Single Fixation Durations Research Articles

Semantic feature activation takes time: longer SOA elicits earlier priming effects during reading.

While most previous studies of “semantic” priming confound associative and semantic relations, here we use a simple co-occurrence-based approach to examine “pure” semantic priming, while experimentally controlling for associative relations. We define associative relations by the co-occurrence of words in the sentences of a large text corpus. Contextual-semantic feature overlap, in contrast, is defined by the number of common associates that the prime shares with the target. Then we revisit the spreading activation theory and examine whether a long vs. short time available for semantic feature activation leads to early vs. late viewing time effects on the target words of a sentence reading experiment. We independently manipulate contextual-semantic feature overlap of two primes with one target word in sentences of the form pronoun, verb prime, article, adjective prime and target noun, e. g., "She rides the gray elephant." The results showed that long-SOA (verb-noun) overlap reduces early single and first fixation durations of the target noun, and short-SOA (adjective-noun) overlap reduces late go-past durations. This result pattern can be explained by the spreading activation theory: The semantic features of the prime words need some time to become sufficiently active before they can reliably affect target processing. Therefore, the verb can act on the target noun's early eye-movement measures presented three words later, while the adjective is presented immediately prior to the target—thus a difficult adjective-noun semantic integration leads to a late sentence re-examination of the preceding words.

Language Models Explain Word Reading Times Better Than Empirical Predictability.

Though there is a strong consensus that word length and frequency are the most important single-word features determining visual-orthographic access to the mental lexicon, there is less agreement as how to best capture syntactic and semantic factors. The traditional approach in cognitive reading research assumes that word predictability from sentence context is best captured by cloze completion probability (CCP) derived from human performance data. We review recent research suggesting that probabilistic language models provide deeper explanations for syntactic and semantic effects than CCP. Then we compare CCP with three probabilistic language models for predicting word viewing times in an English and a German eye tracking sample: (1) Symbolic n-gram models consolidate syntactic and semantic short-range relations by computing the probability of a word to occur, given two preceding words. (2) Topic models rely on subsymbolic representations to capture long-range semantic similarity by word co-occurrence counts in documents. (3) In recurrent neural networks (RNNs), the subsymbolic units are trained to predict the next word, given all preceding words in the sentences. To examine lexical retrieval, these models were used to predict single fixation durations and gaze durations to capture rapidly successful and standard lexical access, and total viewing time to capture late semantic integration. The linear item-level analyses showed greater correlations of all language models with all eye-movement measures than CCP. Then we examined non-linear relations between the different types of predictability and the reading times using generalized additive models. N-gram and RNN probabilities of the present word more consistently predicted reading performance compared with topic models or CCP. For the effects of last-word probability on current-word viewing times, we obtained the best results with n-gram models. Such count-based models seem to best capture short-range access that is still underway when the eyes move on to the subsequent word. The prediction-trained RNN models, in contrast, better predicted early preprocessing of the next word. In sum, our results demonstrate that the different language models account for differential cognitive processes during reading. We discuss these algorithmically concrete blueprints of lexical consolidation as theoretically deep explanations for human reading.

Eye movement control in Turkish sentence reading.

Reading requires the assembly of cognitive processes across a wide spectrum from low-level visual perception to high-level discourse comprehension. One approach of unravelling the dynamics associated with these processes is to determine how eye movements are influenced by the characteristics of the text, in particular which features of the words within the perceptual span maximise the information intake due to foveal, spillover, parafoveal, and predictive processing. One way to test the generalisability of current proposals of such distributed processing is to examine them across different languages. For Turkish, an agglutinative language with a shallow orthography-phonology mapping, we replicate the well-known canonical main effects of frequency and predictability of the fixated word as well as effects of incoming saccade amplitude and fixation location within the word on single-fixation durations with data from 35 adults reading 120 nine-word sentences. Evidence for previously reported effects of the characteristics of neighbouring words and interactions was mixed. There was no evidence for the expected Turkish-specific morphological effect of the number of inflectional suffixes on single-fixation durations. To control for word-selection bias associated with single-fixation durations, we also tested effects on word skipping, single-fixation, and multiple-fixation cases with a base-line category logit model, assuming an increase of difficulty for an increase in the number of fixations. With this model, significant effects of word characteristics and number of inflectional suffixes of foveal word on probabilities of the number of fixations were observed, while the effects of the characteristics of neighbouring words and interactions were mixed.

