The time course of word frequency and case alternation effects on fixation times in reading: Evidence for lexical control of eye movements.

Participants' eye movements were monitored while they read sentences in which high-frequency and low-frequency target words were presented either in normal font (e.g., account) or case alternated (e.g., aCcOuNt). The influence of the word frequency and case alternation manipulations on fixation times was examined. Although both manipulations had comparable effects on standard first-pass fixation measures, word frequency, but not case alternation was found to influence the duration of the first fixation in trials with multiple first-pass fixations. Assuming that lexical processing is more often incomplete at the termination of the first in multiple first-pass fixations than at the end of single first-pass fixations, the present findings provide strong evidence for an influence of word frequency on early lexical processing. Importantly, such a demonstration of a fast acting influence of a lexical variable on fixation times satisfies a critical prerequisite for establishing lexical control of eye movements in reading. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Integrating information across fixations during reading: The use of orthographic bodies and of exterior letters.

Eye movements were recorded to determine whether the parafoveally visible orthographic body of a bisyllabic target word facilitated recognition during the next target fixation. Eye-movement-contingent display changes revealed part of the target, including its orthographic body, or its beginning letters, when it was parafoveally available, but the full target was visible after it was fixated. Target viewing durations showed no benefit from parafoveal preview of orthographic bodies. Instead, preview benefits derived primarily from the preview of word-initial letters. Examination of oculomotor activity revealed that single target fixations were common when the pretarget word received more than one fixation; conversely, more than one target fixation was common when the pretarget word had received a single fixation. Interword fixation strategies thus affected target viewing, but use of parafoveal target previews was unaffected by these strategies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eye movements of older and younger readers when reading disappearing text.

Older and younger readers read sentences in which target words were masked 40 to 60 ms after fixation onset. Masking only the target word caused more disruption than did masking each word in the sentence, and this effect was stronger for the younger readers than for the older readers. Although older readers had longer eye fixations than did younger readers, the results indicated that the masking effect was comparable for the 2 groups. However, for both groups, how long the eyes remained in place was strongly influenced by the frequency of the fixated word (even though it had been rapidly replaced by the mask and was no longer there when the eyes did move). This is compelling evidence that for both older and younger readers, cognitive/lexical processing has a very strong influence on when the eyes move in reading. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A perceptual-economy account for the inverted-optimal viewing position effect.

In reading, fixation durations are longer when the eyes fall near the center of words than when fixation occurs toward the words' ends-the inverted-optimal viewing position (I-OVP) effect. This study assessed whether the I-OVP effect was based on the fixation position in the word or the fixation position in the visual stimulus. In Experiments 1-3, words were presented at variable locations within longer strings of symbols. On trials with short fixation durations, there were effects of fixation position in the string. When long fixations were made, there were effects of fixation position in the word. In Experiment 4, an I-OVP effect was found for meaningless number strings, and its strength depended on the task's processing demands. The findings show that (a) the I-OVP effect is unrelated to orthographic informativeness and (b) the eyes are not constrained to spend more time at the center of visual stimuli. These results support a perceptual-economy account: Fixations are held longer when the eyes are estimated to be at locations in words/stimuli in which greater amounts of information are anticipated. Implications for eye movements in reading are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Establishing a time-line of word recognition: evidence from eye movements and event-related potentials

The average duration of eye fixations in reading places constraints on the time for lexical processing. Data from event related potential (ERP) studies of word recognition can illuminate stages of processing within a single fixation on a word. In the present study, high and low frequency regular and exception words were used as targets in an eye movement reading experiment and a high-density electrode ERP lexical decision experiment. Effects of lexicality (words vs pseudowords vs consonant strings), word frequency (high vs low frequency) and word regularity (regular vs exception spelling-sound correspondence) were examined. Results suggest a very early time-course for these aspects of lexical processing within the context of a single eye fixation.     

Investigating the Effects of a Set of Intercorrelated Variables on Eye Fixation Durations in Reading.

