Development of the Psychophysiological Mechanisms in the Comprehension of Printed Texts: Eye Tracking during Text Reading in Healthy and Dyslexic Children Aged 9–11 and 12–14 Years

Abstract

Development of the psychophysiological mechanisms of reading and understanding written texts is an important issue, which is still poorly studied. From this perspective, on-line evaluation of text processing is a very promising method. This provides a wide range of opportunities for studying the nature of dyslexia, a socially significant developmental disability. In this study, the oculomotor behavior during text reading was studied in healthy and dyslexic children aged 9–11 and 12–14 years. A total sample of 58 subjects was divided into four groups based on their age and clinical condition. The gaze movements were recorded by an eye-tracker in the settings of natural text reading. Two kinds of texts were presented to each participant: two narratives and two expository texts. We used the following parameters of gaze movements: (1) duration of fixations, (2) number of fixations, (3) amplitude, (4) duration and (5) number of progressive and regressive saccades, and (6) saccade velocity. According to the results of ANOVA, most of the eye tracking measures were significantly different in the dyslexic and healthy children. The most pronounced differences were observed in children aged 12–14 years. This is the first study that describes the differences in saccade velocity between dyslexic and healthy children and between the age groups of healthy children. The article discusses a two-level model of the gaze regulation cerebral mechanisms that develop with reading skills.