汉字间空格大小对青年人和老年人阅读的影响:眼动研究

Effects of Inter-Character Spacing on the Reading of Chinese Young and Older Adults:An Eye Movement Study

拼音文字阅读的眼动研究发现,老年人会采取一种"风险"阅读策略来弥补因视力和认知的自然老化所造成的阅读困难。本研究通过控制字间空格的大小对青年人和老年人汉语阅读过程的眼动模式进行了比较,结果发现,相比青年人,老年人读得更慢,有更长的注视时间和更多的回视,这些研究结果与拼音文字一致;但更为重要的发现是,相比青年人,老年人有更短的向前眼跳距离,缩小汉语字间空格给老年人阅读造成了更为显著的困难,但扩大字间空格两组被试表现出相似的阅读眼动模式。结果说明,汉语阅读中老年人并不使用拼音文字研究中发现的"风险"阅读策略,反而采用了更为谨慎的策略,原因可能在于,作为拼音文字阅读中的重要视觉线索,空格是影响两种语言下老年人阅读加工策略不同的重要因素。

We reported an experiment that investigated effects of changes in inter-character spacing on the eye movements of young(18-35 years)and older(65+years)Chinese readers.Compared to young adults,older adults experienced greater reading difficulty due to visual and cognitive declines in older age.In particular,older adults appeared to suffer more from effects of visual crowding,which was increased difficulty recognizing an object when closely surrounded by visually similar objects.Numerous studies suggested that increased text spacing could offset visual crowding,and therefore benefited readers who were vulnerable to its effects,such as children with developmental dyslexia.However,research has not investigated if similar benefits are observed for older readers.Accordingly,we investigated this issue and conducted an eye movement experiment with skilled young and older adult readers.Participants were 24 young adults aged 18-26 years(M=21 years)and 24 older adults aged 65~76 years(M=66 years)from the Tianjin Normal University and community near the university.All were native Chinese speakers and the two age groups were closely matched for years of formal education.Finally,all participants reported reading for(at least)several hours per week.An EyeLink 2000 eye-tracker recorded each participant’s right-eye gaze location every millisecond during binocular viewing.The design of the experiment was a 2(age:older adults,young adults)×3(intercharacter spacing:decreased spacing,normal spacing,increased spacing)mixed design,with the between-participants factor of age group(young adult,older adult)and within-participants factor of character spacing(decreased,normal,increased).Stimuli were 48 sentences that all contained three intercharacter spacing.Participants read sentences composed mostly of complex(number of strokes>9)characters,presented either with normal intercharacter spacing or increased(3 pt)or decreased(3 pt)inter-character spacing.Typical patterns of age-related reading difficulty were observed.Compared to young adults,older adults read more slowly,had longer sentences reading times,more and longer fixations,more regressions and shorter forward saccades.Inter-character spacing also had influences,compared to normal spacing,decreased spacing produced longer average fixation durations,less fixation counts and shorter forward saccade length;increased spacing produced shorter average fixation durations,more fixation counts and longer forward saccade length.More importantly,significant interactions between age-group and spacing condition were found for average fixation durations,forward saccade length and number of forward saccade fixations.Under the condition of decreased and normal inter-character spacing,older adults had great differences in eye movements than young adults,which were due to more disrupted reading processes for the older than younger adults when spacing was decreased compared to increased.Therefore,the results indicate that in Chinese reading,compared to young adults,older adults have typical patterns of age-related reading difficulty,showing eye movement patterns consistent with the alphabetic languages.However,instead of using the"risk reading strategy"found in alphabetic languages,a"cautious reading strategy"is used instead.Increasing the inter-character spacing reduces the average fixation durations for young and older adults during the reading,but decreased inter-character spacing can significantly interfere with the reading behavior of the older adults,which indicates that the older adults are more sensitive to changes in visual characteristics and more susceptible to visual crowding.