In two experiments, we explored the degree to which sentence context effects operate at a lexical or conceptual level by examining the processing of mixed-language sentences by fluent Spanish-English bilinguals. In Experiment 1, subjects' eye movements were monitored while they read English sentences in which sentence constraint, word frequency, and language of target word were manipulated. A frequency x constraint interaction was found when target words appeared in Spanish, but not in English. First fixation durations were longer for high-frequency Spanish words when these were embedded in high-constraint sentences than in low-constraint sentences. This result suggests that the conceptual restrictions produced by the sentence context were met, but that the lexical restrictions were not. The same result did not occur for low-frequency Spanish words, presumably because the slower access of low-frequency words provided more processing time for the resolution of this conflict. Similar results were found in Experiment 2 using rapid serial visual presentation when subjects named the target words aloud. It appears that sentence context effects are influenced by both semantic/conceptual and lexical information.

Participants' eye movements were recorded as they inspected a semi-realistic visual scene showing a boy, a cake, and various distractor objects. Whilst viewing this scene, they heard sentences such as 'the boy will move the cake' or 'the boy will eat the cake'. The cake was the only edible object portrayed in the scene. In each of two experiments, the onset of saccadic eye movements to the target object (the cake) was significantly later in the move condition than in the eat condition; saccades to the target were launched after the onset of the spoken word cake in the move condition, but before its onset in the eat condition. The results suggest that information at the verb can be used to restrict the domain within the context to which subsequent reference will be made by the (as yet unencountered) post-verbal grammatical object. The data support a hypothesis in which sentence processing is driven by the predictive relationships between verbs, their syntactic arguments, and the real-world contexts in which they occur.

This study offers a glimpse of the moment-by-moment processes used by highly skilled and average readers during silent reading. The eye movements of adult readers were monitored while they silently read sentences. Fixation durations and the spatial-temporal patterns of eye movements were examined to see whether the two groups of readers exhibited differential effects of frequency and/or predictability. In Experiment 1, high- and low-frequency target words were embedded in nonconstraining sentence contexts. In Experiment 2, the same participants read high- and low-frequency target words that were either predictable or unpredictable, embedded in highly constraining sentence contexts. Results indicated that when target words appeared in highly constraining sentence contexts, the average readers showed different effects of frequency and predictability from those shown in the highly skilled readers. It appears that reading skill can interact with predictability to affect the word recognition processes used during silent reading.

Native Chinese readers' eye movements were monitored as they read text that did or did not demark word boundary information. In Experiment 1, sentences had 4 types of spacing: normal unspaced text, text with spaces between words, text with spaces between characters that yielded nonwords, and finally text with spaces between every character. The authors investigated whether the introduction of spaces into unspaced Chinese text facilitates reading and whether the word or, alternatively, the character is a unit of information that is of primary importance in Chinese reading. Global and local measures indicated that sentences with unfamiliar word spaced format were as easy to read as visually familiar unspaced text. Nonword spacing and a space between every character produced longer reading times. In Experiment 2, highlighting was used to create analogous conditions: normal Chinese text, highlighting that marked words, highlighting that yielded nonwords, and highlighting that marked each character. The data from both experiments clearly indicated that words, and not individual characters, are the unit of primary importance in Chinese reading.

