Gaze-contingent Moving Window Paradigm Research Articles

Deaf readers use leftward information to read more efficiently: Evidence from eye tracking.

Little is known about how information to the left of fixation impacts reading and how it may help to integrate what has been read into the context of the sentence. To better understand the role of this leftward information and how it may be beneficial during reading, we compared the sizes of the leftward span for reading-matched deaf signers (n = 32) and hearing adults (n = 40) using a gaze-contingent moving window paradigm with windows of 1, 4, 7, 10, and 13 characters to the left, as well as a no-window condition. All deaf participants were prelingually and profoundly deaf, used American Sign Language (ASL) as a primary means of communication, and were exposed to ASL before age eight. Analysis of reading rates indicated that deaf readers had a leftward span of 10 characters, compared to four characters for hearing readers, and the size of the span was positively related to reading comprehension ability for deaf but not hearing readers. These findings suggest that deaf readers may engage in continued word processing of information obtained to the left of fixation, making reading more efficient, and showing a qualitatively different reading process than hearing readers.

Eye movements and the perceptual span in disordered reading: A comparison of schizophrenia and dyslexia

Increasing evidence of a common neurodevelopmental etiology between schizophrenia and developmental dyslexia suggests that neurocognitive functions, such as reading, may be similarly disrupted. However, direct comparisons of reading performance in these disorders have yet to be conducted. To address this gap in the literature, we employed a gaze-contingent moving window paradigm to examine sentence-level reading fluency and perceptual span (breadth of parafoveal processing) in adults with schizophrenia (dataset from Whitford et al., 2013) and psychiatrically healthy adults with dyslexia (newly collected dataset). We found that the schizophrenia and dyslexia groups exhibited similar reductions in sentence-level reading fluency (e.g., slower reading rates, more regressions) compared to matched controls. Similar reductions were also found for standardized language/reading and executive functioning measures. However, despite these reductions, the dyslexia group exhibited a larger perceptual span (greater parafoveal processing) than the schizophrenia group, potentially reflecting a disruption in normal foveal-parafoveal processing dynamics. Taken together, our findings suggest that reading and reading-related functions are largely similarly disrupted in schizophrenia and dyslexia, providing additional support for a common neurodevelopmental etiology.

The role of L1 reading direction on L2 perceptual span: An eye-tracking study investigating Hindi and Urdu speakers

In the current study we used the gaze-contingent moving window paradigm to directly compare the second language (L2) English perceptual span of two groups that speak languages with essentially the same lexicon and grammar but crucially with different writing directions (and scripts): Hindi (read left to right) and Urdu (read right to left). This is the first study to directly compare first language (L1) speakers of languages that differ primarily in reading direction in a common L2, English. While Urdu speakers had a slightly faster reading rate, we found no additional differences between Hindi and Urdu speakers when reading L2 English; both groups showed a perceptual span between 9 and 11 characters to the right of the fixation based on saccade length. This suggests little to no influence of L1 reading direction on L2 perceptual span, but rather that L2 perceptual span is influenced by allocation of attention during reading. Our data are in line with research by Leung et al. (2014) finding that L2 speakers have a smaller perceptual span than native speakers (L1 perceptual span is approximately 15 characters to the right of the fixation). This most likely stems from the increased demands associated with reading in a second language, which led to a reduction in the amount of attention that can be allocated outside of the current fixation.

Deafness enhances perceptual span size in Chinese reading: Evidence from a gaze-contingent moving-window paradigm.

Using a gaze-contingent moving-window paradigm, we investigated whether/how deafness affects perceptual processing in Chinese reading. Besides the manipulation of window size, word length of sentences used in the experiment was also manipulated to check whether deafness enhanced the word length effect on perceptual span. Significant interactions of window constraints and deafness and a three-way interaction were observed on reading rate. Smaller effects of window constraints for deaf Chinese readers and nonreliable three-way interactions were observed on forward saccade length. This suggests that deaf Chinese readers exhibit a larger perceptual span, and word length affected the span from which information was acquired for comprehension whereas both deafness and word length might have little impact on the span from which information is acquired for oculomotor targeting during natural reading of Chinese.

