Visual-orthographic Processing Research Articles

Common predictors of spoken and written language performance in aphasia, alexia, and agraphia.

Language performance requires support from central cognitive/linguistic abilities as well as the more peripheral sensorimotor skills to plan and implement spoken and written communication. Both output modalities are vulnerable to impairment following damage to the language-dominant hemisphere, but much of the research to date has focused exclusively on spoken language. In this study we aimed to examine an integrated model of language processing that includes the common cognitive processes that support spoken and written language, as well as modality-specific skills. To do so, we evaluated spoken and written language performance from 87 individuals with acquired language impairment resulting from damage to left perisylvian cortical regions that collectively constitute the dorsal language pathway. Comprehensive behavioral assessment served to characterize the status of central and peripheral components of language processing in relation to neurotypical controls (n = 38). Performance data entered into principal components analyses (with or without control scores) consistently yielded a strong five-factor solution. In line with a primary systems framework, three central cognitive factors emerged: semantics, phonology, and orthography that were distinguished from peripheral processes supporting speech production and allographic skill for handwriting. The central phonology construct reflected performance on phonological awareness and manipulation tasks and showed the greatest deficit of all the derived factors. Importantly, this phonological construct was orthogonal to the speech production factor that reflected repetition of words/non-words. When entered into regression analyses, semantics and phonological skill were common predictors of language performance across spoken and written modalities. The speech production factor was also a strong, distinct predictor of spoken naming and oral reading, in contrast to allographic skills which only predicted written output. As expected, visual orthographic processing contributed more to written than spoken language tasks and reading/spelling performance was strongly reliant on phonological and semantic abilities. Despite the heterogeneity of this cohort regarding aphasia type and severity, the marked impairment of phonological skill was a unifying feature. These findings prompt greater attention to clinical assessment and potential treatment of underlying phonological skill in individuals with left perisylvian damage.

Letter processing in upright bigrams predicts reading fluency variations in children.

Fluent reading is an important milestone in education, but we lack a clear understanding of why children vary so widely in attaining it. Language-related factors such as rapid automatized naming (RAN) and phonological awareness have been identified as important factors that explain reading fluency. However, whether any aspects of visual orthographic processing also explain reading fluency beyond phonology is unclear. To investigate these issues, we tested primary school children (n = 68) on four tasks: two reading fluency tasks (word reading and passage reading), a RAN task to measure naming speed, and a visual search task using letters and bigrams. Bigram processing in visual search was accurately explained by single-letter discrimination, and error patterns were unrelated to fluency or bigram frequency, ruling out the contribution of specialized bigram detectors. As expected, the RAN score was strongly correlated with reading fluency. Importantly, there was a highly specific association between reading fluency and upright bigram processing in visual search. This association was specific to upright but not inverted bigrams and to bigrams with normal but not large letter spacing. It was explained by increased letter discrimination across bigrams and reduced interactions between letters within bigrams. Thus, fluent reading is accompanied by specialized changes in letter processing within bigrams. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Impact of visual processing skills on reading ability in Chinese deaf children

BackgroundReading activity involves visual processing in nature. Compared with hearing people, visual processing may be more critical for deaf people. However, much less research has explored the impact of visual processing on the reading ability of deaf children, and the mechanism underlying this relationship is unclear. AimsThis study aimed to examine whether and how visual processing skills predict reading ability in elementary school deaf children in China. Methods and proceduresA total of 118 Chinese deaf children (mean age = 14.60 years) from grades 4–6 were tested on the tasks of visual-graphic processing, visual-orthographic processing, word segmentation, reading comprehension, and reading fluency. Outcomes and resultsThe results showed that after chronological age was controlled, visual-graphic processing and visual-orthographic processing significantly predicted Chinese deaf children’s reading ability. Specifically, visual-orthographic processing played a mediating role in the effect of visual-graphic processing on reading ability, whereas word segmentation played a mediating role in the effect of visual-orthographic processing on reading ability. However, the mediating role of word segmentation, as well as the chain mediating effect of visual-orthographic processing and word segmentation in the influence of visual-graphic processing on reading ability, were not significant. Conclusions and implicationsThese findings emphasized the importance of visual processing skills in reading activity and offered potential mechanisms underlying the contribution of visual processing skills to reading ability in Chinese deaf children.

