Normal and dyslexic children: EEG topography versus fMRI brain images during letters writing

Abstract

Dyslexia is a neurological disorder that needs to be detected at an early stage. It is defined as difficulty with learning due to impairment of the left hemisphere of the brain associated with language processing. The excellent time resolution of electroencephalography (EEG) provides a unique window on the dynamics of the human brain functions. Even though EEG is said to be time accurate and spatial inaccurate, the approximate spatial information is still useful. In this paper, we presented initial work to study correspondence between the 2D EEG topography and brain images from fMRI for the normal and dyslexic children during letters writing, being the first attempt ever reported. Under the OpenViBE programming environment, the EEG signal acquired was filtered and extracted for significant features, before the EEG 2D topography is generated. Despite difficulty in finding the corresponding brain images, it is found that the 2D EEG topography along the reading-writing pathway for normal and dyslexic children, is a close match to images from previous fMRI studies and neurological theories. Differences in hemispheric activation are found, between normal, dyslexic Capable and dyslexic Poor children.