It is widely agreed upon that linguistic predictions are an integral part of language comprehension. Yet, experimental proof of their existence remains challenging. Here, we introduce a new predictive eye gaze reading task combining eye tracking and functional magnetic resonance imaging (fMRI) that allows us to infer the existence and timing of linguistic predictions via anticipatory eye-movements. Participants read different types of word sequences (i.e., regular sentences, meaningless jabberwocky sentences, non-word lists) up to the pre-final word. The final target word was displayed with a temporal delay and its screen position was dependent on the syntactic word category (nouns vs verbs). During the delay, anticipatory eye-movements into the correct target word area were indicative of linguistic predictions. For fMRI analysis, the predictive sentence conditions were contrasted to the non-word condition, with the anticipatory eye-movements specifying differences in timing across conditions. A conjunction analysis of both sentence conditions revealed the neural substrate of word category prediction, namely a distributed network of cortical and subcortical brain regions including language systems, basal ganglia, thalamus, and hippocampus. Direct contrasts between the regular sentence condition and the jabberwocky condition indicate that prediction of word category in meaningless jabberwocky sentences relies on classical left-hemispheric language systems involving Brodman's area 44/45 in the left inferior frontal gyrus, left superior temporal areas, and the dorsal caudate nucleus. Regular sentences, in contrast, allowed for the prediction of specific words. Word-specific predictions were specifically associated with more widely distributed temporal and parietal cortical systems, most prominently in the right hemisphere. Our results support the presence of linguistic predictions during sentence processing and demonstrate the validity of the predictive eye gaze paradigm for measuring syntactic and semantic aspects of linguistic predictions, as well as for investigating their neural substrates.

Effects of frequency, predictability, and position of words on event-related potentials were assessed during word-by-word sentence reading in 48 subjects in an early and in a late time window corresponding to P200 and N400. Repeated measures multiple regression analyses revealed a P200 effect in the high-frequency range; also the P200 was larger on words at the beginning and end of sentences than on words in the middle of sentences (i.e., a quadratic effect of word position). Predictability strongly affected the N400 component; the effect was stronger for low than for high-frequency words. The P200 frequency effect indicates that high-frequency words are lexically accessed very fast, independent of context information. Effects on the N400 suggest that predictability strongly moderates the late access especially of low-frequency words. Thus, contextual facilitation on the N400 appears to reflect both lexical and post-lexical stages of word recognition, questioning a strict classification into lexical and post-lexical processes.

Mathematical models have become an important tool for understanding the control of eye movements during reading. Main goals of the development of the SWIFT model (R. Engbert, A. Longtin, & R. Kliegl, 2002) were to investigate the possibility of spatially distributed processing and to implement a general mechanism for all types of eye movements observed in reading experiments. The authors present an advanced version of SWIFT that integrates properties of the oculomotor system and effects of word recognition to explain many of the experimental phenomena faced in reading research. They propose new procedures for the estimation of model parameters and for the test of the model's performance. They also present a mathematical analysis of the dynamics of the SWIFT model. Finally, within this framework, they present an analysis of the transition from parallel to serial processing.

A word's frequency of occurrence and its predictability from a prior context are key factors determining how long the eyes remain on that word in normal reading. Past reaction-time and eye movement research can be distinguished by whether these variables, when combined, produce interactive or additive results, respectively. Our study addressed possible methodological limitations of prior experiments. Initial results showed additive effects of frequency and predictability. However, we additionally examined launch site (the distance from the pretarget fixation to the target) to index the extent of parafoveal target processing. Analyses revealed both additive and interactive effects on target fixations, with the nature of the interaction depending on the quality of the parafoveal preview. Target landing position and pretarget fixation time were also considered. Results were interpreted in terms of models of language processing and eye movement control. Our findings with respect to parafoveal preview and fixation time constraints aim to help parameterize eye movement behavior.

Eye-movement-contingent display changes were used to control the visibility of characters during the reading of Chinese text. Characters outside a window of legible text were masked by dissimilar characters, and effects of viewing constraints were ascertained in several oculomotor measures. The results revealed an asymmetric perceptual span that extended 1 character to the left of the fixated character and 3 characters to its right. The size of right-directed saccades extended across 2 to 2 1/2 character spaces, indicating that the perceptual spans of successive fixations overlapped slightly and that some linguistic information was integrated across fixations. The relatively small spatial overlap of successive spans appears to reflect a text-specific process. However, the results also revealed substantial similarities in the coding of morphographic Chinese and alphabetic English texts, indicating that text-specific coding routines are subordinated to general coding principles.

