Visual Word Processing Research Articles

Poor reading is characterized by a more connected network with wrong hubs

Using graph theory, we examined topological organization of the language network in Chinese children with poor reading during an auditory rhyming task and a visual spelling task, compared to reading-matched controls and age-matched controls. First, poor readers (PR) showed reduced clustering coefficient in the left inferior frontal gyrus (IFG) and higher nodal efficiency in the bilateral superior temporal gyri (STG) during the visual task, indicating a less functionally specialized cluster around the left IFG and stronger functional links between bilateral STGs and other regions. Furthermore, PR adopted additional right-hemispheric hubs in both tasks, which may explain increased global efficiency across both tasks and lower normalized characteristic shortest path length in the visual task for the PR. These results underscore deficits in the left IFG during visual word processing and conform previous findings about compensation in the right hemisphere in children with poor reading.

Decoding the role of the cerebellum in the early stages of reading acquisition

Numerous studies have consistently reported functional activation of the cerebellum during reading tasks, especially in the right cerebellar hemisphere. However, it remains unclear whether this region is also involved in reading during the earliest stages of reading acquisition. Here, we investigated whether and how the cerebellum contributes to reading acquisition. We tested 80 5-6-year-old kindergarteners, who performed a visual word matching task during which functional MRI (fMRI) data were collected. We found that bilateral cerebellar hemispheres were significantly activated during visual word processing. Moreover, activation of left cerebellar lobule VII extending to lobule VIII negatively and significantly correlated with current reading ability, whereas activation of right cerebellar lobule VII extending to lobule VIII significantly and positively correlated with future reading ability. Functional decoding via functional connectivity patterns further revealed that left and right cerebellar lobules connected with different cerebral cortex regions. Our results suggest a division of labor between the left and right cerebellar lobules in beginning readers.

Neural patterns of word processing differ in children with dyslexia and isolated spelling deficit

There is an ongoing debate concerning the extent to which deficits in reading and spelling share cognitive components and whether they rely, in a similar fashion, on sublexical and lexical pathways of word processing. The present study investigates whether the neural substrates of word processing differ in children with various patterns of reading and spelling deficits. Using functional magnetic resonance imaging, we compared written and auditory processing in three groups of 9–13-year olds (N = 104): (1) with age-adequate reading and spelling skills; (2) with reading and spelling deficits (i.e., dyslexia); (3) with isolated spelling deficits but without reading deficits. In visual word processing, both deficit groups showed hypoactivations in the posterior superior temporal cortex compared to typical readers and spellers. Only children with dyslexia exhibited hypoactivations in the ventral occipito-temporal cortex compared to the two groups of typical readers. This is the result of an atypical pattern of higher activity in the occipito-temporal cortex for non-linguistic visual stimuli than for words, indicating lower selectivity. The print–speech convergence was reduced in the two deficit groups. Impairments in lexico-orthographic regions in a reading-based task were associated primarily with reading deficits, whereas alterations in the sublexical word processing route could be considered common for both reading and spelling deficits. These findings highlight the partly distinct alterations of the language network related to reading and spelling deficits.

Can rotated words be processed automatically? Evidence from rotated repetition priming.

Visual word processing has its own dedicated neural system that, due to the novelty of this activity, is unlikely to have acquired its specialization through natural selection. Understanding the properties of this system could shed light on its recruitment and the background of its disorders. Although recognition of simple visual objects is orientation invariant, this is not necessarily the case for written words. We used a masked repetition priming paradigm to find out whether words retain their readability when viewed in atypical orientations. Subjects had to read out upright target words that were preceded by rotated prime words of the same or different identity. Priming duration was varied in Experiment 1 to assess the temporal emergence of a rotated priming effect. In Experiment 2, the letter order of the prime words was reversed in order to differentiate the processing stage where priming occurs. The orientational pattern of the priming effects seen in our results mostly confirms earlier word recognition models, but also serves a more detailed view about the effects of orientation on word form processing.

