EyeLink Reading and Language Eye-Tracking Publications
All EyeLink reading and language research publications up until 2022 (with some early 2023s) are listed below by year. You can search the publications using keywords such as Visual World, Comprehension, Speech Production, etc. You can also search for individual author names. If we missed any EyeLink reading or language articles, please email us!
Wei Zhou; Yi Fan; Yulin Chang; Wenjuan Liu; Jiuju Wang; Yufeng Wang
Pathogenesis of comorbid ADHD and Chinese developmental dyslexia: Evidence from eye-movement tracking and rapid automatized naming Journal Article
In: Journal of Attention Disorders, pp. 1–13, 2022.
Background: ADHD and Chinese developmental dyslexia (DD) have a very high comorbidity rate; however, which cognitive deficits characterize the comorbidity and when they occur during cognitive processing are still under debate. Methods: Rapid automatic naming (RAN) tasks with eye-movement tracking were conducted with 75 children who were typically developing, had comorbid ADHD and DD, had only ADHD, and had only DD. Results: The clinical groups had longer first fixation durations than the control for RAN digits. Temporal eye-movement measures, such as gaze duration and total reading time, were found to vary between the comorbidity and ADHD groups. Spatial eye-movement measures, such as regression probability and incoming saccade amplitude, differed between the comorbidity and DD groups. Conclusions: These results indicate that investigation with eye-movement measures combined with RAN tasks can strengthen the understanding of the pathogenesis of comorbid ADHD and DD.
Marianna Stella; Paul E. Engelhardt
Use of parsing heuristics in the comprehension of passive sentences: Evidence from dyslexia and individual differences Journal Article
In: Brain Sciences, vol. 12, pp. 1–19, 2022.
This study examined the comprehension of passive sentences in order to investigate whether individuals with dyslexia rely on parsing heuristics in language comprehension to a greater extent than non‐dyslexic readers. One hundred adults (50 dyslexics and 50 controls) read active and passive sentences, and we also manipulated semantic plausibility. Eye movements were monitored, while participants read each sentence, and afterwards, participants answered a comprehension question. We also assessed verbal intelligence and working memory in all participants. Results showed dyslexia status interacted with sentence structure and plausibility, such that participants with dyslexia showed significantly more comprehension errors with passive and implausible sentence. With respect to verbal intelligence and working memory, we found that individuals with lower verbal intelligence were overall more likely to make comprehension errors, and individuals with lower working memory showed particular difficulties with passive and implausible sentences. For reading times, we found that individuals with dyslexia were overall slower readers. These findings suggest that (1) individuals with dyslexia do rely on heuristics to a greater extent than do nondyslexic individuals, and (2) individual differences variables (e.g., verbal intelligence and working memory) are also related to the use of parsing heuristics. For the latter, lower ability individuals tended to be more consistent with heuristic processing (i.e., good‐enough representations).
Julie A. Kirkby; Rhiannon S. Barrington; Denis Drieghe; Simon P. Liversedge
Parafoveal processing and transposed-letter effects in dyslexic reading Journal Article
In: Dyslexia, vol. 28, pp. 359–374, 2022.
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.
Holly Joseph; Daisy Powell
Does a specialist typeface affect how fluently children with and without dyslexia process letters, words, and passages? Journal Article
In: Dyslexia, vol. 28, no. 4, pp. 448–470, 2022.
Children with dyslexia are at risk of poor academic attainment and lower life chances if they do not receive the support they need. Alongside phonics-based interventions which already have a strong evidence base, specialist dyslexia typefaces have been offered as an additional or alternative form of support. The current study examined whether one such typeface, Dyslexie, had a benefit over a standard typeface in identifying letters, reading words, and reading passages. 71 children, aged 8–12 years, 37 of whom had a diagnosis of dyslexia, completed a rapid letter naming task, a word reading efficiency task, and a passage reading task in two typefaces, Dyslexie and Calibri. Spacing between letters and words was kept constant. Results showed no differences in word or passage reading between the two typesfaces, but letter naming did appear to be more fluent when letters were presented in Dyslexie rather than Calibri text for all children. The results suggest that a typeface in which letters are designed to be distinctive from one another may be beneficial for letter identification and that an intervention in which children are taught letters in a specialist typeface is worthy of consideration.
Svetlana Alexeeva; Vladislav Zubov; Alena Konina
The effect of a dyslexia-specific Cyrillic font, LexiaD, on reading speed: further exploration in adolescents with and without dyslexia Journal Article
In: Primenjena Psihologija, vol. 15, no. 2, pp. 199–236, 2022.
The current study aims to test the assumption that a specially designed Cyrillic font, LexiaD, can assist adolescents with reading problems and facilitate their reading experience. LexiaD was compared with the widely used Arial font. Two groups of adolescents with dyslexia (N = 34) and without dyslexia (N = 28) silently read 144 sentences from the Russian Sentence Corpus (Laurinavichyute et al., 2019), some of which were presented in LexiaD, and others in Arial, while their eye movements were recorded. LexiaD did not show the desired effect for adolescents at the beginning of the experiment: Arial outperformed it in reading speed in both participant groups. However, by the end of the experiment, LexiaD showed a better performance. Although the speed of the higher-level cognitive processing (e.g., lexical access) in both fonts did not differ significantly, the feature extraction was found to be better in LexiaD than in Arial. Thus, we found some positive effect of LexiaD when participants with and without dyslexia got accustomed to it. A follow-up study with an explicit exposure session is needed to confirm this conclusion.
Olga Parshina; Anastasiya Lopukhina; Sofya Goldina; Ekaterina Iskra; Margarita Serebryakova; Vladislava Staroverova; Nina Zdorova; Olga Dragoy
Global reading processes in children with high risk of dyslexia: A scanpath analysis Journal Article
In: Annals of Dyslexia, vol. 72, no. 3, pp. 403–425, 2022.
The study presents the first systematic comparison of the global reading processes via scanpath analysis in Russian-speaking children with and without reading difficulties. First, we compared basic eye-movement characteristics in reading sentences in two groups of children in grades 1 to 5 (N = 72 in high risk of developmental dyslexia group and N = 72 in the control group). Next, using the scanpath method, we investigated which global reading processes these children adopt to read the entire sentence and how these processes differ between the groups. Finally, we were interested in the timeframe of the change in the global reading processes from the 1st to the 5th grades for both groups. We found that the main difference in word-level measures between groups was the reading speed reflected in fixation durations. However, the examination of the five identified global reading processes revealed qualitative similarities in reading patterns between groups. Children in the control group progressed quickly and by the 4th grade engaged in an adult-like fluent reading process. The high-risk group started with the beginner reading process, then similar to first graders in the control group, engaged mostly in the intermediate and upper-intermediate reading processes in 2nd to 4th grades. They reach the advanced process in the 5th grade, the same pattern preferred by the control group second graders. Overall, the scanpath analysis reveals that although there are quantitative differences in the word-level eye-tracking measures between groups, qualitatively children in the high-risk group read on par with typically developing peers but with a 3-year reading delay.
