Abstract
Purpose :
Visual factors have long been investigated to try and restore functional reading in individuals with central field loss (CFL). However, none have clearly led to clinically significant improvements. Recently, psycholinguistic factors (word frequency and orthographic neighborhood size) have been studied in the context of low vision, showing an undocumented influence on reading abilities with CFL. Here, we investigated the specific effect of word predictability in context.
Methods :
29 normally sighted young adults read aloud short sentences in the presence of a simulated gaze-contingent central scotoma. Participants read 304 sentences presented within 19 blocks and had to adjust to the presence of the scotoma in order to read. Each sentence contained a primer and a target word, which were either semantically related or not, providing a range of predictability in context values. Sentences were displayed using self-paced reading paradigm. For each target word, reading time, accuracy, number and duration of fixations were collected. Data were analyzed using linear mixed-effects models to inspect the effect of word predictability on these outcome measures across the adaptation process.
Results :
Reading time was significantly longer for low predictability words during the 1st block, with an average value of 2.6s, against 1.6s for high predictability words (p<0.001). During the last block, reading time was significantly decreased (p<0.001) but showed no significant difference between high and low predictability. Similarly, as predictability increased, the number of fixations decreased significantly by 40% during the 1st block (p<0.001). With practice, this difference became non-significant, despite a significant decrease in fixation number in both conditions (p<0.001).
Conclusions :
As reported before with normal readers, predictability significantly affects reading speed. This effect is modulated by the amount of practice with a simulated scotoma. We concluded that prior to their adaptation to the scotoma, participants rely on semantical inference, leading to a strong effect of predictability. As they adapt, their need for inference decreases, reducing the amplitude of the predictability effect. Finally, our results show that word predictability influences reading time by modifying oculo-motor patterns of the reader. These results will help better understand the reading deficit induced by CFL.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.