Whole-Brain Functional Networks for Phonological and Orthographic Processing in Chinese Good and Poor Readers.

The neural basis of dyslexia in different languages remains unresolved, and it is unclear whether the phonological deficit as the core deficit of dyslexia is language-specific or universal. The current functional magnetic resonance imaging (fMRI) study using whole-brain data-driven network analyses investigated the neural mechanisms for phonological and orthographic processing in Chinese children with good and poor reading ability. Sixteen good readers and 16 poor readers were requested to make homophone judgments (phonological processing) and component judgments (visual-orthographic processing) of presented Chinese characters. Poor readers displayed worse performance than the good readers in phonological processing, but not in orthographic processing. Whole-brain activation analyses showed compensatory activations in the poor readers during phonological processing and automatic phonological production activation in the good readers during orthographic processing. Significant group differences in the topological properties of their brain networks were found only in orthographic processing. Analyses of nodal degree centrality and betweenness centrality revealed significant group differences in both phonological and orthographic processing. The present study supports the phonological core deficit hypothesis of reading difficulty in Chinese. It also suggests that Chinese good and poor readers might recruit different strategies and neural mechanisms for orthographic processing.

Interaction of top-down category-level expectation and bottom-up sensory input in early stages of visual-orthographic processing

How and when top-down information modulates visual-orthographic processing is an essential question in reading research. In a previous study, we showed that task modulation of print-tuning started at around 170 ms after stimulus presentation in the N1 offset of the ERP, while the N1 onset was yet unaffected. Here we test how prior category-level expectation affects visual-orthographic processing. Familiar, left/right-structured Chinese characters and stroke number matched, unfamiliar Korean characters were presented, while expectation about the upcoming stimuli was manipulated with green and blue colored frames (high Chinese vs. high Korean expectation). EEG data of 18 native Chinese speakers were recorded while participants performed an expectation judgment task. Results from occipito-temporal and whole map analyses revealed that effects of prior expectation changed throughout the N1. Accordingly in the N1 onset, a print tuning main effect was found, with a stronger N1 to Chinese characters than Korean characters, irrespective of expectation. In the N1 offset, an expectation-by-character interaction was observed at the whole map level, with a more negative N1 to Korean characters than Chinese characters when expecting a Chinese character, but no such difference when expecting a Korean character. Moreover, the expectation-by-character interaction continued to the N250, with similar responses to Chinese and Korean characters under the Chinese expectation condition, while less negative N250 to Korean than Chinese under the Korean expectation condition. Taken together, the current study provides evidence that prior category-level expectation starts to take effect at an early stage even within 200 ms by facilitating the processing of expected stimuli, suggesting that category-level expectation can influence early visual-orthographic processing during word recognition.

How are visual words represented? Insights from EEG-based visual word decoding, feature derivation and image reconstruction.

Investigations into the neural basis of reading have shed light on the cortical locus and the functional role of visual‐orthographic processing. Yet, the fine‐grained structure of neural representations subserving reading remains to be clarified. Here, we capitalize on the spatiotemporal structure of electroencephalography (EEG) data to examine if and how EEG patterns can serve to decode and reconstruct the internal representation of visually presented words in healthy adults. Our results show that word classification and image reconstruction were accurate well above chance, that their temporal profile exhibited an early onset, soon after 100 ms, and peaked around 170 ms. Further, reconstruction results were well explained by a combination of visual‐orthographic word properties. Last, systematic individual differences were detected in orthographic representations across participants. Collectively, our results establish the feasibility of EEG‐based word decoding and image reconstruction. More generally, they help to elucidate the specific features, dynamics, and neurocomputational principles underlying word recognition.