Word Frequency Effect in Middle and High School Students: Reading Characteristics of School-Age Using Eye tracking

안구운동추적 기법은 자연스러운 글읽기 과정 중에 이해 처리의 양상을 객관적으로 측정한다는 점에서 읽기 숙련도에 따른 발달적 특성을 파악하는데 의미 있게 활용될 수 있다. 본 연구는 글읽기의 기본 단위라 할 수 있는 단어 수준의 처리 과정을 살펴볼 수 있는 대표적인 변인으로 단어 빈도 효과를 다루었다. 일반 중학생 14명과 고등학생 20명이 연구에 참가하였으며, 실험 자극은 3음절의 고/저빈도 단어를 포함된 문장으로 빈도 외의 요소는 두 조건이 동일하도록 통제하였다. 표적 영역에서 발생한 고정 시간 및 고정 수 에 대한 분석 결과, 두 집단 모두에서 단어 빈도 효과가 확인되었다. 본 연구 결과는 안구운동추적을 통해 읽기 기술이 발달 중인 일반 중고등학생의 문장 처리 특성을 살펴봄으로써 추후 연령을 비롯한 읽기 수준에 따른 글이해 과정의 차이를 알아보기 위한 경험적 토대를 마련하였다는데 의의가 있다.Eye movement data afford researchers valuable temporal information about exactly when in the reading record a given manipulated variable has an effect. One advantage of using eye movements is data are collected online during silent reading; therefore, they are uncontaminated by memory demands, articulation processes, or conscious strategies. In the present study, the eye movements are measured during Korean-speaking middle and high school students’ silent reading tasks. To investigate the word frequency effects, the study employs controlled sentence frames with embedded target words in an experimental design. Word frequency effects are interesting because they can demonstrate if less skilled readers’ mental lexicons are organized according to the same criteria as those of adults. For direct comparison, the participants read 36 experimental sentences using Koh et al.’s (2008) study that contains target words manipulated for high vs. low frequency. The word frequency effects are observed, with significant effects seen in single-fixation duration (cases where only a single fixation is made on a target) and total viewing time (all fixations on a target) eye movement measures. These results indicate that linguistic influences are primary in driving eye movements during reading for middle and high school students. This study suggests that further research should investigate the developmental trend in relationship to chronological age and reading ability. As the understanding of less skilled readers’ eye movement behavior while reading increases, measuring eye movements offers a promising approach to charting individual differences in reading.

Pattern of reading eye movements during monovision contact lens wear in presbyopes

Monovision can be used as a method to correct presbyopia with contact lenses (CL) but its effect on reading behavior is still poorly understood. In this study eye movements (EM) were recorded in fifteen presbyopic participants, naïve to monovision, whilst they read arrays of words, non-words, and text passages to assess whether monovision affected their reading. Three conditions were compared, using daily disposable CLs: baseline (near correction in both eyes), conventional monovision (distance correction in the dominant eye, near correction in the non-dominant eye), and crossed monovision (the reversal of conventional monovision). Behavioral measures (reading speed and accuracy) and EM parameters (single fixation duration, number of fixations, dwell time per item, percentage of regressions, and percentage of skipped items) were analyzed. When reading passages, no differences in behavioral and EM measures were seen in any comparison of the three conditions. The number of fixations and dwell time significantly increased for both monovision and crossed monovision with respect to baseline only with word and non-word arrays. It appears that monovision did not appreciably alter visual processing when reading meaningful texts but some limited stress of the EM pattern was observed only with arrays of unrelated or meaningless items under monovision, which require the reader to have more in-depth controlled visual processing.

