Direct lexical control of eye movements in reading: evidence from a survival analysis of fixation durations

Neural correlates for word-frequency effect in Chinese natural reading

Word frequency effect has always been of interest for reading research because of its critical role in exploring mental processing underlying reading behaviors. Access to word frequency information has long been considered an indicator of the beginning of lexical processing and the most sensitive marker for studying when the brain begins to extract semantic information Sereno & Rayner, Brain and Cognition, 42, 78-81, (2000), Trends in Cognitive Sciences, 7, 489-493, (2003). While the word frequency effect has been extensively studied in numerous eye-tracking and traditional EEG research using the RSVP paradigm, there is a lack of corresponding evidence in studies of natural reading. To find the neural correlates of the word frequency effect, we conducted a study of Chinese natural reading using EEG and eye-tracking coregistration to examine the time course of lexical processing. Our results reliably showed that the word frequency effect first appeared in the N200 time window and the bilateral occipitotemporal regions. Additionally, the word frequency effect was reflected in the N400 time window, spreading from the occipital region to the central parietal and frontal regions. Our current study provides the first neural correlates for word-frequency effect in natural Chinese reading so far, shedding new light on understanding lexical processing in natural reading and could serve as an important basis for further reading study when considering neural correlates in a realistic manner.

Mask-related costs in measuring preview benefit: Evidence from a distributional analysis based on target word reading times

Skilled reading involves processing the upcoming word in parafoveal vision before it is fixated, leading to shorter fixations on that word. This phenomenon, parafoveal preview benefit, is a key component of theoretical models of reading; it is measured using the invisible boundary paradigm, in which reading times on a target word are compared for instances when preview is accurate and when the target word is masked while in the parafovea. However, parafoveal masks have been shown to induce unintentional processing costs, thereby inflating measures of preview benefit. The degraded mask has been explored as a potential solution to this problem, leading to mixed results. While previous work has analyzed the preview effect by comparing mean reading times on the target word, the present study provides a more comprehensive analysis by examining the distribution of the preview effect across target word fixation times for unrelated and degraded masks. Participants read sentences containing target words whose preview was either identical, unrelated, or degraded, and their eye movements were recorded. Analyses revealed that although there were no mean differences between reading times for the unrelated and degraded conditions, the pattern of the effects varied as a function of target word fixation times. Unrelated masks resulted in positively sloped generally linear delta plots, while degraded masks resulted in relatively flat delta plots for fixations longer than 200 ms. These differences suggest that different cognitive mechanisms are involved in the processing of the two mask types. Implications for understanding and measuring preview benefit are discussed.

Presbyopia correction with multifocal contact lenses: Evaluation of silent reading performance using eye movements analysis

PURPOSE

Many activities of daily living rely on reading, thus is not surprising that complaints from presbyopes originate in reading difficulties rather in visual acuity. Here, the effectiveness of presbyopia correction with multifocal contact lenses (CLs) is evaluated using an eye-fixation based method of silent reading performance. ΜETHODS: Visual performance of thirty presbyopic volunteers (age: 50 ± 5 yrs) was assessed monocularly and binocularly following 15 days of wear of monthly disposable CLs (AIR OPTIX™ plus HydraGlyde™, Alcon Laboratories) with: (a) single vision (SV) lenses - uncorrected for near (b) aspheric multifocal (MF) CLs. LogMAR acuity was measured with ETDRS charts. Reading performance was evaluated using standard IReST paragraphs displayed on a screen (0.4 logMAR print size at 40 cm distance). Eye movements were monitored with an infrared eyetracker (Eye-Link II, SR Research Ltd). Data analysis included computation of reading speed, fixation duration, fixations per word and percentage of regressions.

RESULTS

Average reading speed was 250 ± 68 and 235 ± 70 wpm, binocularly and monocularly, with SV CLs, improving statistically significantly to 280 ± 67 (p = 0.002) and 260 ± 59 wpm (p = 0.01), respectively, with MF CLs. Moreover, fixation duration, fixations per word and ex-Gaussian parameter of fixation duration, μ, showed a statistically significant improvement when reading with MF CLs, with fixation duration exhibiting the stronger correlation (r = 0.79, p < 0.001) with improvement in reading speed. The correlation between improvement in VA and reading speed was moderate (r = 0.46, p = 0.016), as was the correlation between VA and any eye fixation parameter.

CONCLUSION

Average silent reading speed in a presbyopic population was found improved with MF compared to SV CL correction and was faster with binocular compared to monocular viewing: this was mainly due to the faster average fixation duration and the lower number of fixations. Evaluating reading performance using eye fixation analysis could offer a reliable outcome of functional vision in presbyopia correction.

An Application of Eye Movement Parameters Collected from Mass Market Devices for the Estimation of a Text Comprehension

The growing interest in evaluating the reader's comprehension leads to the search for new methods that allow such estimation in real-time (or pseudo-real-time). This can be used for more effective educational processes and to adopt textual content for various purposes. The present study used the Oken Reader eye-tracking application (60 Hz) for mass-market devices to assess reading comprehension processes. Twenty-three (23) respondents aged between 19 and 31 (mean = 24. 5, SE = 1. 4, 65% female) participated in the study. The mean, mu, and sigma parameters differed significantly depending on the level of text comprehension. This result indicates the possibility of using mass-market devices with eye-tracking technology to assess comprehension in reading. Furthermore, the study's results confirm the possibility of searching the correlations between physiological indicators such as eye movements and comprehension.

Eye Movement and Pupil Measures: A Review

Our subjective visual experiences involve complex interaction between our eyes, our brain, and the surrounding world. It gives us the sense of sight, color, stereopsis, distance, pattern recognition, motor coordination, and more. The increasing ubiquity of gaze-aware technology brings with it the ability to track gaze and pupil measures with varying degrees of fidelity. With this in mind, a review that considers the various gaze measures becomes increasingly relevant, especially considering our ability to make sense of these signals given different spatio-temporal sampling capacities. In this paper, we selectively review prior work on eye movements and pupil measures. We first describe the main oculomotor events studied in the literature, and their characteristics exploited by different measures. Next, we review various eye movement and pupil measures from prior literature. Finally, we discuss our observations based on applications of these measures, the benefits and practical challenges involving these measures, and our recommendations on future eye-tracking research directions.

