مدل‌سازی معادلات ساختاری است. جامعه آماری شامل کلیه دانش آموزان نارساخوان پایه سوم ابتدایی شهر مشهد بود. از بین جامعه هدف، 205 نفر ( 130 پسر و 75 دختر) به روش نمونه گیری در دسترس از مراکز اختلالات یادگیری شهر مشهد در سال تحصیلی 1389-1399 انتخاب شدند. از مقیاس هوشی استنفورد بینه - ویراست پنجم، آزمون دسته بندی کارت های ویسکانسین و آزمون رنگ-واژه استروپ برای جمع‌آوری داده‌ها استفاده شد.یافته‌ها: نتایج مدل برازش شده، نشان داد که حافظه‌ی کاری با استدلال سیال رابطه‌ی معنی‌داری دارد (p=0/04)، 28/1 درصد از تغییرات متغیر استدلال سیال تحت تاثیر عملکرد اجرایی و حافظه‌ی کاری است، عملکرد اجرایی در رابطه ی بین حافظه ی کاری و استدلال سیال نقش میانجی ندارد و تقویت حافظه ی کاری منجر به تقویت استدلال سیال کودکان نارساخوان می گردد.

the relationship between working memory and fluid reasoning in children with dyslexia: mediating role of executive functions

introduction: dyslexia is among the most common disorders in the childhood period. various studies show a prevalence of 3-15% for this disorder. the most significant cognitive functions involved in dyslexia are working memory, fluid reasoning, and executive functions. the malfunction of working memory disrupts the processing of information necessary for fluid reasoning, resulting in dyslexia. through monitoring cognitive information, the executive functions enhance the effectiveness of fluid reasoning. however, due to the high diversity of the executive functions, the contribution of each function has not been clarified. multiple studies have tried to determine the association between the executive functions of working memory and fluid reasoning; nevertheless, fundamental issues, the nature, the logical basis, and the impact of executive functions on complex cognitive phenomena, such as reading, are not sufficiently clarified. as executive functions are considered to be the significant factors predicting educational success, determining their role in the association between working memory and fluid reasoning of children with dyslexia is important. clarifying the role of executive functions as the mechanisms to explain the dysfunction of children with dyslexia may help to develop interventions aimed at cognitive rehabilitation. by addressing existing research gaps, this study tried to investigate whether executive functions play a mediating role in the relationship between working memory and fluid reasoning among children with dyslexia.method: this descriptive and correlational study was ethically approved by the ethics committee of the islamic azad university, neyshabur branch, neyshabur, iran (no. ir.iau.neyshabur.rec.1397.005). the statistical population of this study consisted of 440 third-grade students of elementary schools in mashhad, iran in the 2018-2019 iranian academic year. among these students, 205 participants were selected using the convenience sampling method. the inclusion criteria were a diagnosis of dyslexic learning disorder, the third grade of elementary school, the age of at least 8 years, and an iq of 85 or higher. the stanford–binet intelligence scales (5th edition) was applied to measure working memory and fluid reasoning. moreover, the electronic version of the wisconsin card sorting test (wcst) and the stroop color and word test (scwt) were used to evaluate executive functions. the data were analyzed using appropriate statistical methods in spss software (version 23) and pls software (version 2).results: the results indicated that there was a positive and significant correlation between working memory and fluid reasoning with an intensity of 0.13 (p = 0.049). the coefficient of fluid reasoning was 0.28, indicating that 0.28% of the changes in fluid reasoning were due to executive functions and working memory, and the remaining was due to the factors not considered in the model. the results also showed that the path of working memory to fluid reasoning was significant (p = 0.04), and the coefficient of the path was positive (b = 0.51), indicating that when the working memory improved, the fluid reasoning also enhanced. the path of the independent variable (working memory) to the mediating variable (executive functions) and the path of the mediating variable to the dependent variable were not found significant. although the hypothesis of the mediating role of executive functions in the association between working memory and fluid reasoning was rejected, the direct correlation between the two variables was found significant.discussion and conclusion: the main purpose of this study was to explore the mediating role of executive functions in the relationship between working memory and fluid reasoning among children with dyslexia. the present study showed that there is a significant relationship between working memory and fluid reasoning. the aforementioned finding is in line with the findings of previous studies conducted on the relationship between working memory and fluid reasoning (johann et al., 2020; kim & park, 2018; orzechowski et al., 2020; rey-mermet et al., 2019). previous studies investigated the conceptual path between working memory and fluid reasoning among the general population in other countries; therefore, the significance of this study lies in examining the assumed paths using a sample of children with dyslexia in iran. the results showed that only 28% of changes in fluid reasoning could be influenced by executive functions and working memory. the aforementioned finding is in line with the findings of a study by mermet et al. (2019) (rey-mermet et al., 2019). moreover, the results did not confirm the mediating role of executive functions in the association between working memory and fluid reasoning among children with dyslexia. considering the findings of the present study and the findings of barbosa et al.’s study (2019) (barbosa et al., 2019), by focusing on dyslexic children, it can be said that only verbal working memory, specifically in phonological manipulation and not mental maintenance, is associated with executive functions. therefore, the association between working memory and fluid reasoning through the mediating role of executive functions is confirmed only in the verbal working memory domain.