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.

Several studies have shown that parafoveal processing is essential in reading development. In this study, we explore the effect of transposing and substituting inner and outer letters in a flanker lexical decision task administered to 78 children and 65 adults. The results show a significant interaction between the Group factor and the Flanker factor, suggesting differences in the effects of flankers for children and adults. In the case of adults, transposed and substituted letters generated benefit of the same magnitude in comparison with the unrelated condition, but of lesser magnitude than the Identity condition. In the case of children, the results show facilitation for the transposed conditions of the same magnitude as the Identity condition. However, the substitution conditions failed to generate any benefit in comparison with the unrelated condition. The results for the adults are in line with the predictions of the open bigram model, whereas the results for the children are explained through a developmental perspective of the dual-route architecture and open bigram framework.

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.

Reading fluency deficits in schizophrenia (Sz) have been attributed to dysfunction in both lower-level, oculomotor processing and higher-level, lexical processing, according to the two-hit deficit model. Given that prior work examining reading deficits in individuals with Sz has primarily focused on single-line and single-word reading tasks, eye movements that are unique to passage reading, such as return-sweep saccades, have not yet been examined in Sz. Return-sweep saccades are large eye movements that are made when readers move from the end of one line to the beginning of the next line during natural passage reading. Examining return-sweeps provides an opportunity to examine lower-level, oculomotor deficits during reading under circumstances when upcoming higher-level, lexical information is not available for visual processing because visual acuity constraints do not permit detailed lexical processing of line-initial words when return-sweeps are programmed. To examine the source of reading deficits in Sz, we analysed an existing data set in which participants read multi-line passages with manipulations to line spacing. Readers with Sz made significantly more return-sweep targeting errors followed by corrective saccades compared with healthy controls. Both groups showed similar effects of line spacing on return-sweep targeting accuracy, suggesting similar sensitivities to visual crowding during reading. Furthermore, the patterns of fixation durations in readers with Sz corroborate prior work indicating reduced parafoveal processing of upcoming words. Together, these findings suggest that lower-level visual and oculomotor dysfunction contribute to reading deficits in Sz, providing support for the two-hit deficit model.

Visual crowding, generally defined as the deleterious influence of clutter on visual discrimination, is a form of inhibitory interaction between nearby objects. While the role of crowding in reading has been established in psychophysics research using rapid serial visual presentation (RSVP) paradigms, how crowding affects additional processes involved in natural reading, including parafoveal processing and saccade targeting, remains unclear. The current study investigated crowding effects on reading via two eye-tracking experiments. Experiment 1 was a sentence-reading experiment incorporating an eye-contingent boundary change in which reader\'s parafoveal processing was quantified through comparing reading times after valid or invalid information was presented in the parafovea. Letter spacing was jointly manipulated to compare how crowding affects parafoveal processing. Experiment 2 was a passage-reading experiment with a line spacing manipulation. In addition to replicating previously observed letter spacing effects on global reading parameters (i.e., more but shorter fixations with wider spacing), Experiment 1 found an interaction between preview validity and letter spacing indicating that the efficiency of parafoveal processing was constrained by crowding and visual acuity. Experiment 2 found reliable but subtle influences of line spacing. Participants had shorter fixation durations, higher skipping probabilities, and less accurate return sweeps when line spacing was increased. In addition to extending the literature on the role of crowding to reading in ecologically valid scenarios, the current results inform future research on characterizing the influence of crowding in natural reading and comparing effects of crowding across reader populations.

In the present investigation we adopted the Rapid Parallel Visual Presentation Paradigm with the aim of studying the timing of parafoveal semantic processing. The paradigm consisted in the simultaneous presentation of couple of words, one in fovea (W1) and one in parafovea (W2). In three experiments, we manipulated word frequency, semantic relatedness between the two words and the effect of stimulus duration (150, 100, 50 ms). Accuracy on W2 was higher when W1 and W2 were both of high-frequency and when they were semantically related. W1 reading times were faster when both words were highly-frequent but only when the two words were semantically related (150 ms); when W2 was highly frequent and semantically related to the foveal word (100 ms). When the stimuli were presented for 50 ms, the reading times were reduced when W1 was highly frequent and, crucially, in case of a semantic relation between the two words. Our results suggest that it is possible to extract semantic information from the parafovea very fast (within 100 ms) and in parallel to the processing of the foveal word, especially when the cognitive load required for the latter is reduced, as is the case for high-frequency words. We discuss the resulting data in terms of word recognition and eye movements\' models.

Studies on German and English have shown that children and adults can rely on phonological and orthographic information from the parafovea during reading, but this reliance differs between ages and languages. In the current study, we investigated the development of phonological and orthographic parafoveal processing during silent reading in Russian-speaking 8-year-old children, 10-year-old children, and adults using the gaze-contingent boundary paradigm. The participants read sentences with embedded nouns that were presented in original, pseudohomophone, control for pseudohomophone, transposed-letter, and control for transposed-letter conditions in the parafoveal area to assess phonological and orthographic preview benefit effects. The results revealed that all groups of participants relied only on orthographic but not phonological parafoveal information. These findings indicate that 8-year-old children already preprocess parafoveal information similarly to adults.

We compared processing of letter and symbol stimuli presented briefly in the right or left visual field, and either in isolation or surrounded by two flanking characters of the same category. The flankers could be arranged horizontally or vertically. Participants performed a two-alternative forced choice (2AFC) task with the isolated character or the central character in flanked displays as target. Alternatives in the 2AFC task were characters from the same category as the target that were not present in the display. We recorded EEG in order to investigate the timing of crowding effects (isolated vs. flanked conditions) and the hypothesized differential impact of crowding on letters and symbols. Behavioral results showed no significant difference between isolated letters and symbols, but significantly higher accuracy to flanked letters compared with flanked symbols - and the effect of stimulus type was significantly greater with horizontally aligned stimuli. Likewise, amplitude of the N170 and a following negativity (identified here as the N250) did not differ significantly when comparing isolated letters and symbols but did differ for flanked stimuli. Flanked letters showed significantly greater N170 and N250 amplitudes compared with flanked symbols. N170 and N250 amplitudes were also significantly greater for flanked vs. isolated letters whereas symbols showed a significant difference in the opposite direction for the N250. We conclude that the processing of compact strings of letters is optimized for skilled reading via changes in the mapping of visual features onto letter identities in multi-letter arrays in order to reduce the interfering effects of excessive crowding.

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.

During parafoveal processing, skilled readers encode letter identity independently of letter position (Johnson et al., 2007). In the current experiment, we examined orthographic parafoveal processing in readers with dyslexia. Specifically, the eye movements of skilled readers and adult readers with dyslexia were recorded during a boundary paradigm experiment (Rayner, 1975). Parafoveal previews were either identical to the target word (e.g., nearly), a transposed-letter preview (e.g., enarly), or a substituted-letter preview (e.g., acarly). Dyslexic and non-dyslexic readers demonstrated orthographic parafoveal preview benefits during silent sentence reading and both reading groups encoded letter identity and letter position information parafoveally. However, dyslexic adults showed, that very early in lexical processing, during parafoveal preview, the positional information of a word\'s initial letters were encoded less flexibly compared to during skilled adult reading. We suggest that dyslexic readers are less able to benefit from correct letter identity information (i.e., in the letter transposition previews) due to the lack of direct mapping of orthography to phonology. The current findings demonstrate that dyslexic readers show consistent and dyslexic-specific reading difficulties in foveal and parafoveal processing during silent sentence reading.