The neurocognitive basis of skilled reading in prelingually and profoundly deaf adults.

Deaf individuals have unique sensory and linguistic experiences that influence how they read and become skilled readers. This review presents our current understanding of the neurocognitive underpinnings of reading skill in deaf adults. Key behavioural and neuroimaging studies are integrated to build a profile of skilled adult deaf readers and to examine how changes in visual attention and reduced access to auditory input and phonology shape how they read both words and sentences. Crucially, the behaviours, processes, and neural circuity of deaf readers are compared to those of hearing readers with similar reading ability to help identify alternative pathways to reading success. Overall, sensitivity to orthographic and semantic information is comparable for skilled deaf and hearing readers, but deaf readers rely less on phonology and show greater engagement of the right hemisphere in visual word processing. During sentence reading, deaf readers process visual word forms more efficiently and may have a greater reliance on and altered connectivity to semantic information compared to their hearing peers. These findings highlight the plasticity of the reading system and point to alternative pathways to reading success.

Morpheme Transposition of Two-Character Chinese Words in Vertical Visual Fields.

The present study explored the morpheme transposition process of two-character Chinese words in the upper and lower visual fields by adopting a dual-target rapid serial visual presentation paradigm. The results showed that the identification accuracy of canonical words was better in the lower visual field, whereas the accuracy of transposed words was almost identical in the upper and lower visual fields. Furthermore, there was no significant difference between canonical and transposed words at 0°, 2°, 4°, and 6° eccentricities in the upper visual field. However, the accuracy of canonical words was markedly higher than that of transposed words at 2°, 4°, and 6° eccentricities in the lower visual field. Finally, the character order errors mainly occurred at 0°eccentricity with a duration of 100ms in vertical visual fields. These findings, taken together, indicated that the character transposition affected the lexical process of two-character Chinese words in the lower visual field but not in the upper visual field, and the character order of words was more likely to be reversed at 0° eccentricity and the initial stage of visual word processing in vertical reading.

Neural Representation in Visual Word Form Area during Word Reading

The visual word form area (VWFA) has been consistently identified as a crucial structure in visual word processing. Nevertheless, it is controversial whether the VWFA represents external visual information (e.g., case information) of visual words. To address that question, we functionally localized VWFA at the group level (gVWFA) and at the individual level (iVWFA), and used multivariate pattern analysis (MVPA) to explore the information representation in the VWFA during an implicit reading task (i.e., a passive viewing task). Univariate activation analysis revealed that participants showed stronger activations for uppercase English words compared to lowercase ones in the VWFA. MVPA further revealed that the classifier trained based on lowercase words versus letter strings significantly distinguished uppercase words versus letter strings in the iVWFA, while that trained based on lowercase words versus uppercase words distinguished lowercase letter strings versus uppercase letter strings neither in the gVWFA nor in the iVWFA. These results suggest that the VWFA does not represent case information, but represents case-independent linguistic information. Our findings elaborate the function in the VWFA and support the VWFA hypothesis.

Visual word form processing deficits driven by severity of reading impairments in children with developmental dyslexia

The visual word form area (VWFA) in the left ventral occipito-temporal (vOT) cortex is key to fluent reading in children and adults. Diminished VWFA activation during print processing tasks is a common finding in subjects with severe reading problems. Here, we report fMRI data from a multicentre study with 140 children in primary school (7.9–12.2 years; 55 children with dyslexia, 73 typical readers, 12 intermediate readers). All performed a semantic task on visually presented words and a matched control task on symbol strings. With this large group of children, including the entire spectrum from severely impaired to highly fluent readers, we aimed to clarify the association of reading fluency and left vOT activation during visual word processing. The results of this study confirm reduced word-sensitive activation within the left vOT in children with dyslexia. Interestingly, the association of reading skills and left vOT activation was especially strong and spatially extended in children with dyslexia. Thus, deficits in basic visual word form processing increase with the severity of reading disability but seem only weakly associated with fluency within the typical reading range suggesting a linear dependence of reading scores with VFWA activation only in the poorest readers.