Dyslexia in Chinese

We highlight the nature of dyslexia across Chinese societies. The review includes an overview of some main differences across societies that may influence the nature of dyslexia (including script, language, and educational variations), the social context of Chinese learning, and the cognitive-linguistic aspects of learning Chinese. We also list some basic criteria for the diagnosis of dyslexia and point out some promising remediation techniques. Focusing on the cognitive-linguistic skills of phonological sensitivity, morphological awareness, visual-orthographic processing, and fluency for identifying and remediating dyslexia is key. Those with dyslexia tend to have difficulties with one or more of these constructs. Thus, training studies focused on improving these skills have led to improvements in character and word-reading overall. The underlying mechanisms of dyslexia in Chinese are increasingly better understood. A focus on improving cognitive-linguistic skills is essential for ameliorating severe reading problems in Chinese.

Differences between child and adult large-scale functional brain networks for reading tasks.

Reading is an important high-level cognitive function of the human brain, requiring interaction among multiple brain regions. Revealing differences between children's large-scale functional brain networks for reading tasks and those of adults helps us to understand how the functional network changes over reading development. Here we used functional magnetic resonance imaging data of 17 adults (19-28 years old) and 16 children (11-13 years old), and graph theoretical analyses to investigate age-related changes in large-scale functional networks during rhyming and meaning judgment tasks on pairs of visually presented Chinese characters. We found that: (1) adults had stronger inter-regional connectivity and nodal degree in occipital regions, while children had stronger inter-regional connectivity in temporal regions, suggesting that adults rely more on visual orthographic processing whereas children rely more on auditory phonological processing during reading. (2) Only adults showed between-task differences in inter-regional connectivity and nodal degree, whereas children showed no task differences, suggesting the topological organization of adults' reading network is more specialized. (3) Children showed greater inter-regional connectivity and nodal degree than adults in multiple subcortical regions; the hubs in children were more distributed in subcortical regions while the hubs in adults were more distributed in cortical regions. These findings suggest that reading development is manifested by a shift from reliance on subcortical to cortical regions. Taken together, our study suggests that Chinese reading development is supported by developmental changes in brain connectivity properties, and some of these changes may be domain-general while others may be specific to the reading domain.

Top-down modulation of early print-tuned neural activity in reading.

Fast neural tuning to print has been found within the first 250ms of stimulus processing across different writing systems, indicated by larger N1 negativity in the ERP to words (or characters) compared to control stimuli, such as symbols. However, whether print tuning effects can be modulated by task demands at early stages of visual word recognition is still under debate. To further explore this issue, an ERP study in Chinese was conducted. Familiar, high-frequency, left/right-structured Chinese characters and unfamiliar, stroke number-matched symbols (Korean characters) were used as stimulus conditions. While viewing the characters and symbols, 20 native Chinese speakers performed three tasks: delayed naming, repetition detection, and blue color detection. Results from occipito-temporal and whole map analyses suggest that the influence of task on print tuning changes throughout the N1. Accordingly in the N1 onset, a print tuning main effect was found, with a stronger N1 to words than symbols, irrespective of task. In the N1 offset, a print-by-task interaction reflected a more negative N1 to symbols than words in both delayed naming and color detection, but not in the repetition detection. After the N1 an N2 was observed with task and condition main effects at the whole map level. Taken together, the current study provides evidence that neural tuning to print is modulated by task demands already within the first 250ms, suggesting that early visual-orthographic processing may be less automatic than it was thought, and the possible top-down modulation may be much faster than it was previously assumed.

An ERP investigation of vertical reading fluency in Scrabble® experts

Previous studies have found that competitive Scrabble expertise is associated with enhanced performance on visual lexical decision tasks (LDT), particularly for vertically presented stimuli. In the current study, we investigated the underlying mechanisms responsible for this vertical fluency. We examined behaviour and neural activity during LDT in 19 competitive Scrabble players and 18 matched controls. Using event related potentials (ERP), we investigated whether Scrabble expertise modulates the N170, P300, and late positive component (LPC), associated with visual-orthographic processing, working memory, and stimulus classification, respectively. Behavioural results replicated those from previous studies: Scrabble experts were significantly faster than controls to respond to vertical stimuli in LDT. ERP results showed Scrabble experts had larger P300 amplitudes in right parietal electrodes compared to controls, as well as greater differentiation in LPC amplitudes between vertical words and nonwords. These findings suggest that the mechanism underlying vertical fluency in Scrabble experts involves enhanced domain-specific working memory and stimulus classification processes. The results have implications for understanding the flexibility of the adult visual word recognition system, as well as the behavioural and neural consequences of training within this system.