How radiographers visually perceive X-ray images with the task of accepting or rejecting them – a pilot study

Introduction: Radiographer´s usual role in the medical imaging chain is to acquire relevant and qualitatively good images that help the radiologist or physician to diagnose most accurately. After the image acquisition, the radiographer does a quality evaluation based on established imaging criteria to decide if the image is satisfactory, or otherwise reject it and subsequently take a new one. Contrary to expectations that the number of image rejects should decrease substantially with the introduction of digital imaging, a number of studies have shown that it has not, although the reasons for rejects has changed from exposure errors to positioning and centring errors. Very little research has been on examining how radiographers visually perceive and evaluate the X-ray images in this acceptance/rejection process.Purpose: Investigate how radiographers and radiography students visually perceives X-ray images in the process of accepting or rejecting them on basis of radiographic imaging criteria, and see if there are differences in strategies across experience levels.Materials and methods: Three radiography students and five radiographers with varying years of experience were given the task of accepting or rejecting shoulder and knee projection images based on positioning criteria. Using eye tracking, we measured the participants’ number and duration of gaze fixations within 1) the field of view defined by the monitor display, 2) the part of the monitor displaying the X-ray image only, and 3) the region within the X-ray images considered to be most relevant given the imaging criteria task. The quantitative eye-tracking measurements were followed-up by four qualitative questions.Results: Some differences in fixation patterns between the groups were found; the medium experienced radiographers spent statistically significant lesser number of fixations and lesser average single fixation durations than both the radiography students and the most experienced radiographers did, whereas the two latter groups scored almost equally. Conclusion: The study revealed that work experience might have some influence on how radiographers and radiography students assess X-ray images, but in subtler ways than expected. The study also revealed, however, quite large individual differences across experience.

An eye movement corpus study of the age-of-acquisition effect.

In the present study, we investigated the effects of word-level age of acquisition (AoA) on natural reading. Previous studies, using multiple language modalities, showed that earlier-learned words are recognized, read, spoken, and responded to faster than words learned later in life. Until now, in visual word recognition the experimental materials were limited to single-word or sentence studies. We analyzed the data of the Ghent Eye-tracking Corpus (GECO; Cop, Dirix, Drieghe, & Duyck, in press), an eyetracking corpus of participants reading an entire novel, resulting in the first eye movement megastudy of AoA effects in natural reading. We found that the ages at which specific words were learned indeed influenced reading times, above other important (correlated) lexical variables, such as word frequency and length. Shorter fixations for earlier-learned words were consistently found throughout the reading process, in both early (single-fixation durations, first-fixation durations, gaze durations) and late (total reading times) measures. Implications for theoretical accounts of AoA effects and eye movements are discussed.

Evidence for a global oculomotor program in reading.

Recent corpus studies of eye-movements in reading revealed a substantial increase in saccade amplitudes and fixation durations as the eyes move over the first words of a sentence. This start-up effect suggests a global oculomotor program, which operates on the level of an entire line, in addition to the well-established local programs operating within the visual span. The present study investigates the nature of this global program experimentally and examines whether the start-up effect is predicated on generic visual or specific linguistic characteristics and whether it is mainly reflected in saccade amplitudes, fixation durations or both measures. Eye movements were recorded while 38 participants read (a) normal sentences, (b) sequences of randomly shuffled words and (c) sequences of z-strings. The stimuli were, therefore, similar in their visual features, but varied in the amount of syntactic and lexical information. Further, the stimuli were composed of words or strings that either varied naturally in length (Nonequal condition) or were all restricted to a specific length within a sentence (Equal). The latter condition constrained the variability of saccades and served to dissociate effects of word position in line on saccade amplitudes and fixation durations. A robust start-up effect emerged in saccade amplitudes in all Nonequal stimuli, and-in an attenuated form-in Equal sentences. A start-up effect in single fixation durations was observed in Nonequal and Equal normal sentences, but not in z-strings. These findings support the notion of a global oculomotor program in reading particularly for the spatial characteristics of motor planning, which rely on visual rather than linguistic information.

Child readers’ eye movements in reading Thai

It has recently been found that adult native readers of Thai, an alphabetic scriptio continua language, engage similar oculomotor patterns as readers of languages written with spaces between words; despite the lack of inter-word spaces, first and last characters of a word appear to guide optimal placement of Thai readers’ eye movements, just to the left of word-centre. The issue addressed by the research described here is whether eye movements of Thai children also show these oculomotor patterns. Here the effect of first and last character frequency and word frequency on the eye movements of 18 Thai children when silently reading normal unspaced and spaced text was investigated. Linear mixed-effects model analyses of viewing time measures (first fixation duration, single fixation duration, and gaze duration) and of landing site location revealed that Thai children’s eye movement patterns were similar to their adult counterparts. Both first character frequency and word frequency played important roles in Thai children’s landing sites; children tended to land their eyes further into words, close to the word centre, if the word began with higher frequency first characters, and this effect was facilitated in higher frequency words. Spacing also facilitated more effective use of first character frequency and it also assisted in decreasing children’s viewing time. The use of last-character frequency appeared to be a later development, affecting mainly single fixation duration and gaze duration. In general, Thai children use the same oculomotor control mechanisms in reading spaced and unspaced texts as Thai adults, who in turn have similar oculomotor control as readers of spaced texts. Thus, it appears that eye movements in reading converge on the optimal landing site using whatever cues are available to guide such placement.

