Abstract
Purpose :
Reading with central field loss (CFL) relies on peripheral vision and requires adaptation of visuo-attentional and oculo-motor processes. It is still unclear whether reading performance depends on the systematic use of a specific portion of peripheral vision, often referred to as Preferred Retinal Locus (PRL). Here we investigate whether eye movement patterns adapt to simulated CFL and how these changes influences reading performance.
Methods :
35 young normally sighted subjects read short sentences with a gaze-contingent artificial scotoma (a 10° disk centered on the fovea). Sentences were displayed using the self-paced reading paradigm, allowing to reveal one word at a time by masking all other words with x strings. Eight experimental blocks were run, representing a 2-hour adaptation period. For each subject and block, characteristics of the preferred area for fixation were derived by plotting a heatmap of fixation location with respect to the words center. Change in reading speed over the course of the adaptation process was analyzed using characteristics of the preferred area for fixation (position, size, number) as well as linguistic properties of the text (word length, frequency).
Results :
Overall, the preferred area for fixation changed progressively from bloc1 to bloc8, showing a significant and gradual increase in eccentricity both in the vertical and horizontal directions, as well as a small yet significant increase in the number of preferred areas. Importantly, these changes correlated with a significant increase in reading speed over the course of the adaptation process.
Conclusions :
Our results confirm that, over the course of a short adaptation period, young adults are able to adapt eye movements in the presence of simulated CFL. By increasing the eccentricity of their fixation to identify words beyond the limits of their scotoma, while developing flexible strategies with more than one single preferred area of fixation, individuals with CFL might be able to improve their reading performance.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.