Dual Input Stream Transformer for Vertical Drift Correction in Eye-tracking Reading Data.

We introduce a novel Dual Input Stream Transformer (DIST) for the challenging problem of assigning fixation points from eye-tracking data collected during passage reading to the line of text that the reader was actually focused on. This post-processing step is crucial for analysis of the reading data due to the presence of noise in the form of vertical drift. We evaluate DIST against eleven classical approaches on a comprehensive suite of nine diverse datasets. We demonstrate that combining multiple instances of the DIST model in an ensemble achieves high accuracy across all datasets. Further combining the DIST ensemble with the best classical approach yields an average accuracy of 98.17 %. Our approach presents a significant step towards addressing the bottleneck of manual line assignment in reading research. Through extensive analysis and ablation studies, we identify key factors that contribute to DIST's success, including the incorporation of line overlap features and the use of a second input stream. Via rigorous evaluation, we demonstrate that DIST is robust to various experimental setups, making it a safe first choice for practitioners in the field.

Processing difficulty while reading words with neighbors is not due to increased foveal load: Evidence from eye movements.

Words with high orthographic relatedness are termed "word neighbors" (angle/angel; birch/birth). Activation-based models of word recognition assume that lateral inhibition occurs between words and their activated neighbors. However, studies of eye movements during reading have not found inhibitory effects in early measures assumed to reflect lexical access (e.g., gaze duration). Instead, inhibition in eye-movement studies has been found in later measures of processing (e.g., total time, regressions in). We conducted an eye-movement boundary change study (Rayner, Cognitive Psychology, 7(1), 65-81, 1975) that manipulated the parafoveal preview of the word following the neighbor word (word N+1). In this way, we explored whether the late inhibitory effects seen with transposed letter words and words with higher-frequency neighbors result from reduced parafoveal preview due to increased foveal load and/or interference during late stages of lexical processing (the L2 stage within the E-Z Reader framework). For word N+1, while there were clear preview effects, there was not an effect of the neighborhood status of word N, nor a significant interaction. This suggests that the late inhibitory effects of earlier eye-movement studies are driven by misidentification of neighbor words rather than being due to increased foveal load.

Age-related changes in visual encoding strategy preferences during a spatial memory task.

Ageing is associated with declines in spatial memory, however, the source of these deficits remains unclear. Here we used eye-tracking to investigate age-related differences in spatial encoding strategies and the cognitive processes underlying the age-related deficits in spatial memory tasks. To do so we asked young and older participants to encode the locations of objects in a virtual room shown as a picture on a computer screen. The availability and utility of room-based landmarks were manipulated by removing landmarks, presenting identical landmarks rendering them uninformative, or by presenting unique landmarks that could be used to encode object locations. In the test phase, participants viewed a second picture of the same room taken from the same (0°) or a different perspective (30°) and judged whether the objects occupied the same or different locations in the room. We found that the introduction of a perspective shift and swapping of objects between encoding and testing impaired performance in both age groups. Furthermore, our results revealed that although older adults performed the task as well as younger participants, they relied on different visual encoding strategies to solve the task. Specifically, gaze analysis revealed that older adults showed a greater preference towards a more categorical encoding strategy in which they formed relationships between objects and landmarks.

Sentence context modulates the neighborhood frequency effect in Chinese reading: Evidence from eye movements.

In the current study, we conducted 2 eye-tracking reading experiments to explore whether sentence context can influence neighbor effects in word recognition during Chinese reading. Chinese readers read sentences in which the targets' orthographic neighbors were either plausible or implausible with the pretarget context. The results revealed that the neighbor effect was influenced by context: The context in the biased condition (where only targets but not neighbors can fit in the pretarget context) evoked a significantly weaker inhibitory neighbor effect than in the neutral condition (where both targets and neighbors can fit in the pretarget context). These results indicate that contextual information can be used to modulate neighbor effects during online sentence reading in Chinese. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Return-sweep saccades in oral reading.