The eye-voice span during reading aloud.

Although eye movements during reading are modulated by cognitive processing demands, they also reflect visual sampling of the input, and possibly preparation of output for speech or the inner voice. By simultaneously recording eye movements and the voice during reading aloud, we obtained an output measure that constrains the length of time spent on cognitive processing. Here we investigate the dynamics of the eye-voice span (EVS), the distance between eye and voice. We show that the EVS is regulated immediately during fixation of a word by either increasing fixation duration or programming a regressive eye movement against the reading direction. EVS size at the beginning of a fixation was positively correlated with the likelihood of regressions and refixations. Regression probability was further increased if the EVS was still large at the end of a fixation: if adjustment of fixation duration did not sufficiently reduce the EVS during a fixation, then a regression rather than a refixation followed with high probability. We further show that the EVS can help understand cognitive influences on fixation duration during reading: in mixed model analyses, the EVS was a stronger predictor of fixation durations than either word frequency or word length. The EVS modulated the influence of several other predictors on single fixation durations (SFDs). For example, word-N frequency effects were larger with a large EVS, especially when word N-1 frequency was low. Finally, a comparison of SFDs during oral and silent reading showed that reading is governed by similar principles in both reading modes, although EVS maintenance and articulatory processing also cause some differences. In summary, the EVS is regulated by adjusting fixation duration and/or by programming a regressive eye movement when the EVS gets too large. Overall, the EVS appears to be directly related to updating of the working memory buffer during reading.

Frequency effects in monolingual and bilingual natural reading.

This paper presents the first systematic examination of the monolingual and bilingual frequency effect (FE) during natural reading. We analyzed single fixation durations on content words for participants reading an entire novel. Unbalanced bilinguals and monolinguals show a similarly sized FE in their mother tongue (L1), but for bilinguals the FE is considerably larger in their second language (L2) than in their L1. The FE in both L1 and L2 reading decreased with increasing L1 proficiency, but it was not affected by L2 proficiency. Our results are consistent with an account of bilingual language processing that assumes an integrated mental lexicon with exposure as the main determiner for lexical entrenchment. This means that no qualitative difference in language processing between monolingual, bilingual L1, or bilingual L2 is necessary to explain reading behavior. We present this account and argue that not all groups of bilinguals necessarily have lower L1 exposure than monolinguals do and, in line with Kuperman and Van Dyke (Journal of Experimental Psychology, 39 (3), 802-823, 2013), that individual vocabulary size and language exposure change the accuracy of the relative corpus word frequencies and thereby determine the size of the FEs in the same way for all participants.

Eye movements during reading and topic scanning: effects of word frequency.

The study examined the nature of eye movement control and word recognition during scanning for a specific topic, compared with reading for comprehension. Experimental trials included a manipulation of word frequency: the critical word was frequent (and orthographically familiar) or infrequent (2 conditions: orthographically familiar and orthographically unfamiliar). First-pass reading times showed effects of word frequency for both reading and scanning, with no interactions between word characteristics and task. Therefore, in contrast to the task of searching for a single specific word (Rayner & Fischer, 1996), there were immediate and localized influences of lexical processing when scanning for a specific topic, indicating that early word recognition processes are similar during reading and topic scanning. In contrast, there were interactions for later measures, with larger effects of word frequency during reading than scanning, indicating that reading goals can modulate later processes such as the integration of words into sentence context. Additional analyses of the distribution of first-pass single fixation durations indicated that first-pass fixations of all durations were shortened during scanning compared with reading, and reading for comprehension produced a larger subset of longer first-pass fixations compared with scanning. The implications for the nature of word recognition and eye movement control are discussed.