Eye movements during text reading align with the rate of speech production

Across languages, the speech signal is characterized by a predominant modulation of the amplitude spectrum between about 4.3 and 5.5 Hz, reflecting the production and processing of linguistic information chunks (syllables and words) every ~200 ms. Interestingly, ~200 ms is also the typical duration of eye fixations during reading. Prompted by this observation, we demonstrate that German readers sample written text at ~5 Hz. A subsequent meta-analysis of 142 studies from 14 languages replicates this result and shows that sampling frequencies vary across languages between 3.9 Hz and 5.2 Hz. This variation systematically depends on the complexity of the writing systems (character-based versus alphabetic systems and orthographic transparency). Finally, we empirically demonstrate a positive correlation between speech spectrum and eye movement sampling in low-skilled non-native readers, with tentative evidence from post hoc analysis suggesting the same relationship in low-skilled native readers. On the basis of this convergent evidence, we propose that during reading, our brain's linguistic processing systems imprint a preferred processing rate-that is, the rate of spoken language production and perception-onto the oculomotor system.

An oscillatory pipelining mechanism supporting previewing during visual exploration and reading

Humans have a remarkable ability to efficiently explore visual scenes and text using eye movements. Humans typically make eye movements (saccades) every ~250 ms. Since saccade initiation and execution take 100 ms, this leaves only ~150 ms to recognize the fixated object (or word) while simultaneously previewing candidates for the next saccade goal. We propose a pipelining mechanism where serial processing occurs within a specific brain region, whereas parallel processing occurs across different brain regions. The mechanism is timed by alpha oscillations that coordinate the saccades, visual recognition, and previewing in the cortical hierarchy. Consequently, the neuronal mechanism supporting natural vision and saccades must be studied in unison to uncover the brain mechanisms supporting visual exploration and reading.

Neural evidence for lexical parafoveal processing

In spite of the reduced visual acuity, parafoveal information plays an important role in natural reading. However, competing models on reading disagree on whether words are previewed parafoveally at the lexical level. We find neural evidence for lexical parafoveal processing by combining a rapid invisible frequency tagging (RIFT) approach with magnetoencephalography (MEG) and eye-tracking. In a silent reading task, target words are tagged (flickered) subliminally at 60 Hz. The tagging responses measured when fixating on the pre-target word reflect parafoveal processing of the target word. We observe stronger tagging responses during pre-target fixations when followed by low compared with high lexical frequency targets. Moreover, this lexical parafoveal processing is associated with individual reading speed. Our findings suggest that reading unfolds in the fovea and parafovea simultaneously to support fluent reading.

Parafoveal processing of orthographic, morphological, and semantic information during reading Arabic: A boundary paradigm investigation

Evidence shows that skilled readers extract information about upcoming words in the parafovea. Using the boundary paradigm, we investigated native Arabic readers' processing of orthographic, morphological, and semantic information available parafoveally. Target words were embedded in frame sentences, and prior to readers fixating them, one of the following previews were made available: (a) Identity preview; (b) Preview that shared the pattern morpheme with the target; (c) Preview that shared the root morpheme with the target; (d) Preview that was a synonym with the target word; (e) Preview with two of the root letters were transposed thus creating a new root, while preserving all letter identities of the target; (f) Preview with two of the root letters were transposed thus creating a pronounceable pseudo root, while also preserving all letter identities of the target; and (g) Previews that was unrelated to the target word and shared no information with it. The results showed that identity, root-preserving, and synonymous preview conditions yielded preview benefit. On the other hand, no benefit was obtained from the pattern-preserving previews, and significant disruption to processing was obtained from the previews that contained transposed root letters, particularly when this letter transposition created a new real root. The results thus reflect Arabic readers' dependance on morphological and semantic information, and suggest that these levels of representation are accessed as early as orthographic information. Implications for theory- and model-building, and the need to accommodate early morphological and semantic processing activities in more comprehensive models are further discussed.

Letter processing in Russian: Does orthography matter?

Prior research has suggested that the identification and encoding of letter positions within letter strings might be influenced by orthography. Letters in transparent languages (e.g., Greek) with regular grapheme-to-phoneme correspondences are processed sequentially, whereas letters in deep languages (e.g., English) are processed in parallel. In three experiments, we used a visual search paradigm to test this hypothesis on Russian-a relatively transparent language. In Experiment 1, we measured the identification speed of Cyrillic letters at each position in the five-element real words or pronounceable pseudowords. In Experiment 2, the performance was compared to random letter strings, and in Experiment 3, to non-linguistic symbol strings. Our results reveal a search pattern similar to English, excluding strictly serial letter computation, which is inconsistent with the orthography hypothesis. Moreover, we showed that the lexical status and the nature of the string (linguistic/non-linguistic) affect response times for Russian and therefore must be accounted for in models of visual word recognition.

Percentile rank pooling: A simple nonparametric method for comparing group reaction time distributions with few trials

Although many studies of reaction time (RT) focus on a single measure of central tendency such as the mean RT, a more detailed picture of the underlying processes can be gained by looking at full distributions of RTs. Unfortunately, for practical reasons it is sometimes difficult to obtain enough trials per participant in a condition of interest to construct such a distribution with existing methods. The purpose of this article is to propose a method of forming group RT distributions that can be used to compare the full distributions of RTs even in an infrequent condition with only a few trials per participant. In brief, the percentile ranks of each participant's infrequent-condition RTs are scored relative to a larger pool including that participant's RTs in other conditions, and a histogram of the infrequent-condition's percentile ranks is then formed by pooling across participants. The resulting histogram of infrequent-condition RT ranks shows where the RTs in that condition tend to fall relative to the other conditions, and this histogram can reveal systematic patterns in the infrequent-condition's RT distribution. To illustrate the method, I present histograms of the ranks of infrequent error RTs (~ 5% of trials), ranked relative to correct responses, in real data sets from Simon and lexical decision tasks.

Manipulating Interword and Interletter Spacing in Cursive Script: An Eye Movements Investigation of Reading Persian

Persian is an Indo-Iranian language that features a derivation of Arabic cursive script, where most letters within words are connectable to adjacent letters with ligatures. Two experiments are reported where the properties of Persian script were utilized to investigate the effects of reducing interword spacing and increasing the interletter distance (ligature) within a word. Experiment 1 revealed that decreasing interword spacing while extending interletter ligature by the same amount was detrimental to reading speed. Experiment 2 largely replicated these findings. The experiments show that providing the readers with inaccurate word boundary information is detrimental to reading rate. This was achieved by reducing the interword space that follows letters that do not connect to the next letter in Experiment 1, and replacing the interword space with ligature that connected the words in Experiment 2. In both experiments, readers were able to comprehend the text read, despite the considerable costs to reading rates in the experimental conditions.