Recent research on return-sweep saccades has improved our understanding of eye movements when reading paragraphs. However, these saccades, which take our gaze from the end of one line to the start of the next line, have been studied only within the context of silent reading. Articulatory demands and the coordination of the eye-voice span (EVS) at line boundaries suggest that the execution of this saccade may be different in oral reading. We compared launch and landing positions of return-sweeps, corrective saccade probability and fixations adjacent to return-sweeps in skilled adult readers while reading paragraphs aloud and silently. Compared to silent reading, return-sweeps were launched from closer to the end of the line and landed closer to the start of the next line when reading aloud. The probability of making a corrective saccade was higher for oral reading than silent reading. These indicate that oral reading may compel readers to rely more on foveal processing at the expense of parafoveal processing. We found an interaction between reading modality and fixation type on fixation durations. The reading modality effect (i.e., increased fixation durations in oral compared to silent reading) was greater for accurate line-initial fixations and marginally greater for line-final fixations compared to intra-line fixations. This suggests that readers may use the fixations adjacent to return-sweeps as natural pause locations to modulate the EVS.

Do readers use character information when programming return-sweep saccades?

Reading saccades that occur within a single line of text are guided by the size of letters. However, readers occasionally need to make longer saccades (known as return-sweeps) that take their eyes from the end of one line of text to the beginning of the next. In this study, we tested whether return-sweep saccades are also guided by font size information and whether this guidance depends on visual acuity of the return-sweep target area. To do this, we manipulated the font size of letters (0.29 vs 0.39° per character) and the length of the first line of text (16 vs 26°). The larger font resulted in return-sweeps that landed further to the right of the line start and in a reduction of under-sweeps compared to the smaller font. This suggests that font size information is used when programming return-sweeps. Return-sweeps in the longer line condition landed further to the right of the line start and the proportion of under-sweeps increased compared to the short line condition. This likely reflects an increase in saccadic undershoot error with the increase in intended saccade size. Critically, there was no interaction between font size and line length. This suggests that when programming return-sweeps, the use of font size information does not depend on visual acuity at the saccade target. Instead, it appears that readers rely on global typographic properties of the text in order to maintain an optimal number of characters to the left of their first fixation on a new line.

Spelling ability influences early letter encoding during reading: Evidence from return-sweep eye movements.

In recent years, there has been an increase in research concerning individual differences in readers' eye movements. However, this body of work is almost exclusively concerned with the reading of single-line texts. While spelling and reading ability have been reported to influence saccade targeting and fixation times during intra-line reading, where upcoming words are available for parafoveal processing, it is unclear how these variables affect fixations adjacent to return-sweeps. We, therefore, examined the influence of spelling and reading ability on return-sweep and corrective saccade parameters for 120 participants engaged in multiline text reading. Less-skilled readers and spellers tended to launch their return-sweeps closer to the end of the line, prefer a viewing location closer to the start of the next, and made more return-sweep undershoot errors. We additionally report several skill-related differences in readers' fixation durations across multiline texts. Reading ability influenced all fixations except those resulting from return-sweep error. In contrast, spelling ability influenced only those fixations following accurate return-sweeps-where parafoveal processing was not possible prior to fixation. This stands in contrasts to an established body of work where fixation durations are related to reading but not spelling ability. These results indicate that lexical quality shapes the rate at which readers access meaning from the text by enhancing early letter encoding, and influences saccade targeting even in the absence of parafoveal target information.

Age-related differences in visual encoding and response strategies contribute to spatial memory deficits.

Successful navigation requires memorising and recognising the locations of objects across different perspectives. Although these abilities rely on hippocampal functioning, which is susceptible to degeneration in older adults, little is known about the effects of ageing on encoding and response strategies that are used to recognise spatial configurations. To investigate this, we asked young and older participants to encode the locations of objects in a virtual room shown as a picture on a computer screen. Participants were then shown a second picture of the same room taken from the same (0°) or a different perspective (45° or 135°) and had to judge whether the objects occupied the same or different locations. Overall, older adults had greater difficulty with the task than younger adults although the introduction of a perspective shift between encoding and testing impaired performance in both age groups. Diffusion modelling revealed that older adults adopted a more conservative response strategy, while the analysis of gaze patterns showed an age-related shift in visual-encoding strategies with older adults attending to more information when memorising the positions of objects in space. Overall, results suggest that ageing is associated with declines in spatial processing abilities, with older individuals shifting towards a more conservative decision style and relying more on encoding target object positions using room-based cues compared to younger adults, who focus more on encoding the spatial relationships among object clusters.

