Eye movement control during reading: Evidence for direct control

In three experiments, subjects read text as their eye movements were monitored and display changes in the text were made contingent upon the eye movements. In one experiment, a window of text moved in synchrony with the eyes. In one condition, the size of the window was constant from fixation to fixation, while in the other condition the size of the window varied from fixation to fixation. In the other experiments, a visual mask was presented at the end of each saccade which delayed the onset of the text, and the length of the delay was varied. The pattern of eye movements was influenced by both the size of the window and the delay of the onset of the text, even when the window size or text delay was varying from fixation to fixation. However, there was also evidence that saccade length was affected by the size of the window on the prior fixation and that certain decisions to move the eye are programmed either before the fixation begins or are programmed during the fixation but without regard to the text fixated on. The results thus provide support for a mixed control model of eye movements in reading, in which decisions about when and where to move the eyes are based on information from the current fixation, the prior fixations, and possibly, other sources as well.     

Taking on semantic commitments, II: Collective versus distributive readings

In earlier work, Frazier and Rayner (1990) provided evidence for a processing principle termed the Minimal Semantic Commitment (MSC)hypothesis. In the present study, we used the MSC hypothesis as a starting point in addressing the issue of when to treat mental representations as vague versus determinate and ambiguous. Given ambiguous representations, the MSC hypothesis predicts that the processor will commit to one interpretation (the grammatical ambiguity hypothesis). On the other hand, given a single underspecified representation, the MSC hypothesis predicts that the processor will await disambiguating information before fully committing to an interpretation (the vagueness hypothesis). In an experiment designed to evaluate these hypotheses with respect to the representation of distributivity, participants' eye movements were recorded as they read sentences containing distributive or collective predicates that were either disambiguated by a preceding adverb or left locally ambiguous by delaying the disambiguating adverb until the end of the predicate. The results suggested that a semantic commitment is made in locally indeterminate cases as evidenced by a significant interaction of ambiguity and distributivity in first pass times, total times, and regressions. If the difficulty of distributives simply reflected the difficulty of postulating a distributive operator when evidence warranting it is encountered, then no interaction would be expected. Hence we argue that the distributive/collective distinction is treated as a matter of ambiguity rather than as one of vagueness. In the absence of evidence for a distributive reading, the processor commits itself to a collective reading sometime during the processing of the predicate (before the disambiguation in our late disambiguation examples). The findings are discussed in relation to recent linguistic work on the representation of distributivity.     

On the segmentation of Chinese words during reading

Given that there are no spaces between words in Chinese, how words are segmented when reading is something of a mystery. Four Chinese characters, which either constituted one 4-character word or two 2-character words, were shown briefly to subjects. Subjects were quite accurate in reporting the 4-character word, but could usually only report the first 2-character word, demonstrating that word segmentation influences character recognition. The results suggest that even with these simple 4-character strings, there is an element of seriality in reading Chinese words: processing is initially focused at least to some extent on the first word. We also found that the processing of characters that are not consistent with the context is inhibited, suggesting inhibition from word representations to character representations. A simple model of Chinese word segmentation and word recognition is presented to account for the data.     

Effects of contextual predictability and transitional probability on eye movements during reading

In 2 eye-movement experiments, the authors tested whether transitional probability (the statistical likelihood that a word precedes or follows another word) affects reading times and whether this occurs independently from contextual predictability effects. Experiment 1 showed early effects of predictability, replicating S. A. McDonald and R. C. Shillcock's (2003a) finding that words with a high transitional probability (defeat following accept) are read faster than words with a low transitional probability (losses following accept). However, further analyses suggested that the transitional probability effect was likely due to differences in predictability rather than transitional probability. Experiment 2, using a better controlled set of items, again showed an effect of predictability, but no effect of transitional probability. The authors conclude that effects of transitional probability are part of regular predictability effects. Their data also show that predictability effects are detectable very early in the eye-movement record and between contexts that are weakly constraining.     

Reading disappearing text: cognitive control of eye movements

Participants read sentences containing high- or low-frequency target words under normal reading conditions or disappearing-text conditions (in which the word that was fixated disappeared after 60 ms). Even though the fixated word had disappeared after 60 ms, there was still a robust frequency effect wherein readers fixated longer on low-frequency words than on high-frequency words. Thus, the results are consistent with cognitive-control models of eye movement control and inconsistent with visual/oculomotor-control models. Although the uptake of visual information is clearly important for reading, it is the cognitive processes associated with understanding the fixated words that drive the eyes through the text.     

Attention to one word at a time in reading is still a viable hypothesis: rejoinder to Inhoff, Radach, and Eiter (2006)

A. W. Inhoff, R. Radach, and B. Eiter argue that the current version of the E-Z Reader model (A. Pollatsek, E. D. Reichle, & K. Rayner) cannot explain 2 key findings in their data, and as a result, the assumption of words being attended to 1 at a time is likely to be false. In this rejoinder, the authors argue that the E-Z Reader model can easily explain the 1st of the 2 phenomena and that the 2nd phenomenon is likely to be at least partially an artifact of changing displays during fixations. The authors also argue that their assumptions about attention shifting are not contrary to the attention literature and that the assumption that A. W. Inhoff et al. deem to be unrealistic (i.e., instantaneous shifting of attention) is easily modified within the architecture of the model.