The Effect of Painting Beauty on Eye Movements

The current study aimed to determine relationships between oculomotor behavior and aesthetical evaluation of paintings. We hypothesized that paintings evaluated as beautiful compared to nonbeautiful would be associated with different oculomotor behavior in terms of fixation duration, viewing time, and temporal and spatial distribution of attention. To verify these hypotheses, we examined forty participants that looked at and evaluated 140 figurative paintings while their eye movements were recorded. To analyze data, we used divergence point analysis (DPA) and recurrence quantification analysis (RQA). The results of the DPA suggested that fixation durations longer than 229 ms are sensitive to the effect of aesthetical evaluation. We also found that the effect of aesthetical evaluation was significant in the time window between 2.3 s and 19.8 s of viewing a painting. The results of the RQA suggested that the participants viewed paintings evaluated as beautiful in a more structured manner compared to those evaluated as nonbeautiful, which suggests higher involvement of top-down processes while facing beautiful artwork. We discuss and refer these results to the literature on cognitive processes related to aesthetical evaluation of paintings.

Not all fixations are created equal: The benefits of using ex-Gaussian modeling of fixation durations

Various cognitive and perceptual factors have been shown to modulate the duration of fixations during visual exploration of complex scenes. The majority of these studies have only considered the mean of the distribution of fixation durations. However, this distribution is skewed to the right, so that an increase in the mean may be driven by a lengthening of all fixations (i.e., a right shift of the whole distribution) or only the relatively longer ones (i.e., a longer right tail of the distribution). To determine which factor is at play, the distribution can be modeled with an ex-Gaussian distribution, which is a convolution of a Gaussian and an exponential distribution. Here we demonstrate the usefulness of applying the ex-Gaussian model to empirical distributions of fixation durations and the reliability of its parameters across time. We demonstrate how the ex-Gaussian model had advantages over exclusive consideration of the mean, by showing that an increase in the mean can stem from specific changes in the components of the ex-Gaussian distribution. Specifically, the type of image leads to a change in the Gaussian component alone, indicating a right shift of the main mass of the distribution. By contrast, familiarity with the inspected image modifies the exponential component, and results in a more specific modulation of a subset of relatively long fixations. Hence, estimating the ex-Gaussian parameters may provide novel insights into the underlying processes that determine fixation duration and can contribute to the future development of process-based computational models of gaze behavior.

Literacy Advantages Beyond Reading: Prediction of Spoken Language

Literacy has many obvious benefits: it exposes the reader to a wealth of new information and enhances syntactic knowledge. However, we argue that literacy has an additional, often overlooked, benefit: it enhances people's ability to predict spoken language thereby aiding comprehension. Readers are under pressure to process information more quickly than listeners and reading provides excellent conditions - in particular, a stable environment - for training the predictive system. It also leads to increased awareness of words as linguistic units and to more fine-grained phonological and additional orthographic representations, which sharpen lexical representations and facilitate the retrieval of predicted representations. Thus, reading trains core processes and representations involved in language prediction that are common to both reading and listening.

Neurophysiological, Oculomotor, and Computational Modeling of Impaired Reading Ability in Schizophrenia

Schizophrenia (Sz) is associated with deficits in fluent reading ability that compromise functional outcomes. Here, we utilize a combined eye-tracking, neurophysiological, and computational modeling approach to analyze underlying visual and oculomotor processes. Subjects included 26 Sz patients (SzP) and 26 healthy controls. Eye-tracking and electroencephalography data were acquired continuously during the reading of passages from the Gray Oral Reading Tests reading battery, permitting between-group evaluation of both oculomotor activity and fixation-related potentials (FRP). Schizophrenia patients showed a marked increase in time required per word (d = 1.3, P < .0001), reflecting both a moderate increase in fixation duration (d = .7, P = .026) and a large increase in the total saccade number (d = 1.6, P < .0001). Simulation models that incorporated alterations in both lower-level visual and oculomotor function as well as higher-level lexical processing performed better than models that assumed either deficit-type alone. In neurophysiological analyses, amplitude of the fixation-related P1 potential (P1f) was significantly reduced in SzP (d = .66, P = .013), reflecting reduced phase reset of ongoing theta-alpha band activity (d = .74, P = .019). In turn, P1f deficits significantly predicted increased saccade number both across groups (P = .017) and within SzP alone (P = .042). Computational and neurophysiological methods provide increasingly important approaches for investigating sensory contributions to impaired cognition during naturalistic processing in Sz. Here, we demonstrate deficits in reading rate that reflect both sensory/oculomotor- and semantic-level impairments and that manifest, respectively, as alterations in saccade number and fixation duration. Impaired P1f generation reflects impaired fixation-related reset of ongoing brain rhythms and suggests inefficient information processing within the early visual system as a basis for oculomotor dyscontrol during fluent reading in Sz.

Are divergence point analyses suitable for response time data?

Estimating the time course of the influence of different factors in human performance is one of the major topics of research in cognitive psychology/neuroscience. Over the past decades, researchers have proposed several methods to tackle this question using latency data. Here we examine a recently proposed procedure that employs survival analyses on latency data to provide precise estimates of the timing of the first discernible influence of a given factor (e.g., word frequency on lexical access) on performance (e.g., fixation durations or response times). A number of articles have used this method in recent years, and hence an exploration of its strengths and its potential weaknesses is in order. Unfortunately, our analysis revealed that the technique has conceptual flaws, and it might lead researchers into believing that they are obtaining a measurement of processing components when, in fact, they are obtaining an uninterpretable measurement.