The present experiment investigated the influence of 5 intercorrelated variables on word recognition using a multiple regression analysis. The 5 variables were word frequency, subjective familiarity, word length, concreteness, and age of acquisition (AoA). Target words were embedded in sentences and eye tracking methodology was used to investigate the predictive power of these variables. All 5 variables were found to influence reading time. However, the time course of these variables differed. Both word frequency and familiarity showed an early but lasting influence on eye fixation durations. Word length only significantly predicted fixation durations after refixations on the target words were taken into account. This is the 1st experiment to demonstrate concreteness and AoA effects on eye fixations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eye movement control during reading: Effects of word frequency and orthographic familiarity.

Word frequency and orthographic familiarity were independently manipulated as readers' eye movements were recorded. Word frequency influenced fixation durations and the probability of word skipping when orthographic familiarity was controlled. These results indicate that lexical processing of words can influence saccade programming (as shown by fixation durations and which words are fixated). Orthographic familiarity, but not word frequency, influenced the duration of prior fixations. These results provide evidence for orthographic, but not lexical, parafoveal-on-foveal effects. Overall, the findings have a crucial implication for models of eye movement control in reading: There must be sufficient time for lexical factors to influence saccade programming before saccade metrics and timing are finalized. The conclusions are critical for the fundamental architecture of models of eye movement control in reading- namely, how to reconcile long saccade programming times and complex linguistic influences on saccades during reading. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Re-evaluating split-fovea processing in word recognition: Effects of retinal eccentricity on hemispheric dominance.

Several studies have claimed that hemispheric asymmetries affect word recognition right up to the point of fixation because each fovea is split precisely at its vertical midline and information presented either side of this midline projects unilaterally to different, contralateral hemispheres. To investigate this claim, four-letter words were presented to the left or right of fixation, either close to fixation entirely in foveal vision (0.15, 0.25, and 0.35 degrees from fixation) or further from fixation entirely in extrafoveal vision (2.00, 2.10, and 2.20 degrees from fixation). Fixation location and stimulus presentation were controlled using an eye-tracker linked to a fixation-contingent display and performance was assessed using a forced-choice task to suppress confounding effects of guesswork. A left hemisphere advantage was observed for words presented in extrafoveal locations but no hemisphere advantage (left or right) was observed for words presented in any foveal location. These findings support the well-established view that words encountered outside foveal vision project to different, contralateral hemispheres but indicate that this division for word recognition occurs only outside the fovea and provide no support for the claim that a functional split in hemispheric processing exists at the point of fixation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reading Finnish compound words: eye fixations are affected by component morphemes

The role of morphemic processing in reading was investigated in 2 experiments in which participants read sentences as their eye movements were monitored. The target words were 2-morpheme Finnish compound words. In Experiment 1, the length of the component morphemes was varied and word length was held constant, and in Experiment 2, the uniqueness of the initial morpheme was varied and the rated familiarity and length of the word were held constant. The length of the initial morpheme influenced the location of the second fixation on the target word and the pattern of fixation durations (although it had a negligible influence on the gaze duration of the word). The frequency of the initial morpheme influenced the duration of the first fixation on the target word, had a substantial effect on the gaze duration, and also influenced the location of the first and second fixations on the target word. Subsidiary analyses indicated that these effects were unlikely to stem from orthographic factors such as bigram frequency.     

Tracking the mind during reading via eye movements: Comments on Kliegl, Nuthmann, and Engbert (2006).

R. Kliegl, A. Nuthmann, and R. Engbert (see record 2006-01956-002) reported an impressive set of data analyses dealing with the influence of the prior, present, and next word on the duration of the current eye fixation during reading. They argued that outcomes of their regression analyses indicate that lexical processing is distributed across a number of words during reading. The authors of this comment question their conclusions and address 4 different issues: (a) whether there is evidence for distributed lexical processing, (b) whether so-called parafoveal-on-foveal effects are widespread, (c) the role of correlational analyses in reading research, and (d) problems in their analyses because they use only cases in which words are fixated exactly once. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eye movement control in reading: A comparison of two types of models.

