Effects of word frequency and visual complexity on eye movements of young and older Chinese readers

Abstract

Research using alphabetic languages shows that, compared to young adults, older adults employ a risky reading strategy in which they are more likely to guess word identities and skip words to compensate for their slower processing of text. However, little is known about how ageing affects reading behaviour for naturally unspaced, logographic languages like Chinese. Accordingly, to assess the generality of age-related changes in reading strategy across different writing systems we undertook an eye movement investigation of adult age differences in Chinese reading. Participants read sentences containing a target word (a single Chinese character) that had a high or low frequency of usage and was constructed from either few or many character strokes, and so either visually simple or complex. Frequency and complexity produced similar patterns of influence for both age groups on skipping rates and fixation times for target words. Both groups therefore demonstrated sensitivity to these manipulations. But compared to the young adults, the older adults made more and longer fixations and more forward and backward eye movements overall. They also fixated the target words for longer, especially when these were visually complex. Crucially, the older adults skipped words less and made shorter progressive saccades. Therefore, in contrast with findings for alphabetic languages, older Chinese readers appear to use a careful reading strategy according to which they move their eyes cautiously along lines of text and skip words infrequently. We propose they use this more careful reading strategy to compensate for increased difficulty processing word boundaries in Chinese.

Keywords:

• Ageing
• Eye movements
• Word frequency
• Visual complexity
• Chinese reading

Notes

¹We also conducted a comparison of age group on progressive saccade length between the older adult group in the present experiment and the young group in the Liversedge et al. (2014). The result showed that older adults made significantly shorter progressive saccades than the young adults (b = 0.30, p < .001).

²An LMM analysis that included years of schooling as an additional factor produced the same pattern of results, with the exception that the effect of age group on word-skipping probability was no longer robust. This finding, nevertheless, still contrasts sharply with findings from studies with alphabetic languages showing that older adults typically skip words more often than younger adults as a result of employing a more risky reading strategy.