Two very reliable influences on eye fixation durations in reading are word frequency, as measured by corpus counts, and word predictability, as measured by cloze norming. Several studies have reported strictly additive effects of these 2 variables. Predictability also reliably influences the amplitude of the N400 component in event-related potential studies. However, previous research suggests that while frequency affects the N400 in single-word tasks, it may have little or no effect on the N400 when a word is presented with a preceding sentence context. The present study assessed this apparent dissociation between the results from the 2 methods using a coregistration paradigm in which the frequency and predictability of a target word were manipulated while readers' eye movements and electroencephalograms were simultaneously recorded. We replicated the pattern of significant, and additive, effects of the 2 manipulations on eye fixation durations. We also replicated the predictability effect on the N400, time-locked to the onset of the reader's first fixation on the target word. However, there was no indication of a frequency effect in the electroencephalogram record. We suggest that this pattern has implications both for the interpretation of the N400 and for the interpretation of frequency and predictability effects in language comprehension.

Sentence comprehension depends on continuous prediction of upcoming words. However, when and how contextual information affects the bottom-up streams of visual word recognition is unknown. This study examined the effects of word frequency and contextual predictability (cloze probability of a target word embedded in the sentence) on N1, P200, and N400 components, which are related to various cognitive operations in early visual processing, perceptual decoding, and semantic processing. The data exhibited a significant interaction between predictability and frequency at the anterior N1 component. The predictability effect, in which the low predictability words elicited a more negative N1 than high predictability words, was only observed when reading a high frequency word. A significant predictability effect occurred during the P200 time window, in which the low predictability words elicited a less positive P200 than high predictability words. There is also a significant predictability effect on the N400 component; low predictability words elicited a greater N400 than high predictability words, although this effect did not interact with frequency. The temporal dynamics of the manner in which contextual information affects the visual word recognition is discussed. These findings support the interactive account, suggesting that contextual information facilitates visual-feature and orthographic processing in the early stage of visual word processing and semantic integration in the later stage.

In two experiments, we examined whether context information can affect the activity of the nodes at the character level. Chinese readers viewed two Chinese characters; one was intact, but the other (the target) was embedded in a rectangle of visual noise and increased in visibility over time. The two characters constituted a word in one condition but did not in the other condition. The task was to press a button to indicate whether the character in the noise was at the top or bottom of the rectangle. (They did not have to identify the character.) Response times were faster in the word condition than in the nonword condition. Because the

A number of cognitive studies have indicated that words play a critical role in reading. Hence, word segmentation is an important procedure in reading. Unlike alphabetic writing systems such as English, there are no spaces between words. Without spaces, how do Chinese readers segment words? In this article, recent progresses in the following topics on Chinese word segmentation are reviewed: 1) Evidences that Chinese characters belonging to a word are processed as a unit; 2) Some recent psychological studies on Chinese word segmentation and some of the models; 3) Word segmentation studies in computer sciences; 4) Future directions on this topic.

AbstractGiven 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.]]>

Unlike in English, there are no spaces between printed words in Chinese. In this study, we explored how inserting a space before or after a word affects the processing of that word in Chinese reading. Native Chinese readers' eye movements were monitored as they read sentences with different presentation conditions. The results show that inserting a space after a word facilitates its processing, but inserting a space before a word does not show this effect and inhibits the processing of that word in some cases. Our results are consistent with the prediction of a word segmentation and recognition model in Chinese Li et al., 2009, Cognit. Psychol., 58, 525. Additionally, we found that a space guides the initial landing position on the word: the initial landing position was further away from the space that inserted into the text, whether it was before or after a word.

How does a word's within-sentence predictability influence saccade length during reading? An eye-movement experiment manipulating the predictability of target words indicates that, relative to low-predictability target words, high-predictability targets elicit longer saccades to themselves. Simulations using computational models that respectively instantiate the targeting of saccades to default locations (Yan, Kliegl, Richter, Nuthmann, & Shu in Journal of Experimental Psychology, 63, 705-725, 2010) versus the dynamic adjustment of saccade length (Liu, Reichle, & Li in Journal of Experimental Psychology Learning Memory and Cognition, 41, 1229-1236, 2015, Journal of Experimental Psychology: Human Perception and Performance, 42, 1008-1025, 2016) indicate that the latter model provides a more accurate and parsimonious account of saccade-targeting behavior in Chinese reading. The implications of these conclusions are discussed with respect to current models of eye-movement control during reading and the necessity to explain eye movements in languages as different as Chinese versus English.

