E–Z Reader: A cognitive-control, serial-attention model of eye-movement behavior during reading

Neural correlates for word-frequency effect in Chinese natural reading

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

Early parafoveal semantic integration in natural reading

Humans can read and comprehend text rapidly, implying that readers might process multiple words per fixation. However, the extent to which parafoveal words are previewed and integrated into the evolving sentence context remains disputed. We investigated parafoveal processing during natural reading by recording brain activity and eye movements using MEG and an eye tracker while participants silently read one-line sentences. The sentences contained an unpredictable target word that was either congruent or incongruent with the sentence context. To measure parafoveal processing, we flickered the target words at 60 Hz and measured the resulting brain responses (i.e. Rapid Invisible Frequency Tagging, RIFT) during fixations on the pre-target words. Our results revealed a significantly weaker tagging response for target words that were incongruent with the previous context compared to congruent ones, even within 100ms of fixating the word immediately preceding the target. This reduction in the RIFT response was also found to be predictive of individual reading speed. We conclude that semantic information is not only extracted from the parafovea but can also be integrated with the previous context before the word is fixated. This early and extensive parafoveal processing supports the rapid word processing required for natural reading. Our study suggests that theoretical frameworks of natural reading should incorporate the concept of deep parafoveal processing.

Neural mechanism underlying preview effects and masked priming effects in visual word processing

Two classic experimental paradigms - masked repetition priming and the boundary paradigm - have played a pivotal role in understanding the process of visual word recognition. Traditionally, these paradigms have been employed by different communities of researchers, with their own long-standing research traditions. Nevertheless, a review of the literature suggests that the brain-electric correlates of word processing established with both paradigms may show interesting similarities, in particular with regard to the location, timing, and direction of N1 and N250 effects. However, as of yet, no direct comparison has been undertaken between the two paradigms. In the current study, we used combined eye-tracking/EEG to perform such a within-subject comparison using the same materials (single Chinese characters) as stimuli. To facilitate direct comparisons, we used a simplified version of the boundary paradigm - the single word boundary paradigm. Our results show the typical early repetition effects of N1 and N250 for both paradigms. However, repetition effects in N250 (i.e., a reduced negativity following identical-word primes/previews as compared to different-word primes/previews) were larger with the single word boundary paradigm than with masked priming. For N1 effects, repetition effects were similar across the two paradigms, showing a larger N1 after repetitions as compared to alternations. Therefore, the results indicate that at the neural level, a briefly presented and masked foveal prime produces qualitatively similar facilitatory effects on visual word recognition as a parafoveal preview before a single saccade, although such effects appear to be stronger in the latter case.

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.

Severe processing capacity limits for sub-lexical features of letter strings

When reading, the visual system is confronted with many words simultaneously. How much of that information can a reader process at once? Previous studies demonstrated that low-level visual features of multiple words are processed in parallel, but lexical attributes are processed serially, for one word at a time. This implies that an internal bottleneck lies somewhere between early visual and lexical analysis. We used a dual-task behavioral paradigm to investigate whether this bottleneck lies at the stage of letter recognition or phonological decoding. On each trial, two letter strings were flashed briefly, one above and one below fixation, and then masked. In the letter identification experiment, participants indicated whether a vowel was present in a particular letter string. In the phonological decoding experiment, participants indicated whether the letter string was pronounceable. We compared accuracy in a focused attention condition, in which participants judged only one of the two strings, with accuracy in a divided attention condition, in which participants judged both strings independently. In both experiments, the cost of dividing attention was so large that it supported a serial model: participants were able to process only one letter string per trial. Furthermore, we found a stimulus processing trade-off that is characteristic of serial processing: When participants judged one string correctly, they were less likely to judge the other string correctly. Therefore, the bottleneck that constrains word recognition under these conditions arises at a sub-lexical level, perhaps due to a limit on the efficiency of letter recognition.

Dynamic reading in a digital age: new insights on cognition

People increasingly read text displayed on digital devices, including computers, handheld e-readers, and smartphones. Given this, there is rapidly growing interest in understanding how the cognitive processes that support the reading of static text (e.g., books, magazines, or newspapers) might be adapted to reading digital texts. Evidence from recent experiments suggests a complex interplay of visual and cognitive influences on how people engage with digital reading. Although readers can strategically adjust their reading behaviors in response to their immediate reading context, the efficacy of these strategies depends on cognitive, metacognitive, and motivational factors. A better understanding of the factors that influence reading offers the promise of leveraging digital technologies to enhance the reading experience.

