Chaparro Alex, Liao Corrina
Department of Psychology, Wichita State University, 1845 Fairmount, Wichita, KS 67260-0034, USA.
Perception. 2003;32(11):1339-50. doi: 10.1068/p5118.
Previous research has demonstrated that the masking effects of flankers about a target in the peripheral retina are not isotropic. Rather, regions of lateral interaction are ellipsoid in shape with the major axis oriented radially along a meridian through the fovea. This finding leads to the counterintuitive prediction that horizontal text positioned to the right of fixation might be read more slowly than similarly positioned text oriented diagonally or vertically. Similarly, vertically oriented text above fixation might be read more slowly than horizontally or diagonally oriented text above fixation. We investigated the effect of text orientation and inter-character spacing on word identification in the retinal periphery. Text was presented by rapid serial visual presentation. Words were centered 3 degrees from fixation along four visual field meridians (VM) (right horizontal, upper-right diagonal, vertical, and upper-left diagonal). Regardless of VM identification, performance was best for horizontal text, declining slightly for orientations between +60 degrees and -60 degrees and declining more quickly for acute orientations. A weak effect of VM was observed for text with normal inter-character spacing. Performance was best for text centered along the horizontal meridian and declined slightly along the other VM. Finally, identification rates increased by approximately 33 words min(-1) with the addition of one character space between adjacent letters. The word-recognition processes are very tolerant of text orientation, exhibiting a modest decline for orientations within +/- 60 of horizontal regardless of VM.
先前的研究表明，周边视网膜中围绕目标的侧翼刺激的掩蔽效应并非各向同性。相反，侧向相互作用区域呈椭圆形，其长轴沿通过中央凹的子午线径向排列。这一发现导致了一个与直觉相反的预测，即位于注视点右侧的水平文本可能比同样位置的对角或垂直方向的文本阅读速度更慢。同样，位于注视点上方的垂直方向文本可能比位于注视点上方的水平或对角方向文本阅读速度更慢。我们研究了文本方向和字符间距对视网膜周边单词识别的影响。文本通过快速序列视觉呈现呈现。单词沿着四个视野子午线（VM）（右水平、右上对角、垂直和左上对角）在距注视点3度处居中。无论VM识别如何，水平文本的表现最佳，在+60度至-60度之间的方向上略有下降，在锐角方向上下降更快。对于字符间距正常的文本，观察到VM有微弱影响。沿着水平子午线居中的文本表现最佳，沿着其他VM略有下降。最后，相邻字母之间增加一个字符间距，识别率提高了约33个单词/分钟。单词识别过程对文本方向非常宽容，无论VM如何，在水平方向±60度范围内的方向上表现仅略有下降。
