Korinth Sebastian P, Gerstenberger Kerstin, Fiebach Christian J
Department of Psychology, Goethe University Frankfurt, Frankfurt am Main, Germany.
Center for Research on Individual Development and Adaptive Education of Children at Risk (IDeA), Frankfurt am Main, Germany.
Front Psychol. 2020 Mar 17;11:444. doi: 10.3389/fpsyg.2020.00444. eCollection 2020.
Previous reports of improved oral reading performance for dyslexic children but not for regular readers when between-letter spacing was enlarged led to the proposal of a dyslexia-specific deficit in visual crowding. However, it is in this context also critical to understand how letter spacing affects visual word recognition and reading in unimpaired readers. Adopting an individual differences approach, the present study, accordingly, examined whether wider letter spacing improves reading performance also for non-impaired adults during silent reading and whether there is an association between letter spacing and crowding sensitivity. We report eye movement data of 24 German students who silently read texts presented either with normal or wider letter spacing. Foveal and parafoveal crowding sensitivity were estimated using two independent tests. Wider spacing reduced first fixation durations, gaze durations, and total fixation time for all participants, with slower readers showing stronger effects. However, wider letter spacing also reduced skipping probabilities and elicited more fixations, especially for faster readers. In terms of words read per minute, wider letter spacing did not provide a benefit, and faster readers in particular were slowed down. Neither foveal nor parafoveal crowding sensitivity correlated with the observed letter-spacing effects. In conclusion, wide letter spacing reduces single word processing time in typically developed readers during silent reading, but affects reading rates negatively since more words must be fixated. We tentatively propose that wider letter spacing reinforces serial letter processing in slower readers, but disrupts parallel processing of letter chunks in faster readers. These effects of letter spacing do not seem to be mediated by individual differences in crowding sensitivity.
先前的报告显示，扩大字母间距时，诵读困难儿童的朗读表现有所改善，但普通读者却没有，这导致了关于诵读困难存在特定视觉拥挤缺陷的提议。然而，在这种情况下，了解字母间距如何影响正常读者的视觉单词识别和阅读也至关重要。因此，本研究采用个体差异方法，检验了更宽的字母间距是否也能提高未受损成年人默读时的阅读表现，以及字母间距与拥挤敏感度之间是否存在关联。我们报告了24名德国学生的眼动数据，他们默读的文本呈现的是正常字母间距或更宽的字母间距。使用两项独立测试估计了中央凹和副中央凹的拥挤敏感度。更宽的间距缩短了所有参与者的首次注视持续时间、注视持续时间和总注视时间，阅读速度较慢的读者表现出更强的效果。然而，更宽的字母间距也降低了跳读概率并引发了更多注视，尤其是对于阅读速度较快的读者。就每分钟阅读的单词数而言，更宽的字母间距没有带来益处，尤其是阅读速度较快的读者速度减慢了。中央凹和副中央凹的拥挤敏感度均与观察到的字母间距效应无关。总之，在默读时，宽字母间距会减少典型发育读者处理单个单词的时间，但会对阅读速度产生负面影响，因为必须注视更多单词。我们初步提出，更宽的字母间距会加强阅读速度较慢读者的连续字母处理，但会扰乱阅读速度较快读者对字母组块的并行处理。字母间距的这些影响似乎不是由拥挤敏感度的个体差异介导的。