Parallel phonological processing of Chinese characters revealed by flankers tasks

An important and extensively researched question in the field of reading is whether readers can process multiple words in parallel. An unresolved issue regarding this question is whether the phonological information from foveal and parafoveal words can be processed in parallel, i.e., parallel phonological processing. The present study aims to investigate whether there is parallel phonological processing of Chinese characters. The original and the revised flankers tasks were applied. In both tasks, a foveal target character was presented in isolation in the no-flanker condition, flanked on both sides by a parafoveal homophone in the homophone-flanker condition, and by a non-homophonic character in the unrelated-flanker condition. Participants were instructed to fixate on the target characters and press two keys to indicate whether they knew the target characters (lexical vs. non-lexical). In the original flankers task, the stimuli were presented for 150 ms without a post-mask. In the revised flankers task, we set the stimulus exposure time (duration of the stimuli plus the blank interval between the stimuli and the post-mask) to each participant's lexical decision threshold to prevent participants from processing the target and flanker characters serially. In both tasks, reaction times to the lexical targets were significantly shorter in the homophone-flanker condition than in the unrelated-flanker condition, suggesting parallel phonological processing of Chinese characters. In the revised flankers task, accuracy rates to the lexical targets were significantly lower in the unrelated-flanker condition compared to the homophone-flanker condition, further supporting parallel phonological processing of Chinese characters. Moreover, reaction times to the lexical targets were the shortest in the no-flanker condition in both tasks, reflecting the attention distribution over both the target and flanker characters. The findings of this study provide valuable insights into the parallel processing mechanisms involved in reading.

The transposed word effect is consistent with serial word recognition and varies with reading speed

The scientific study of reading has long been animated by questions of parallel vs. serial processing. Do readers recognize words serially, adding each one sequentially to a representation of the sentence structure? One fascinating phenomenon to emerge from this research is the transposed word effect: when asked to judge whether sentences are grammatical, readers often fail to notice grammatical errors caused by transposing two words. This effect could be evidence that readers recognize multiple words in parallel. Here we provide converging evidence that the transposed word effect is also consistent with serial processing because it occurs robustly when the words in each sentence are presented serially. We further investigated how the effect relates to individual differences in reading speed, to gaze fixation patterns, and to differences in difficulty across sentences. In a pretest, we first measured the natural English reading rate of 37 participants, which varied widely. In a subsequent grammatical decision task, we presented grammatical and ungrammatical sentences in two modes: one with all words presented simultaneously, and the other with single words presented sequentially at each participant's natural rate. Unlike prior studies that used a fixed sequential presentation rate, we found that the magnitude of the transposed word effect was at least as strong in the sequential presentation mode as in the simultaneous mode, for both error rates and response times. Moreover, faster readers were more likely to miss transpositions of words presented sequentially. We argue that these data favor a "noisy channel" model of comprehension in which skilled readers rely on prior knowledge to rapidly infer the meaning of sentences, allowing for apparent errors in spatial or temporal order, even when the individual words are recognized one at a time.

Eye movements during reading in beginning and skilled readers: Impact of reading level or physiological maturation?

We begin by presenting and examining relevant data in the literature on eye movements in reading, from childhood to adulthood. In particular, we discuss the differences found in eye movements during reading between children in different age groups and with different reading levels and skilled adult readers in terms of word recognition and sentence processing. We then critically discuss two hypotheses that account for the differences between children and adults' eye movement during reading: one being reading age itself - the changes in eye movement patterns in reading are regulated by the level of reading proficiency and its automatization - and the other being the role of maturation of oculomotor control and, consequently, its possible changes in eye movement patterns during reading. Finally, we list gaps in the research field and suggest that future research will benefit from investigating eye movements during reading in ex-illiterate adults who are in the process of learning to read in order to isolate both reading and maturational factors.

Fixation-related fMRI analysis reveals the neural basis of parafoveal processing in self-paced reading of Chinese words

While parafoveal word processing plays an important role in natural reading, the underlying neural mechanism remains unclear. The present study investigated the neural basis of parafoveal processing during Chinese word reading with the co-registration of eye-tracking and functional magnetic resonance imaging (fMRI) using fixation-related fMRI analysis. In the gaze-contingent boundary paradigm, preview conditions (words that are identical, orthographically similar, and unrelated to target words), pre-target word frequency and target word frequency were manipulated. When fixating the pre-target word, the identical preview condition elicited lower brain activation in the left fusiform gyrus relative to unrelated and orthographically similar preview conditions and there were significant interactions of preview condition and pre-target word frequency on brain activation of the left middle frontal gyrus, left fusiform gyrus and supplementary motor area. When fixating the target word, there was a significant main effect of preview condition on brain activation of the right fusiform gyrus and a significant interaction of preview condition and pre-target word frequency on brain activation of the left middle frontal gyrus. These results suggest that fixation-related brain activation provides immediate measures and new perspectives to understand the mechanism of parafoveal processing in self-paced reading.

