Revealing similarities in the perceptual span of young and older Chinese readers

Older readers (aged 65+ years) of both alphabetic languages and character-based languages like Chinese read more slowly than their younger counterparts (aged 18-30 years). A possible explanation for this slowdown is that, due to age-related visual and cognitive declines, older readers have a smaller perceptual span and so acquire less information on each fixational pause. However, although aging effects on the perceptual span have been investigated for alphabetic languages, no such studies have been reported to date for character-based languages like Chinese. Accordingly, we investigated this issue in three experiments that used different gaze-contingent moving window paradigms to assess the perceptual span of young and older Chinese readers. In these experiments, text was shown either entirely as normal or normal only within a narrow region (window) comprising either the fixated word, the fixated word, and one word to its left, or the fixated word and either one or two words to its right. Characters outside these windows were replaced using a pattern mask (Experiment 1) or a visually similar character (Experiment 2), or blurred to render them unidentifiable (Experiment 3). Sentence reading times were overall longer for the older compared with the younger adults and differed systematically across display conditions. Crucially, however, the effects of display condition were essentially the same across the two age groups, indicating that the perceptual span for Chinese does not differ substantially for the older and young adults. We discuss these findings in relation to other evidence suggesting the perceptual span is preserved in older adulthood.