Word frequency in fast priming: Evidence for immediate cognitive control of eye movements during reading

Numerous studies have demonstrated effects of word frequency on eye movements during reading, but the precise timing of this influence has remained unclear. The fast priming paradigm was previously used to study influences of related versus unrelated primes on the target word. Here, we use this procedure to investigate whether the frequency of the prime word has a direct influence on eye movements during reading when the prime–target relation is not manipulated. We found that with average prime intervals of 32 ms readers made longer single fixation durations on the target word in the low than in the high frequency prime condition. Distributional analyses demonstrated that the effect of prime frequency on single fixation durations occurred very early, supporting theories of immediate cognitive control of eye movements. Finding prime frequency effects only 207 ms after visibility of the prime and for prime durations of 32 ms yields new time constraints for cognitive processes controlling eye movements during reading. Our variant of the fast priming paradigm provides a new approach to test early influences of word processing on eye movement control during reading.

The Adaptive Nature of Eye Movements in Linguistic Tasks: How Payoff and Architecture Shape Speed‐Accuracy Trade‐Offs

We explore the idea that eye-movement strategies in reading are precisely adapted to the joint constraints of task structure, task payoff, and processing architecture. We present a model of saccadic control that separates a parametric control policy space from a parametric machine architecture, the latter based on a small set of assumptions derived from research on eye movements in reading (Engbert, Nuthmann, Richter, & Kliegl, 2005; Reichle, Warren, & McConnell, 2009). The eye-control model is embedded in a decision architecture (a machine and policy space) that is capable of performing a simple linguistic task integrating information across saccades. Model predictions are derived by jointly optimizing the control of eye movements and task decisions under payoffs that quantitatively express different desired speed-accuracy trade-offs. The model yields distinct eye-movement predictions for the same task under different payoffs, including single-fixation durations, frequency effects, accuracy effects, and list position effects, and their modulation by task payoff. The predictions are compared to-and found to accord with-eye-movement data obtained from human participants performing the same task under the same payoffs, but they are found not to accord as well when the assumptions concerning payoff optimization and processing architecture are varied. These results extend work on rational analysis of oculomotor control and adaptation of reading strategy (Bicknell & Levy, ; McConkie, Rayner, & Wilson, 1973; Norris, 2009; Wotschack, 2009) by providing evidence for adaptation at low levels of saccadic control that is shaped by quantitatively varying task demands and the dynamics of processing architecture.

Eye movements while reading an unspaced writing system: The case of Thai

Thai has an alphabetic script with a distinctive feature - it has no spaces between words. Since previous research with spaced alphabetic systems (e.g., English) has suggested that readers use spaces to guide eye movements, it is of interest to investigate what physical factors might guide Thai readers' eye movements. Here the effects of word-initial and word-final position-specific character frequency, word-boundary bigram frequency, and overall word frequency on 30 Thai adults' eye movements when reading unspaced and spaced text was investigated. Linear mixed-effects model analyses of viewing time measures (first fixation duration, single fixation duration, and gaze duration) and of landing sites were conducted. Thai readers tended to land their first fixation at or near the centre of words, just as readers of spaced texts do. A critical determinant of this was word boundary characters: higher position-specific frequency of initial and of final characters significantly facilitated landing sites closer to the word centre while word-boundary bigram frequency appeared to behave as a proxy for initial and final position-specific character frequency. It appears, therefore, that Thai readers make use of the position-specific frequencies of word boundary characters in targeting words and directing eye movements to an optimal landing site.

Review of Eye-movement Measures in Reading Research

Saccade and fixation are the elementary ocularmotor activities during reading.The eye-movement measures in reading research can be classified into two different categories.One category is temporal dimension measure related to the time course of eye movements and it includes the measures in area of interest of character or word(such as single fixation duration,first fixation duration,second fixation duration,gaze duration,regression time and total fixation duration and so on.) and the measures in area of interest of phrase or sentence(such as first-pass reading time,forward reading time,second-pass reading time,regression path reading time,re-reading time and so on.).The other category is spatial dimension measure related to the location of eye movement and it includes saccade amplitude,landing position,number of fixations,skipping rate,refixation rate and regression count.Finally,when using the eye movement measures we should pay attention to the classification of oculomotor measures,the cutoff criterion of raw data,the psychological interpretation of the measures and so on.