We performed 2 eye movement studies to explore whether readers can extract character or word frequency information from nonfixated-target words in Chinese reading. In Experiments 1A and 1B, we manipulated the character frequency of the first character in a 2-character target word and the word frequency of a 2-character target word, respectively. We found that fixation durations on the pretarget words were shorter when the first character of a 2-character target word was presented with high frequency. Such effects were not observed for word frequency manipulations of a 2-character target word. In particular, further analysis revealed that such effects only occurred for long pretarget fixations. These results for character and word frequency manipulations were replicated in a within-subjects design in Experiment 2. These findings are generally consistent with the notion that characters are processed in parallel during Chinese reading. However, we did not find evidence that words are processed in parallel during Chinese reading.

French readers' eye movements were monitored as they read a passage of text. Initial global analyses of word frequency, accounting for the majority of fixations in the text, revealed a good fit between the observed data and the simulated data from the E-Z Reader 7 model of eye movement control. However, the model did not perform as well on simulations of contextual predictability effects. A subset of 20 controlled words from the passage were used to examine the combined effects of frequency and predictability. Results from the observed data showed main effects of frequency and predictability but no interaction. With certain modifications, the E-Z Reader 7 model was able to adequately simulate the pattern of data. Although the E-Z Reader model successfully accounted for the present data, we believe that further modifications will be necessary in order to better account for data in the literature.

Recent studies of eye movements in reading and other information processing tasks, such as music reading, typing, visual search, and scene perception, are reviewed. The major emphasis of the review is on reading as a specific example of cognitive processing. Basic topics discussed with respect to reading are (a) the characteristics of eye movements, (b) the perceptual span, (c) integration of information across saccades, (d) eye movement control, and (e) individual differences (including dyslexia). Similar topics are discussed with respect to the other tasks examined. The basic theme of the review is that eye movement data reflect moment-to-moment cognitive processes in the various tasks examined. Theoretical and practical considerations concerning the use of eye movement data are also discussed.

The effect of contextual constraint on eye movements in reading was examined by asking subjects to read sentences that contained a target word that varied in contextual constraint; high-, medium-, or low-constraint target words were used. Subjects fixated low-constraint target words longer than they did either high- or medium-constraint target words. In addition, they skipped high-constraint words more than they did either medium- or low-constraint target words. The results further confirm that contextual constraint has a strong influence on eye movements during reading.

Readers read sentences containing target words varying in frequency and predictability. The observed pattern of data for fixation durations only mildly departed from additivity, with predictability effects that were slightly larger for low-frequency than for high-frequency words. The pattern of data for skipping was different as predictability affected only the probability of skipping for high-frequency target words. Simulations of these data using the E-Z Reader model indicated that a single-process model was unlikely to provide a good fit for both measures. A version of the model that assumes that (a) word-encoding time is additively affected by frequency and predictability and (b) difficulty with postlexical processing of the target word causes a double take accounted for the data while indicating that the relationship between the duration of hypothesized word-encoding stages and observed fixation durations is not likely to be transparent.

We examined the initial landing position of the eyes in target words that were either predictable or unpredictable from the preceding sentence context. Although readers skipped over predictable words more than unpredictable words and spent less time on predictable words when they did fixate on them, there was no difference in the launch site of the saccade to the target word. Moreover, there was only a very small difference in the initial landing position on the target word as a function of predictability when the target words were fixated which is most parsimoniously explained by positing that a few programmed skips of the target word fell short of their intended target. These results suggest that low-level processing is primarily responsible for landing position effects in reading.

Eye movements of Chinese readers were monitored as they read sentences containing target words whose predictability from the preceding context was high, medium, or low. Readers fixated for less time on high- and medium-predictable target words than on low-predictable target words. They were also more likely to fixate on low-predictable target words than on high- or medium-predictable target words. The results were highly similar to those of a study by Rayner and Well (1996) with English readers and demonstrate that Chinese readers, like readers of English, exploit target word predictability during reading.

