Parker Adam J, Slattery Timothy J, Kirkby Julie A
Department of Psychology, Faculty of Science & Technology, Bournemouth University, Talbot Campus, Poole BH12 5BB, United Kingdom.
Vision Res. 2019 Feb;155:35-43. doi: 10.1016/j.visres.2018.12.007. Epub 2019 Jan 12.
During reading, eye movement patterns differ between children and adults. Children make more fixations that are longer in duration and make shorter saccades. Return-sweeps are saccadic eye movements that move a reader's fixation to a new line of text. Return-sweeps move fixation further than intra-line saccades and often undershoot their target. This necessitates a corrective saccade to bring fixation closer to the start of the line. There have been few empirical investigations of return-sweep saccades in adults, and even fewer in children. In the present study, we examined return-sweeps of 47 adults and 48 children who read identical multiline texts. We found that children launch their return-sweeps closer to the end of the line and target a position closer to the left margin. Therefore, children fixate more extreme positions on the screen when reading for comprehension. Furthermore, children required a corrective saccade following a return-sweep more often than adults. Analysis of the duration of the fixation preceding the corrective saccade indicated that children are as efficient as adults at responding to retinal feedback following a saccade. Rather than consider differences in adult's and children's return-sweep behaviour an artefact of oculomotor control, we believe that these differences represent adult's ability to utilise parafoveal processing to encode text at extreme positions.
在阅读过程中，儿童和成人的眼动模式存在差异。儿童的注视次数更多，持续时间更长，扫视距离更短。回扫是一种将读者的注视点移动到新一行文本的眼跳运动。回扫比行内扫视移动注视点的距离更远，且常常会低于目标位置。这就需要进行一次校正扫视，以使注视点更接近行首。目前针对成人回扫扫视的实证研究较少，针对儿童的研究更少。在本研究中，我们考察了47名成人和48名儿童阅读相同多行文本时的回扫情况。我们发现，儿童发起回扫的位置更靠近行尾，目标位置更靠近左边界。因此，儿童在为理解而阅读时，会在屏幕上注视更极端的位置。此外，儿童在回扫后比成人更频繁地需要进行校正扫视。对校正扫视前注视持续时间的分析表明，儿童在对扫视后的视网膜反馈做出反应方面与成人一样高效。我们认为，成人和儿童回扫行为的差异并非眼动控制的假象，而是成人利用副中央凹加工在极端位置编码文本的能力体现。