Ciara Egan; Anna Siyanova-Chanturia; Paul Warren; Manon W. Jones
As clear as glass: How figurativeness and familiarity impact simile processing in readers with and without dyslexia Journal Article
In: Quarterly Journal of Experimental Psychology, vol. 76, no. 2, pp. 231–247, 2022.
For skilled readers, idiomatic language confers faster access to overall meaning compared with non-idiomatic language, with a processing advantage for figurative over literal interpretation. However, currently very little research exists to elucidate whether atypical readers—such as those with developmental dyslexia—show such a processing advantage for figurative interpretations of idioms, or whether their reading impairment implicates subtle differences in semantic access. We wanted to know whether an initial figurative interpretation of similes, for both typical and dyslexic readers, is dependent on familiarity. Here, we tracked typical and dyslexic readers' eye movements as they read sentences containing similes (e.g., as cold as ice), orthogonally manipulated for novelty (e.g., familiar: as cold as ice, novel: as cold as snow) and figurativeness (e.g., literal: as cold as ice [low temperature], figurative: as cold as ice [emotionally distant]), with figurativeness being defined by the sentence context. Both participant groups exhibited a processing advantage for familiar and figurative similes over novel and literal similes. However, compared with typical readers, participants with dyslexia had greater difficulty processing similes both when they were unfamiliar and when the context biased the simile meaning towards a literal rather than a figurative interpretation. Our findings suggest a semantic processing anomaly in dyslexic readers, which we discuss in light of recent literature on sentence-level semantic processing.
Zoey Stark; Léon Franzen; Aaron P. Johnson
Insights from a dyslexia simulation font: Can we simulate reading struggles of individuals with dyslexia? Journal Article
In: Dyslexia, vol. 28, no. 2, pp. 228–243, 2022.
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.
Xiuhong Li; Weidong Li; Buyun Liu; Jinxin Zhang; Jingwen Ma; Chuanbo Xie; Jing Wu; Jin Jing
The influence of articulatory suppression on reading among chinese children with developmental dyslexia: An eye-movement study Journal Article
In: Frontiers in Pediatrics, vol. 9, pp. 758615, 2021.
Objective: The study aimed to examine how the phonological loop influences reading ability and processing in Chinese children with developmental dyslexia (DD). Methods: This study included 30 children with DD and 37 children without DD. Two types of articles (i.e., scenery prose and narrative story) and two conditions (under the conditions of articulatory-suppression and silent reading) were applied. An eye-link II High-Speed Eye Tracker was used to track a series of eye-movement parameters. The data were analyzed by the linear Mixed-Effects model. Results: Compared with children without DD, Children with DD had lower reading achievement (RA), frequency of saccades (FS) and frequency of fixations (FF), longer reading time (RT) and average fixation duration (AFD), slower reading speed (RS), shorter average saccade amplitude (ASA) and fixation distance (FD), more number of fixations (NF), and number of saccades (NS). There were significant interactions between participant group and articulatory suppression on RT and FD. We also observed interaction effects between article types and articulatory suppression on RA, AFD, ASA, and FS. Conclusion: Children DD exhibit abnormal phonological loop and eye movements while reading. The role of articulatory suppression on reading varies with the presentation of DD and the article type.
Samy Rima; Michael C. Schmid
Reading specific small saccades predict individual phonemic awareness and reading speed Journal Article
In: Frontiers in Neuroscience, vol. 15, pp. 663242, 2021.
Small fixational eye-movements are a fundamental aspect of vision and thought to reflect fine shifts in covert attention during active viewing. While the perceptual benefits of these small eye movements have been demonstrated during a wide range of experimental tasks including during free viewing, their function during reading remains surprisingly unclear. Previous research demonstrated that readers with increased microsaccade rates displayed longer reading speeds. To what extent increased fixational eye movements are, however, specific to reading and might be indicative of reading skill deficits remains, however, unknown. To address this topic, we compared the eye movement scan paths of 13 neurotypical individuals and 13 subjects diagnosed with developmental dyslexia during short story reading and free viewing of natural scenes. We found that during reading only, dyslexics tended to display small eye movements more frequently compared to neurotypicals, though this effect was not significant at the population level, as it could also occur in slow readers not diagnosed as dyslexics. In line with previous research, neurotypical readers had twice as many regressive compared to progressive microsaccades, which did not occur during free viewing. In contrast, dyslexics showed similar amounts of regressive and progressive small fixational eye movements during both reading and free viewing. We also found that participants with smaller fixational saccades from both neurotypical and dyslexic samples displayed reduced reading speeds and lower scores during independent tests of reading skill. Slower readers also displayed greater variability in the landing points and temporal occurrence of their fixational saccades. Both the rate and spatio-temporal variability of fixational saccades were associated with lower phonemic awareness scores. As none of the observed differences between dyslexics and neurotypical readers occurred during control experiments with free viewing, the reported effects appear to be directly related to reading. In summary, our results highlight the predictive value of small saccades for reading skill, but not necessarily for developmental dyslexia.
Miriam Rivero-Contreras; Paul E. Engelhardt; David Saldaña
An experimental eye-tracking study of text adaptation for readers with dyslexia: Effects of visual support and word frequency Journal Article
In: Annals of Dyslexia, vol. 71, no. 1, pp. 170–187, 2021.
Easy-to-read guidelines recommend visual support and lexical simplification to facilitate text processing, but few empirical studies confirm a positive effect from these recommendations in individuals with dyslexia. This study examined the influence of the visual support and lexical simplification on sentence processing through eye movements at both the text- and word-level, and the differences between readers with and without dyslexia. Furthermore, we explored the influence of reading experience and vocabulary, as control variables. We tested 20 young adults with dyslexia and 20 chronological age-matched controls. Participants read 60 sentences in total. Half the sentences contained an image and the other half did not, and half contained a low-frequency word and half a high-frequency word. Results showed that visual support and lexical simplification facilitated sentence processing, potentially by jointly facilitating lexical semantic access. We also found that participants with lower print exposure and lower vocabulary benefited more from word-level lexical simplification. We conclude that both adaptations could benefit readers with low print exposure and smaller vocabularies, and therefore, to many dyslexic readers who show these characteristics.
Léon Franzen; Zoey Stark; Aaron P. Johnson
Individuals with dyslexia use a different visual sampling strategy to read text Journal Article
In: Scientific Reports, vol. 11, pp. 6449, 2021.
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.
Roberta Daini; Silvia Primativo; Andrea Albonico; Laura Veronelli; Manuela Malaspina; Massimo Corbo; Marialuisa Martelli; Lisa S. Arduino
The focal attention window size explains letter substitution errors in reading Journal Article
In: Brain Sciences, vol. 11, no. 2, pp. 1–18, 2021.