Eye movements and the perceptual span among skilled Uighur readers

In the present study, we explored the perceptual span of skilled Uighur readers during their natural reading of sentences. The Uighur script is based on Arabic letters and it runs horizontally from right to left, offering a test to understand the effect of text direction. We utilized the gaze contingent moving window paradigm, in which legible text was provided only within a window that moved in synchrony with readers’ eyes while all other letters were masked. The size of the window was manipulated systematically to determine the smallest size that allowed readers to show normal reading behaviors. Comparisons of window conditions with the baseline condition showed that the Uighur readers reached asymptotic performance in reading speed and gaze duration when windows revealed at least five letters to the right and twelve letters to the left of the currently fixated one. The present study is the first to document the size of the perceptual span in a horizontally leftwards running script. Cross-script comparisons with prior findings suggest that the size of the perceptual span for a certain writing system is likely influenced by its reading direction and visual complexity.

Reading proficiency predicts the extent of the right, but not left, perceptual span in older readers.

The gaze-contingent moving-window paradigm was used to assess the size and symmetry of the perceptual span in older readers. The eye movements of 49 cognitively intact older adults (60-88 years of age) were recorded as they read sentences varying in difficulty, and the availability of letter information to the right and left of fixation was manipulated. To reconcile discrepancies in previous estimates of the perceptual span in older readers, individual differences in written language proficiency were assessed with tests of vocabulary, reading comprehension, reading speed, spelling ability, and print exposure. The results revealed that higher proficiency older adults extracted information up to 15 letter spaces to the right of fixation, while lower proficiency readers showed no additional benefit beyond 9 letters to the right. However, all readers showed improvements to reading with the availability of up to 9 letters to the left-confirming previous evidence of reduced perceptual span asymmetry in older readers. The findings raise questions about whether the source of age-related changes in parafoveal processing lies in the adoption of a risky reading strategy involving an increased propensity to both guess upcoming words and make corrective regressions.

Binocular advantages for parafoveal processing in reading

During reading, binocular visual input results in superior performance and is particularly important in the pre-processing of parafoveal text prior to direct fixation. It is not yet clear whether binocular vision in the parafovea is necessary for accurate saccadic targeting, or for efficient pre-processing of upcoming text, prior to direct fixation. In the present sentence reading experiment, we used a dichoptic gaze-contingent moving window paradigm in order to establish 1) how much parafoveal binocular input is necessary for fluent reading and 2) which aspect of parafoveal processing is more reliant on binocular vision. Eye movement measures revealed that reading was disrupted unless word N + 1 was entirely binocular in the parafovea, though no additional benefit was observed when word N + 2 was also binocular. Additionally, while fixation durations and reading times were clearly affected by the manipulation, similarly pronounced changes in binocular saccadic parameters such as accuracy, speed, amplitude and velocity were not observed. We concluded that the disruption to reading caused by presenting monocular text to the right of fixation cannot be attributed to difficulties in targeting binocular saccacdes, but instead results from a decreased efficiency in the pre-processing of parafoveal text. These results provide further demonstration for the importance of binocular vision during written text processing.

Investigating the Effectiveness of Spatial Frequencies to the Left and Right of Central Vision during Reading: Evidence from Reading Times and Eye Movements.

Printed words are complex visual stimuli containing a range of different spatial frequencies, and several studies have suggested that various spatial frequencies are effective for skilled adult reading. But while it is well known that the area of text from which information is acquired during reading extends to the left and right of each fixation, the effectiveness of spatial frequencies falling each side of fixation has yet to be determined. To investigate this issue, we used a spatial frequency adaptation of the gaze-contingent moving-window paradigm in which sentences were shown to skilled adult readers either entirely as normal or filtered to contain only low, medium, or high spatial frequencies except for a window of normal text around each point of fixation. Windows replaced filtered text either symmetrically 1 character to the left and right of each fixated character, or asymmetrically, 1 character to the left and 7 or 13 to the right, or 1 character to the right and 7 or 13 to the left. Reading times and eye-movement measures showed that reading performance for sentences presented entirely as normal generally changed very little with filtered displays when windows extended to the right but was often disrupted when windows extended to the left. However, asymmetrical windows affected performance on both sides of fixation. Indeed, increasing the leftward extent of windows from 7 to 13 characters produced decreases in both reading times and fixation durations, suggesting that reading was influenced by the spatial frequency content of leftward areas of text some considerable distance from fixation. Overall, the findings show that while a range of different spatial frequencies can be used by skilled adult readers, the effectiveness of spatial frequencies differs for text on each side of central vision, and may reflect different roles played by these two areas of text during reading.