Literacy skill and intra-individual variability in eye-fixation durations during reading: Evidence from a diverse community-based adult sample

To understand the effects of literacy on fundamental processes involved in reading, we report a secondary data analysis examining individual differences in global eye-movement measures and first-pass eye-movement distributions in a diverse sample of community-dwelling adults aged 16 to 64. Participants (n = 80) completed an assessment battery probing verbal and non-verbal cognitive abilities and read simple two-sentence passages while their eye movements were recorded. Analyses were focused on characterising the effects of literacy skill on both global indices of eye-fixation distributions and distributional differences in the sensitivity to lexical features. Global reading measures showed that lower literate adults read more slowly on average. However, distributional analyses of fixation durations revealed that the first-pass fixation durations of adults with lower literacy skill were not slower in general (i.e., there was no shift in the fixation duration distribution among lower literate adults). Instead, lower literacy was associated with greater intra-individual variability in first-pass fixation durations, including an increased proportion of extremely long fixations, differentially skewing the distribution of both first-fixation and gaze durations. Exploratory repeated-measures quantile regression analyses of gaze duration revealed differentially greater influences of word length among lower literate readers and greater activation of phonological and orthographic neighbours among higher literate readers, particularly in the tail of the distribution. Collectively, these findings suggest that literacy skill in adulthood is associated with systematic differences in both global and lexically driven eye-movement control during reading.

Return sweeps in reading: Processing implications of undersweep-fixations

Models of eye-movement control during reading focus on reading single lines of text. However, with multiline texts, return sweeps, which bring fixation from the end of one line to the beginning of the next, occur regularly and influence ~20% of all reading fixations. Our understanding of return sweeps is still limited. One common feature of return sweeps is the prevalence of oculomotor errors. Return sweeps, often initially undershoot the start of the line. Corrective saccades then bring fixation closer to the line start. The fixation occurring between the undershoot and the corrective saccade (undersweep-fixation) has important theoretical implications for the serial nature of lexical processing during reading, as they occur on words ahead of the intended attentional target. Furthermore, since the attentional target of a return sweep will lie far outside the parafovea during the prior fixation, it cannot be lexically preprocessed during this prior fixation. We explore the implications of undersweep-fixations for ongoing processing and models of eye movements during reading by analysing two existing eye-movement data sets of multiline reading.

Zooming in on zooming out: Partial selectivity and dynamic tuning of bilingual language control during reading

Prominent models of bilingual visual word recognition posit a bottom-up nonselective view of lexical processing with parallel access to lexical candidates of both languages. However, these accounts do not accommodate recent findings of top-down effects on the relative global activation level of each language during bilingual reading. We conducted two eye-tracking experiments to systematically assess the degree of accessibility of each language in different global language contexts. When critical words were presented overtly in Experiment 1, code switches disrupted reading early during lexical processing, but not as much as pseudowords did. Participants zoomed out of the target language with increasing exposure to language switches. In Experiment 2, a monolingual language context was created by presenting critical words covertly as parafoveal previews. Here, code-switched words were treated like pseudowords, and participants remained zoomed in to the target language throughout the experiment. Switch direction analyses confirmed and extended these interpretations to provide further support for the role of global language control on lexical access, above and beyond effects due to proficiency differences across languages. Together, these data provide strong evidence for dynamic top-down adjustment of the degree of language selectivity during bilingual reading.

The time course of age-of-acquisition effects on eye movements during reading: Evidence from survival analyses

Adults process words that are rated as being learned earlier in life faster than words that are rated as being acquired later in life. This age-of-acquisition (AoA) effect has been observed in a variety of word-recognition tasks when word frequency is controlled. AoA has also previously been found to influence fixation durations when words are embedded into sentences and eye movements are recorded. However, the time course of AoA effects during reading has been inconsistent across studies. The current study further explored the time course of AoA effects on distributions of first-fixation durations during reading. Early and late acquired words were embedded into matched neutral sentence frames. Participants read the sentences while their eye movements were recorded. AoA effects were observed in both early and late fixation duration measures, suggesting that AoA has an early and long-lasting effect on word-recognition processes during reading. Survival analysis revealed that the earliest discernable effect of AoA on distributions of first-fixation durations emerged beginning at 158 ms. This rapid influence of AoA was confirmed through the use of Vincentile plots, which demonstrated that the effect of AoA occurred early and was relatively consistent across the distribution of fixations. This pattern of results provides support for the direct lexical-control hypothesis, as well as the viewpoint that AoA may exert an influence at multiple loci within the mental lexicon.

The location-based Simon effect: Reliability of ex-Gaussian analysis

Task-irrelevant stimulus location can influence the response performance to task-relevant attributes, generating the location-based Simon effect. Using a Monte Carlo study and other methods, we examined whether the ex-Gaussian distribution provides a good fit to empirical reaction time (RT) distributions in the Simon task and whether reliable Simon effects occur on the ex-Gaussian parameters: (a) the mean (μ), (b) the standard deviation (σ) of the normal distribution, and (c) the tail (τ). Results showed that the ex-Gaussian function fits well to empirical RT distributions, and that these ex-Gaussian parameters are reliable between two trial blocks at the group level. At the individual level, correlation analysis showed that the Simon effect was reliable on the μ parameter but not on σ and τ. Moreover, a partial correlation analysis, with μs of the two blocks as controlling variables, showed that the Simon effect on τ was reliable. These results provide evidence that the ex-Gaussian function is a valuable tool for analyzing the Simon effect and can be considered as an alternative for analyzing RT distributions in Simon-type tasks.

Co-registration of eye movements and neuroimaging for studying contextual predictions in natural reading

Sixteen years ago, Sereno and Rayner (2003. Measuring word recognition in reading: eye movements and event-related potentials. Trends in Cognitive Sciences, 7(11), 489-493) illustrated how "by means of review and comparison" eye movement (EM) and event-related potential (ERP) studies may advance our understanding of visual word recognition. Attempts to simultaneously record EMs and ERPs soon followed. Recently, this co-registration approach has also been transferred to fMRI and oscillatory EEG. With experimental settings close to natural reading, co-registration enables us to directly integrate insights from EM and neuroimaging studies. This should extend current experimental paradigms by moving the field towards studying sentence-level processing including effects of context and parafoveal preview. This article will introduce the basic principles and applications of co-registration and selectively review how this approach may shed light on one of the most controversially discussed issues in reading research, contextual predictions in online language processing.

