Differences in eye movements control among dyslexic, retarded and normal readers in the Spanish population

Abstract

This paper reports a research which examined the relationship between dyslexia and eye movement control in Spanish speaking children. The study compared the eye movements recordings of 30 dyslexic, 30 retarded and 30 normal readers, aged between 7 and 14, in one ocular tracking task and two reading tasks which differed in their degree of reading difficulty. Within each group the subjects were divided into 3 subgroups of 10 in accordance with the following chronological ages: 7–9, 10–11 and 12 years and above. Dependent variables were saccadics (number, size and fixation pause), regressives (number, size and fixation pause), total number of movements and percentage of regressives over the total number of movements. The following results were obtained: (1) In the two reading tasks significant differences were found between dyslexic and normal readers and between retarded and normal readers in most of the parameters, no differences being found between dyslexic and retarded readers except in a few parameters; (2) in the ocular tracking task significant differences both between dyslexic and normal readers and between dyslexic and retarded readers were found in all dependent variables, no differences being found between retarded and normal readers at all, and (3) the age factor produced a significant main effect in the two reading tasks indicating a general improvement of eye movements as age increases but an interaction effect with reading disability in the ocular tracking task-indicating a deterioration in eye movements in the dyslexic group as a function of age-was also found. The results are discussed in the context of alternative theoretical explanations of developmental dyslexia.