International Journal of Biomedical Research ISSN: 0976-9633 (Online) Journal DOI:10.7439/ijbr CODEN:IJBRFA Research Article A Brief Study on EEG Signals of Dysgraphia Children in Different Conditions: Relaxing and Writing Moods Mahboubeh Parastar Feizabadi* 1 , Mohammadreza Yazdchi 1 , Majid Ghoshuni 2 , Peyman Hashemian 3 1 Assistant Professor, Department of Biomedical Engineering, University of Isfahan, Isfahan, Iran 2 Assistant Professor Department of Biomedical Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran 3 Assistant Professor Department of Psychiatry, Mashhad University of Medical Science, Mashhad, Iran *Correspondence Info: Assistant Professor, Department of Biomedical Engineering, University of Isfahan, Isfahan, Iran Email : M.Parastar7@gmail.com 1. Introduction Learning disorders are one of the most common problems in school which many children grapple with today 1 . Dysgraphia is one of the learning disorders involved problems with handwriting. Handwriting is a complex, overlearned motor skill in which biomechanical and cognitive processes contribute to the spatial form and the kinematic features of the handwritten product 2,3 . Handwriting difficulties or dysgraphia have a profound impact on children's psychosocial development, and yet, 10–30% of school-aged children are reported to experience difficulties mastering this skill 4 . It occurs regardless of the ability to read and is not due to intellectual impairments 5 . The EEG is defined as electrical activity of an alternating type recorded from the scalp surface after being picked up by metal electrodes and conductive media 6 . The common classification of EEG frequency is listed as follows 7,8 : delta waves at 0.5 to 4 Hz with variable amplitude are closely linked to deep sleep. Theta waves which arise from emotional frustration or disappointment ranged at 4 to 8 Hz. The frequency of alpha wave is set in the range of 8 to 13 Hz. Alpha is the most dominant wave in the brain region which linked to relaxed awareness, reflecting and inattention. Beta waves exhibit at the range of 13 to 30 Hz and are always associated to active thinking, alert and busy state. Meanwhile Gamma waves have the highest frequency range of 30 to 40 Hz. In most studies, which use quantitative EEG analysis, the properties of IJBAR (2013) 04 (01) www.ssjournals.com Abstract Background : Electroencephalography (EEG) is the one of the important tools to study the brain behavior. Therefore, we have investigated the brain signals function of children with learning disabilities (LD) in order to compare the EEG signals during writing and after relaxing with eyes open. Aims: The aim of this work is comparing the brain electrical activity of dysgraphia children during writing task with their signals during the rest condition. Materials and Methods: The used method in this work is based on power spectral density (PSD) proposed with Welch. Participants in this study were included 6 girls and 10 boys with age of 9.2±0.64 who have dysgraphia disorder. Results: The results show that a frequency ratio of writhing mode is more than the resting mode. It is also indicated that the brain signals during writhing are more complex for dysgraphia children. Conclusion : Our results reveal that insufficient maturity of the brain increase during writing rather than relaxing mode. Finally, to overcome the LD situation neurofeedback can be proposed. Keywords: Electroencephalography, Power Spectral Density; Frequency ratios; Learning disabilities