Shared mechanisms underlying the location-, word- and arrow-based Simon effects

A left or right keypress response to a relevant stimulus attribute (e.g., color) is faster when irrelevant left or right stimulus-location information corresponds with the correct response than when it does not. This phenomenon, known as the Simon effect, is obtained not only for physical locations, but also location words "left" and "right" and left- or right-pointing arrows. However, these location-, word-, and arrow-based Simon effects show different patterns in the reaction-time (RT) distributions, as evident in delta plots. In the present study, we employed procedures, analysis of survival curves and divergence point analysis, which have not previously been applied to the Simon effect, to investigate differences in time course of these various Simon effects in more detail. Also, we examined whether the diffusion model for conflict tasks (DMC), which assumes that automatic activation of task-irrelevant information occurs in a pulse-like function, can capture not only features of the RT distributions for the location-based Simon effect, to which it has been fit previously, but also features of the word- and arrow-based Simon effects, to which it has not. Results showed different survival curves and earliest, maximum, and latest divergence points for the three Simon effects, but DMC was able to capture the basic features of the RT distributions reflected by delta plot and survival curves for all effects. The results imply that the location-, word-, and arrow-based Simon effects have shared mechanisms, although they have different RT distributions.

Parafoveal previews and lexical frequency in natural reading: Evidence from eye movements and fixation-related potentials

Participants' eye movements and electroencephalogram (EEG) signal were recorded as they read sentences displayed according to the gaze-contingent boundary paradigm. Two target words in each sentence were manipulated for lexical frequency (high vs. low frequency) and parafoveal preview of each target word (identical vs. string of random letters vs. string of Xs). Eye movement data revealed visual parafoveal-on-foveal (PoF) effects, as well as foveal visual and orthographic preview effects and word frequency effects. Fixation-related potentials (FRPs) showed visual and orthographic PoF effects as well as foveal visual and orthographic preview effects. Our results replicated the early preview positivity effect (Dimigen, Kliegl, & Sommer, 2012) in the X-string preview condition, and revealed different neural correlates associated with a preview comprised of a string of random letters relative to a string of Xs. The former effects seem likely to reflect difficulty associated with the integration of parafoveal and foveal information, as well as feature overlap, while the latter reflect inhibition, and potentially disruption, to processing underlying reading. Interestingly, and consistent with Kretzschmar, Schlesewsky, and Staub (2015), no frequency effect was reflected in the FRP measures. The findings provide insight into the neural correlates of parafoveal processing and written word recognition in reading and demonstrate the value of utilizing ecologically valid paradigms to study well established phenomena that occur as text is read naturally. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

How Does Domain Expertise Affect Users’ Search Interaction and Outcome in Exploratory Search?

People often conduct exploratory search to explore unfamiliar information space and learn new knowledge. While supporting the highly dynamic and interactive exploratory search is still challenging for the search system, we want to investigate which factors can make the exploratory search successful and satisfying from the user’s perspective. Previous research suggests that domain experts have different search strategies and are more successful in finding domain-specific information, but how the domain expertise level will influence users’ interaction and search outcomes in exploratory search, especially in different knowledge domains, is still unclear. In this work, via a carefully designed user study that involves 30 participants, we investigate the influence of domain expertise levels on the interaction and outcome of exploratory search in three different domains: environment, medicine, and politics. We record participants’ search behaviors, including their explicit feedback and eye fixation sequences, in a laboratory setting. With this dataset, we identify both domain-independent and domain-dependent effects on user behaviors and search outcomes. Our results extend existing research on the effect of domain expertise in search and suggest different strategies for exploiting domain expertise to support exploratory search in different knowledge domains.

A paradox of apparent brainless behavior: The time-course of compound word recognition

A review of the behavioral and neurophysiological estimates of the time-course of compound word recognition brings to light a paradox whereby temporal activity associated with lexical variables in behavioral studies predates temporal activity of seemingly comparable lexical processing in neuroimaging studies. However, under the assumption that brain activity is a cause of behavior, the earliest reliable behavioral effect of a lexical variable must represent an upper temporal bound for the origin of that effect in the neural record. The present research provides these behavioral bounds for lexical variables involved in compound word processing. We report data from five naturalistic reading studies in which participants read sentences containing English compound words, and apply a distributional technique of survival analysis to resulting eye-movement fixation durations (Reingold & Sheridan, 2014). The results of the survival analysis of the eye-movement record place a majority of the earliest discernible onsets of orthographic, morphological, and semantic effects at less than 200 ms (with a range of 138-269 ms). Our results place constraints on the absolute time-course of effects reported in the neurolinguistic literature, and support theories of complex word recognition which posit early simultaneous access of form and meaning.

Influences on and consequences of parafoveal preview in reading

During reading, information is extracted from upcoming words to the right of the currently fixated word, which facilitates recognition of those words when they are later fixated. According to the foveal load hypothesis (Henderson & Ferreira, 1990), this parafoveal preview benefit depends on how difficult the currently fixated word is to recognize. Furthermore, there is evidence that the influence of lexical variables (frequency and predictability) on word processing changes when no preview of that word is available. The present study reports two moving-window experiments in which the upcoming word to the right of fixation was either included in or excluded from the window. Through this manipulation, accurate parafoveal information was either available or not for each word in the paragraph. Two critical interactions between preview condition and lexical variables were observed. First, the word frequency at word N was found to be the primary influence on the amount of preview benefit obtained at word N+1, consistent with the foveal load hypothesis. Second, denial of preview eliminated the word predictability effect. These findings have implications for models of eye movement control in reading.

Survival analyses reveal how early phonological processing affects eye movements during reading

Numerous studies have provided evidence that readers generate phonological codes while reading. However, a central question in much of this research has been how early these codes are generated. Answering this question has implications for the roles that phonological coding might play for skilled readers, especially whether phonological codes affect the identification of most words, which can only be the case if these codes are generated rapidly. To investigate the time course of phonological coding during silent reading, the present series of experiments examined survival analyses of first-fixation durations on phonologically related (homophones, pseudohomophones) and orthographic control (orthographically matched words and nonwords) stimuli that were either embedded in sentences in place of correct targets (Experiments 1 and 2) or presented as parafoveal previews for correct targets using the boundary paradigm (Experiments 3 and 4). Survival analyses revealed a discernible difference between processing the phonologically related versus the orthographic control items by as early as 160 ms from the start of fixation on average (160-173 ms across experiments). Because only approximately 18% of first fixation durations were shorter than these mean estimates and follow-up tests revealed that earlier divergence point estimates were associated with shorter gaze durations (e.g., more rapid word identification), results suggest that skilled readers rapidly generate phonological codes during normal, silent reading and that these codes may affect the identification of most words. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The perception of text triggers reflexive oculomotor orienting