The impact of cognitive aging on route learning rate and the acquisition of landmark knowledge.

Aging is accompanied by changes in general cognitive functioning which may impact the learning rate of older adults; however, this is often not controlled for in cognitive aging studies. We investigated the contribution of differences in learning rates to age-related differences in landmark knowledge acquired from route learning. In Experiment 1 we used a standard learning procedure in which participants received a fixed amount of exposure to a route. Consistent with previous research, we found age-related deficits in associative cue and landmark sequence knowledge. Experiment 2 controlled for differences in learning rates by using a flexible exposure learning procedure. Specifically, participants were trained to a performance criterion during route learning before being tested on the content of their route knowledge. While older adults took longer to learn the route than younger adults, the age-related differences in associative cue knowledge were abolished. The deficit in landmark sequence knowledge, however, remained. Experiment 3 replicated these results and introduced a test situation in which a deficit in landmark sequence knowledge yielded an increased likelihood of disorientation in older adults. The findings of this study suggest that age-related deficits in landmark associative cue knowledge are attenuated by controlling for learning rates. In contrast, landmark sequence knowledge deficits persist and are best explained by changes in the learning strategy of older adults to acquire task essential associative cue knowledge at the expense of supplementary sequence knowledge.

Parafoveal degradation during reading reduces preview costs only when it is not perceptually distinct.

There is a growing understanding that the parafoveal preview effect during reading may represent a combination of preview benefits and preview costs due to interference from parafoveal masks. It has been suggested that visually degrading the parafoveal masks may reduce their costs, but adult readers were later shown to be highly sensitive to degraded display changes. Four experiments examined how preview benefits and preview costs are influenced by the perception of distinct parafoveal degradation at the target word location. Participants read sentences with four preview types (identity, orthographic, phonological, and letter-mask preview) and two levels of visual degradation (0% vs. 20%). The distinctiveness of the target word degradation was either eliminated by degrading all words in the sentence (Experiments 1a-2a) or remained present, as in previous research (Experiments 1b-2b). Degrading the letter masks resulted in a reduction in preview costs, but only when all words in the sentence were degraded. When degradation at the target word location was perceptually distinct, it induced costs of its own, even for orthographically and phonologically related previews. These results confirm previous reports that traditional parafoveal masks introduce preview costs that overestimate the size of the true benefit. However, they also show that parafoveal degradation has the unintended consequence of introducing additional costs when participants are aware of distinct degradation on the target word. Parafoveal degradation appears to be easily perceived and may temporarily orient attention away from the reading task, thus delaying word processing.

Differences in Encoding Strategy as a Potential Explanation for Age-Related Decline in Place Recognition Ability.

The ability to recognise places is known to deteriorate with advancing age. In this study, we investigated the contribution of age-related changes in spatial encoding strategies to declining place recognition ability. We recorded eye movements while younger and older adults completed a place recognition task first described by Muffato et al. (2019). Participants first learned places, which were defined by an array of four objects, and then decided whether the next place they were shown was the same or different to the one they learned. Places could be shown from the same spatial perspective as during learning or from a shifted perspective (30° or 60°). Places that were different to those during learning were changed either by substituting an object in the place with a novel object or by swapping the locations of two objects. We replicated the findings of Muffato et al. (2019) showing that sensitivity to detect changes in a place declined with advancing age and declined when the spatial perspective was shifted. Additionally, older adults were particularly impaired on trials in which object locations were swapped; however, they were not differentially affected by perspective changes compared to younger adults. During place encoding, older adults produced more fixations and saccades, shorter fixation durations, and spent less time looking at objects compared to younger adults. Further, we present an analysis of gaze chaining, designed to capture spatio-temporal aspects of gaze behaviour. The chaining measure was a significant predictor of place recognition performance. We found significant differences between age groups on the chaining measure and argue that these differences in gaze behaviour are indicative of differences in encoding strategy between age groups. In summary, we report a direct replication of Muffato et al. (2019) and provide evidence for age-related differences in spatial encoding strategies, which are related to place recognition performance.

Undersweep fixations during reading in adults and children.

