A dynamic adjustment account of word skipping in reading: Evidence from simulations and invisible boundary experiments

Prevalent models of eye movement control in reading of word-spaced orthographies assume a discrete control account to explain word skipping. Accordingly, word skipping results from advanced parafoveal word activation during preview, leading to the selection of word n+2 as a saccade target. Consequently, visual and linguistic content of the parafoveal word affect which word is selected as a saccade target. In contrast, according to dynamic adjustment view, saccade lengths in reading are affected by current and next word properties in a continuous manner. First, these predictions were confirmed via simulations for representative models of discrete and dynamic control. Then results of three gaze-contingent invisible boundary experiments studying the visuo-attentional mechanism of skipping are being reported. The results support the dynamic adjustment view by showing a unimodal landing position distribution across a candidate word for skipping and its subsequent word, and that the content of parafoveal word modulates the saccade length only slightly and in a continuous manner. In addition, the location of a visual anomaly within a word had no effect on saccade length, suggesting that parafoveal vision of next word is subject of attention enhancement early enough to affect saccade length computation.