EXPRESS: Lexical Competition Influences Correct and Incorrect Visual Word Recognition

A growing body of research suggests that visual word recognition is error-prone, and that errors may contribute to inhibitory neighbor frequency effects in word identification and reading. The present study used the neighborhood frequency effect to examine the relationship between lexical competition and error-making during visual word recognition. A novel adaptation of the visual world paradigm (VWP) was used, in which participants selected a briefly-presented printed target word from an array containing the target, its higher- or lower-frequency neighbor, an orthographic onset competitor, and an orthographically unrelated distractor word. Analyses of the visual inspection of the arrays suggested that lexical competition occurred when words were correctly identified, as competitors were preferentially viewed as a function of their orthographic similarity with the target, and higher-frequency neighbors were preferentially viewed over lower-frequency neighbors. Orthographic similarity and neighbor frequency also influenced error-making. Targets were often mistaken for their neighbors, and these errors were more common for targets with higher-frequency neighbors. The time course of target and neighbor viewing for error trials also provided preliminary evidence for two kinds of errors: early-occurring, perceptual errors and later-occurring selection errors that resulted from unsuccessfully resolved lexical competition. Together, these findings suggest that neighbor frequency effects reflect the contribution of both general lexical competition and occasional errors.

Insights from a dyslexia simulation font: Can we simulate reading struggles of individuals with dyslexia?

Individuals with dyslexia struggle at explaining what it is like to have dyslexia and how they perceive letters and words differently. This led the designer Daniel Britton to create a font that aims to simulate the perceptual experience of how effortful reading can be for individuals with dyslexia (http://danielbritton.info/dyslexia). This font removes forty percent of each character stroke with the aim of increasing reading effort, and in turn empathy and understanding for individuals with dyslexia. However, its efficacy has not yet been empirically tested. In the present study, we compared participants without dyslexia reading texts in the dyslexia simulation font to a group of individuals with dyslexia reading the same texts in Times New Roman font. Results suggest that the simulation font amplifies the struggle of reading, surpassing that experienced by adults with dyslexia-as reflected in increased reading time and overall number of eye movements in the majority of typical readers reading in the simulation font. Future research could compare the performance of the Daniel Britton simulation font against a sample of beginning readers with dyslexia as well as seek to design and empirically test an adapted simulation font with an increased preserved percentage of letter strokes [Correction added on 10 December 2021, after initial online publication. Abstract has been added].

Connecting and considering: Electrophysiology provides insights into comprehension

The ability to rapidly and systematically access knowledge stored in long-term memory in response to incoming sensory information-that is, to derive meaning from the world-lies at the core of human cognition. Research using methods that can precisely track brain activity over time has begun to reveal the multiple cognitive and neural mechanisms that make this possible. In this article, I delineate how a process of connecting affords an effortless, continuous infusion of meaning into human perception. In a relatively invariant time window, uncovered through studies using the N400 component of the event-related potential, incoming sensory information naturally induces a graded landscape of activation across long-term semantic memory, creating what might be called "proto-concepts". Connecting can be (but is not always) followed by a process of further considering those activations, wherein a set of more attentionally demanding "active comprehension" mechanisms mediate the selection, augmentation, and transformation of the initial semantic representations. The result is a limited set of more stable bindings that can be arranged in time or space, revised as needed, and brought to awareness. With this research, we are coming closer to understanding how the human brain is able to fluidly link sensation to experience, to appreciate language sequences and event structures, and, sometimes, to even predict what might be coming up next.

Neural evidence for lexical parafoveal processing

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

Reading: The Confluence of Vision and Language

The scientific study of reading has a rich history that spans disciplines from vision science to linguistics, psychology, cognitive neuroscience, neurology, and education. The study of reading can elucidate important general mechanisms in spatial vision, attentional control, object recognition, and perceptual learning, as well as the principles of plasticity and cortical topography. However, literacy also prompts the development of specific neural circuits to process a unique and artificial stimulus. In this review, we describe the sequence of operations that transforms visual features into language, how the key neural circuits are sculpted by experience during development, and what goes awry in children for whom learning to read is a struggle. Expected final online publication date for the Annual Review of Vision Science, Volume 7 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Context but not reading speed modulates transposed-word effects in Chinese reading