As you read this text, your brain is busy integrating numerous different processes-perceptual, cognitive and motor. While you acquire the semantic and linguistic contents of this abstract, your eyes traverse its lines with speed and coordination. The oculomotor response to text is so rapid and precise that it is hypothesized it to be partially based on reflexive orienting mechanisms. In this study we examined the hypothesis that the presentation of written text triggers reflexive orienting toward the direction of reading, similarly to the effect of peripheral stimulation or that of symbolic directional cues (arrows or gazing eyes). In three experiments, participants (N = 120) were presented with task-irrelevant text, shortly followed by a left/right pro-saccade task. The first experiment confirmed the hypothesis by showing that saccades which are congruent with the direction of reading are faster than those which are incongruent. This was observed both in right-to-left (Hebrew) and in left-to-right (English) reading-systems and similarly in native-Hebrew and native-English readers. A second experiment showed that this directional bias is found not only for readable text but also for meaningless strings of letters. This confirmed that the bias is driven pre-reading non-lexical processes. The third experiment examined the time-course of this effect. We conclude that text-perception actives early reflexive eye-movements programs and suggest that this link is an essential building-block of fast and effortless reading.

Using eye movements to understand the leakage of information during Chinese reading

How is attention allocated during reading? The present eye-movement experiment used a paradigm developed by Liu and Reichle (Psychological Science, 29, 278-287, 2018) to examine object-based attention during reading: Participants were instructed to read one of two spatially overlapping sentences containing colocated target/distractor words of varying frequency. Although target-word frequency modulated fixation-duration measures on the target word, the distractor-word frequency also had a smaller, independent effect. Survival analyses indicate that the distractor-word effect occurred later than the target-word effect, suggesting that subtle orthographic cues were noticed either later or occasionally, thereby modulating decisions about when to move the eyes. The theoretical ramifications of this "leakage" of information are discussed with respect to the general question of attention allocation during reading and possible differences between the reading of Chinese versus English.

Effects of aging, word frequency, and text stimulus quality on reading across the adult lifespan: Evidence from eye movements

Reductions in stimulus quality may disrupt the reading performance of older adults more when compared with young adults because of sensory declines that begin early in middle age. However, few studies have investigated adult age differences in the effects of stimulus quality on reading, and none have examined how this affects lexical processing and eye movement control. Accordingly, we report two experiments that examine the effects of reduced stimulus quality on the eye movements of young (18–24 years), middle-aged (41–51 years), and older (65+ years) adult readers. In Experiment 1, participants read sentences that contained a high- or low-frequency critical word and that were presented normally or with contrast reduced so that words appeared faint. Experiment 2 further investigated effects of reduced stimulus quality using a gaze-contingent technique to present upcoming text normally or with contrast reduced. Typical patterns of age-related reading difficulty (e.g., slower reading, more regressions) were observed in both experiments. In addition, eye movements were disrupted more for older than younger adults when all text (Experiment 1) or just upcoming text (Experiment 2) appeared faint. Moreover, there was an interaction between stimulus quality and word frequency (Experiment 1), such that readers fixated faint low-frequency words for disproportionately longer. Crucially, this effect was similar across all age groups. Thus, although older readers suffer more from reduced stimulus quality, this additional difficulty primarily affects their visual processing of text. These findings have important implications for understanding the role of stimulus quality on reading behavior across the lifespan.

Parafoveal preview effects from word N + 1 and word N + 2 during reading: A critical review and Bayesian meta-analysis

The use of gaze-contingent display techniques to study reading has shown that readers attend not only the currently fixated word, but also the word to the right of the current fixation. However, a critical look at the literature shows that a number of questions cannot be readily answered from the available literature reviews on the topic. First, there is no consensus as to whether readers also attend the second word to the right of fixation. Second, it is not clear whether parafoveal processing is more efficient in languages such as Chinese. Third, it is not well understood whether the measured effects are confounded by the properties of the parafoveal mask. In the present study, we addressed these issues by performing a Bayesian meta-analysis of 93 experiments that used the boundary paradigm (Rayner, Cognitive Psychology, 7, 65-81. doi: 10.1016/0010-028590005-5 , 1975). We describe three main findings: (1) The advantage of previewing the second word to the right is modest in size and likely is not centered on zero; (2) Chinese readers do seem to make more efficient use of parafoveal processing, but this is mostly evident in gaze durations; and (3) there are interference effects associated with using different parafoveal masks that roughly increase when the mask is less word-like.

Testing the limits of contextual constraint: Interactions with word frequency and parafoveal preview during fluent reading

Contextual constraint is a key factor affecting a word's fixation duration and its likelihood of being fixated during reading. Previous research has generally demonstrated additive effects of predictability and frequency in fixation times. Studies examining the role of parafoveal preview have shown that greater preview benefit is obtained from more predictable and higher frequency words versus less predictable and lower frequency words. In two experiments, we investigated effects of target word predictability, frequency and parafoveal preview. A 3 (Predictability: low, medium, high) × 2 (Frequency: low, high) design was used with Preview (valid, invalid) manipulated between experiments. With valid previews, we found main effects of Predictability and Frequency in both fixation time and fixation probability measures, including an interaction in early fixation measures. With invalid preview, we again found main effects of Predictability and Frequency in fixation times, but no evidence of an interaction. Fixation probability showed a weak Predictability effect and Predictability-Frequency interaction. Predictability interacted with Preview in early fixation time and fixation probability measures. Our findings suggest that high levels of contextual constraint exert an early influence during lexical processing in reading. Results are discussed in terms of models of language processing and eye movement control.