Eye movements and the perceptual span during first- and second-language sentence reading in bilingual older adults.

This study addressed a central yet previously unexplored issue in the psychological science of aging, namely, whether the advantages of healthy aging (e.g., greater lifelong experience with language) or disadvantages (e.g., decreases in cognitive and sensory processing) drive L1 and L2 reading performance in bilingual older adults. To this end, we used a gaze-contingent moving window paradigm to examine both global aspects of reading fluency (e.g., reading rates, number of regressions) and the perceptual span (i.e., allocation of visual attention into the parafovea) in bilingual older adults during L1 and L2 sentence reading, as a function of individual differences in current L2 experience. Across the L1 and L2, older adults exhibited reduced reading fluency (e.g., slower reading rates, more regressions), but a similar perceptual span compared with matched younger adults. Also similar to matched younger adults, older adults' reading fluency was lower for L2 reading than for L1 reading as a function of current L2 experience. Specifically, greater current L2 experience increased L2 reading fluency, but decreased L1 reading fluency (for global reading measures only). Taken together, the dissociation between intact perceptual span and impaired global reading measures suggests that older adults may prioritize parafoveal processing despite age-related encoding difficulties. Consistent with this interpretation, post hoc analyses revealed that older adults with higher versus lower executive control were more likely to adopt this strategy.

Second-language experience modulates eye movements during first- and second-language sentence reading: evidence from a gaze-contingent moving window paradigm.

Eye movement measures demonstrate differences in first-language (L1) and second-language (L2) paragraph-level reading as a function of individual differences in current L2 exposure among bilinguals (Whitford & Titone, 2012). Specifically, as current L2 exposure increases, the ease of L2 word processing increases, but the ease of L1 word processing decreases. Here, we investigate whether current L2 exposure also relates to more general aspects of reading performance, including global eye movement measures and how bilinguals use parafoveal information to the right of fixation during L1 and L2 sentence-level reading, through use of a gaze-contingent moving window paradigm (McConkie & Rayner, 1975). We found that bilinguals with high versus low current L2 exposure exhibited increased L2 reading fluency (faster reading rates, shorter forward fixation durations), but decreased L1 reading fluency (slower reading rates, longer forward fixation durations). We also found that bilinguals with high versus low current L2 exposure were more affected by reductions in window size during L2 reading (indicative of a larger L2 perceptual span), but were less affected by reductions in window size during L1 reading (indicative of a smaller L1 perceptual span). Taken together, these findings suggest that individual differences in current L2 exposure among bilinguals also modulate more general aspects of reading behavior, including global measures of reading difficulty and the allocation of visual attention into the parafovea during both L1 and L2 sentence-level reading.

Peripheral guidance in scenes: The interaction of scene context and object content.

In the present study, we examined how gaze guidance is affected by immediately available information in the periphery and investigated how search strategies differed across manipulations in the availability of scene context and object content information. Across 3 experiments, participants performed a visual search task in scenes while using a gaze-contingent moving-window paradigm. Extrafoveal information was manipulated across conditions to examine the contributions of object content, scene context, or some combination of the two. Experiment 1 demonstrated a possible interaction between scene context and object content information in improving guidance. Experiments 2 and 3 supported the notion that object content is selected for further scrutiny based on its position within scene context. These results suggest a prioritization of object information based on scene context, such that contextual information acts as a framework in the selection of relevant regions, and object information can then affect which specific locations in those regions are selected for further examination.

Lexical Quality and Eye Movements: Individual Differences in the Perceptual Span of Skilled Adult Readers

Two experiments used the gaze-contingent moving-window paradigm to investigate whether reading comprehension and spelling ability modulate the perceptual span of skilled adult readers during sentence reading. Highly proficient reading and spelling were both associated with increased use information to the right of fixation, but did not systematically modulate the extraction of information to the left of fixation. Individuals who were high in both reading and spelling ability showed the greatest benefit from window sizes larger than 11 characters, primarily because of increases in forward saccade length. They were also significantly more disrupted by being denied close parafoveal information than those poor in reading and/or spelling. These results suggest that, in addition to supporting rapid lexical retrieval of fixated words, the high quality lexical representations indexed by the combination of high reading and spelling ability support efficient processing of parafoveal information and effective saccadic targeting.