An Association between Auditory-Visual Synchrony Processing and Reading Comprehension: Behavioral and Electrophysiological Evidence.

The perceptual system integrates synchronized auditory-visual signals in part to promote individuation of objects in cluttered environments. The processing of auditory-visual synchrony may more generally contribute to cognition by synchronizing internally generated multimodal signals. Reading is a prime example because the ability to synchronize internal phonological and/or lexical processing with visual orthographic processing may facilitate encoding of words and meanings. Consistent with this possibility, developmental and clinical research has suggested a link between reading performance and the ability to compare visual spatial/temporal patterns with auditory temporal patterns. Here, we provide converging behavioral and electrophysiological evidence suggesting that greater behavioral ability to judge auditory-visual synchrony (Experiment 1) and greater sensitivity of an electrophysiological marker of auditory-visual synchrony processing (Experiment 2) both predict superior reading comprehension performance, accounting for 16% and 25% of the variance, respectively. These results support the idea that the mechanisms that detect auditory-visual synchrony contribute to reading comprehension.

Internal Structure and Development of Keyboard Skills in Spanish-Speaking Primary-School Children With and Without LD in Writing

This study had two purposes: examining the internal structure of the Test Estandarizado para la Evaluación Inicial de la Escritura con Teclado (TEVET; Spanish Keyboarding Writing Test), and analyzing the development of keyboarding skills in Spanish elementary school children with and without learning disabilities (LD) in writing. A group of 1,168 elementary school children carried out the following writing tasks: writing the alphabet in order from memory, allograph selection, word copying, writing dictated words with inconsistent spelling, writing pseudowords from dictation, and independent composition of sentence. For this purpose, exploratory factor analysis for the TEVET was conducted. Principal component analysis with a varimax rotation identified three factors with eigenvalues greater than 1.0. Based on factorial analysis, we analyzed the keyboarding skills across grades in Spanish elementary school children with and without LD (i.e., poor handwriters compared with poor spellers, who in turn were compared with mixed compared with typically achieving writers). The results indicated that poor handwriters did not differ from typically achieving writers in phonological processing, visual-orthographic processing, and sentence production components by keyboarding. The educational implications of the findings are analyzed with regard to acquisition of keyboarding skills in children with and without LD in transcription.

Orthographic processing deficits in developmental dyslexia: Beyond the ventral visual stream

Fast effortless reading has been associated with the Visual Word Form Area (VWFA), a region in the ventral visual stream that specializes in the recognition of letter strings. Several neuroimaging studies of dyslexia revealed an underactivation of this region. However, most of these studies used reading tasks and/or were carried out on adults. Given that fluent reading is severely impaired in dyslexics, any underactivation might simply reflect a well-established reading deficit in impaired readers and could be the consequence rather than the cause of dyslexia. Here, we designed a task that does not rely on reading per se but that tapped early visual orthographic processing that forms the basis of reading. Dyslexic children aged 8–12years and age-matched controls were asked to search for letters, digits, and symbols in 5-element strings (Experiment 1). This novel task was complemented by a classic task known to activate the VWFA, namely the passive viewing of pseudowords and falsefonts (Experiment 2). We found that in addition to significant group differences in the VWFA, dyslexic children showed a significant underactivation of the middle occipital gyrus (MOG) relative to the control group. Several areas in the MOG are known for their engagement in visuospatial processing, and it has been proposed that the MOG is necessary for ordering the symbols in unfamiliar strings. Our results suggest that the VWFA deficit might be secondary to an impairment of visuospatial processing in the MOG. We argue that efficient processing in MOG in the course of reading acquisition is critical for the development of effortless fast visual word recognition in the VWFA.