Acquired Neglect Dyslexia is often associated with right-hemisphere brain damage and is mainly characterized by omissions and substitutions in reading single words. Martelli et al. proposed in 2011 that these two types of error are due to different mechanisms. Omissions should depend on neglect plus an oculomotor deficit, whilst substitutions on the difficulty with which the letters are perceptually segregated from each other (i.e., crowding phenomenon). In this study, we hypothesized that a deficit of focal attention could determine a pathological crowding effect, leading to imprecise letter identification and consequently substitution errors. In Experiment 1, three brain-damaged patients, suffering from peripheral dyslexia, mainly characterized by substitutions, underwent an assessment of error distribution in reading pseudowords and a T detection task as a function of cue size and timing, in order to measure focal attention. Each patient, when compared to a control group, showed a deficit in adjusting the attentional focus. In Experiment 2, a group of 17 right-brain-damaged patients were asked to perform the focal attention task and to read single words and pseudowords as a function of inter-letter spacing. The results allowed us to confirm a more general association between substitution-type reading errors and the performance in the focal attention task.
Susana Araújo; Falk Huettig; Antje S. Meyer
What underlies the deficit in rapid automatized naming (RAN) in adults with dyslexia? Evidence from eye movements Journal Article
In: Scientific Studies of Reading, vol. 25, no. 6, pp. 534–549, 2021.
This eye-tracking study explored how phonological encoding and speech production planning for successive words are coordinated in adult readers with dyslexia (N = 22) and control readers (N = 25) during rapid automatized naming (RAN). Using an object-RAN task, we orthogonally manipulated the word-form frequency and phonological neighborhood density of the object names and assessed the effects on speech and eye movements and their temporal coordination. In both groups, there was a significant interaction between word frequency and neighborhood density: shorter fixations for dense than for sparse neighborhoods were observed for low- but not for high-frequency words. This finding does not suggest a specific difficulty in lexical phonological access in dyslexia. However, in readers with dyslexia only, these lexical effects percolated to the late processing stages, indicated by longer offset eye-speech lags. We close by discussing potential reasons for this finding, including suboptimal specification of phonological representations and deficits in attention control or in multi-item coordination.
Marianna Stella; Paul E. Engelhardt
Comprehension and eye movements in the processing of subject-and object-relative clauses: Evidence from dyslexia and individual differences Journal Article
In: Brain Sciences, vol. 11, pp. 915, 2021.
In this study, we examined eye movements and comprehension in sentences containing a relative clause. To date, few studies have focused on syntactic processing in dyslexia and so one goal of the study is to contribute to this gap in the experimental literature. A second goal is to contribute to theoretical psycholinguistic debate concerning the cause and the location of the processing difficulty associated with object-relative clauses. We compared dyslexic readers (n = 50) to a group of non-dyslexic controls (n = 50). We also assessed two key individual differences variables (working memory and verbal intelligence), which have been theorised to impact reading times and comprehension of subject-and object-relative clauses. The results showed that dyslexics and controls had similar comprehension accuracy. However, reading times showed participants with dyslexia spent significantly longer reading the sentences compared to controls (i.e., a main effect of dyslexia). In general, sentence type did not interact with dyslexia status. With respect to individual differences and the theoretical debate, we found that processing difficulty between the subject and object relatives was no longer significant when individual differences in working memory were controlled. Thus, our findings support theories, which assume that working memory demands are responsible for the processing difficulty incurred by (1) individuals with dyslexia and (2) object-relative clauses as compared to subject relative clauses.
Ambre Denis-Noël; Chotiga Pattamadilok; Éric Castet; Pascale Colé
Activation time-course of phonological code in silent word recognition in adult readers with and without dyslexia Journal Article
In: Annals of Dyslexia, vol. 70, no. 3, pp. 313–338, 2020.
In skilled adult readers, reading words is generally assumed to rapidly and automatically activate the phonological code. In adults with dyslexia, despite the main consensus on their phonological processing deficits, little is known about the activation time course of this code. The present study investigated this issue in both populations. Participants' accuracy and eye movements were recorded while they performed a visual lexical decision task in which phonological consistency of written words was manipulated. Readers with dyslexia were affected by phonological consistency during second fixation duration of visual word recognition suggesting a late activation of the phonological code. Regarding skilled readers, no influence of phonological consistency was found when the participants were considered a homogeneous population. However, a different pattern emerged when they were divided into two subgroups according to their phonological and semantic abilities: Those who showed better decoding than semantic skills were affected by phonological consistency at the earliest stage of visual word recognition while those who showed better semantic than decoding skills were not affected by this factor at any processing stage. Overall, the findings suggest that the presence of phonological deficits in readers with dyslexia is associated with a delayed activation of phonological representations during reading. In skilled readers, the contribution of phonology varies with their reading profile, i.e., being phonologically or semantically oriented.
Hazel I. Blythe; Jonathan H. Dickins; Colin R. Kennedy; Simon P. Liversedge
The role of phonology in lexical access in teenagers with a history of dyslexia Journal Article
In: PLoS ONE, vol. 15, no. 3, pp. e0229934, 2020.
We examined phonological recoding during silent sentence reading in teenagers with a history of dyslexia and their typically developing peers. Two experiments are reported in which participants' eye movements were recorded as they read sentences containing correctly spelled words (e.g., church), pseudohomophones (e.g., cherch), and spelling controls (e.g., charch). In Experiment 1 we examined foveal processing of the target word/nonword stimuli, and in Experiment 2 we examined parafoveal pre-processing. There were four participant groups-older teenagers with a history of dyslexia, older typically developing teenagers who were matched for age, younger typically developing teenagers who were matched for reading level, and younger teenagers with a history of dyslexia. All four participant groups showed a pseudohomophone advantage, both from foveal processing and parafoveal preprocessing, indicating that teenagers with a history of dyslexia engage in phonological recoding for lexical identification during silent sentence reading in a comparable manner to their typically developing peers.
Elizabeth Carolina Jiménez; August Romeo; Laura Pérez Zapata; Maria Solé Puig; Patricia Bustos-Valenzuela; José Cañete; Paloma Varela Casal; Hans Supèr
Eye vergence responses in children with and without reading difficulties during a word detection task Journal Article
In: Vision Research, vol. 169, pp. 6–11, 2020.
Vergence eye movements are movements of both eyes in opposite directions. Vergence is known to have a role in binocular vision. However recent studies link vergence eye movements also to attention and attention disorders. As attention may be involved in dyslexia, it is sensible to guess that the presence of reading difficulties can be associated with specific patterns in vergence responses. Data from school children performing a word-reading task have been analysed. In the task, children had to distinguish words from non-words (scrambled words or row of X's), while their eye positions were recorded. Our findings show that after stimulus presentation eyes briefly converge. These vergence responses depend on the stimulus type and age of the child, and are different for children with reading difficulties. Our findings support the idea of a role of attention in word reading and offer an explanation of altered attention in dyslexia.
Samy Rima; Grace Kerbyson; Elizabeth Jones; Michael C. Schmid
Advantage of detecting visual events in the right hemifield is affected by reading skill Journal Article
In: Vision Research, vol. 169, pp. 41–48, 2020.