The gaze-contingent moving window in reading: Development and review

The development of the gaze-contingent moving window paradigm (McConkie & Rayner, 1975, 1976) is discussed and the results of the earliest research are reviewed. The original work suggested that the region from which readers can obtain useful information during an eye fixation in reading, or the perceptual span, was asymmetric around the fixation point, and extended from 3–4 letter spaces to the left of fixation to about 14–15 letter spaces to the right of fixation. Subsequent research which substantiated these findings is discussed. Then more recent research using the moving window paradigm to investigate the following topics (1) effects of reading speed, (2) effects of reading skill, (3) effects of the writing system, (4) effects due to age, (5) effects related to deafness, and (5) effects related to schizophrenia is discussed. Finally, some extensions of gaze-contingent paradigms to areas other than reading are discussed.

Reading Direction and the Central Perceptual Span in Urdu and English

BackgroundNormal reading relies on the reader making a series of saccadic eye movements along lines of text, separated by brief fixational pauses during which visual information is acquired from a region of text. In English and other alphabetic languages read from left to right, the region from which useful information is acquired during each fixational pause is generally reported to extend further to the right of each fixation than to the left. However, the asymmetry of the perceptual span for alphabetic languages read in the opposite direction (i.e., from right to left) has received much less attention. Accordingly, in order to more fully investigate the asymmetry in the perceptual span for these languages, the present research assessed the influence of reading direction on the perceptual span for bilingual readers of Urdu and English.Methods and FindingsText in Urdu and English was presented either entirely as normal or in a gaze-contingent moving-window paradigm in which a region of text was displayed as normal at the reader's point of fixation and text outside this region was obscured. The windows of normal text extended symmetrically 0.5° of visual angle to the left and right of fixation, or asymmetrically by increasing the size of each window to 1.5° or 2.5° to either the left or right of fixation. When participants read English, performance for the window conditions was superior when windows extended to the right. However, when reading Urdu, performance was superior when windows extended to the left, and was essentially the reverse of that observed for English.ConclusionThese findings provide a novel indication that the perceptual span is modified by the language being read to produce an asymmetry in the direction of reading and show for the first time that such an asymmetry occurs for reading Urdu.

The Perceptual Span in Second Language Reading: An Eye-Tracking Study Using a Gaze-Contingent Moving Window Paradigm

The perceptual span, which is the visual area providing useful information to a reader during eye fixation, has been well investigated among native or first language (L1) readers, but not among second language (L2) readers. Our goal was to investigate the size of the perceptual span among Japanese university students who learn English as a foreign language (EFL) to investigate parafoveal processing during L2 reading. In an experiment using the gaze-contingent moving window paradigm, we compared perceptual span between Japanese EFL readers (N = 42) and native English L1 readers (N = 14). Our results showed that (1) the EFL readers had a smaller perceptual span than the L1 readers did, and (2) the facilitating effect of parafoveal information was greater for faster EFL readers than it was for slower EFL readers. These findings provide evidence that EFL readers can only utilize little parafoveal information during fixation when compared with L1 readers.

On the visual span during object search in real-world scenes

The current study investigated from how large a region around their current point of gaze viewers can take in information when searching for objects in real-world scenes. Visual span size was estimated using the gaze-contingent moving window paradigm. Experiment 1 featured window radii measuring 1, 3, 4, 4.7, 5.4, and 6.1°. Experiment 2 featured six window radii measuring between 5 and 10°. Each scene occupied a 24.8 × 18.6° field of view. Inside the moving window, the scene was presented in high resolution. Outside the window, the scene image was low-pass filtered to impede the parsing of the scene into constituent objects. Visual span was defined as the window size at which object search times became indistinguishable from search times in the no-window control condition; this occurred with windows measuring 8° and larger. Notably, as long as central vision was fully available (window radii ≥ 5°), the distance traversed by the eyes through the scene to the search target was comparable to baseline performance. However, to move their eyes to the target, viewers made shorter saccades, requiring more fixations to cover the same image space, and thus more time. Moreover, a gaze-data based decomposition of search time revealed disruptions in specific subprocesses of search. In addition, nonlinear mixed models analyses demonstrated reliable individual differences in visual span size and parameters of the search time function.

Filtered text reveals adult age differences in reading: Evidence from eye movements.

