Abstract: Words identification is essential for both the comprehension of reading of alphabetic and logographic Chinese scripts. Although there are no interword spaces to mark word boundaries in Chinese scripts, native Chinese readers have no difficulty in reading Chinese characters. A growing number of evidence have shown that word segmentation is necessary to word and text processing in Chinese reading (Bai et al., 2008, 2013; Blythe et al., 2012; Li et al., 2009; Ma et al., 2019; Shen et al., 2012). It is also well known that age has an impact on word processing in reading (Liu et al., 2020; Wang et al., 2018; Zhao et al., 2019). As far as we know, the literature on whether or how aging impacts word segmentation in Chinese reading is scant. Therefore, to examine this, we conducted this study—we carried out two eye-tracking experiments, manipulating age groups and word segmentation cues.
56 young and 40 old (aged over 60) native Chinese speakers participated in the experiments. There was no group difference in vision. Participants in the experimental group were asked to read a sentence having three boundary markings (e.g. red colour, gray highlighting, and spacing), and those in the control group were asked to read a sentence with no marking. Conditions with boundary markings provided correct word boundary cues in experiment 1 and incorrect word boundary cues in experiment 2. We hypothesized that if aging impacts word segmentation in Chinese reading, then the effect of word segmentation cues would be larger in the older adults than that in their younger counterparts. The eye movement measures of local two-character-word, namely total fixation time, gaze duration, and probability of skip and regression, were used to check the aforementioned hypothesis.
The results of experiment 1 showed that the sentences with correct boundary signs on words produced less total fixation time of the old group than that of young group on word areas, and there were also different patterns of word segmentation cues effects on the probability measures of skip and regression. In contrast, the results of experiment 2 showed that the conditions providing incorrect word boundary cues with gray highlighting and spacing resulted in more negative effects on the older group's total fixation time and gaze duration than those of the younger group, while the condition providing incorrect cues with red colour led to equal effects on those eye-movement measures of both groups.
In summary, we found that the older adults were more susceptible to word boundary cues. Findings suggest that boundary markings on words facilitate local word processing in older readers more than that in younger ones, which confirmed our hypothesis that aging impacts word segmentation in Chinese reading. It should be pointed out that the condition providing incorrect cues with red colour led to equal effects on those eye-movement measures of both groups, which suggests that some mechanisms of word segmentation in Chinese reading are immune to aging impacts. In this article, we present our study on how visual cues facilitate word processing in older readers, and discuss the mechanisms of word segmentation.

Key words: Chinese reading, word segmentation, aging, eye movements

摘要： 研究采用眼动技术,通过观察词边界效应的年龄差异,探讨阅读中词切分机制的年老化。实验1要求青年组与老年组被试阅读正常呈现条件和3种提示正确词界信息(颜色词界、空格词界、阴影词界)的句子。结果发现,正确词界积极影响老年组眼动数据的程度大于青年组,说明正确词边界效应代表的词切分机制受年老化的影响。实验2要求两组被试阅读正常呈现条件和3种提示错误词界信息(错误颜色词界、错误空格词界、错误阴影词界)的句子。结果发现,错误空格词界、错误阴影词界消极影响老年组的眼动数据的程度大于青年组,但其消极影响两组眼动数据的程度没有差异,说明错误词边界效应代表的词切分机制具有稳定性。综合两项结果可知,中文阅读中至少存在两种词切分机制,它们的易老化性不同。

关键词: 中文阅读, 词切分, 年老化, 眼动