Two classes of models have been proposed to account for eye movement control during reading. Proponents of the 1st class of model claim that the decision of when to move the eyes (reflected in fixation duration) is primarily influenced by the status of on-line language processing such as lexical access. Supporters of the 2nd class of model, however, maintain that (a) lower level oculomotor factors such as fixation location govern the decision of when to move the eyes and (b) lexical variables exert only a weak influence. In this study, fixation duration on low- and high-frequency target words was examined as a function of fixation location and the number of fixations on a target word. The data are inconsistent with an oculomotor model. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The word grouping hypothesis and eye movements during reading.

The distribution of landing positions and durations of first fixations in a region containing a noun preceded by either an article (e.g., the soldiers) or a high-frequency 3-letter word (e.g., all soldiers) were compared. Although there were fewer first fixations on the blank space between the high-frequency 3-letter word and the noun than on the surrounding letters (and the fixations on the blank space were shorter), this pattern did not occur when the noun was preceded by an article. R. Radach (1996) inferred from a similar experiment that did not manipulate the type of short word that 2 words could be processed as a perceptual unit during reading when the first word is a short word. As this different pattern of fixations is restricted to article-noun pairs, it indicates that word grouping does not occur purely on the basis of word length during reading; moreover, as the authors demonstrate, one can explain the observed patterns in both conditions more parsimoniously without adopting a word-grouping mechanism in eye movement control during reading. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How initial fixation position influences visual word recognition: a comparison of French and Arabic

The position the eye initially fixates in a written word influences the ease with which this word is recognized. Prior research has shown that the function relating ease of word recognition and initial fixation position in the word is not symmetric. Word recognition is generally superior when the initial fixation is left rather than right of the center of the word. This asymmetry in the function relating initial fixation position to word identifiability could be due to (a) hemispheric specialization, (b) reading habits, or (c) variations in lexical constraint. The present experiments tested these alternative explanations by comparing the effects of initial fixation position in prefixed and suffixed words in French and Arabic. The results show that, contrary to both the hemispheric specialization and reading habit hypotheses, the average initial fixation curves for Arabic are asymmetric neither to the left nor to the right but depend on the morphological structure of the stimuli, thus lending support to the lexical constraint hypothesis.     

Visual word recognition: Reattending to the role of spatial attention.

Three experiments examine whether spatial attention and visual word recognition processes operate independently or interactively in a spatially cued lexical-decision task. Participants responded to target strings that had been preceded first by a prime word at fixation and then by an abrupt onset cue either above or below fixation. Targets appeared either in the cued (i.e., valid) or uncued (i.e., invalid) location. The proportion of validly cued trials and the proportion of semantically related prime-target pairs were manipulated independently. It is concluded that spatial attention and visual word recognition processes are best seen as interactive. Spatial attention affects word recognition in 2 distinct ways: (a) it affects the uptake of orthographic information, possibly acting as "glue" to hold letters in their proper places in words, and (b) it (partly) determines whether or not activation from the semantic level feeds down to the lexical level during word recognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prioritization of New Objects in Real-World Scenes: Evidence From Eye Movements.

The authors examined the prioritization of abruptly appearing objects in real-world scenes by measuring the eyes' propensity to be directed to the new object. New objects were fixated more often than chance whether they appeared during fixations (transient onsets) or saccades (nontransient onsets). However, onsets that appeared during fixations were fixated sooner and more often than those coincident with saccades. Prioritization of onsets during saccades, but not fixations, were affected by manipulations of memory: Reducing scene viewing time prior to the onset eliminated prioritization, whereas prior study of the scenes increased prioritization. Transient objects draw attention quickly and do not depend on memory, but without a transient signal, new objects are prioritized over several saccades as memory is used to explicitly identify the change. These effects were not modulated by observers' expectations concerning the appearance of new objects, suggesting the prioritization of a transient is automatic and that memory-guided prioritization is implicit. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Eye-fixation behavior, lexical storage, and visual word recognition in a split processing model.