Return sweeps take a reader's fixation from the end of one line to the start of the next. Return sweeps frequently undershoot their target and are followed by a corrective saccade toward the left margin. The pauses prior to corrective saccades are typically considered to be uninvolved in linguistic processing. However, recent findings indicate that these undersweep fixations influence skilled adult readers' subsequent reading pass across the line and provide preview of line-initial words. The current research examined these effects in children. First, a children's reading corpus analysis revealed that words receiving an undersweep fixation were more likely skipped and received shorter gaze durations during a subsequent pass. Second, a novel eye movement experiment that directly compared adults' and children's eye movements indicated that, during an undersweep fixation, readers very briefly allocate their attention to the fixated word-as indicated by inhibition of return effects during a subsequent pass-prior to deploying attention toward the line-initial word. We argue that prior to the redeployment of attention, readers extract information at the point of fixation that facilitates later encoding and saccade targeting. Given similar patterns of results for adults and children, we conclude that the mechanisms controlling for oculomotor coordination and attention necessary for reading across line boundaries are established from a very early point in reading development.

Are age-related deficits in route learning related to control of visual attention?

Typically aged adults show reduced ability to learn a route compared to younger adults. In this experiment, we investigate the role of visual attention through eye-tracking and engagement of attentional resources in age-related route learning deficits. Participants were shown a route through a realistic virtual environment before being tested on their route knowledge. Younger and older adults were compared on their gaze behaviour during route learning and on their reaction time to a secondary probe task as a measure of attentional engagement. Behavioural results show a performance deficit in route knowledge for older adults compared to younger adults, which is consistent with previous research. We replicated previous findings showing that reaction times to the secondary probe task were longer at decision points than non-decision points, indicating stronger attentional engagement at navigationally relevant locations. However, we found no differences in attentional engagement and no differences for a range of gaze measures between age groups. We conclude that age-related changes in route learning ability are not reflected in changes in control of visual attention or regulation of attentional engagement.

Do Readers Integrate Phonological Codes Across Saccades? A Bayesian Meta-Analysis and a Survey of the Unpublished Literature.

It is commonly accepted that phonological codes can be activated parafoveally during reading and later used to aid foveal word recognition- a finding known as the phonological preview benefit. However, a closer look at the literature shows that this effect may be less consistent than what is sometimes believed. To determine the extent to which phonology is processed parafoveally, a Bayesian meta-analysis of 27 experiments and a survey of the unpublished literature were conducted. While the results were generally consistent with the phonological preview benefit (>90% probability of a true effect in gaze durations), the size of the effect was small. Readers of alphabetical orthographies obtained a modest benefit of only 4 ms in gaze durations. Interestingly, Chinese readers showed a larger effect (6-14 ms in size). There was no difference in the magnitude of the phonological preview benefit between homophone and pseudo-homophone previews, thus suggesting that the modest processing advantage is indeed related to the activation of phonological codes from the parafoveal word. Simulations revealed that the results are relatively robust to missing studies, although the effects may be 19-22% smaller if all missing studies found a null effect. The results suggest that while phonology can be processed parafoveally, this happens only to a limited extent. Because phonological priming effects in single-word recognition are small (10-13 ms; Rastle & Brysbaert, 2006) and there is a loss of visual acuity in the parafovea, it is argued that large phonological preview benefit effects may be unlikely.

Word frequency, predictability, and return-sweep saccades: Towards the modeling of eye movements during paragraph reading.

Models of eye movement control during reading focus on the reading of single lines of text. Within these models, word frequency and predictability are important input variables which influence fixation probabilities and durations. However, a comprehensive model of eye movement control will have to account for readers' eye movements across multiline texts. Line-initial words are unlike those presented midline; they are routinely unavailable for parafoveal preprocessing. Therefore, it is unclear whether and how word frequency and predictability influence reading times on line-initial words. To address this, we present an analysis of the Provo Corpus (Luke & Christianson, 2018) followed by a novel eye-movement experiment. We conclude that word frequency and predictability impact single-fixation and gaze durations on line-initial words. We also observed that return-sweep error (undersweep-fixations) may, among several other possibilities, allow for parafoveal processing of line-initial words prior to their direct fixation. Implications for models of eye movement control during reading are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

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.

An eye-movement exploration into return-sweep targeting during reading.