Recent research using a speeded grammaticality decision revealed novel transposed-word effects when reading alphabetic languages such as French (Mirault, Snell, & Grainger, 2018), and nonalphabetic languages such as Chinese (Liu, Li, Paterson, & Wang, 2020). Transposed-word effects are considered to reflect flexibility in word order processing, but the factors that might modulate such effects remain unknown. The present study investigated this issue by using a within-subjects design in Chinese reading. In experiment 1, the participants were asked to read sentences at their normal and speeded reading speed and to make grammaticality decisions as accurately as possible. No significant interaction between transposed-word effects and reading speed was found, suggesting that transposed-word effects are not modulated by reading speed and that they are similar regardless of whether the participants read slowly or quickly. In experiment 2, we manipulated the context before the transposed words and used a speeded grammaticality decision task. We observed significant interactive effects between transposed-word effects and context, and analyses revealed that transposed-word effects decreased when the first and second words were transposed in a sentence. We conclude that context rather than reading speed modulates transposed-word effects in Chinese reading and discuss these findings with regard to the noisy bottom-up allocation of word identities and top-down sentence-level constraints.

Individuals with dyslexia use a different visual sampling strategy to read text

Individuals with dyslexia present with reading-related deficits including inaccurate and/or less fluent word recognition and poor decoding abilities. Slow reading speed and worse text comprehension can occur as secondary consequences of these deficits. Reports of visual symptoms such as atypical eye movements during reading gave rise to a search for these deficits' underlying mechanisms. This study sought to replicate established behavioral deficits in reading and cognitive processing speed while investigating their underlying mechanisms in more detail by developing a comprehensive profile of eye movements specific to reading in adult dyslexia. Using a validated standardized reading assessment, our findings confirm a reading speed deficit among adults with dyslexia. We observed different eye movements in readers with dyslexia across numerous eye movement metrics including the duration of a stop (i.e., fixation), the length of jumps (i.e., saccades), and the number of times a reader's eyes expressed a jump atypical for reading. We conclude that individuals with dyslexia visually sample written information in a laborious and more effortful manner that is fundamentally different from those without dyslexia. Our findings suggest a mix of aberrant cognitive linguistic and oculomotor processes being present in adults with dyslexia.

Readers detect an low-level phonological violation between two parafoveal words

In two eye-tracking studies we investigated whether readers can detect a violation of the phonological-grammatical convention for the indefinite article an to be followed by a word beginning with a vowel when these two words appear in the parafovea. Across two experiments participants read sentences in which the word an was followed by a parafoveal preview that was either correct (e.g. Icelandic), incorrect and represented a phonological violation (e.g. Mongolian), or incorrect without representing a phonological violation (e.g. Ethiopian), with this parafoveal preview changing to the target word as participants made a saccade into the space preceding an. Our data suggests that participants detected the phonological violation while the target word was still two words to the right of fixation, with participants making more regressions from the previewed word and having longer go-past times on this word when they received a violation preview as opposed to a non-violation preview. We argue that participants were attempting to perform aspects of sentence integration on the basis of low-level orthographic information from the previewed word.

Visual word recognition: Evidence for a serial bottleneck in lexical access

Reading is a demanding task, constrained by inherent processing capacity limits. Do those capacity limits allow for multiple words to be recognized in parallel? In a recent study, we measured semantic categorization accuracy for nouns presented in pairs. The words were replaced by post-masks after an interval that was set to each subject's threshold, such that with focused attention they could categorize one word with ~80% accuracy. When subjects tried to divide attention between both words, their accuracy was so impaired that it supported a serial processing model: on each trial, subjects could categorize one word but had to guess about the other. In the experiments reported here, we investigated how our previous result generalizes across two tasks that require lexical access but vary in the depth of semantic processing (semantic categorization and lexical decision), and across different masking stimuli, word lengths, lexical frequencies and visual field positions. In all cases, the serial processing model was supported by two effects: (1) a sufficiently large accuracy deficit with divided compared to focused attention; and (2) a trial-by-trial stimulus processing tradeoff, meaning that the response to one word was more likely to be correct if the response to the other was incorrect. However, when the task was to detect colored letters, neither of those effects occurred, even though the post-masks limited accuracy in the same way. Altogether, the results are consistent with the hypothesis that visual processing of words is parallel but lexical access is serial.