How preview space/time translates into preview cost/benefit for fixation durations during reading

Eye-movement control during reading depends on foveal and parafoveal information. If the parafoveal preview of the next word is suppressed, reading is less efficient. A linear mixed model (LMM) reanalysis of McDonald (2006) confirmed his observation that preview benefit may be limited to parafoveal words that have been selected as the saccade target. Going beyond the original analyses, in the same LMM, we examined how the preview effect (i.e., the difference in single-fixation duration, SFD, between random-letter and identical preview) depends on the gaze duration on the pretarget word and on the amplitude of the saccade moving the eye onto the target word. There were two key results: (a) The shorter the saccade amplitude (i.e., the larger preview space), the shorter a subsequent SFD with an identical preview; this association was not observed with a random-letter preview. (b) However, the longer the gaze duration on the pretarget word, the longer the subsequent SFD on the target, with the difference between random-letter string and identical previews increasing with preview time. A third pattern-increasing cost of a random-letter string in the parafovea associated with shorter saccade amplitudes-was observed for target gaze durations. Thus, LMMs revealed that preview effects, which are typically summarized under "preview benefit", are a complex mixture of preview cost and preview benefit and vary with preview space and preview time. The consequence for reading is that parafoveal preview may not only facilitate, but also interfere with lexical access.

Sentence context modifies compound word recognition: Evidence from eye movements

Two eye movement experiments are reported that examine the influence of sentence context on morphological processing. English compound words which vary in beginning lexeme frequency (Experiment 1) and ending lexeme frequency (Experiment 2) were embedded into sentence contexts that were either predictive of the compound word or were neutral with respect to the compound. A predictable sentence context reduced the effect of beginning lexeme frequency on first fixation and single fixation durations. However, sentence context did not modify effects of beginning and ending lexeme frequency in later fixation measures. These results further support the theoretical position that morphology plays a role at multiple levels within readers' mental lexicons. In addition, these results suggest that access to early morpho-orthographic processes can be influenced by sentence context, a finding that suggests an interactive relationship between sentence context and word recognition.

Aging, parafoveal preview, and semantic integration in sentence processing: Testing the cognitive workload of wrap-up.

The current study investigated the degree to which semantic-integration processes ("wrap-up") during sentence understanding demand attentional resources by examining the effects of clause and sentence wrap-up on the parafoveal preview benefit (PPB) in younger and older adults. The PPB is defined as facilitation in processing word N + 1, based on information extracted while the eyes are fixated on word N, and is known to be reduced by processing difficulty at word N. Participants read passages in which word N occurred in a sentence-internal, clause-final, or sentence-final position, and a gaze-contingent boundary-change paradigm was used to manipulate the information available in parafoveal vision for word N + 1. Wrap-up effects were found on word N for both younger and older adults. Early-pass measures (first-fixation duration and single-fixation duration) of the PPB on word N + 1 were reduced by clause wrap-up and sentence wrap-up on word N, with similar effects for younger and older adults. However, for intermediate (gaze duration) and later-pass measures (regression-path duration, and selective regression-path duration), sentence wrap-up (but not clause wrap-up) on word N differentially reduced the PPB of word N + 1 for older adults. These findings suggest that wrap-up is demanding and may be less efficient with advancing age, resulting in a greater cognitive processing load for older readers.

Word-Initial Letters Influence Fixation Durations during Fluent Reading

The present study examined how word-initial letters influence lexical access during reading. Eye movements were monitored as participants read sentences containing target words. Three factors were independently manipulated. First, target words had either high or low constraining word-initial letter sequences (e.g., dwarf or clown, respectively). Second, targets were either high or low in frequency of occurrence (e.g., train or stain, respectively). Third, targets were embedded in either biasing or neutral contexts (i.e., targets were high or low in their predictability). This 2 (constraint) × 2 (frequency) × 2 (context) design allowed us to examine the conditions under which a word’s initial letter sequence could facilitate processing. Analyses of fixation duration data revealed significant main effects of constraint, frequency, and context. Moreover, in measures taken to reflect “early” lexical processing (i.e., first and single fixation duration), there was a significant interaction between constraint and context. The overall pattern of findings suggests lexical access is facilitated by highly constraining word-initial letters. Results are discussed in comparison to recent studies of lexical features involved in word recognition during reading.