Long-range regressions to previously read words are guided by spatial and verbal memory

To examine the nature of the information that guides eye movements to previously read text during reading (regressions), we used a relatively novel technique to request a regression to a particular target word when the eyes reached a predefined location during sentence reading. A regression was to be directed to a close or a distant target when either the first or the second line of a complex two-line sentence was read. In addition, conditions were created that pitted effects of spatial and linguistic distance against each other. Initial regressions were more accurate when the target was spatially near, and effects of spatial distance dominated effects of verbal distance. Initial regressions rarely moved the eyes onto the target, however, and subsequent "corrective" regressions that homed in on the target were subject to general linguistic processing demands, being more accurate during first-line reading than during second-line reading. The results suggest that spatial and verbal memory guide regressions in reading. Initial regressions are primarily guided by fixation-centered spatial memory, and corrective regressions are primarily guided by linguistic knowledge.     

Distinct subsystems for the parafoveal processing of spatial and linguistic information during eye fixations in reading

Two experiments examined readers' use of parafoveally obtained word length information for word recognition. Both experiments manipulated the length (number of constituent characters) of a parafoveally previewed target word so that it was either accurately or inaccurately specified. In Experiment 1, previews also either revealed or denied useful orthographic information. In Experiment 2, parafoveal targets were either high- or low-frequency words. Eye movement contingent display changes were used to show the intact target upon its fixation. Examination of target viewing duration showed completely additive effects of word length previews and of ortho-graphic previews in Experiment 1, viewing duration being shorter in the accurate-length and the orthographic preview conditions. Experiment 2 showed completely additive effects of word length and word frequency, target viewing being shorter in the accurate-length and the high-frequency conditions. Together these results indicate that functionally distinct subsystems control the use of parafoveally visible spatial and linguistic information in reading. Parafoveally visible spatial information appears to be used for two distinct extralinguistic computations: visual object selection and saccade specification.     

The function of regressions in reading: Backward eye movements allow rereading

Standard text reading involves frequent eye movements that go against normal reading order. The function of these “regressions” is still largely unknown. The most obvious explanation is that regressions allow for the rereading of previously fixated words. Alternatively, physically returning the eyes to a word’s location could cue the reader’s memory for that word, effectively aiding the comprehension process via location priming (the “deictic pointer hypothesis”). In Experiment 1, regression frequency was reduced when readers knew that information was no longer available for rereading. In Experiment 2, readers listened to auditorily presented text while moving their eyes across visual placeholders on the screen. Here, rereading was impossible, but deictic pointers remained available, yet the readers did not make targeted regressions in this experiment. In Experiment 3, target words in normal sentences were changed after reading. Where the eyes later regressed to these words, participants generally remained unaware of the change, and their answers to comprehension questions indicated that the new meaning of the changed word was what determined their sentence representations. These results suggest that readers use regressions to reread words and not to cue their memory for previously read words.     

The whereabouts of visual attention: Involuntary attentional bias toward the default gaze direction

This study proposed and verified a new hypothesis on the relationship between gaze direction and visual attention: attentional bias by default gaze direction based on eye-head coordination. We conducted a target identification task in which visual stimuli appeared briefly to the left and right of a fixation cross. In Experiment 1, the direction of the participant’s head (aligned with the body) was manipulated to the left, front, or right relative to a central fixation point. In Experiment 2, head direction was manipulated to the left, front, or right relative to the body direction. This manipulation was based on results showing that bias of eye position distribution was highly correlated with head direction. In both experiments, accuracy was greater when the target appeared at a position where the eyes would potentially be directed. Consequently, eye–head coordination influences visual attention. That is, attention can be automatically biased toward the location where the eyes tend to be directed.     

Eye movements of highly skilled and average readers: Differential effects of frequency and predictability

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.     