Young adult and older readers' eye movements were recorded as they read sentences containing target words that varied in frequency or predictability. In addition, half of the sentences were printed in a font that was easy to read (Times New Roman) and the other half were printed in a font that was more difficult to read (Old English). Word frequency, word predictability, and font difficulty effects were apparent in the eye movement data of both groups of readers. In the fixation time data, the pattern of results was the same, but the older readers had larger frequency and predictability effects than the younger readers. The older readers skipped words more often than the younger readers (as indicated by their skipping rate on selected target words), but they made more regressions back to the target words and more regressions overall. The E-Z Reader model was used as a platform to evaluate the results, and simulations using the model suggest that lexical processing is slowed in older readers and that, possibly as a result of this, they adopt a more risky reading strategy.

The authors present several versions of a general model, titled the E-Z Reader model, of eye movement control in reading. The major goal of the modeling is to relate cognitive processing (specifically aspects of lexical access) to eye movements in reading. The earliest and simplest versions of the model (E-Z Readers 1 and 2) merely attempt to explain the total time spent on a word before moving forward (the gaze duration) and the probability of fixating a word; later versions (E-Z Readers 3-5) also attempt to explain the durations of individual fixations on individual words and the number of fixations on individual words. The final version (E-Z Reader 5) appears to be psychologically plausible and gives a good account of many phenomena in reading. It is also a good tool for analyzing eye movement data in reading. Limitations of the model and directions for future research are also discussed.

The E-Z Reader model (Reichle et al. 1998; 1999) provides a theoretical framework for understanding how word identification, visual processing, attention, and oculomotor control jointly determine when and where the eyes move during reading. In this article, we first review what is known about eye movements during reading. Then we provide an updated version of the model (E-Z Reader 7) and describe how it accounts for basic findings about eye movement control in reading. We then review several alternative models of eye movement control in reading, discussing both their core assumptions and their theoretical scope. On the basis of this discussion, we conclude that E-Z Reader provides the most comprehensive account of eye movement control during reading. Finally, we provide a brief overview of what is known about the neural systems that support the various components of reading, and suggest how the cognitive constructs of our model might map onto this neural architecture.

AbstractThis paper describes some empirical tests of an interactive activation model of eye movement control in reading (the “Glenmore” model). Qualitatively, the Glenmore model can account within one mechanism for preview and spillover effects, regressions, progressions, and refixations. It decouples the decision about when to move the eyes from the word recognition process. The time course of activity in a fixate centre (FC) determines the triggering of a saccade. The other main feature of the model is the use of a saliency map that acts as an arena for the interplay of bottom-up visual features of the text, and top-down lexical features. These factors combine to create a pattern of activation that selects one word as the saccade target. Even within the relatively simple framework proposed here, a coherent account can be provided for a range of eye movement control phenomena that have hitherto proved problematic to reconcile. The paper examines the performance of the model compared to data gathered in an empirical study of subjects reading a German text. The quantitative fit of the model, while reasonable, highlighted some limitations in the model that will need to be addressed in future versions.]]>

AbstractModels of eye movement control are very useful for gaining insights into the intricate connections of different cognitive and oculomotor subsystems involved in reading. The SWIFT model (Engbert, Longtin, & Kliegl (2002). Vision Research, 42, 621–636) proposed a unified mechanism to account for all types of eye movement patterns that might be observed in reading behavior. The model is based on the notion of spatially distributed, or parallel, processing of words in a sentence. We present a refined version of SWIFT introducing a letter-based approach that proposes a processing gradient in the shape of a smooth function. We show that SWIFT extents its capabilities by accounting for distributions of landing positions.]]>

In this article, we present a Bayes factor solution for inference in multiple regression. Bayes factors are principled measures of the relative evidence from data for various models or positions, including models that embed null hypotheses. In this regard, they may be used to state positive evidence for a lack of an effect, which is not possible in conventional significance testing. One obstacle to the adoption of Bayes factor in psychological science is a lack of guidance and software. Recently, developed computationally attractive default Bayes factors for multiple regression designs. We provide a web applet for convenient computation and guidance and context for use of these priors. We discuss the interpretation and advantages of the advocated Bayes factor evidence measures.