Early stage visual-orthographic processes predict long-term retention of word form and meaning: A visual encoding training study

Adult learners of Chinese learned new characters through writing, visual chunking or reading-only. Following training, ERPs were recorded during character recognition tasks, first shortly after the training and then three months later. We hypothesized that the character training effects would be seen in ERP components associated with word recognition and episodic memory. Results confirmed a larger N170 for visual chunking training than other training and a larger P600 for learned characters than novel characters. Another result was a training effect on the amplitude of the P100, which was greater following writing training than other training, suggesting that writing training temporarily lead to increased visual attention to the orthographic forms. Furthermore, P100 amplitude at the first post-test was positively correlated with character recall 3 months later. Thus the marker of early visual attention (P100) was predictive of retention of orthographic knowledge acquired in training.

A dual-route perspective on poor reading in a regular orthography: An fMRI study

This study examined functional brain abnormalities in dyslexic German readers who – due to the regularity of German in the reading direction – do not exhibit the reading accuracy problem of English dyslexic readers, but suffer primarily from a reading speed problem. The in-scanner task required phonological lexical decisions (i.e., Does xxx sound like an existing word?) and presented familiar and unfamiliar letter strings of existing phonological words (e.g., Taxi-Taksi) together with nonwords (e.g., Tazi). Dyslexic readers exhibited the same response latency pattern (words<pseudohomophones<nonwords) as nonimpaired readers, but latencies to all item types were much prolonged. The imaging results were suggestive for a different neural organization of reading processes in dyslexic readers. Specifically, dyslexic readers, in response to lexical route processes, exhibited underactivation in a left ventral occipitotemporal (OT) region which presumably is engaged by visual-orthographic whole word recognition. This region was also insensitive to the increased visual-orthographic processing demands of the sublexical route. Reduced engagement in response to sublexical route processes was also found in a left inferior parietal region, presumably engaged by attentional processes, and in a left inferior frontal region, presumably engaged by phonological processes. In contrast to this reduced engagement of the optimal left hemisphere reading network (ventral OT, inferior parietal, inferior frontal), our dyslexic readers exhibited increased engagement of visual occipital regions and of regions presumably engaged by silent articulatory processes (premotor/motor cortex and subcortical caudate and putamen).

The temporal dynamics of implicit processing of non-letter, letter, and word-forms in the human visual cortex.

The decoding of visually presented line segments into letters, and letters into words, is critical to fluent reading abilities. Here we investigate the temporal dynamics of visual orthographic processes, focusing specifically on right hemisphere contributions and interactions between the hemispheres involved in the implicit processing of visually presented words, consonants, false fonts, and symbolic strings. High-density EEG was recorded while participants detected infrequent, simple, perceptual targets (dot strings) embedded amongst a of character strings. Beginning at 130 ms, orthographic and non-orthographic stimuli were distinguished by a sequence of ERP effects over occipital recording sites. These early latency occipital effects were dominated by enhanced right-sided negative-polarity activation for non-orthographic stimuli that peaked at around 180 ms. This right-sided effect was followed by bilateral positive occipital activity for false-fonts, but not symbol strings. Moreover the size of components of this later positive occipital wave was inversely correlated with the right-sided ROcc180 wave, suggesting that subjects who had larger early right-sided activation for non-orthographic stimuli had less need for more extended bilateral (e.g., interhemispheric) processing of those stimuli shortly later. Additional early (130–150 ms) negative-polarity activity over left occipital cortex and longer-latency centrally distributed responses (>300 ms) were present, likely reflecting implicit activation of the previously reported ‘visual-word-form’ area and N400-related responses, respectively. Collectively, these results provide a close look at some relatively unexplored portions of the temporal flow of information processing in the brain related to the implicit processing of potentially linguistic information and provide valuable information about the interactions between hemispheres supporting visual orthographic processing.