Effects of prime and target eccentricity on masked repetition priming

Three experiments examined the influence of briefly presented, pattern-masked prime stimuli on target word recognition at varying eccentricities. The prime was either the same word as the targets or a different word, and prime position varied horizontally from a central fixation point. The targets were either in the same location as the primes (Experiment 1A) or always centrally located (Experiments 1B and 2). In Experiment 1A, target word recognition showed a typical right visual field advantage, and priming effects diminished with increasing prime and target eccentricity. With centrally located targets, priming effects tended to be more constrained by prime location. After eye fixation location and prime visibility were controlled for (Experiment 2), a right visual field advantage for priming effects was also evident for central targets, suggesting an influence of endogenous attentional biases in masked repetition priming.     

Semantic codes are not used in integrating information across eye fixations in reading: Evidence from fluent Spanish-English bilinguals

The question of whether meaning can be extracted from unidentified parafoveal words was examined using fluent Spanish-English bilinguals. In Experiment 1, subjects fixated on a central cross, and a preview word was presented to the right of fixation in parafoveal vision. During the saccade to the parafoveal preview word, the preview was replaced by the target word, which the subject was required to name. In Experiment 2, subjects read sentences containing the target word, and, as in the naming task, a preview word was replaced by the target word when the subject’s saccade crossed a boundary location. In both experiments, preview words were identical to the target word, translations, orthographic controls for the translations, or unrelated words in the opposite language. In both experiments, the preview benefit from the translation conditions was no greater than would be predicted by the orthographic similarity of the preview to the target. Hence, the data indicated that subjects obtained no useful semantic information from words seen parafoveally that enabled them to identify them more quickly on the subsequent fixation.     

Use of parafoveally visible characters during the reading of Chinese sentences

Chinese readers' use of parafoveal character previews was examined. In Experiment 1, the preview of target characters consisted of targets or of graphemically similar, homophonic, or dissimilar characters. Each preview was replaced with the corresponding target when the eyes reached the target location. Oculomotor measures revealed preview benefits for targets, for graphemically similar characters, and for homophonic characters. Experiment 2 showed that parafoveal preview of graphemically similar characters yielded benefits primarily when they shared the phonetic radical with their targets. The phonological relationship between previewed radicals and subsequently viewed targets was ineffective. Chinese character processing thus involves the initial use of orthographic information from the phonetic radical and the activation of the character's phonological form.     

Knowledge of word length does not constrain word identification

Use of word length for word identification was examined in three naming experiments and one sentence reading experiment in which a foveally presented cue either matched or mismatched the length of a subsequently presented target word. Properties of the target were also manipulated so that it was either a high- or low-frequency word or so that its exterior letters were either consistent with a large or small pool of candidate words. The experiments converged in showing that effects of prior word length cuing were either negligible or absent. The word frequency of the target influenced its recognition but not the lexical constraint of its exterior letters. Importantly, effects of target word properties did not interact with effects of prior target length cuing. Together, these results indicate that knowledge of a word's spatial properties does not constrain its lexical processing.     

Fast priming during eye fixations in reading.

Near-threshold primes were "flashed" in a target location prior to the onset of a target word while Ss read. The type and duration of the prime were manipulated. In Exp. 1, identical, related, and unrelated primes were presented for 60, 45, or 30 ms from onset of an eye fixation. The prime was then replaced with the target word, which remained in place while Ss finished reading the sentence. Fixation time on the target word was measured. Exp. 2 replicated Exp. 1, with two exceptions: A random letter string replaced the identical prime condition, and prime durations of 39, 30, or 21 ms were used. In both experiments, significant priming effects (related vs. unrelated) were obtained when the prime was presented for 30 ms. Results are discussed with regard to subliminal priming effects. Applications to the study of word recognition processes are also discussed.     

The influence of lexical and conceptual constraints on reading mixed-language sentences: Evidence from eye fixations and naming times

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 × 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.     