Exponentially Modified Peak Functions in Biomedical Sciences and Related Disciplines

In many cases relevant to biomedicine, a variable time, which features a certain distribution, is required for objects of interest to pass from an initial to an intermediate state, out of which they exit at random to a final state. In such cases, the distribution of variable times between exiting the initial and entering the final state must conform to the convolution of the first distribution and a negative exponential distribution. A common example is the exponentially modified Gaussian (EMG), which is widely used in chromatography for peak analysis and is long known as ex-Gaussian in psychophysiology, where it is applied to times from stimulus to response. In molecular and cell biology, EMG, compared with commonly used simple distributions, such as lognormal, gamma, and Wald, provides better fits to the variabilities of times between consecutive cell divisions and transcriptional bursts and has more straightforwardly interpreted parameters. However, since the range of definition of the Gaussian component of EMG is unlimited, data approximation with EMG may extend to the negative domain. This extension may seem negligible when the coefficient of variance of the Gaussian component is small but becomes considerable when the coefficient increases. Therefore, although in many cases an EMG may be an acceptable approximation of data, an exponentially modified nonnegative peak function, such as gamma-distribution, can make more sense in physical terms. In the present short review, EMG and exponentially modified gamma-distribution (EMGD) are discussed with regard to their applicability to data on cell cycle, gene expression, physiological responses to stimuli, and other cases, some of which may be interpreted as decision-making. In practical fitting terms, EMG and EMGD are equivalent in outperforming other functions; however, when the coefficient of variance of the Gaussian component of EMG is greater than ca. 0.4, EMGD is preferable.

Neural correlates of individual differences in fixation duration during natural reading

Reading requires integration of language and cognitive processes with attention and eye movement control. Individuals differ in their reading ability, but little is known about the neurocognitive processes associated with these individual differences. To investigate this issue, we combined eyetracking and fMRI, simultaneously recording eye movements and BOLD activity while subjects read text passages. We found that the variability and skew of fixation duration distributions across individuals, as assessed by ex-Gaussian analyses, decreased with increasing neural activity in regions associated with the cortical eye movement control network (Left FEF, Left IPS, Left IFG, and Right IFG). The results suggest that individual differences in fixation duration during reading are related to underlying neurocognitive processes associated with the eye movement control system and its relationship to language processing. The results also show that eye movements and fMRI can be combined to investigate the neural correlates of individual differences in natural reading.

The onset and time course of semantic priming during rapid recognition of visual words

In 2 experiments, we assessed the effects of response latency and task-induced goals on the onset and time course of semantic priming during rapid processing of visual words as revealed by ocular response tasks. In Experiment 1 (ocular lexical decision task), participants performed a lexical decision task using eye movement responses on a sequence of 4 words. In Experiment 2, the same words were encoded for an episodic recognition memory task that did not require a metalinguistic judgment. For both tasks, survival analyses showed that the earliest observable effect (divergence point [DP]) of semantic priming on target-word reading times occurred at approximately 260 ms, and ex-Gaussian distribution fits revealed that the magnitude of the priming effect increased as a function of response time. Together, these distributional effects of semantic priming suggest that the influence of the prime increases when target processing is more effortful. This effect does not require that the task include a metalinguistic judgment; manipulation of the task goals across experiments affected the overall response speed but not the location of the DP or the overall distributional pattern of the priming effect. These results are more readily explained as the result of a retrospective, rather than a prospective, priming mechanism and are consistent with compound-cue models of semantic priming. (PsycINFO Database Record

Surviving blind decomposition: A distributional analysis of the time-course of complex word recognition

The current study addresses a discrepancy in the psycholinguistic literature about the chronology of information processing during the visual recognition of morphologically complex words. Form-then-meaning accounts of complex word recognition claim that morphemes are processed as units of form prior to any influence of their meanings, whereas form-and-meaning models posit that recognition of complex word forms involves the simultaneous access of morphological and semantic information. The study reported here addresses this theoretical discrepancy by applying a nonparametric distributional technique of survival analysis (Reingold & Sheridan, 2014) to 2 behavioral measures of complex word processing. Across 7 experiments reported here, this technique is employed to estimate the point in time at which orthographic, morphological, and semantic variables exert their earliest discernible influence on lexical decision RTs and eye movement fixation durations. Contrary to form-then-meaning predictions, Experiments 1-4 reveal that surface frequency is the earliest lexical variable to exert a demonstrable influence on lexical decision RTs for English and Dutch derived words (e.g., badness; bad + ness), English pseudoderived words (e.g., wander; wand + er) and morphologically simple control words (e.g., ballad; ball + ad). Furthermore, for derived word processing across lexical decision and eye-tracking paradigms (Experiments 1-2; 5-7), semantic effects emerge early in the time-course of word recognition, and their effects either precede or emerge simultaneously with morphological effects. These results are not consistent with the premises of the form-then-meaning view of complex word recognition, but are convergent with a form-and-meaning account of complex word recognition. (PsycINFO Database Record

The Word Frequency Effect on Saccade Targeting during Chinese Reading: Evidence from a Survival Analysis of Saccade Length

Our study employs distributional analysis (i.e., survival analysis) to examine how the frequency of target words influences saccade lengths into and out of these target words in Chinese reading. The results of survival analysis indicate the survival curves in the high- and low-frequency conditions diverge for a short saccade length, with more than 80% of the lengths of incoming and outgoing saccades being larger than the divergence points. These results as well as simulations using the novel Dynamic-adjustment Model of saccadic targeting (Liu et al., 2016) are consistent with previous mean-based results and provide more precise information to support this novel model. The implications for saccade target selection during the reading of Chinese are discussed.

So Much to Read, So Little Time: How Do We Read, and Can Speed Reading Help?

The prospect of speed reading--reading at an increased speed without any loss of comprehension--has undeniable appeal. Speed reading has been an intriguing concept for decades, at least since Evelyn Wood introduced her Reading Dynamics training program in 1959. It has recently increased in popularity, with speed-reading apps and technologies being introduced for smartphones and digital devices. The current article reviews what the scientific community knows about the reading process--a great deal--and discusses the implications of the research findings for potential students of speed-reading training programs or purchasers of speed-reading apps. The research shows that there is a trade-off between speed and accuracy. It is unlikely that readers will be able to double or triple their reading speeds (e.g., from around 250 to 500-750 words per minute) while still being able to understand the text as well as if they read at normal speed. If a thorough understanding of the text is not the reader's goal, then speed reading or skimming the text will allow the reader to get through it faster with moderate comprehension. The way to maintain high comprehension and get through text faster is to practice reading and to become a more skilled language user (e.g., through increased vocabulary). This is because language skill is at the heart of reading speed.

