Understanding reading strategies: eye movements in acquired dyslexia

JAICHENCO, VIRGINIA; SÁNCHEZ, MARÍA ELINA; SHALÓM, DIEGO

Baltimore

Conferencia; Academy of Aphasia 55th Annual Meeting; 2017

Academy of Aphasia

The purpose of this work was to study differences in eye movements between Spanish acquired dyslexics and controls to understand the cognitive processes underlying. As there is not much research with this technique in acquired dyslexic population, we wanted to know which kind of ocular strategies use patients with reading impaired. We designed a sentence reading task, where length (long and short) and frequency (high and low) of a critical noun were manipulated to create four experimental groups of 20 sentences each. All sentences have the same grammatical structure with a critical word in a fixed position. Four patients diagnosed with phonological acquired dyslexia and their controls age and educational level matched participated in the study. Eye movements were registered. The general results showed that patients presented a pattern of ocular behavior different from controls in time and localization measures. Compared to normal controls, 3 patients showed more fixation time, not skipping behavior, and progressive/regressive pattern of refixations. Also, they always fixed early, near the beginning of the word. Contrary, the fourth patient (BG) seems to read in a very different way, she skipped words abnormally more than controls and other patients, showed a constant regressive pattern, fixed later near the end of the words and presented saccades longer than other groups.The pattern of eye movements can be explained by the EZ Reader Model. It assumes that in reading the eyes and visual attention are focused on one word (n) and word identification processes are performed. Programming of the saccade to word n + 1 begins with successful orthographic recognition (familiarity check) and movement of attention to word n + 1 is triggered by accessing word phonology and meaning (lexical completion). Based on the EZ Reader Model, the group of patient ´s performance could reveal a slow lexical access. The consequences would be more fixation time, lack of skips, and refixations, modulated by frequency. More difficult to analyze is BG´s ocular pattern, although she seems a phonological dyslexic too. In sum, these findings allow us to suggest the usefulness of this technique for clinical purposes, in order to understand the reading strategies of the patients and to guide the rehabilitation.