Visual perception is often not homogenous across the visual field and can vary depending on situational demands. The reasons behind this inhomogeneity are not clear. Here we show that directing attention that is consistent with a western reading habit from left to right, results in a $sim$32% higher sensitivity to detect transient visual events in the right hemifield. This right visual field advantage was largely reduced in individuals with reading difficulties from developmental dyslexia. Similarly, visual detection became more symmetric in skilled readers, when attention was guided opposite to the reading pattern. Taken together, these findings highlight a higher sensitivity in the right visual field for detecting the onset of sudden visual events that is well accounted for by left hemisphere dominated reading habit.
Sebastian P. Korinth; Kerstin Gerstenberger; Christian J. Fiebach
Wider letter-spacing facilitates word processing but impairs reading rates of fast readers Journal Article
In: Frontiers in Psychology, vol. 11, pp. 444, 2020.
Previous reports of improved oral reading performance for dyslexic children but not for regular readers when between-letter spacing was enlarged led to the proposal of a dyslexia-specific deficit in visual crowding. However, it is in this context also critical to understand how letter spacing affects visual word recognition and reading in unimpaired readers. Adopting an individual differences approach, the present study, accordingly, examined whether wider letter spacing improves reading performance also for non-impaired adults during silent reading and whether there is an association between letter spacing and crowding sensitivity. We report eye movement data of 24 German students who silently read texts presented either with normal or wider letter spacing. Foveal and parafoveal crowding sensitivity were estimated using two independent tests. Wider spacing reduced first fixation durations, gaze durations, and total fixation time for all participants, with slower readers showing stronger effects. However, wider letter spacing also reduced skipping probabilities and elicited more fixations, especially for faster readers. In terms of words read per minute, wider letter spacing did not provide a benefit, and faster readers in particular were slowed down. Neither foveal nor parafoveal crowding sensitivity correlated with the observed letter-spacing effects. In conclusion, wide letter spacing reduces single word processing time in typically developed readers during silent reading, but affects reading rates negatively since more words must be fixated. We tentatively propose that wider letter spacing reinforces serial letter processing in slower readers, but disrupts parallel processing of letter chunks in faster readers. These effects of letter spacing do not seem to be mediated by individual differences in crowding sensitivity.
Marianna Stella; Paul E. Engelhardt
Syntactic ambiguity resolution in dyslexia: An examination of cognitive factors underlying eye movement differences and comprehension failures Journal Article
In: Dyslexia, vol. 25, no. 2, pp. 115–141, 2019.
This study examined eye movements and comprehension of temporary syntactic ambiguities in individuals with dyslexia, as few studies have focused on sentence-level comprehension in dyslexia. We tested 50 participants with dyslexia and 50 typically developing controls, in order to investigate (a) whether dyslexics have difficulty revising temporary syntactic misinterpretations and (b) underlying cognitive factors (i.e., working memory and processing speed) associated with eye movement differences and comprehension failures. In the sentence comprehension task, participants read subordinate-main structures that were either ambiguous or unambiguous, and we also manipulated the type of verb contained in the subordinate clause (i.e., reflexive or optionally transitive). Results showed a main effect of group on comprehension, in which individuals with dyslexia showed poorer comprehension than typically developing readers. In addition, participants with dyslexia showed longer total reading times on the disambiguating region of syntactically ambiguous sentences. With respect to cognitive factors, working memory was more associated with group differences than was processing speed. Conclusions focus on sentence-level syntactic processing issues in dyslexia (a previously under-researched area) and the relationship between online and offline measures of syntactic ambiguity resolution.
Erin K. Robertson; Jennifer E. Gallant
Eye tracking reveals subtle spoken sentence comprehension problems in children with dyslexia Journal Article
In: Lingua, vol. 228, pp. 1–17, 2019.
Children with dyslexia who did not have SLI (n = 31) and typically-developing (TD
Helen L. Breadmore; Julia M. Carroll
Sublexical and syntactic processing during reading: Evidence from eye movements of typically developing and dyslexic readers Journal Article
In: Journal of Cognitive Psychology, vol. 30, no. 2, pp. 177–197, 2018.
Skilled, typically developing readers and children with dyslexia read correct sentences and sentences that contained verb errors that were pseudo-homophones, morphological over-regularisations or syntactic errors. All errors increased looking time but the nature of the error and participant group influenced the time course of the effects. The pseudo-homophone effect was significant in all eye-movement measures for adults (N= 26), intermediate (N= 37) and novice typically developing readers (N= 38). This effect was larger for intermediate readers than other groups in total duration. In contrast, morphological over-regularisations increased gaze and total duration (but not first fixation) for intermediate and novice readers, and only total duration for adult readers. Syntactic errors only increased total duration. Children with dyslexia (N= 19) demonstrated smaller effects of pseudo-homophones and over-regularisations than controls, but their processing of syntactic errors was similar. We conclude that dyslexic children's difficulties with reading are linked to overreliance on phonological decoding and underspecified morphological processing, which impacts on word level reading. We highlight that the findings fit well within the grain-size model of word reading [Grainger, J., & Ziegler, J. C. (2011). A dual-route approach to orthographic processing. Frontiers in Psychology, 2, 54. doi:10.3389/fpsyg.2011.00054].
Melanie Gangl; Kristina Moll; Manon W. Jones; Chiara Banfi; Gerd Schulte-Körne; Karin Landerl
Lexical reading in dysfluent readers of German Journal Article
In: Scientific Studies of Reading, vol. 22, no. 1, pp. 24–40, 2018.
Dyslexia in consistent orthographies like German is characterized by dysfluent reading, which is often assumed to result from failure to build up an orthographic lexicon and overreliance on decoding. However, earlier evidence indicates effects of lexical processing at least in some German dyslexic readers. We investigated variations in reading style in an eye-tracking paradigm with German dysfluent 3rd and 4th graders. Twenty-six TypFix-readers (fixation counts within the range of 47 age-matched typical readers) were compared with 42 HighFix-readers (increased fixation counts). Both groups showed lexical access: Words were read more efficiently than nonwords and pseudohomophones. TypFix-readers showed stronger reliance on lexical reading than HighFix-readers (smaller length effects for number of fixations and total reading time, stronger lexicality effects for gaze duration, stronger word-pseudohomophone effects for mean saccade amplitude). We conclude that in both groups, sublexical and lexical reading processes were impaired due to inefficient visual-verbal integration.
Chiara Banfi; Ferenc Kemény; Melanie Gangl; Gerd Schulte-Körne; Kristina Moll; Karin Landerl
Visual attention span performance in German-speaking children with differential reading and spelling profiles: No evidence of group differences Journal Article
In: PLoS ONE, vol. 13, no. 6, pp. e0198903, 2018.
An impairment in the visual attention span (VAS) has been suggested to hamper reading performance of individuals with dyslexia. It is not clear, however, if the very nature of the deficit is visual or verbal and, importantly, if it affects spelling skills as well. The current study investigated VAS by means of forced choice tasks with letters and symbols in a sample of third and fourth graders with age-adequate reading and spelling skills (n= 43), a typical dyslexia profile with combined reading and spelling deficits (n= 26) and isolated spelling deficits (n= 32). The task was devised to contain low phonological short-term memory load and to overcome the limitations of oral reports. Notably, eye-movements were monitored to control that children fixated the center of the display when stimuli were presented. Results yielded no main effect of group as well as no group-related interactions, thus showing that children with dyslexia and isolated spelling deficits did not manifest a VAS deficit for letters or symbols once certain methodological aspects were controlled for. The present results could not replicate previous evidence for the involvement of VAS in reading and dyslexia.