中文句子阅读中语义信息对眼动预视效应的影响

采用句子为阅读材料,变化句子中一个单字词形成语义连贯与语义违背两种实验条件,通过两个眼动实验探讨中文句子阅读中预视效应的产生是否受语义信息的影响。实验一运用自然阅读范式,考察当语义连贯与违背两类信息被读者直接注视时,读者眼动模式的变化。结果发现,在语义连贯与违背两种条件下,读者的眼动模式在目标位置立即产生差异,违背条件下首次注视时间更长,说明中文句子理解中语义加工可以进行得十分即时。实验二运用边界技术,使实验一的语义连贯与违背两类关键字只呈现在预视位置上,当读者的注视点越过边界时,两类预视字均变为另一个与句子意义连贯的目标字。结果发现,语义违背预视条件下,读者对预视位置将进行更长时间的加工。上述结果表明,中文句子阅读过程中,语义信息可以对预视效应产生影响     

Phonological representation of words in working memory during sentence reading

The temporal dynamics of a visual target word’s phonological representation was examined by presentation of an irrelevant spoken companion word when the participant’s eyes reached the target’s location during sentence reading. The spoken word was identical, similar, or dissimilar to the phonological specification of the visual target. All spoken words increased the time spent viewing the target, with larger effects in thesimilar anddissimilar spoken word conditions than in theidentical condition. The reading of posttarget text was disrupted when the spoken word was similar but not when it was identical or dissimilar to the target. Phonological interference indicates that a word’s phonological representation remains active after it has been identified during sentence reading.     

并列和偏正结构双字合成词的注视位置效应

采用EyeLink II眼动仪, 选取并列结构和偏正结构两种类型的目标词, 要求大学生被试阅读包含有目标词的句子, 以探讨两种双字合成词的注视位置效应。结果发现：在阅读并列和偏正结构的目标词时, 单次注视条件下读者往往将首次注视定位于词的中心位置, 多次注视时首次注视往往落在词的开端部分; 当首次注视落在词的开端时再注视该词的概率增加, 而且再注视往往落在词的结尾部分。结果提示：在单次注视条件下存在偏向注视位置; 双字合成词结构不影响偏向和最佳注视位置; 研究结果支持“战略-战术”模型。     

The influence on recognition of spoken words that are misperceived

Two experiments were performed that involved an initial word-identification task in which the acoustic signal was degraded by either 50% or 60% compression of the recorded words. A control group was tested at the original recording rate (0% compression). The compression manipulation was successful in increasing the number of identification errors. During the second stage of the experiments, words were read at a normal rate. In Experiment 1, the subjects indicated whether each word had appeared on the prior list, and in Experiment 2, the subjects estimated the number of times each word had been read on the prior list. The false-negative rate decreased and frequency ratings increased as a function of the number of prior presentations (one, two, or three) of the target words. The most interesting result was that the effect of repetitions was present even for words that had been misperceived.     

A contingent speech technique in eye movement research on reading

A novel eye-movement-contingent method is presented. It builds on and extends established eye-movement-contingent visual display change methods in that it uses movements of the eyes to control the presentation of acoustic information during sentence reading. In one implementation, an irrelevant spoken word is presented when the eyes cross a predetermined spatial boundary before they move on to a selected visual target word. The relationship between the spoken word and the visual target is manipulated, and the pattern of interference, caused by the presentation of the spoken word, is used to determine the nature and time course of activated representations. Results from three recently completed experiments in which the technique was used show that a word’s phonological code remains active after it has been read and that the activated code has speech-like properties.     

Auditory psychomotor coordination and visual search performance

In Experiments 1 and 2, the time to locate and identify a visual target (visual search performance in a two-alternative forced-choice paradigm) was measured as a function of the location of the target relative to the subject's initial line of gaze. In Experiment 1, tests were conducted within a 260 degree region on the horizontal plane at a fixed elevation (eye level). In Experiment 2, the position of the target was varied in both the horizontal (260 degrees) and the vertical (+/- 46 degrees from the initial line of gaze) planes. In both experiments, and for all locations tested, the time required to conduct a visual search was reduced substantially (175-1,200 msec) when a 10-Hz click train was presented from the same location as that occupied by the visual target. Significant differences in latencies were still evident when the visual target was located within 10 degrees of the initial line of gaze (central visual field). In Experiment 3, we examined head and eye movements that occur as subjects attempt to locate a sound source. Concurrent movements of the head and eyes are commonly encountered during auditorily directed search behavior. In over half of the trials, eyelid closures were apparent as the subjects attempted to orient themselves toward the sound source. The results from these experiments support the hypothesis that the auditory spatial channel has a significant role in regulating visual gaze.     