Sensitivity to certain spatial frequencies declines with age and this may have profound effects on reading performance. However, the spatial frequency content of text actually used by older adults (aged 65+), and how this differs from that used by young adults (aged 18-30), remains to be determined. To investigate this issue, the eye movement behavior of young and older adult readers was assessed using a gaze-contingent moving-window paradigm in which text was shown normally within a region centered at the point of gaze, whereas text outside this region was filtered to contain only low, medium, or high spatial frequencies. For young adults, reading times were affected by spatial frequency content when windows of normal text extended up to nine characters wide. Within this processing region, the reading performance of young adults was affected little when text outside the window contained either only high or medium spatial frequencies, but was disrupted substantially when text contained only low spatial frequencies. By contrast, the reading performance of older adults was affected by spatial frequency content when windows extended up to 18 characters wide. Moreover, within this extended processing region, reading performance was disrupted when text contained any one band of spatial frequencies, but was disrupted most of all when text contained only high spatial frequencies. These findings indicate that older adults are sensitive to the spatial frequency content of text from a much wider region than young adults, and rely much more than young adults on coarse-scale components of text when reading.

Parafoveal processing efficiency in rapid automatized naming: A comparison between Chinese normal and dyslexic children

Dyslexic children are known to be slower than normal readers in rapid automatized naming (RAN). This suggests that dyslexics encounter local processing difficulties, which presumably induce a narrower perceptual span. Consequently, dyslexics should suffer less than normal readers from removing parafoveal preview. Here we used a gaze-contingent moving window paradigm in a RAN task to experimentally test this prediction. Results indicate that dyslexics extract less parafoveal information than control children. We propose that more attentional resources are recruited to the foveal processing because of dyslexics’ less automatized translation of visual symbols into phonological output, thereby causing a reduction of the perceptual span. This in turn leads to less efficient preactivation of parafoveal information and, hence, more difficulty in processing the next foveal item.

Reading impairments in schizophrenia relate to individual differences in phonological processing and oculomotor control: Evidence from a gaze-contingent moving window paradigm.

Language and oculomotor disturbances are 2 of the best replicated findings in schizophrenia. However, few studies have examined skilled reading in schizophrenia (e.g., Arnott, Sali, Copland, 2011; Hayes & O'Grady, 2003; Revheim et al., 2006; E. O. Roberts et al., 2012), and none have examined the contribution of cognitive and motor processes that underlie reading performance. Thus, to evaluate the relationship of linguistic processes and oculomotor control to skilled reading in schizophrenia, 20 individuals with schizophrenia and 16 demographically matched controls were tested using a moving window paradigm (McConkie & Rayner, 1975). Linguistic skills supporting reading (phonological awareness) were assessed with the Comprehensive Test of Phonological Processing (R. K. Wagner, Torgesen, & Rashotte, 1999). Eye movements were assessed during reading tasks and during nonlinguistic tasks tapping basic oculomotor control (prosaccades, smooth pursuit) and executive functions (predictive saccades, antisaccades). Compared with controls, schizophrenia patients exhibited robust oculomotor markers of reading difficulty (e.g., reduced forward saccade amplitude) and were less affected by reductions in window size, indicative of reduced perceptual span. Reduced perceptual span in schizophrenia was associated with deficits in phonological processing and reduced saccade amplitudes. Executive functioning (antisaccade errors) was not related to perceptual span but was related to reading comprehension. These findings suggest that deficits in language, oculomotor control, and cognitive control contribute to skilled reading deficits in schizophrenia. Given that both language and oculomotor dysfunction precede illness onset, reading may provide a sensitive window onto cognitive dysfunction in schizophrenia vulnerability and be an important target for cognitive remediation.

Controlling the spotlight of attention: Visual span size and flexibility in schizophrenia

The current study investigated the size and flexible control of visual span among patients with schizophrenia during visual search performance. Visual span is the region of the visual field from which one extracts information during a single eye fixation, and a larger visual span size is linked to more efficient search performance. Therefore, a reduced visual span may explain patients’ impaired performance on search tasks. The gaze-contingent moving window paradigm was used to estimate the visual span size of patients and healthy participants while they performed two different search tasks. In addition, changes in visual span size were measured as a function of two manipulations of task difficulty: target–distractor similarity and stimulus familiarity. Patients with schizophrenia searched more slowly across both tasks and conditions. Patients also demonstrated smaller visual span sizes on the easier search condition in each task. Moreover, healthy controls’ visual span size increased as target discriminability or distractor familiarity increased. This modulation of visual span size, however, was reduced or not observed among patients. The implications of the present findings, with regard to previously reported visual search deficits, and other functional and structural abnormalities associated with schizophrenia, are discussed.