Investigation of the brain connectivity disturbance in dyslexic patients

Rasoulzadeh, Vesal
Dyslexia is a learning disability that makes reading a challenge, despite normal level of intelligence and receiving adequate instructions. The core deficit in dyslexia is attributed to phonological processing. It’s been suggested that dyslexia is a disconnection syndrome. In this sense, the major sites of phonological processing in the brain are intact and the interconnection between these areas are disturbed. In this study, the disturbance in dyslectic brains based on effective connectivity models in “pre-reading” and “while reading” stages is investigated, which explains the causal interactions between different regions of the brain. Dynamic Bayesian Networks were constructed for the EEG data in theta, alpha and beta frequency bands to model the effective connectivity patterns of the brain in dyslectic and normal subjects in these bands. Analysis was performed based on the data obtained from two independent experiments, reading a word and a non-word by each subject. As the main objective of the thesis, dyslexic and normal children were classified based on the information obtained from the underlying effective connectivity models of their brains which reveal the abnormal patterns in the brain that may lead to detection and diagnosis of the condition. Dyslectic subjects were found to have a different effective connectivity patterns in “pre-reading” period, regardless of the reading task and theta frequency vi band is reported to be the most informative one about the disturbance in the casual influence between two groups in this period. The classification rate of 86.21% were obtained based on “pre-reading” models. the classification rates of 86.21% in reading a word experiment and 81.03% in reading a non-word experiment were obtained in alpha band. Features used to classify two groups are the connectvity weights (obtained fron DBN models) that are significantly different between dyslectics and controls. The connection include the ones from both dorsal (which is more activated while reading a word) and ventral (which is more activated while reading a non-word) pathways. This indicates the distruption of them both in dyslectic brains.


Graph theory analyses on connectivity maps obtained by partial directed coherence using EEG data of dyslexic and healthy children
Erkuş, Ekin Can; Ulusoy, İlkay; Çiçek, Metehan; Department of Biomedical Engineering (2017)
Dyslexia is a common brain disorder which is defined as reading and sometimes learning disability. In this thesis study, EEG data which were collected from 31 dyslexics and 27 non-dyslexic children during reading task were used. First, multivariate autoregressive modelling was made. Then using MVAR models, brain connectivity networks were obtained with partial directed coherence (PDC) algorithms. Using brain connectivity networks, graph theory properties such as “characteristic path length”, “clustering coe...
Meta-analysis of gene expression reversals in ageing brain
Dönertaş, Handan Melike; Somel, Mehmet; Department of Biology (2016)
Brain ageing is characterised by disruptive changes in cognitive abilities, histology, and anatomy. The underlying molecular nature of brain ageing, on the other hand, is little understood, partly due to the stochastic and heterogeneous nature of ageing process. In this study, using published microarray studies spanning 22 brain regions with 1,015 samples, gene expression changes in ageing are analysed in comparison to those in postnatal development. A previous observation that mRNA abundance of a large num...
Analyzing Complex Problem Solving by Dynamic Brain Networks
Alchihabi, Abdullah; Ekmekci, Ömer; Kivilcim, Baran B.; Newman, Sharlene D.; Yarman Vural, Fatos T. (2021-12-01)
Complex problem solving is a high level cognitive task of the human brain, which has been studied over the last decade. Tower of London (TOL) is a game that has been widely used to study complex problem solving. In this paper, we aim to explore the underlying cognitive network structure among anatomical regions of complex problem solving and its subtasks, namely planning and execution. A new computational model for estimating a brain network at each time instant of fMRI recordings is proposed. The suggested...
Developing Adaptive Serious Games for the Training of Children with Specific Learning Difficulties: A Two-Phase Usability and Technology Acceptance Study with Children and their Educators
Yildirim, Oguzcan; Sürer, Elif (2021-05-01)
Background: Specific learning difficulties (SpLD) include several disorders such as dyslexia, dyscalculia, and dysgraphia, and the children with these SpLD receive special education. However, the studies and the educational material so far focus mainly on one specific disorder. Objective: This study’s primary goal is to develop comprehensive training material for different types of SpLD, with five serious games addressing different aspects of the SpLD. The second focus is measuring the impact of adaptive d...
Developing bodily movement games to teach basic life skills for children with mental disabilities
Nazirzadeh, Mohammad Javad; Çağıltay, Kürşat; Department of Modeling and Simulation (2015)
Students with mental disabilities often have trouble generalizing concepts and skills from one setting to another. An alternative way to teach generalization is to teach students solve problems pertinent to their daily lives and to reinforce behaviors that would occur in the natural environment. In this thesis, we propose a system to augment the environment for mentally disabled students in order to easily cope with life skills by game and fun. The games were developed for motion sensing input devices by fo...
Citation Formats
V. Rasoulzadeh, “Investigation of the brain connectivity disturbance in dyslexic patients,” M.S. - Master of Science, Middle East Technical University, 2016.