Epelboim J, Booth J R, Steinman R M
Department of Psychology, University of Maryland, College Park 20742-4411.
Vision Res. 1994 Jul;34(13):1735-66. doi: 10.1016/0042-6989(94)90130-9.
According to current theories of reading, the reader's saccades are guided primarily by spaces between words, clearly the most prominent visual feature in most modern texts. This belief was investigated by recording eye movements with unprecedented accuracy and precision while subjects read spaced and unspaced passages both silently and aloud. Modest increases in fixation durations and decreases in overall reading speed were observed when unspaced texts were read. However, subjects read unspaced texts with the same level of comprehension and percentage of regressions as they read spaced texts. The only global eye movement parameter that changed appreciably when spaces were removed was progressive (rightward) saccade length. Progressive saccades were shorter in unspaced texts. However, unspaced texts were denser and narrower because they were constructed so as to contain the same number of words/line as the spaced texts. This meant that unspaced texts contained more informational characters/degree of visual angle. The observed decrease in progressive saccade lengh tended to be proportional to this increase in text density. Therefore, the number of saccades/line of text remained approximately the same in both spaced and unspaced texts. Furthermore, a detailed examination of local eye movement properties, i.e. where within words the subjects fixated and how many times they fixated words of different lengths, suggested that the same oculomotor strategy was used for reading spaced and unspaced texts. This was true for both silent reading and reading aloud. Thus, a model that could explain reading spaced texts could also explain reading unspaced texts with only a change of a single global parameter, namely, saccade length. We conclude that the current tendency to emphasize spaces as guides to reading eye movements must be reconsidered. Words, not spaces, may serve as the perceptual units that guide the line of sight through the text.
根据当前的阅读理论，读者的扫视主要由单词之间的空格引导，显然这是大多数现代文本中最突出的视觉特征。通过以前所未有的准确性和精确性记录眼动，对这一观点进行了研究，研究对象默读和朗读间隔文本与无间隔文本。当阅读无间隔文本时，注视持续时间略有增加，整体阅读速度有所下降。然而，受试者阅读无间隔文本时的理解水平和回视百分比与阅读间隔文本时相同。去除空格后，唯一明显变化的全局眼动参数是渐进（向右）扫视长度。在无间隔文本中，渐进扫视较短。然而，无间隔文本更密集、更窄，因为它们的构造使得每行包含与间隔文本相同数量的单词。这意味着无间隔文本每度视角包含更多的信息字符。观察到的渐进扫视长度的减少往往与文本密度的增加成正比。因此，间隔文本和无间隔文本每行的扫视次数大致相同。此外，对局部眼动特性的详细检查，即受试者在单词内的注视位置以及他们对不同长度单词的注视次数，表明阅读间隔文本和无间隔文本使用了相同的眼动策略。默读和朗读都是如此。因此，一个能够解释阅读间隔文本的模型，只需改变一个全局参数，即扫视长度，也能够解释阅读无间隔文本。我们得出结论，当前强调空格作为阅读眼动引导的趋势必须重新考虑。引导视线浏览文本的感知单元可能是单词，而不是空格。
