Bournemouth University, Department of Psychology, United Kingdom.
Bournemouth University, Department of Psychology, United Kingdom.
Vision Res. 2021 Jun;183:30-40. doi: 10.1016/j.visres.2021.01.003. Epub 2021 Feb 27.
Reading saccades that occur within a single line of text are guided by the size of letters. However, readers occasionally need to make longer saccades (known as return-sweeps) that take their eyes from the end of one line of text to the beginning of the next. In this study, we tested whether return-sweep saccades are also guided by font size information and whether this guidance depends on visual acuity of the return-sweep target area. To do this, we manipulated the font size of letters (0.29 vs 0.39° per character) and the length of the first line of text (16 vs 26°). The larger font resulted in return-sweeps that landed further to the right of the line start and in a reduction of under-sweeps compared to the smaller font. This suggests that font size information is used when programming return-sweeps. Return-sweeps in the longer line condition landed further to the right of the line start and the proportion of under-sweeps increased compared to the short line condition. This likely reflects an increase in saccadic undershoot error with the increase in intended saccade size. Critically, there was no interaction between font size and line length. This suggests that when programming return-sweeps, the use of font size information does not depend on visual acuity at the saccade target. Instead, it appears that readers rely on global typographic properties of the text in order to maintain an optimal number of characters to the left of their first fixation on a new line.
阅读单行文本内的眼球跳动由字母大小来引导。然而，读者偶尔需要进行更长的眼球跳动（称为回扫），将眼睛从一行文本的末尾移动到下一行的开头。在这项研究中，我们测试了回扫眼球跳动是否也由字体大小信息引导，以及这种引导是否依赖于回扫目标区域的视力。为此，我们操纵了字母的字体大小（0.29 与 0.39 度/字符）和第一行文本的长度（16 与 26 度）。较大的字体使回扫的落点更偏右，与较小的字体相比，下扫的数量减少。这表明在编程回扫时会使用字体大小信息。在较长的行条件下的回扫落点更偏右，与短行条件相比，下扫的比例增加。这可能反映了随着预期扫视大小的增加，扫视的下冲误差增加。关键的是，字体大小和行长度之间没有相互作用。这表明在编程回扫时，使用字体大小信息不依赖于扫视目标的视力。相反，读者似乎依赖于文本的全局排版属性，以便在新行的第一次注视时保持最佳数量的字符在其左侧。
