Natural Word Segmentation Cue in Chinese Sentence Reading

The absence of clear word boundaries in Chinese raises questions about how readers segment continuous lines of characters into words for the purposes of their identification and saccade targeting.  Findings from other unspaced languages (e.g., Thai; Kasisopa et al., 2013) suggest that skilled readers can utilise orthographic cues to guide their eyes and segment words. This research investigates whether similar cues are used in Chinese by examining whether the frequently occurring, single-character function word ‘de’ (的) facilitates saccadic targeting and word segmentation. The eye movements of 41 native Chinese-speaking participants were recorded as they read sentences where the position of the character ‘de’ (i.e., the beginning vs. middle of a 5-character string, e.g., 的雪白天鹅 vs. 雪白的天鹅) and its presence (i.e., ‘de’ vs. a substitution character, e.g., 的雪白天鹅 vs. 只雪白天鹅) were orthogonally manipulated.  Our results showed that the character 'de' facilitated word segmentation: readers spent less time fixating five-character strings when ‘de’ was present than absent, and when it occurred in the middle of the five-character strings. However, our results also suggest that readers employ two distinct saccade-targeting processes: one that utilises cues such as ‘de’ to constrain saccade targets, and another that dynamically adjusts saccade lengths in response to processing difficulty.  These results are discussed in relation to models of Chinese reading (Li & Pollatek, 2020; Liu et al., 2024).