Chiara Banfi; Ferenc Kemény; Melanie Gangl; Gerd Schulte-Körne; Kristina Moll; Karin Landerl
Visuo-spatial cueing in children with differential reading and spelling profiles Journal Article
In: PLoS ONE, vol. 12, no. 7, pp. e0180358, 2017.
Dyslexia has been claimed to be causally related to deficits in visuo-spatial attention. In particular, inefficient shifting of visual attention during spatial cueing paradigms is assumed to be associated with problems in graphemic parsing during sublexical reading. The current study investigated visuo-spatial attention performance in an exogenous cueing paradigm in a large sample (N = 191) of third and fourth graders with different reading and spelling profiles (controls, isolated reading deficit, isolated spelling deficit, combined deficit in reading and spelling). Once individual variability in reaction times was taken into account by means of z-transformation, a cueing deficit (i.e. no significant difference between valid and invalid trials) was found for children with combined deficits in reading and spelling. However, poor readers without spelling problems showed a cueing effect comparable to controls, but exhibited a particularly strong right-over-left advantage (position effect). Isolated poor spellers showed a significant cueing effect, but no position effect. While we replicated earlier findings of a reduced cueing effect among poor nonword readers (indicating deficits in sublexical processing), we also found a reduced cueing effect among children with particularly poor orthographic spelling (indicating deficits in lexical processing). Thus, earlier claims of a specific association with nonword reading could not be confirmed. Controlling for ADHD-symptoms reported in a parental questionnaire did not impact on the statistical analysis, indicating that cueing deficits are not caused by more general attentional limitations. Between 31 and 48% of participants in the three reading and/or spelling deficit groups as well as 32% of the control group showed reduced spatial cueing. These findings indicate a significant, but moderate association between certain aspects of visuo-spatial attention and subcomponents of written language processing, the causal status of which is yet unclear.
Noor Z. Al Dahhan; John R. Kirby; Donald C. Brien; Douglas P. Munoz
Eye movements and articulations during a letter naming speed task: Children with and without Dyslexia Journal Article
In: Journal of Learning Disabilities, vol. 50, no. 3, pp. 275–285, 2017.
Abstract Naming speed (NS) refers to how quickly and accurately participants name a set of familiar stimuli (e.g., letters). NS is an established predictor of reading ability, but controversy remains over why it is related to reading. We used three techniques (stimulus manipulations to emphasize phonological and/or visual aspects, decomposition of NS times into pause and articulation components, and analysis of eye movements during task performance) with three groups of participants (children with dyslexia, ages 9–10; chronological-age [CA] controls, ages 9–10; reading-level [RL] controls, ages 6–7) to examine NS and the NS–reading relationship. Results indicated (a) for all groups, increasing visual similarity of the letters decreased letter naming efficiency and increased naming errors, saccades, regressions (rapid eye movements back to letters already fixated), pause times, and fixation durations; (b) children with dyslexia performed like RL controls and were less efficient, had longer articulation times, pause times, fixation durations, and made more errors and regressions than CA controls; and (c) pause time and fixation duration were the most powerful predictors of reading. We conclude that NS is related to reading via fixation durations and pause times: Longer fixation durations and pause times reflect the greater amount of time needed to acquire visual/orthographic information from stimuli and prepare the correct response.
Irene Ablinger; Ralph Radach
Diverging receptive and expressive word processing mechanisms in a deep dyslexic reader Journal Article
In: Neuropsychologia, vol. 81, pp. 12–21, 2016.
We report on KJ, a patient with acquired dyslexia due to cerebral artery infarction. He represents an unusually clear case of an "output" deep dyslexic reader, with a distinct pattern of pure semantic reading. According to current neuropsychological models of reading, the severity of this condition is directly related to the degree of impairment in semantic and phonological representations and the resulting imbalance in the interaction between the two word processing pathways. The present work sought to examine whether an innovative eye movement supported intervention combining lexical and segmental therapy would strengthen phonological processing and lead to an attenuation of the extreme semantic over-involvement in KJ's word identification process. Reading performance was assessed before (T1) between (T2) and after (T3) therapy using both analyses of linguistic errors and word viewing patterns. Therapy resulted in improved reading aloud accuracy along with a change in error distribution that suggested a return to more sequential reading. Interestingly, this was in contrast to the dynamics of moment-to-moment word processing, as eye movement analyses still suggested a predominantly holistic strategy, even at T3. So, in addition to documenting the success of the therapeutic intervention, our results call for a theoretically important conclusion: Real-time letter and word recognition routines should be considered separately from properties of the verbal output. Combining both perspectives may provide a promising strategy for future assessment and therapy evaluation.
Manon W. Jones; Margaret J. Snowling; Kristina Moll
What automaticity deficit? Activation of lexical information by readers with dyslexia in a rapid automatized naming Stroop-switch task Journal Article
In: Journal of Experimental Psychology: Learning, Memory, and Cognition, vol. 42, no. 3, pp. 465–474, 2016.
Reading fluency is often predicted by rapid automatized naming (RAN) speed, which as the name implies, measures the automaticity with which familiar stimuli (e.g., letters) can be retrieved and named. Readers with dyslexia are considered to have less "automatized" access to lexical information, reflected in longer RAN times compared with nondyslexic readers. We combined the RAN task with a Stroop-switch manipulation to test the automaticity of dyslexic and nondyslexic readers' lexical access directly within a fluency task. Participants named letters in 10 × 4 arrays while eye movements and speech responses were recorded. Upon fixation, specific letter font colors changed from black to a different color, whereupon the participant was required to rapidly switch from naming the letter to naming the letter color. We could therefore measure reading group differences on "automatic" lexical processing, insofar as it was task-irrelevant. Readers with dyslexia showed obligatory lexical processing and a timeline for recognition that was overall similar to typical readers, but a delay emerged in the output (naming) phase. Further delay was caused by visual-orthographic competition between neighboring stimuli. Our findings outline the specific processes involved when researchers speak of "impaired automaticity" in dyslexic readers' fluency, and are discussed in the context of the broader literature in this field.
Yun Ding; Jing Zhao; Tao He; Yufei Tan; Lingshuang Zheng; Zhiguo Wang
Selective impairments in covert shifts of attention in Chinese dyslexic children Journal Article
In: Dyslexia, vol. 22, no. 4, pp. 362–378, 2016.