Developmental changes in brain regions involved in phonological and orthographic processing during spoken language processing

Developmental differences in brain activation of 9- to 15-year-old children were examined during an auditory rhyme decision task to spoken words using functional magnetic resonance imaging (fMRI). As a group, children showed activation in the left superior/middle temporal gyri (BA 22, 21), right middle temporal gyrus (BA 21), dorsal (BA 45, pars opercularis) and ventral (BA 46, pars triangularis) aspects of the left inferior frontal gyrus, and left fusiform gyrus (BA 37). There was a developmental increase in activation in the left middle temporal gyrus (BA 22) across all lexical conditions, suggesting that automatic semantic processing increases with age regardless of task demands. Activation in the left dorsal inferior frontal gyrus also showed developmental increases for the conflicting (e.g. PINT–MINT) compared to the non-conflicting (e.g. PRESS–LIST) non-rhyming conditions, indicating that this area becomes increasingly involved in strategic phonological processing in the face of conflicting orthographic and phonological representations. Left inferior temporal/fusiform gyrus (BA 37) activation was also greater for the conflicting (e.g. PINT–MINT) condition, and a developmental increase was found in the positive relationship between individuals' reaction time and activation in the left lingual/fusiform gyrus (BA 18) in this condition, indicating an age-related increase in the association between longer reaction times and greater visual-orthographic processing in this conflicting condition. These results suggest that orthographic processing is automatically engaged by children in a task that does not require access to orthographic information for correct performance, especially when orthographic and phonological representations conflict, and especially for longer response latencies in older children.

Cognitive antecedents of early reading ability: A test of the modularity hypothesis

This study tested the hypothesis that the cognitive antecedents of word recognition are uniquely domain-specific and unrelated to higher-order domain-general cognitive abilities. This hypothesis was evaluated in a longitudinal study of 349 Hebrew-speaking children (mean age: 6.0 years) who were tested on a battery of domain-specific (phonological awareness, phonological memory, visual-orthographic processing, and early literacy) and domain-general tasks (general intelligence, higher-order reasoning, and language) at the end of kindergarten. Word recognition and reading comprehension were assessed at the end of Grade 1. Whereas the kindergarten domain-specific measures accounted for significant and substantial variance in word recognition (33%), the domain-general measures explained only 5% of the variance. Furthermore, the contribution of domain-specific variables to word recognition remained unaltered even after controlling for all domain-general and higher-order language tasks. Reading comprehension, in contrast, was predicted by both print-specific skills (51%) and domain-general abilities (44%). These findings strongly support the notion of word recognition modularity in a well-encapsulated orthography.

Spelling performance of Chinese children using English as a second language: Lexical and visual–orthographic processes

The present study compared lexical and visual–orthographic processing in the spelling performance of 30 Cantonese Chinese children who are English as a second language (ESL) learners to that of 33 native English-speaking (L1) children. Chinese ESL children showed poorer performance in spelling to dictation of pseudowords than L1 children. The difference between real word and pseudoword spelling performances for ESL children was significantly greater than that for L1 children. Moreover, Chinese ESL children outperformed their L1 counterparts in a confrontation spelling task of orthographically legitimate and illegitimate letter strings. In line with their advantage in spelling visually presented materials, the difference between spelling performance on legitimate and illegitimate letter strings for the Chinese children was significantly smaller than that for the L1 children. These findings are discussed in terms of early transfer of L1 literacy skills in second language literacy acquisition and support for a multiroute reading model.

Reading in a root–based–morphology language: the case of Arabic

The reading process in Arabic as a function of vowels and sentence context is reviewed. Reading accuracy and reading comprehension results are reviewed in the light of cross–cultural reading, in order to develop a more comprehensive reading theory. Phonology, morphology and sentence context are considered key variables in explaining the reading process in Arabic orthography. Phonology (in the form of short vowels) affects reading accuracy as well as reading comprehension, regardless of reading level, age, material and reading conditions. Initial visual–orthographic processing identifies the morphology (i.e. the triliteral/quadriliteral roots of Arabic words) which then enables access to the mental lexicon. Sentence context is also essential in reading Arabic orthography regardless of the reader’s level, age, material and reading condition. The phonology, morphology and sentence context of Arabic are presented in two suggested reading models for poor/beginner Arabic readers and for skilled Arabic readers.