The present review summarizes research investigating how words are identified parafoveally (and foveally) in reading. Parafoveal and foveal processing are compared when no other concurrent task is required (e.g., in single-word recognition tasks) and when both are required simultaneously (e.g., during reading). We first review methodologies used to study parafoveal processing (e.g., corpus analyses and experimental manipulations, including gaze-contingent display change experiments such as the boundary, moving window, moving mask, and fast priming paradigms). We then turn to a discussion of the levels of representation at which words are processed (e.g., orthographic, phonological, morphological, lexical, syntactic, and semantic). Next, we review relevant research regarding parafoveal processing, summarizing the extent to which words are processed at each of those levels of representation. We then review some of the most controversial aspects of parafoveal processing, as they relate to reading: (1) word skipping, (2) parafoveal-on-foveal effects, and (3) n + 1 and n + 2 preview benefit effects. Finally, we summarize two of the most advanced models of eye movements during reading and how they address foveal and parafoveal processing.

Semantic preview benefit in reading is an elusive and controversial effect because empirical studies do not always (but sometimes) find evidence for it. Its presence seems to depend on (at least) the language being read, visual properties of the text (e.g., initial letter capitalization), the type of relationship between preview and target, and as shown here, semantic constraint generated by the prior sentence context. Schotter (2013) reported semantic preview benefit for synonyms, but not semantic associates when the preview/target was embedded in a neutral sentence context. In Experiment 1, we embedded those same previews/targets into constrained sentence contexts and in Experiment 2 we replicated the effects reported by Schotter (2013; in neutral sentence contexts) and Experiment 1 (in constrained contexts) in a within-subjects design. In both experiments, we found an early (i.e., first-pass) apparent preview benefit for semantically associated previews in constrained contexts that went away in late measures (e.g., total time). These data suggest that sentence constraint (at least as manipulated in the current study) does not operate by making a single word form expected, but rather generates expectations about what kinds of words are likely to appear. Furthermore, these data are compatible with the assumption of the E-Z Reader model that early oculomotor decisions reflect

The investigation of visual word recognition has been a major accomplishment of cognitive science. Two on-line methodologies, eye movements and event-related potentials, stand out in the search for the holy grail - an absolute time measure of when, how and why we recognize visual words while reading. Although each technique has its own experimental limitations, we suggest, by means of review and comparison, that these two methodologies can be used in complementary ways to produce a better picture of the mental action we call reading.

An important question in research on eye movements in reading is whether word frequency and word predictability have additive or interactive effects on fixation durations. A fair number of studies have reported only additive effects of the frequency and predictability of a target word on reading times on that word, failing to show significant interactions. Recently, however, Hand, Miellet, O'Donnell, and Sereno (see record 2010-19099-001) reported interactive effects in a study that included the distance of the prior fixation from the target word (launch site). They reported that when the saccade into the target word was launched from very near to the word (within 3 characters), the predictability effect was larger for low frequency words, but when the saccade was launched from a medium distance (4-6 characters from the word) the predictability effect was larger for high frequency words. Hand et al. argued for the importance of including launch site in analyses of target word fixation durations. Here we describe several problems with Hand et al.'s use of analyses of variance in which launch site is divided into distinct ordinal levels. We describe a more appropriate way to analyze such data-linear mixed-effect models-and we use this method to show that launch site does not modulate the interaction between frequency and predictability in two other data sets.

