Abstract
Mathematical disorder is one of the common learning disabilities among students, where, despite having normal intelligence and physical health, students do not perform well in mathematical calculations. The aim of the present study was to compare the effectiveness of neuropsychological intervention with and without electrical brain stimulation on the executive functions and problem-solving abilities of students with mathematical learning disabilities. The research design was a factorial experimental design of the pretest-posttest type with a control group. The statistical population of the study included all male students aged 9 to 12 in the city of Tabriz during the academic year 2021-2022. The sample consisted of 60 students with mathematical learning disabilities (15 in each group), selected through convenience sampling based on entry criteria and diagnostic interviews for learning disabilities based on DSM-5. The research tools included the Kimmat Mathematical Test, Mathematical Problem Solving Test, and Barkley Executive Function Deficits Questionnaire. Data were analyzed using SPSS-24 software and multivariate covariance analysis, univariate analysis, and Bonferroni pairwise comparison tests. The results showed that there was a significant difference between the mean scores of the experimental groups (neuropsychological intervention with and without electrical brain stimulation) and the control group (p < 0.001). Bonferroni pairwise comparisons indicated that the scores of the interactive group were significantly higher than those of the other groups (p < 0.001). Mathematics plays an important role in the education and daily lives of individuals, and neuropsychological interventions with electrical brain stimulation are one of the essential tools for enhancing mathematical problem-solving skills and executive functions.
Keywords: mathematical learning disorder, electrical brain stimulation, problem solving, executive functions, neuropsychological Intervention
 
 
 