Reading depends heavily on the efficient shift of attention. Mounting evidence has suggested that dyslexics have deficits in covert attentional shift. However, it remains unclear whether dyslexics also have deficits in overt attentional shift. With the majority of relevant studies carried out in alphabetic writing systems, it is also unknown whether the attentional deficits observed in dyslexics are restricted to a particular writing system. The present study examined inhibition of return (IOR)-a major driving force of attentional shifts-in dyslexic children learning to read a logographic script (i.e., Chinese). Robust IOR effects were observed in both covert and overt attentional tasks in two groups of typically developing children, who were age- or reading ability-matched to the dyslexic children. In contrast, the dyslexic children showed IOR in the overt but not in the covert attentional task. We conclude that covert attentional shift is selectively impaired in dyslexic children. This impairment is not restricted to alphabetic writing systems, and it could be a significant contributor to the difficulties encountered by children learning to read.
Falk Huettig; Susanne Brouwer
Delayed anticipatory spoken language processing in adults with dyslexia - Evidence from eye-tracking Journal Article
In: Dyslexia, vol. 21, no. 2, pp. 97–122, 2015.
It is now well established that anticipation of upcoming input is a key characteristic of spoken language comprehension. It has also frequently been observed that literacy influences spoken language processing. Here, we investigated whether anticipatory spoken language processing is related to individuals' word reading abilities. Dutch adults with dyslexia and a control group participated in two eye-tracking experiments. Experiment 1 was conducted to assess whether adults with dyslexia show the typical language-mediated eye gaze patterns. Eye movements of both adults with and without dyslexia closely replicated earlier research: spoken language is used to direct attention to relevant objects in the environment in a closely time-locked manner. In Experiment 2, participants received instructions (e.g., 'Kijk naar deCOM afgebeelde pianoCOM ', look at the displayed piano) while viewing four objects. Articles (Dutch 'het' or 'de') were gender marked such that the article agreed in gender only with the target, and thus, participants could use gender information from the article to predict the target object. The adults with dyslexia anticipated the target objects but much later than the controls. Moreover, participants' word reading scores correlated positively with their anticipatory eye movements. We conclude by discussing the mechanisms by which reading abilities may influence predictive language processing.
Irene Ablinger; Walter Huber; Ralph Radach
Eye movement analyses indicate the underlying reading strategy in the recovery of lexical readers Journal Article
In: Aphasiology, vol. 28, no. 6, pp. 640–657, 2014.
Background: Psycholinguistic error analysis of dyslexic responses in various reading tasks provides the primary basis for clinically discriminating subtypes of pathological reading. Within this framework, phonology-related errors are indicative of a sequential word processing strategy, whereas lexical and semantic errors are associated with a lexical reading strategy. Despite the large number of published intervention studies, relatively little is known about changes in error distributions during recovery in dyslexic patients.Aims: The main purpose of the present work was to extend the scope of research on the time course of recovery in readers with acquired dyslexia, using eye tracking methodology to examine word processing in real time. The guiding hypothesis was that in lexical readers a reduction of lexical errors and an emerging predominant production of phonological errors should be associated with a change to a more segmental moment-to-moment reading behaviour.Methods & Procedures: Five patients participated in an eye movement supported reading intervention, where both lexical and segmental reading was facilitated. Reading performance was assessed before (T1) and after (T2) therapy intervention via recording of eye movements. Analyses included a novel way to examine the spatiotemporal dynamics of processing using distributions of fixation positions as different time intervals. These subdistributions reveal the gradual shifting of fixation positions during word processing, providing an adequate metric for objective classification of online reading strategies.Outcome & Results: Therapy intervention led to improved reading accuracy in all subjects. In three of five participants, analyses revealed a restructuring in the underlying reading mechanisms from predominantly lexical to more segmental word processing. In contrast, two subjects maintained their lexical reading procedures. Importantly, the fundamental assumption that a high number of phonologically based reading errors must be associated with segmental word processing routines, while the production of lexical errors is indicative of a holistic reading strategy could not be verified.Conclusions: Our results indicate that despite general improvements in reading performance, only some patients reorganised their word identification process. Contradictive data raise doubts on the validity of psycholinguistic error analysis as an exclusive indicator of changes in reading strategy. We suggest this traditional approach to combine with innovative eye tracking methodology in the interest of more comprehensive diagnostic strategies.
Richard Kunert; Christoph Scheepers
Speed and accuracy of dyslexic versus typical word recognition: An eye-movement investigation Journal Article
In: Frontiers in Psychology, vol. 5, pp. 1129, 2014.
Developmental dyslexia is often characterized by a dual deficit in both word recognition accuracy and general processing speed. While previous research into dyslexic word recognition may have suffered from speed-accuracy trade-off, the present study employed a novel eye-tracking task that is less prone to such confounds. Participants (10 dyslexics and 12 controls) were asked to look at real word stimuli, and to ignore simultaneously presented non-word stimuli, while their eye-movements were recorded. Improvements in word recognition accuracy over time were modeled in terms of a continuous non-linear function. The words' rhyme consistency and the non-words' lexicality (unpronounceable, pronounceable, pseudohomophone) were manipulated within-subjects. Speed-related measures derived from the model fits confirmed generally slower processing in dyslexics, and showed a rhyme consistency effect in both dyslexics and controls. In terms of overall error rate, dyslexics (but not controls) performed less accurately on rhyme-inconsistent words, suggesting a representational deficit for such words in dyslexics. Interestingly, neither group showed a pseudohomophone effect in speed or accuracy, which might call the task-independent pervasiveness of this effect into question. The present results illustrate the importance of distinguishing between speed- vs. accuracy-related effects for our understanding of dyslexic word recognition.
Irene Ablinger; Kerstin Heyden; Christian Vorstius; Katja Halm; Walter Huber; Ralph Radach
An eye movement based reading intervention in lexical and segmental readers with acquired dyslexia Journal Article
In: Neuropsychological Rehabilitation, vol. 24, no. 6, pp. 833–867, 2014.
Due to their brain damage, aphasic patients with acquired dyslexia often rely to a greater extent on lexical or segmental reading procedures. Thus, therapy intervention is mostly targeted on the more impaired reading strategy. In the present work we introduce a novel therapy approach based on real-time measurement of patients' eye movements as they attempt to read words. More specifically, an eye movement contingent technique of stepwise letter de-masking was used to support sequential reading, whereas fixation-dependent initial masking of non-central letters stimulated a lexical (parallel) reading strategy. Four lexical and four segmental readers with acquired central dyslexia received our intensive reading intervention. All participants showed remarkable improvements as evident in reduced total reading time, a reduced number of fixations per word and improved reading accuracy. Both types of intervention led to item-specific training effects in all subjects. A generalisation to untrained items was only found in segmental readers after the lexical training. Eye movement analyses were also used to compare word processing before and after therapy, indicating that all patients, with one exclusion, maintained their preferred reading strategy. However, in several cases the balance between sequential and lexical processing became less extreme, indicating a more effective individual interplay of both word processing routes.
Noor Z. Al Dahhan; George K. Georgiou; Rickie Hung; Douglas P. Munoz; Rauno Parrila; John R. Kirby
Eye movements of university students with and without reading difficulties during naming speed tasks Journal Article
In: Annals of Dyslexia, vol. 64, no. 2, pp. 137–150, 2014.