Return-sweeps are an essential eye-movement that takes the readers' eyes from the end of one line of text to the start of the next. While return-sweeps are common during normal reading, the eye-movement literature is dominated by single-line reading studies where no return-sweeps are needed. The present experiment was designed to explore what readers are targeting with their return-sweeps. Participants read two short stories by Frank L. Baum while their eye-movements were being recorded. In one story, every line-initial word was highlighted by formatting it in bold, while the other story was presented normally (i.e., without any bolding). The bolding manipulation significantly reduced oculomotor error associated with return-sweeps, as these saccades landed closer to the left margin and were less likely to require corrective saccades compared to the control condition. However, despite this reduction in oculomotor error, the bolding had no influence on local fixation durations or global reading-time measures. Moreover, return-sweep landing sites were not impacted by line-initial word length nor did the effect of bolding interact with the length of the line-initial word, suggesting that readers were not targeting the centre of line-initial words. We discuss the implication of these findings for return-sweep targeting and eye-movement control during reading.

Binocular coordination and return-sweep saccades among skilled adult readers.

During reading, binocular coordination ensures that a unified perceptual representation of the text is maintained across eye movements. However, slight vergence errors exist. The magnitude of disparity at fixation onset is related to the length of the preceding saccade. Return-sweeps are saccadic eye movements that span a line of text and direct gaze from the end of one line to the start of the next. As these eye movements travel much farther than intraline saccades, increased binocular disparity following a return-sweep is likely. Indeed, increased disparity has been a proposed explanation for longer line-initial fixations. Thus, we sought to address the following questions: Is binocular disparity larger following a return-sweep saccade than it is following an intraline saccade, and is the duration of a line-initial fixation related to binocular disparity and coordination processes? To examine these questions, we recorded binocular eye movements as participants read multiline texts. We report that, following return-sweeps, the magnitude of disparity at fixation onset is increased. However, this increased magnitude of disparity is unrelated to the duration of line-initial fixations. We argue that longer line-initial fixations result from a lack of parafoveal preview for words at the start of the line.

Individual differences in spelling ability influence phonological processing during visual word recognition.

In the research reported here, we investigated how phonological processing in the lexical decision task is influenced by individual differences in the reading and spelling abilities of participants. We used phonological neighborhood spread as a measure of phonological processing. Spread refers to the number of phoneme positions in a word that can be changed to form a phonological neighbor. Replicating previous research, we found that words forming neighbors across three positions (P3) were recognized more rapidly than those forming neighbors across only two positions (P2). Importantly, we found that this spread effect interacted with spelling ability. The difference between P3 and P2 was largest when spelling recognition was high and spelling production low. These opposing effects of spelling ability are explained in terms of a language system that consists of separate orthographic systems for reading and spelling. Although these two orthographic systems are separate, they share information through a shared response buffer (Jones & Rawson, 2016). Within this framework, it is argued that lexical decisions are made once the information in the response buffer reaches threshold and that time to reach this threshold is influenced by two sources. One is the quality of the orthographic connections in the reading system and is measured by spelling recognition. The other is the quality of the orthographic connections in the spelling system and is measured by spelling production.

Return-sweep saccades during reading in adults and children.

During reading, eye movement patterns differ between children and adults. Children make more fixations that are longer in duration and make shorter saccades. Return-sweeps are saccadic eye movements that move a reader's fixation to a new line of text. Return-sweeps move fixation further than intra-line saccades and often undershoot their target. This necessitates a corrective saccade to bring fixation closer to the start of the line. There have been few empirical investigations of return-sweep saccades in adults, and even fewer in children. In the present study, we examined return-sweeps of 47 adults and 48 children who read identical multiline texts. We found that children launch their return-sweeps closer to the end of the line and target a position closer to the left margin. Therefore, children fixate more extreme positions on the screen when reading for comprehension. Furthermore, children required a corrective saccade following a return-sweep more often than adults. Analysis of the duration of the fixation preceding the corrective saccade indicated that children are as efficient as adults at responding to retinal feedback following a saccade. Rather than consider differences in adult's and children's return-sweep behaviour an artefact of oculomotor control, we believe that these differences represent adult's ability to utilise parafoveal processing to encode text at extreme positions.