 
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Extended Abstract

Introduction

Specific learning disorder is a neurodevelopmental condition characterized by an individual's performance being lower than expected for their age. This disorder disrupts the proper development and evolution of the brain or central nervous system during childhood, negatively impacting the individual’s emotions, learning ability, and memory as they grow (Abedi, 2017). Experts classify learning disorders into three main categories: Dyslexia, Dysgraphia, and Dyscalculia (Hall, Hughes, Charles & Filbert, 2015). In British Columbia, students with mathematical learning disorders exhibit deficits in information processing, which includes language processing, visual-spatial processing, processing speed, memory, attention, and executive functions (American Psychiatric Association, 2017; Ahadi & Kakavand, 2019). Additionally, these students face challenges with number perception, understanding numerical facts, calculation, and problem-solving (Aghaei Sabet et al., 2018). Problem-solving is a cognitive-behavioral process that involves taking logical steps to find and implement solutions (Demayr et al., 2015).
The primary goal of assessing learning disabilities is to identify strengths and weaknesses to provide an appropriate educational program. Mathematical learning disabilities often have a neurological origin. Neuropsychological tests can help study the characteristics of students with learning disabilities, and addressing these through intervention, treatment, and education can improve their symptoms. Given the numerous deficits in executive functions and problem-solving abilities among students with math disorders, focusing on the development and enhancement of neuropsychological skills can reduce the occurrence of these problems and aid in improving the disorder. Therefore, recognizing these challenges and providing solutions to mitigate them is essential.
In addition to neuropsychological interventions, a treatment gaining traction among researchers in neurology is Transcranial Direct Current Stimulation (tDCS), which uses direct electrical current (San-Juan et al., 2015). The present study aims to investigate the effectiveness of neuropsychological interventions on executive functions and problem-solving in students with mathematical learning disorders. Despite various studies on the effectiveness of neuropsychological interventions for different student disorders, limited research has explored the combined effects of neuropsychological intervention and electrical brain stimulation on learning disorders. Thus, comparing the effectiveness of these interventions in improving mathematical learning disorders, which have multiple neuropsychological bases and neurological symptoms, is crucial.
Research Question
What is the effect of neuropsychological interventions with and without Transcranial direct current stimulation (tDCS) on executive functions and mathematical problem solving in students with mathematical learning disorders?
Literature Review
Cherrier et al. (2020) conducted a study investigating the impact of educational neuroscience on the academic performance of students through a self-awareness and autonomy approach using metacognitive strategies. While the study did not find a significant difference in academic performance, it highlighted that educational neuroscience enhances students' understanding of brain function, leading to greater autonomy and improved self-awareness. Fernanda et al. (2018) examined the effects of neuropsychological intervention in children with functional deficits in planning and control, finding significant improvements in planning, control, and academic performance. This underscores the necessity of child correction approaches in neuropsychology to foster psychological and neuropsychological development.
Rashidi et al. (2020) conducted a meta-analysis on the effectiveness of neuropsychological interventions in improving academic performance among students with specific learning disabilities, demonstrating a significant positive impact. Dehghani and Hekmatianfard (2019) found that executive function training improved attention and response inhibition in students with math disorders, with effects remaining stable over a two-month follow-up. Zemestani et al. (2019) showed that tDCS improved attention and motor performance in students with learning disabilities. Abdollahi, Hassanabadi, and Samiie Sanjani (2015) found that transcranial brain stimulation using direct electric current positively affected executive functions. Similarly, Arjomandnia et al. (2018) reported that electrical brain stimulation interventions effectively improved working memory in students with math disorders.
Methodology
This research employed a quasi-experimental pre-test-post-test design with a control group. The statistical population consisted of male students aged 9 to 12 years during the second half of the 2021-2022 academic year. A total of 60 students were selected through convenience sampling based on inclusion criteria and randomly assigned to three experimental groups (neuropsychological intervention group, electrical brain stimulation group, and a combined intervention group) and a control group. The experimental groups underwent the designed interventions, while the control group continued their regular routine.
 Data collection tools included the Barkley Student and Adolescent Executive Function Deficits Questionnaire, which consists of 70 items across five subscales (time self-regulation, organization and problem-solving, self-control and inhibition, self-motivation, and emotion self-regulation), which measures executive function deficits. Another tool was the Mathematical Problem Solving Questions for Students with Mathematical Learning Disorder, adapted from the fifth grade mathematics textbook, consisting of 19 questions. Cronbach's alpha coefficient was used to confirm the validity from the experts' point of view and for reliability. Neuropsychological intervention was implemented in 10 sessions using the educational programs of Korkman (1998), Bley & Thornton (2001), and Geary (2010). Direct electrical brain stimulation was performed in accordance with the research of Feesera, Prehn, Kazzer, Mungee & Bajbouj (2014). In this method, the black electrode in the middle of the forehead and the red electrode on the left side of the skull were stimulated with a current intensity of two amperes. Descriptive and inferential statistics were used to analyze the data in the present study. Thus, the data obtained from completing the questionnaires after the intervention were analyzed by the SPSS-24 software version, and the statistical methods of analysis of covariance and Bonferroni paired comparison test were used.
Results
In order to conduct the analysis of covariance, all necessary assumptions were first made, including the test of data normality (non-significance of the Shapiro-Wilkstatistic), the assumption of homogeneity of variance (Leven's test), and the examination of the homogeneity of regression slopes. Multivariate analysis of covariance to examine the effect of neurological interventions with and without electrical brain stimulation in the post-test stage on all variables showed that the mean scores of the subscales of parental executive functions, students' executive function deficits, and problem solving in the post-test stage were significantly different in the experimental and control groups (P<0.001). The results indicate that the interventions had a significant effect on each of the variables separately. In terms of the effectiveness of the interventions, the effect size shows that the interventions had the greatest effect on self-regulation of time, self-motivation, problem-solving and organizational, and problem solving, respectively. The results of the Bonferroni test for pairwise comparison of students' executive functions and problem solving among groups show that there is a significant difference in the variables of students' executive functions deficit and problem solving in the post-test stage between the methods studied (P<0.001). According to the results, it can be seen that the greatest difference is observed in the combined intervention method, which indicates the better effectiveness of this method.
Discussion and Conclusion
The results showed that combined neuropsychological intervention along with electrical brain stimulation has a significant effect on improving students' executive function deficits and problem solving. In explaining the findings, neuropsychological interventions allow individuals to better manage and regulate in different situations and increase their planning and organizing abilities. Teaching effective memorization techniques and strategies allows students to use the information and problem-solving methods they have stored efficiently. The type of action of electrical brain stimulation on executive functions is such that the dorsolateral prefrontal cortex, which has a high capacity in specific cognitive functions in working memory, planning, goal-oriented behavior, concentration, and inhibitory control, is targeted and leads to increased cortical excitability in the left dorsolateral prefrontal cortex.