Although naming speed (NS) has been shown to predict reading into adulthood and differentiate between adult dyslexics and controls, the question remains why NS is related to reading. To address this question, eye movement methodology was combined with three letter NS tasks (the original letter NS task by Denckla & Rudel, Cortex 10:186-202, 1974, and two more developed by Compton, The Journal of Special Education 37:81-94, 2003, with increased phonological or visual similarity of the letters). Twenty undergraduate students with reading difficulties (RD) and 27 without (NRD) were tested on letter NS tasks (eye movements were recorded during the NS tasks), phonological processing, and reading fluency. The results indicated first that the RD group was slower than the NRD group on all NS tasks with no differences between the NS tasks. In addition, the NRD group had shorter fixation durations, longer saccades, and fewer saccades and fixations than the RD group. Fixation duration and fixation count were significant predictors of reading fluency even after controlling for phonological processing measures. Taken together, these findings suggest that the NS-reading relationship is due to two factors: less able readers require more time to acquire stimulus information during fixation and they make more saccades.
Manon W. Jones; Jane Ashby; Holly P. Branigan
Dyslexia and fluency: Parafoveal and foveal influences on rapid automatized naming Journal Article
In: Journal of Experimental Psychology: Human Perception and Performance, vol. 39, no. 2, pp. 554–567, 2013.
The ability to coordinate serial processing of multiple items is crucial for fluent reading but is known to be impaired in dyslexia. To investigate this impairment, we manipulated the orthographic and phonological similarity of adjacent letters online as dyslexic and nondyslexic readers named letters in a serial naming (RAN) task. Eye movements and voice onsets were recorded. Letter arrays contained target item pairs in which the second letter was orthographically or phonologically similar to the first letter when viewed either parafoveally (Experiment 1a) or foveally (Experiment 1b). Relative to normal readers, dyslexic readers were more affected by orthographic confusability in Experiment 1a and phonological confusability in Experiment 1b. Normal readers were slower to process orthographically similar letters in Experiment 1b. Findings indicate that the phonological and orthographic processing problems of dyslexic readers manifest differently during parafoveal and foveal processing, with each contributing to slower RAN performance and impaired reading fluency.
Matthew H. Schneps; Jenny M. Thomson; Gerhard Sonnert; Marc Pomplun; Chen Chen; Amanda Heffner-Wong
Shorter lines facilitate reading in those who struggle Journal Article
In: PLoS ONE, vol. 8, no. 8, pp. e71161, 2013.
People with dyslexia, who ordinarily struggle to read, sometimes remark that reading is easier when e-readers are used. Here, we used eye tracking to observe high school students with dyslexia as they read using these devices. Among the factors investigated, we found that reading using a small device resulted in substantial benefits, improving reading speeds by 27%, reducing the number of fixations by 11%, and importantly, reducing the number of regressive saccades by more than a factor of 2, with no cost to comprehension. Given that an expected trade-off between horizontal and vertical regression was not observed when line lengths were altered, we speculate that these effects occur because sluggish attention spreads perception to the left as the gaze shifts during reading. Short lines eliminate crowded text to the left, reducing regression. The effects of attention modulation by the hand, and of increased letter spacing to reduce crowding, were also found to modulate the oculomotor dynamics in reading, but whether these factors resulted in benefits or costs depended on characteristics, such as visual attention span, that varied within our sample.
Maria De Luca; Maria Pontillo; Silvia Primativo; Donatella Spinelli; Pierluigi Zoccolotti
The eye-voice lead during oral reading in developmental dyslexia Journal Article
In: Frontiers in Human Neuroscience, vol. 7, pp. 696, 2013.
In reading aloud, the eye typically leads over voice position. In the present study, eye movements and voice utterances were simultaneously recorded and tracked during the reading of a meaningful text to evaluate the eye-voice lead in 16 dyslexic and 16 same-age control readers. Dyslexic children were slower than control peers in reading texts. Their slowness was characterized by a great number of silent pauses and sounding-out behaviors and a small lengthening of word articulation times. Regarding eye movements, dyslexic readers made many more eye fixations (and generally smaller rightward saccades) than controls. Eye movements and voice (which were shifted in time because of the eye-voice lead) were synchronized in dyslexic readers as well as controls. As expected, the eye-voice lead was significantly smaller in dyslexic than control readers, confirming early observations by Buswell (1921) and Fairbanks (1937). The eye-voice lead was significantly correlated with several eye movements and voice parameters, particularly number of fixations and silent pauses. The difference in performance between dyslexic and control readers across several eye and voice parameters was expressed by a ratio of about 2. We propose that referring to proportional differences allows for a parsimonious interpretation of the reading deficit in terms of a single deficit in word decoding. The possible source of this deficit may call for visual or phonological mechanisms, including Goswami's temporal sampling framework.
Roberta Daini; Andrea Albonico; Manuela Malaspina; Marialuisa Martelli; Silvia Primativo; Lisa S. Arduino
Dissociation in optokinetic stimulation sensitivity between omission and substitution reading errors in neglect dyslexia Journal Article
In: Frontiers in Human Neuroscience, vol. 7, pp. 581, 2013.
Although omission and substitution errors in neglect dyslexia (ND) patients have always been considered as different manifestations of the same acquired reading disorder, recently, we proposed a new dual mechanism model. While omissions are related to the exploratory disorder which characterizes unilateral spatial neglect (USN), substitutions are due to a perceptual integration mechanism. A consequence of this hypothesis is that specific training for omission-type ND patients would aim at restoring the oculo-motor scanning and should not improve reading in substitution-type ND. With this aim we administered an optokinetic stimulation (OKS) to two brain-damaged patients with both USN and ND, MA and EP, who showed ND mainly characterized by omissions and substitutions, respectively. MA also showed an impairment in oculo-motor behavior with a non-reading task, while EP did not. The two patients presented a dissociation with respect to their sensitivity to OKS, so that, as expected, MA was positively affected, while EP was not. Our results confirm a dissociation between the two mechanisms underlying omission and substitution reading errors in ND patients. Moreover, they suggest that such a dissociation could possibly be extended to the effectiveness of rehabilitative procedures, and that patients who mainly omit contralesional-sided letters would benefit from OKS.
Silvia Primativo; Lisa S. Arduino; Maria De Luca; Roberta Daini; Marialuisa Martelli
Neglect dyslexia: A matter of "good looking" Journal Article
In: Neuropsychologia, vol. 51, no. 11, pp. 2109–2119, 2013.
Brain-damaged patients with right-sided unilateral spatial neglect (USN) often make left-sided errors in reading single words or pseudowords (neglect dyslexia, ND). We propose that both left neglect and low fixation accuracy account for reading errors in neglect dyslexia.Eye movements were recorded in USN patients with (ND+) and without (ND-) neglect dyslexia and in a matched control group of right brain-damaged patients without neglect (USN-). Unlike ND- and controls, ND+ patients showed left lateralized omission errors and a distorted eye movement pattern in both a reading aloud task and a non-verbal saccadic task. During reading, the total number of fixations was larger in these patients independent of visual hemispace, and most fixations were inaccurate. Similarly, in the saccadic task only ND+ patients were unable to reach the moving dot. A third experiment addressed the nature of the left lateralization in reading error distribution by simulating neglect dyslexia in ND- patients. ND- and USN- patients had to perform a speeded reading-at-threshold task that did not allow for eye movements. When stimulus exploration was prevented, ND- patients, but not controls, produced a pattern of errors similar to that of ND+ with unlimited exposure time (e.g., left-sided errors).We conclude that neglect dyslexia reading errors may arise in USN patients as a consequence of an additional and independent deficit unrelated to the orthographic material. In particular, the presence of an altered oculo-motor pattern, preventing the automatic execution of the fine saccadic eye movements involved in reading, uncovers, in USN patients, the attentional bias also in reading single centrally presented words.