Minimal Overlap in Language Control Across Production And Comprehension: Evidence from Read-Aloud Versus Eye-Tracking Tasks

Bilinguals are remarkable at language control-switching between languages only when they want. However, language control in production can involve switch costs. That is, switching to another language takes longer than staying in the same language. Moreover, bilinguals sometimes produce language intrusion errors, mistakenly producing words in an unintended language (e.g., Spanish-English bilinguals saying "pero" instead of "but"). Switch costs are also found in comprehension. For example, reading times are longer when bilinguals read sentences with language switches compared to sentences with no language switches. Given that both production and comprehension involve switch costs, some language-control mechanisms might be shared across modalities. To test this, we compared language switch costs found in eye-movement measures during silent sentence reading (comprehension) and intrusion errors produced when reading aloud switched words in mixed-language paragraphs (production). Bilinguals who made more intrusion errors during the read-aloud task did not show different switch cost patterns in most measures in the silent-reading task, except on skipping rates. We suggest that language switching is mostly controlled by separate, modality-specific processes in production and comprehension, although some points of overlap might indicate the role of domain general control and how it can influence individual differences in bilingual language control.

Modulation of oculomotor control during reading of mirrored and inverted texts

The interplay between cognitive and oculomotor processes during reading can be explored when the spatial layout of text deviates from the typical display. In this study, we investigate various eye-movement measures during reading of text with experimentally manipulated layout (word-wise and letter-wise mirrored-reversed text as well as inverted and scrambled text). While typical findings (e.g., longer mean fixation times, shorter mean saccades lengths) in reading manipulated texts compared to normal texts were reported in earlier work, little is known about changes of oculomotor targeting observed in within-word landing positions under the above text layouts. Here we carry out precise analyses of landing positions and find substantial changes in the so-called launch-site effect in addition to the expected overall slow-down of reading performance. Specifically, during reading of our manipulated text conditions with reversed letter order (against overall reading direction), we find a reduced launch-site effect, while in all other manipulated text conditions, we observe an increased launch-site effect. Our results clearly indicate that the oculomotor system is highly adaptive when confronted with unusual reading conditions.

Regressions during Reading

Readers occasionally move their eyes to prior text. We distinguish two types of these movements (regressions). One type consists of relatively large regressions that seek to re-process prior text and to revise represented linguistic content to improve comprehension. The other consists of relatively small regressions that seek to correct inaccurate or premature oculomotor programming to improve visual word recognition. Large regressions are guided by spatial and linguistic knowledge, while small regressions appear to be exclusively guided by knowledge of spatial location. There are substantial individual differences in the use of regressions, and college-level readers often do not regress even when this would improve sentence comprehension.

Parallel word processing in the flanker paradigm has a rightward bias

Reading research is exhibiting growing interest in employing variants of the flanker paradigm to address several questions about reading. The paradigm is particularly suited for investigating parallel word processing, parafoveal-on-foveal influences, and visuospatial attention in a simple but constrained setting. However, this methodological deviation from natural reading warrants careful assessment of the extent to which cognitive processes underlying reading operate similarly in these respective settings. The present study investigated whether readers’ distribution of attention in the flanker paradigm resembles that observed during sentence reading; that is, with a rightward bias. Participants made lexical decisions about foveal target words while we manipulated parafoveal flanking words. In line with prior research, we established a parafoveal-on-foveal repetition effect, and this effect was increased for rightward flankers compared with leftward flankers. In a second experiment, we found that, compared with a no-flanker condition, rightward repetition flankers facilitated target processing, while leftward flankers interfered. Additionally, the repetition effect was larger for rightward than for leftward flankers. From these findings, we infer that attention in the flanker paradigm is indeed biased toward the right, and that the flanker paradigm thus provides an effective analogy to natural reading for investigating the role of visuospatial attention. The enhanced parafoveal-on-foveal effects within the attended region further underline the key role of attention in the spatial integration of orthographic information. Lastly, we conclude that future research employing the flanker paradigm should take the asymmetrical aspect of the attentional deployment into account.

Effect of modulating braille dot height on reading regressions

It is well known that people who read print or braille sometimes make eye or finger movements against the reading direction. The way these regressions are elicited has been studied in detail by manipulating linguistic aspects of the reading material. Actually, it has been shown that reducing the physical intensity or clarity of the visual input signal can also lead to increased regressions during reading. We asked whether the same might be true in the haptic realm while reading braille. We set the height of braille dots at three different levels (high, medium, and low) and asked adult blind, practiced braille readers to read standardized texts without any repetition of content. The results show that setting the braille dot height near the tactile threshold significantly increased the frequency of regressive finger movements. Additionally, at the lowest braille dot height, braille reading speed significantly diminished. These effects did not occur at braille dot heights that were closer to the height of standard braille (medium and high). We tentatively conclude that this effect may be due to a heightened sense of uncertainty elicited by perception near the threshold that seems to be common to the reading process, independent of the sensory input modality. Furthermore, the described effect may be a feature of a brain area that contributes to the reading process mediated by vision as well as touch.