Some of the implications of a model of visual word recognition in which processing is conditioned by the anatomical splitting of the visual field between the two hemispheres of the brain are explored. The authors investigate the optimal processing of visually presented words within such an architecture, and, for a realistically sized lexicon of English, characterize a computationally optimal fixation point in reading. They demonstrate that this approach motivates a range of behavior observed in reading isolated words and text, including the optimal viewing position and its relationship with the preferred viewing location, the failure to fixate smaller words, asymmetries in hemisphere-specific processing, and the priority given to the exterior letters of words. The authors also show that split architectures facilitate the uptake of all the letter-position information necessary for efficient word recognition and that this information may be less specific than is normally assumed. A split model of word recognition captures a range of behavior in reading that is greater than that covered by existing models of visual word recognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Embedded words in visual word recognition: Does the left hemisphere see the rain in brain?

To examine whether interhemispheric transfer during foveal word recognition entails a discontinuity between the information presented to the left and right of fixation, we presented target words in such a way that participants fixated immediately left or right of an embedded word (as in gr*apple, bull*et) or in the middle of an embedded word (grapp*le, bu*llet). Categorization responses to target words were faster and more accurate in a congruent condition (in which the embedded word was associated with the same response; e.g., Does bullet refer to an item of clothing?) than in an incongruent condition (e.g., Does bullet refer to a type of animal?). However, the magnitude of this effect did not vary as a function of position of fixation, relative to the embedded word, as might be expected if information from the 2 visual fields was initially split over the cerebral hemispheres and integrated only late in the word identification process. Equivalent results were observed in Experiment 1 (long stimulus duration) and Experiment 2 (in which stimulus duration was 200 ms; i.e., less than the time required to initiate a refixation). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Happy mouth and sad eyes: Scanning emotional facial expressions.

There is evidence that specific regions of the face such as the eyes are particularly relevant for the decoding of emotional expressions, but it has not been examined whether scan paths of observers vary for facial expressions with different emotional content. In this study, eye-tracking was used to monitor scanning behavior of healthy participants while looking at different facial expressions. Locations of fixations and their durations were recorded, and a dominance ratio (i.e., eyes and mouth relative to the rest of the face) was calculated. Across all emotional expressions, initial fixations were most frequently directed to either the eyes or the mouth. Especially in sad facial expressions, participants more frequently issued the initial fixation to the eyes compared with all other expressions. In happy facial expressions, participants fixated the mouth region for a longer time across all trials. For fearful and neutral facial expressions, the dominance ratio indicated that both the eyes and mouth are equally important. However, in sad and angry facial expressions, the eyes received more attention than the mouth. These results confirm the relevance of the eyes and mouth in emotional decoding, but they also demonstrate that not all facial expressions with different emotional content are decoded equally. Our data suggest that people look at regions that are most characteristic for each emotion. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Comprehension of arithmetic word problems: Evidence from students' eye fixations.

Students have difficulty solving arithmetic word problems containing a relational term that is inconsistent with the required arithmetic operation (e.g., containing the term less, yet requiring addition) rather than consistent. To investigate this consistency effect, students' eye fixations were recorded as they read arithmetic word problems on a computer monitor and stated a solution plan for each problem. As predicted, low-accuracy students made more reversal errors on inconsistent than consistent problems, students took more time for inconsistent than consistent problems, this additional time was localized in the integration/planning stages of problem solving rather than in the initial reading of the problem, these response-time patterns were obtained for high-accuracy but not for low-accuracy students, and high-accuracy students required more rereadings of previously fixated words for inconsistent than for consistent problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eye movements and word skipping during reading: Effects of word length and predictability.

Eye movements were monitored as subjects read sentences containing high- or low-predictable target words. The extent to which target words were predictable from prior context was varied: Half of the target words were predictable, and the other half were unpredictable. In addition, the length of the target word varied: The target words were short (4–6 letters), medium (7–9 letters), or long (10–12 letters). Length and predictability both yielded strong effects on the probability of skipping the target words and on the amount of time readers fixated the target words (when they were not skipped). However, there was no interaction in any of the measures examined for either skipping or fixation time. The results demonstrate that word predictability (due to contextual constraint) and word length have strong and independent influences on word skipping and fixation durations. Furthermore, because the long words extended beyond the word identification span, the data indicate that skipping can occur on the basis of partial information in relation to word identity. (PsycINFO Database Record (c) 2011 APA, all rights reserved)