Deployment of spatial attention to words in central and peripheral vision

Four perceptual identification experiments examined the influence of spatial cues on the recognition of words presented in central vision (with fixation on either the first or last letter of the target word) and in peripheral vision (displaced left or right of a central fixation point). Stimulus location had a strong effect on word identification accuracy in both central and peripheral vision, showing a strong right visual field superiority that did not depend on eccentricity. Valid spatial cues improved word identification for peripherally presented targets but were largely ineffective for centrally presented targets. Effects of spatial cuing interacted with visual field effects in Experiment 1, with valid cues reducing the right visual field superiority for peripherally located targets, but this interaction was shown to depend on the type of neutral cue. These results provide further support for the role of attentional factors in visual field asymmetries obtained with targets in peripheral vision but not with centrally presented targets.     

An electrophysiological investigation of the effects of coreference on word repetition and synonymy

In two experiments the effects of word repetition, synonymy, and coreference on event-related brain potentials during text processing were studied. Participants read one (Experiment 1) or two sentence (Experiment 2) texts in which critical nouns were preceded by the definite (the) or indefinite (a) articles. Experiment 1 was run as a control to verify that differences in article processing in the second sentences of Experiment 2 would not contaminate the ERPs to critical noun items. They did not. In Experiment 2, an initial sentence was used to set up a context and contained either a first presentation or synonym of the critical word from the second sentence. N400 (but not Late Positive Component; LPC) priming effects were found for repetitions and synonyms (larger for repetitions) in second sentences. This extends observations of priming in word lists and single sentences to two-sentence texts. There was also a greater left anterior negativity or "LAN" for coreferential critical nouns (those following the article "The") compared to non-coreferential critical nouns (those following the article "A") suggesting that ERPs are sensitive to working memory processes engaged during referential assignment. In response to the articles themselves, there was a greater N400-700 elicited by the article "A" vs. "The." Finally, there was a greater N400-like negativity to the final words of non-coreferential sentences implying that the meanings of these sentences were difficult to integrate with the discourse level representation established by the prior sentence.     

Evidence for delayed parafoveal-on-foveal effects from word n+2 in reading

During reading information is acquired from word(s) beyond the word that is currently looked at. It is still an open question whether such parafoveal information can influence the current viewing of a word, and if so, whether such parafoveal-on-foveal effects are attributable to distributed processing or to mislocated fixations which occur when the eyes are directed at a parafoveal word but land on another word instead. In two display-change experiments, we orthogonally manipulated the preview and target difficulty of word n+2 to investigate the role of mislocated fixations on the previous word n+1. When the eyes left word n, an easy or difficult word n+2 preview was replaced by an easy or difficult n+2 target word. In Experiment 1, n+2 processing difficulty was manipulated by means of word frequency (i.e., easy high-frequency vs. difficult low-frequency word n+2). In Experiment 2, we varied the visual familiarity of word n+2 (i.e., easy lower-case vs. difficult alternating-case writing). Fixations on the short word n+1, which were likely to be mislocated, were nevertheless not influenced by the difficulty of the adjacent word n+2, the hypothesized target of the mislocated fixation. Instead word n+1 was influenced by the preview difficulty of word n+2, representing a delayed parafoveal-on-foveal effect. The results challenge the mislocated-fixation hypothesis as an explanation of parafoveal-on-foveal effects and provide new insight into the complex spatial and temporal effect structure of processing inside the perceptual span during reading.