Drivers' Visual Search Patterns during Overtaking Maneuvers on Freeway

Drivers gather traffic information primarily by means of their vision. Especially during complicated maneuvers, such as overtaking, they need to perceive a variety of characteristics including the lateral and longitudinal distances with other vehicles, the speed of others vehicles, lane occupancy, and so on, to avoid crashes. The primary object of this study is to examine the appropriate visual search patterns during overtaking maneuvers on freeways. We designed a series of driving simulating experiments in which the type and speed of the leading vehicle were considered as two influential factors. One hundred and forty participants took part in the study. The participants overtook the leading vehicles just like they would usually do so, and their eye movements were collected by use of the Eye Tracker. The results show that participants' gaze durations and saccade durations followed normal distribution patterns and that saccade angles followed a log-normal distribution pattern. It was observed that the type of leading vehicle significantly impacted the drivers' gaze duration and gaze frequency. As the speed of a leading vehicle increased, subjects' saccade durations became longer and saccade angles became larger. In addition, the initial and destination lanes were found to be key areas with the highest visual allocating proportion, accounting for more than 65% of total visual allocation. Subjects tended to more frequently shift their viewpoints between the initial lane and destination lane in order to search for crucial traffic information. However, they seldom directly shifted their viewpoints between the two wing mirrors.

The word frequency effect during sentence reading: A linear or nonlinear effect of log frequency?

The effect of word frequency on eye movement behaviour during reading has been reported in many experimental studies. However, the vast majority of these studies compared only two levels of word frequency (high and low). Here we assess whether the effect of log word frequency on eye movement measures is linear, in an experiment in which a critical target word in each sentence was at one of three approximately equally spaced log frequency levels. Separate analyses treated log frequency as a categorical or a continuous predictor. Both analyses showed only a linear effect of log frequency on the likelihood of skipping a word, and on first fixation duration. Ex-Gaussian analyses of first fixation duration showed similar effects on distributional parameters in comparing high- and medium-frequency words, and medium- and low-frequency words. Analyses of gaze duration and the probability of a refixation suggested a nonlinear pattern, with a larger effect at the lower end of the log frequency scale. However, the nonlinear effects were small, and Bayes Factor analyses favoured the simpler linear models for all measures. The possible roles of lexical and post-lexical factors in producing nonlinear effects of log word frequency during sentence reading are discussed.

Reversed preview benefit effects: Forced fixations emphasize the importance of parafoveal vision for efficient reading

Current theories of eye movement control in reading posit that processing of an upcoming parafoveal preview word is used to facilitate processing of that word once it is fixated (i.e., as a foveal target word). This preview benefit is demonstrated by shorter fixation durations in the case of valid (i.e., identical or linguistically similar) compared with invalid (i.e., dissimilar) preview conditions. However, we suggest that processing of the preview can directly influence fixation behavior on the target, independent of similarity between them. In Experiment 1, unrelated high and low frequency words were used as orthogonally crossed previews and targets and we observed a reversed preview benefit for low frequency targets-shorter fixation durations with an invalid, higher frequency preview compared with a valid, low frequency preview. In Experiment 2, the target words were replaced with orthographically legal and illegal nonwords and we found a similar effect of preview frequency on fixation durations on the targets, as well as a bimodal distribution in the illegal nonword target conditions with a denser early peak for high than low frequency previews. In Experiment 3, nonwords were used as previews for high and low frequency targets, replicating standard findings that "denied" preview increases fixation durations and the influence of target properties. These effects can be explained by forced fixations, cases in which fixations on the target were shortened as a consequence of the timing of word recognition of the preview relative to the time course of saccade programming to that word from the prior one. That is, the preview word was (at least partially) recognized so that it should have been skipped, but the word could not be skipped because the saccade to that word was in a nonlabile stage. In these cases, the system preinitiates the subsequent saccade off the upcoming word to the following word and the intervening fixation is short. (PsycINFO Database Record

Dissociating parafoveal preview benefit and parafovea-on-fovea effects during reading: A combined eye tracking and EEG study

During reading, the parafoveal processing of an upcoming word n+1 can influence word recognition in two ways: It can affect fixation behavior during the preceding fixation on word n (parafovea-on-fovea effect, POF), and it can facilitate subsequent foveal processing once word n+1 is fixated (preview benefit). While preview benefits are established, evidence for POF effects is mixed. Recently, it has been suggested that POF effects exist, but have a delayed impact on saccade planning and thus coincide with preview benefits measured on word n+1. We combined eye movement and EEG recordings to investigate and separate neural correlates of POF and preview benefit effects. Participants read lists of nouns either in a boundary paradigm or the RSVP-with-flankers paradigm, while we recorded fixation- or event-related potentials (FRPs/ERPs), respectively. The validity and lexical frequency of the word shown as preview for the upcoming word n+1 were orthogonally manipulated. Analyses focused on the first fixation on word n+1. Preview validity (correct vs. incorrect preview) strongly modulated fixation times and electrophysiological N1 amplitudes, replicating previous findings. Importantly, gaze durations and FRPs measured on word n+1 were also affected by the frequency of the word shown as preview, with low-frequency previews eliciting a sustained, N400-like centroparietal negativity. Results support the idea that POF effects exist but affect word recognition with a delay. Lastly, once word n+1 was fixated, its frequency also modulated N1 amplitudes in ERPs and FRPs. Taken together, we separated immediate and delayed effects of parafoveal processing on brain correlates of word recognition.

Parafoveal preview effects from word N + 1 and word N + 2 during reading: A critical review and Bayesian meta-analysis

The use of gaze-contingent display techniques to study reading has shown that readers attend not only the currently fixated word, but also the word to the right of the current fixation. However, a critical look at the literature shows that a number of questions cannot be readily answered from the available literature reviews on the topic. First, there is no consensus as to whether readers also attend the second word to the right of fixation. Second, it is not clear whether parafoveal processing is more efficient in languages such as Chinese. Third, it is not well understood whether the measured effects are confounded by the properties of the parafoveal mask. In the present study, we addressed these issues by performing a Bayesian meta-analysis of 93 experiments that used the boundary paradigm (Rayner, Cognitive Psychology, 7, 65-81. doi: 10.1016/0010-028590005-5 , 1975). We describe three main findings: (1) The advantage of previewing the second word to the right is modest in size and likely is not centered on zero; (2) Chinese readers do seem to make more efficient use of parafoveal processing, but this is mostly evident in gaze durations; and (3) there are interference effects associated with using different parafoveal masks that roughly increase when the mask is less word-like.