VISUAL PERCEPTION IN DYSLEXIA : OCULOMOTRICITY INFLUENCE IN READING SKILLS

Abstract

Dyslexia is a heterogeneous neuro disorder that affects language, mainly characterized by an unexpected difficulty in learning to read and write, despite adequate intelligence, motivation, education, absence of sensory or neurological deficits, and an appropriate social environment. It has a prevalence of 5-12% of school-age children. Thus, this disorder should not go unnoticed, being necessary to carry out more and more studies to better understand it. However, beyond the phonological deficits, dyslexic individuals also exhibit deficits in visual perception, which theories cannot explain properly. The objective of the study is to analyze the eye movement of dyslexics in order to identify any pattern related to visual control of these individuals (location, duration and frequency of fixations and saccades). The sample will be composed by 10 patients diagnosed with developmental dyslexia, with deficits in visual processing, aged 8-13 years and 10 participants without learning problems, matched for age and education with dyslexics. The DEM (Developmental Eye Movement) test will be applied to profile the eye movement of the sample. The reading of the participants will be evaluated for decoding, fluency and comprehension through the following tests: Pinheiro's list of words and non-words (for evaluation of decoding) and Reading Process Assessment Test - PROLEC (to assess fluency and reading comprehension). Concomitantly, eye movements during the described reading activities will be monitored by Eye-tracker equipment and the correlation between the duration and frequency of saccades and fixation and the reading performance will be made. Still, eye movements will be monitored during the execution of the Rapid Automatizated Naming Test (RAN), which is a specific test for assessing the access speed to the mental lexicon that requires eye movements during its execution, and therefore the individual's oculomotricity patterns can influence test performance. Then, the correlation between the eye movement and the speed of access to mental lexicon will also be made. The collected data will be analyzed using parametric and non-parametric statistical tests (according to the distribution of results) between groups and within groups. Descriptive and comparative analysis of saccadic movements and fixation by dyslexic and not dyslexic individuals also will be made. For all analyzes will be adopted the 5% significance level.