Integrating Orthographic Information Across Time and Space

Research has suggested that the word recognition process is influenced by the integration of orthographic information across words. The precise nature of this integration process may vary, however, depending on whether words are in temporal or spatial proximity. Here we present a lexical decision experiment, designed to compare temporal and spatial integration processes more directly. Masked priming was used to reveal effects of temporal integration, while the flanker paradigm was used to reveal effects of spatial integration. Primes/flankers were high-frequency orthographic neighbors of the target (blue-blur) or unrelated control words (head-blur). We replicated prior observations of inhibition in trials where the neighbor was used as a masked prime, while facilitation was observed in trials where the neighbor was presented as flanker. We conclude that sub-lexical orthographic information is integrated both temporally and spatially, but that spatial information is used to segregate lexical representations activated by spatially distinct sources.

Two stages of parafoveal processing during reading: Evidence from a display change detection task

We used a display change detection paradigm (Slattery, Angele, & Rayner Human Perception and Performance, 37, 1924–1938 2011) to investigate whether display change detection uses orthographic regularity and whether detection is affected by the processing difficulty of the word preceding the boundary that triggers the display change. Subjects were significantly more sensitive to display changes when the change was from a nonwordlike preview than when the change was from a wordlike preview, but the preview benefit effect on the target word was not affected by whether the preview was wordlike or nonwordlike. Additionally, we did not find any influence of preboundary word frequency on display change detection performance. Our results suggest that display change detection and lexical processing do not use the same cognitive mechanisms. We propose that parafoveal processing takes place in two stages: an early, orthography-based, preattentional stage, and a late, attention-dependent lexical access stage.

The role of character positional frequency on Chinese word learning during natural reading

Readers’ eye movements were recorded to examine the role of character positional frequency on Chinese lexical acquisition during reading and its possible modulation by word spacing. In Experiment 1, three types of pseudowords were constructed based on each character’s positional frequency, providing congruent, incongruent, and no positional word segmentation information. Each pseudoword was embedded into two sets of sentences, for the learning and the test phases. In the learning phase, half the participants read sentences in word-spaced format, and half in unspaced format. In the test phase, all participants read sentences in unspaced format. The results showed an inhibitory effect of character positional frequency upon the efficiency of word learning when processing incongruent pseudowords both in the learning and test phase, and also showed facilitatory effect of word spacing in the learning phase, but not at test. Most importantly, these two characteristics exerted independent influences on word segmentation. In Experiment 2, three analogous types of pseudowords were created whilst controlling for orthographic neighborhood size. The results of the two experiments were consistent, except that the effect of character positional frequency was absent in the test phase in Experiment 2. We argue that the positional frequency of a word’s constituent characters may influence the character-to-word assignment in a process that likely incorporates both lexical segmentation and identification.

Skipping of Chinese characters does not rely on word-based processing

Previous eye-movement studies have indicated that people tend to skip extremely high-frequency words in sentence reading, such as "the" in English and "/de" in Chinese. Two alternative hypotheses have been proposed to explain how this frequent skipping happens in Chinese reading: one assumes that skipping happens when the preview has been fully identified at the word level (word-based skipping); the other assumes that skipping happens whenever the preview character is easy to identify regardless of whether lexical processing has been completed or not (character-based skipping). Using the gaze-contingent display change paradigm, we examined the two hypotheses by substituting the preview of the third character of a four-character Chinese word with the high-frequency Chinese character "/de", which should disrupt the ongoing word-level processing. The character-based skipping hypothesis predicts that this manipulation will enhance the skipping probability of the target character (i.e., the third character of the target word), because the character "/de" has much higher character frequency than the original character. The word-based skipping hypothesis instead predicts a reduction of the skipping probability of the target character because the presence of the character "/de" is lexically infelicitous at word level. The results supported the character-based skipping hypothesis, indicating that in Chinese reading the decision of skipping a character can be made before integrating it into a word.

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.

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

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

Neural Correlates of Word Recognition: A Systematic Comparison of Natural Reading and Rapid Serial Visual Presentation