Jinger Pan; Ming Yan; Jochen Laubrock; Hua Shu; Reinhold Kliegl
Eye-voice span during rapid automatized naming of digits and dice in Chinese normal and dyslexic children Journal Article
In: Developmental Science, vol. 16, no. 6, pp. 967–979, 2013.
We measured Chinese dyslexic and control children's eye movements during rapid automatized naming (RAN) with alphanumeric (digits) and symbolic (dice surfaces) stimuli. Both types of stimuli required identical oral responses, controlling for effects associated with speech production. Results showed that naming dice was much slower than naming digits for both groups, but group differences in eye-movement measures and in the eye-voice span (i.e. the distance between the currently fixated item and the voiced item) were generally larger in digit-RAN than in dice-RAN. In addition, dyslexics were less efficient in parafoveal processing in these RAN tasks. Since the two RAN tasks required the same phonological output and on the assumption that naming dice is less practiced than naming digits in general, the results suggest that the translation of alphanumeric visual symbols into phonological codes is less efficient in dyslexic children. The dissociation of the print-to-sound conversion and phonological representation suggests that the degree of automaticity in translation from visual symbols to phonological codes in addition to phonological processing per se is also critical to understanding dyslexia.
Kerstin I. Schattka; Ralph Radach; Walter Huber
Eye movement correlates of acquired central dyslexia Journal Article
In: Neuropsychologia, vol. 48, no. 10, pp. 2959–2973, 2010.
Based on recent progress in theory and measurement techniques, the analysis of eye movements has become one of the major methodological tools in experimental reading research. Our work uses this approach to advance the understanding of impaired information processing in acquired central dyslexia of stroke patients with aphasia. Up to now there has been no research attempting to analyze both word-based viewing time measures and local fixation patterns in dyslexic readers. The goal of the study was to find out whether specific eye movement parameters reflect pathologically preferred segmental reading in contrast to lexical reading.We compared oral reading of single words of normal controls (n=11) with six aphasic participants (two cases of deep, surface and residual dyslexia each). Participants were asked to read aloud lines of target words differing in length and frequency. Segmental reading was characterized by deviant spatial distribution of saccadic landing positions with initial fixations located mainly at the beginning of the word, while lexical readers showed the normative 'preferred landing positions' left to the center of the words. Contrary to expectation, word length did not distinguish between segmental and lexical readers, while word frequency showed the expected effect for lexical readers only. Their mean fixation duration was already prolonged during first pass reading reflecting their attempts of immediate access to lexical information. After first pass reading, re-reading time was significantly increased in all participants with acquired central dyslexia due to their exceedingly higher monitoring demands for oral reading.
Tobias Pflugshaupt; Klemens Gutbrod; Pascal Wurtz; Roman Von Wartburg; Thomas Nyffeler; Bianca De Haan; Hans-Otto Karnath; René M. Mueri
About the role of visual field defects in pure alexia Journal Article
In: Brain, vol. 132, no. 7, pp. 1907–1917, 2009.
Pure alexia is an acquired reading disorder characterized by a disproportionate prolongation of reading time as a function of word length. Although the vast majority of cases reported in the literature show a right-sided visual defect, little is known about the contribution of this low-level visual impairment to their reading difficulties. The present study was aimed at investigating this issue by comparing eye movement patterns during text reading in six patients with pure alexia with those of six patients with hemianopic dyslexia showing similar right-sided visual field defects. We found that the role of the field defect in the reading difficulties of pure alexics was highly deficit-specific. While the amplitude of rightward saccades during text reading seems largely determined by the restricted visual field, other visuo-motor impairments—particularly the pronounced increases in fixation frequency and viewing time as a function of word length—may have little to do with their visual field defect. In addition, subtracting the lesions of the hemianopic dyslexics from those found in pure alexics revealed the largest group differences in posterior parts of the left fusiform gyrus, occipito-temporal sulcus and inferior temporal gyrus. These regions included the coordinate assigned to the centre of the visual word form area in healthy adults, which provides further evidence for a relation between pure alexia and a damaged visual word form area. Finally, we propose a list of three criteria that may improve the differential diagnosis of pure alexia and allow appropriate therapy recommendations.
Manon W. Jones; Mateo Obregón; M. Louise Kelly; Holly P. Branigan
Elucidating the component processes involved in dyslexic and non-dyslexic reading fluency: An eye-tracking study Journal Article
In: Cognition, vol. 109, no. 3, pp. 389–407, 2008.
The relationship between rapid automatized naming (RAN) and reading fluency is well documented (see Wolf, M. & Bowers, P.G. (1999). The double-deficit hypothesis for the developmental dyslexias. Journal of Educational Psychology, 91(3), 415-438, for a review), but little is known about which component processes are important in RAN, and why developmental dyslexics show longer latencies on these tasks. Researchers disagree as to whether these delays are caused by impaired phonological processing or whether extra-phonological processes also play a role (e.g., Clarke, P., Hulme, C., & Snowling, M. (2005). Individual differences in RAN and reading: A response timing analysis. Journal of Research in Reading, 28(2), 73-86; Wolf, M., Bowers, P.G., & Biddle, K. (2000). Naming-speed processes, timing, and reading: A conceptual review. Journal of learning disabilities, 33(4), 387-407). We conducted an eye-tracking study that manipulated phonological and visual information (as representative of extra-phonological processes) in RAN. Results from linear mixed (LME) effects analyses showed that both phonological and visual processes influence naming-speed for both dyslexic and non-dyslexic groups, but the influence on dyslexic readers is greater. Moreover, dyslexic readers' difficulties in these domains primarily emerge in a measure that explicitly includes the production phase of naming. This study elucidates processes underpinning RAN performance in non-dyslexic readers and pinpoints areas of difficulty for dyslexic readers. We discuss these findings with reference to phonological and extra-phonological hypotheses of naming-speed deficits.
Keith Rayner; Rebecca L. Johnson
Letter-by-letter acquired dyslexia is due to the serial encoding of letters Journal Article
In: Psychological Science, vol. 16, no. 7, pp. 530–534, 2005.
Letter-by-letter acquired dyslexia (pure alexia) is assumed to be related to the serial encoding of letters, but the evidence for this assumption is somewhat indirect. Here, we demonstrate that the deficit is indeed due to serial encoding by comparing the performance of a letter-by-letter dyslexic reader with the performance of normal readers who were forced to read letter by letter; the data patterns are remarkably similar.