Recent studies have revealed that Chinese words are associated with psychological realities that are important for text comprehension. However, given the lack of spaces between words in Chinese text, readers of Chinese have to segment text into words during reading. Previous studies focused on word segmentation have revealed that this ability to preview and process text develops at a very early stage. However, there was little research on what information or cues were used by readers of Chinese to segment text into words. The assumption was that if readers of Chinese parsed a string of characters into words using a character-to-word processing, preview processing would result in word frequency effects on eye movement data, and that if the readers ascertained word boundary by top-down processing, such as anticipation, preview processing would result in word predictability effects. Four experiments were conducted to check these two hypotheses. In the first three experiments, we assumed that readers of Chinese parsed a string of characters into words using a character-to-word style in preview processing. There were two treatments of Chinese sentences in these experiments; all these experiments had a control condition in which as the nth word was fixated, and no words were masked for baseline comparison. An abnormal display condition was manipulated in Experiment 1, wherein the nth word was fixated, but the words located to the right were all masked by a series of “※,” which deprived the reader of previewing processing. The abnormal display condition was manipulated in Experiment 2 by keeping the nth word fixated, and masking the words located to the right of the n+1th word by a series of “※,” which provided a cue about the boundary of the n+1th word. Given that the results from Experiment 2 cannot exclude the influence of exogenous attention, Experiment 3 was conducted. Experiment 3 adopted a similar treatment as Experiment 2, but two adjacent characters that did not belong to a word were masked together. In first three experiments, the word frequencies (high and low) of target words that were embedded in the frame sentences were also manipulated. In the last experiment (Experiment 4), there were three display manipulations: control condition, a condition in which readers were deprived of previewing processing, and a condition involving the provision of boundary information about the n+1th word; the predictability of target words that were embedded in the frame sentences were also manipulated. The results of Experiment 1 showed that although eye movement data was negatively affected by being deprived of previewing processing, this manipulation did not have any influence on word frequency effects and, therefore, there was no interaction effect between display condition and word frequency manipulations. The results of Experiment 2 showed that providing boundary information of the n+1th word led to less gaze time on the target word, but here again, there was no interaction effect between the display condition and word frequency manipulations. The results of Experiment 3 showed that mask manipulation led to more gaze time on the target word than the control that excluded the influence of exogenous attention on the results of Experiment 2. It also showed that there was no interaction effect between display condition and word frequency manipulations. However, the results of Experiment 4 were interesting; there were some significant interaction effects between the display condition and word predictability manipulations. Specifically, we found that the manipulation in which readers are deprived of previewing processing eliminates predictability effects, and providing boundary information of the n+1th word decreases the discrepancy between words of high predictability and words of low predictability. The results of the first three experiments indicate that Chinese word processing in the preview cannot reach the desired vocabulary level, and that it must undergo character processing. Therefore, it was difficult for readers of Chinese to complete the segmentation of the n+1th word through a bottom-up characters-to-word processing. The results of Experiment 4 show that deprivation of preview processing can eliminate predictability and providing boundary information of the n+1th word can lessen predictability thereby indicating that top-bottom processing, such as anticipation, is an important reference cue to readers of Chinese to segment the n+1th word.

Visual cognition is limited by computational capacity, because the brain can process only a fraction of the visual sensorium in detail, and by the inherent ambiguity of the information entering the visual system. Two mechanisms mitigate these burdens: attention prioritizes stimulus processing on the basis of motivational relevance, and expectations constrain visual interpretation on the basis of prior likelihood. Of the two, attention has been extensively investigated while expectation has been relatively neglected. Here, we review recent work that has begun to delineate a neurobiology of visual expectation, and contrast the findings with those of the attention literature, to explore how these two central influences on visual perception overlap, differ and interact.

The present study examined the relationship between the predictability of words within a sentence and the availability of parafoveal word length information, on when and where the eyes move in reading. Predictability influenced first-pass reading times when parafoveal word length preview information was correct, but not when it was incorrect. Similarly, for saccades launched from near the target word (word n), predictability influenced the probability with which it was skipped only when the word length preview was correct. By contrast, for saccades launched farther away from word n, predictability influenced word skipping regardless of the parafoveal word length preview. Taken together, the data suggest that parafoveal word length preview and predictability can act as a joint constraint on the decision of when and where to move the eyes.