Neural correlates of word recognition are commonly studied with (rapid) serial visual presentation (RSVP), a condition that eliminates three fundamental properties of natural reading: parafoveal preprocessing, saccade execution, and the fast changes in attentional processing load occurring from fixation to fixation. We combined eye-tracking and EEG to systematically investigate the impact of all three factors on brain-electric activity during reading. Participants read lists of words either actively with eye movements (eliciting fixation-related potentials) or maintained fixation while the text moved passively through foveal vision at a matched pace (RSVP-with-flankers paradigm, eliciting ERPs). The preview of the upcoming word was manipulated by changing the number of parafoveally visible letters. Processing load was varied by presenting words of varying lexical frequency. We found that all three factors have strong interactive effects on the brain's responses to words: Once a word was fixated, occipitotemporal N1 amplitude decreased monotonically with the amount of parafoveal information available during the preceding fixation; hence, the N1 component was markedly attenuated under reading conditions with preview. Importantly, this preview effect was substantially larger during active reading (with saccades) than during passive RSVP with flankers, suggesting that the execution of eye movements facilitates word recognition by increasing parafoveal preprocessing. Lastly, we found that the N1 component elicited by a word also reflects the lexical processing load imposed by the previously inspected word. Together, these results demonstrate that, under more natural conditions, words are recognized in a spatiotemporally distributed and interdependent manner across multiple eye fixations, a process that is mediated by active motor behavior.

Integration of parafoveal orthographic information during foveal word reading: beyond the sub-lexical level?

Prior research has shown that processing of a given target word is facilitated by the simultaneous presentation of orthographically related stimuli in the parafovea. Here we investigate the nature of such spatial integration processes by presenting orthographic neighbours of target words in the parafovea, considering that neighbours have been shown to inhibit, rather than facilitate, recognition of target words in foveal masked priming research. In Experiment 1, we used the gaze-contingent boundary paradigm to manipulate the parafoveal information subjects received while they fixated a target word within a sentence. In Experiment 2, we used the Flanking Letters Lexical Decision paradigm to manipulate parafoveal information while subjects read isolated words. Parafoveal words were either a higher-frequency orthographic neighbour of targets words (e.g., blue-blur) or a high-frequency unrelated word (e.g., hand-blur). We found that parafoveal orthographic neighbours facilitated, rather than inhibited, processing of the target. Thus, the present findings provide further evidence that orthographic information is integrated across multiple words and suggest that either the integration process does not enable simultaneous access to those words' lexical representations, or that lexical representations activated by spatially distinct stimuli do not compete for recognition.

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.

Integration of Sentence-Level Semantic Information in Parafovea: Evidence from the RSVP-Flanker Paradigm

During text reading, the parafoveal word was usually presented between 2° and 5° from the point of fixation. Whether semantic information of parafoveal words can be processed during sentence reading is a critical and long-standing issue. Recently, studies using the RSVP-flanker paradigm have shown that the incongruent parafoveal word, presented as right flanker, elicited a more negative N400 compared with the congruent parafoveal word. This suggests that the semantic information of parafoveal words can be extracted and integrated during sentence reading, because the N400 effect is a classical index of semantic integration. However, as most previous studies did not control the word-pair congruency of the parafoveal and the foveal words that were presented in the critical triad, it is still unclear whether such integration happened at the sentence level or just at the word-pair level. The present study addressed this question by manipulating verbs in Chinese sentences to yield either a semantically congruent or semantically incongruent context for the critical noun. In particular, the interval between the critical nouns and verbs was controlled to be 4 or 5 characters. Thus, to detect the incongruence of the parafoveal noun, participants had to integrate it with the global sentential context. The results revealed that the N400 time-locked to the critical triads was more negative in incongruent than in congruent sentences, suggesting that parafoveal semantic information can be integrated at the sentence level during Chinese reading.

The effects of crowding on eye movement patterns in reading

Crowding is a phenomenon that characterizes normal periphery limiting letter identification when other letters surround the signal. We investigated the nature of the reading limitation of crowding by analyzing eye-movement patterns. The stimuli consisted of two items varying across trials for letter spacing (spaced, unspaced and increased size), lexicality (words or pseudowords), number of letters (4, 6, 8), and reading modality (oral and silent). In Experiments 1 and 2 (oral and silent reading, respectively) the results show that an increase in letter spacing induced an increase in the number of fixations and in gaze duration, but a reduction in the first fixation duration. More importantly, increasing letter size (Experiment 3) produced the same first fixation duration advantage as empty spacing, indicating that, as predicted by crowding, only center-to-center letter distance, and not spacing per se, matters. Moreover, when the letter size was enlarged the number of fixations did not increase as much as in the previous experiments, suggesting that this measure depends on visual acuity rather than on crowding. Finally, gaze duration, a measure of word recognition, did not change with the letter size enlargement. No qualitative differences were found between oral and silent reading experiments (1 and 2), indicating that the articulatory process did not influence the outcome. Finally, a facilitatory effect of lexicality was found in all conditions, indicating an interaction between perceptual and lexical processing. Overall, our results indicate that crowding influences normal word reading by means of an increase in first fixation duration, a measure of word encoding, which we interpret as a modulatory effect of attention on critical spacing.

