Aging Effects on Perceptual Reading Span: Evidence from an Eye-Tracking Study

Abstract

Objectives: The purpose of this study was to investigate how aging influences the perceptual span and reading through online reading measurement variables using an eye-tracking paradigm. Methods: This study had a total of 38 participants including 20 normal younger and 18 older adults. Offline (reading comprehension accuracy) and online (words per second, mean fixation duration) measurement variables were analyzed through sentence comprehension questions and perceptual span measurement tasks. Results: 1) There were not significant differences between the older adults and younger adults in reading comprehension accuracy. There was no cognitive demand due to the low difficulty of the task, and it did not affect the reading comprehension accuracy of each group. 2) There were significant differences between the older adults and younger adults in both words per second and mean fixation duration. The older group showed a decrease in encoding ability due to the normal aging process. Additionally, the performance of words per second and mean fixation duration was significantly lower under the one fixated word condition (1W) in both groups. 3) In the case of mean fixation duration, the older group fixed their gaze longer than the younger. The older group showed greater difficulty under the 1W condition when the cognitive load was increased by presenting limited language information. Conclusion: This study was intended to examine the perceptual span of older adults and the level which shows the aging-effect concretely. It was possible to predict that the perceptual span of the younger group was between one or two words to the right of the fixated word (W+1 and W+2), and that of the elderly was W+1.