Neural Correlates of Fixation Duration during Real-world Scene Viewing: Evidence from Fixation-related (FIRE) fMRI

During active scene perception, our eyes move from one location to another via saccadic eye movements, with the eyes fixating objects and scene elements for varying amounts of time. Much of the variability in fixation duration is accounted for by attentional, perceptual, and cognitive processes associated with scene analysis and comprehension. For this reason, current theories of active scene viewing attempt to account for the influence of attention and cognition on fixation duration. Yet almost nothing is known about the neurocognitive systems associated with variation in fixation duration during scene viewing. We addressed this topic using fixation-related fMRI, which involves coregistering high-resolution eye tracking and magnetic resonance scanning to conduct event-related fMRI analysis based on characteristics of eye movements. We observed that activation in visual and prefrontal executive control areas was positively correlated with fixation duration, whereas activation in ventral areas associated with scene encoding and medial superior frontal and paracentral regions associated with changing action plans was negatively correlated with fixation duration. The results suggest that fixation duration in scene viewing is controlled by cognitive processes associated with real-time scene analysis interacting with motor planning, consistent with current computational models of active vision for scene perception.

User Activity Patterns During Information Search

Personalization of support for information seeking depends crucially on the information retrieval system's knowledge of the task that led the person to engage in information seeking. Users work during information search sessions to satisfy their task goals, and their activity is not random. To what degree are there patterns in the user activity during information search sessions? Do activity patterns reflect the user's situation as the user moves through the search task under the influence of his or her task goal? Do these patterns reflect aspects of different types of information-seeking tasks? Could such activity patterns identify contexts within which information seeking takes place? To investigate these questions, we model sequences of user behaviors in two independent user studies of information search sessions (N = 32 users, 128 sessions, and N = 40 users, 160 sessions). Two representations of user activity patterns are used. One is based on the sequences of page use; the other is based on a cognitive representation of information acquisition derived from eye movement patterns in service of the reading process. One of the user studies considered journalism work tasks; the other concerned background research in genomics using search tasks taken from the TREC Genomics Track. The search tasks differed in basic dimensions of complexity, specificity, and the type of information product (intellectual or factual) needed to achieve the overall task goal. The results show that similar patterns of user activity are observed at both the cognitive and page use levels. The activity patterns at both representation layers are able to distinguish between task types in similar ways and, to some degree, between tasks of different levels of difficulty. We explore relationships between the results and task difficulty and discuss the use of activity patterns to explore events within a search session. User activity patterns can be at least partially observed in server-side search logs. A focus on patterns of user activity sequences may contribute to the development of information systems that better personalize the user's search experience.

Effects of seductive details evidenced by gaze duration

According to a meta-analysis of empirical studies, seductive details such as emotionally interesting text segments and attention-grabbing pictures have significant negative effects on the reader's recall, reading comprehension, and learning of important textual information. This study investigates the negative effects of seductive details on recall of main ideas and reading comprehension by using an eye-tracking technique. In the experiment, a total of 56 undergraduate students read a block of expository text with seductive details, and the spatial and temporal distribution of attention was measured by gaze duration and recorded by an eye tracker. Then recall and reading comprehension tests were employed. Two multiple regression analyses were conducted to investigate the relationship between attention allocation and reading performance. The results indicate that increased attention to seductive sentences, not to seductive pictures, was a major determinant of poor performance in terms of both recall and reading comprehension, suggesting that increased attentional allocation to seductive sentences may hinder information retrieval and produce a less coherent mental representation of given text.

Synonyms Provide Semantic Preview Benefit in English

While orthographic and phonological preview benefits in reading are uncontroversial (see Schotter, Angele, & Rayner, 2012 for a review), researchers have debated the existence of semantic preview benefit with positive evidence in Chinese and German, but no support in English. Two experiments, using the gazecontingent boundary paradigm (Rayner, 1975), show that semantic preview benefit can be observed in English when the preview and target are synonyms (share the same or highly similar meaning, e.g., curlers-rollers). However, no semantic preview benefit was observed for semantic associates (e.g., curlers-styling). These different preview conditions represent different degrees to which the meaning of the sentence changes when the preview is replaced by the target. When this continuous variable (determined by a norming procedure) was used as the predictor in the analyses, there was a significant relationship between it and all reading time measures, suggesting that similarity in meaning between what is accessed parafoveally and what is processed foveally may be an important influence on the presence of semantic preview benefit. Why synonyms provide semantic preview benefit in reading English is discussed in relation to (1) previous failures to find semantic preview benefit in English and (2) the fact that semantic preview benefit is observed in other languages even for non-synonymous words. Semantic preview benefit is argued to depend on several factors-attentional resources, depth of orthography, and degree of similarity between preview and target.