Sonority as a Phonological Cue in Early Perception of Written Syllables in French.

Many studies focused on the letter and sound co-occurrences to account for the well-documented syllable-based effects in French in visual (pseudo)word processing. Although these language-specific statistical properties are crucial, recent data suggest that studies that go all-in on phonological and orthographic regularities may be misguided in interpreting how—and why—readers locate syllable boundaries and segment clusters. Indeed, syllable-based effects could depend on more abstract, universal phonological constraints that rule and govern how letter and sound occur and co-occur, and readers could be sensitive to sonority—a universal phonological element—for processing (pseudo)words. Here, we investigate whether French adult skilled readers rely on universal phonological sonority-related markedness continuum across the syllable boundaries for segmentation (e.g., from marked, illegal intervocalic clusters /zl/ to unmarked, legal intervocalic clusters /lz/). To address this question, we ran two tasks with 128 French adult skilled readers using two versions of the illusory conjunction paradigm (Task 1 without white noise; Task 2 with white noise). Our results show that syllable location and segmentation in reading is early and automatically modulated by phonological sonority-related markedness in the absence or quasi-absence of statistical information and does not require acoustic-phonetic information. We discuss our results toward the overlooked role of phonological universals and the over-trusted role of statistical information during reading processes.

Sandhi-tone words prolong fixation duration during silent sentence reading in Chinese

The current study examined whether or not lexical access is influenced by detailed phonological features during the silent reading of Chinese sentences. We used two types of two-character target words (Mandarin sandhi-tone and base-tone). The first characters of the words in the sandhi-tone condition had a tonal alternation, but no tonal alternation was involved in the base-tone condition. Recordings of eye movements revealed that native Mandarin Chinese readers viewed the base-tone target words more briefly than the sandhi-tone target words when they were infrequent. Such articulation-specific effects on visual word processing, however, diminished for frequent words. We suggest that a conflict in tonal representation at a character/morpheme level and at a word level induces prolongation in fixation duration on infrequent sandhi-tone words, and conclude that these tonal effects appear to reflect articulation simulation of words during the silent reading of Chinese sentences.

The contribution of phonological information to visual word recognition: Evidence from Chinese phonetic radicals

Lateralization is a critical characteristic of language production and also plays a role in visual word recognition. However, the neural mechanisms underlying the interactions between visual input and spoken word representations are still unclear. We investigated the contribution of sub-lexical phonological information in visual word processing by exploiting the fact that Chinese characters can contain phonetic radicals in either the left or right half of the character. FMRI data were collected while 39 Chinese participants read words in search of target color words. On the basis of whole-brain analysis and three laterality analyses of regions of interest, we argue that visual information from centrally presented Chinese characters is split in the fovea and projected to the contralateral visual cortex, from which phonological information can be extracted rapidly if the character contains a phonetic radical. Extra activation, suggestive of more effortful processing, is observed when the phonetic radical is situated in the left half of the character and therefore initially sent to the visual cortex in the right hemisphere that is less specialized for language processing. Our results are in line with the proposal that phonological information helps written word processing by means of top-down feedback.

Towards a unified understanding of lateralized vision: A large-scale study investigating principles governing patterns of lateralization using a heterogeneous sample

While functional lateralization of the human brain has been a widely studied topic in the past decades, few studies to date have gone further than investigating lateralization of single, isolated processes. With the present study, we aimed to arrive at a more unified view by investigating lateralization patterns in face and word processing, and associated lower-level visual processing. We tested a large and heterogeneous participant group, and used a number of tasks that had been shown to produce replicable indices of lateralized processing of visual information of different types and complexity. Following Bayesian statistics, group-level analyses showed the expected right hemisphere (RH) lateralization for face, global form, low spatial frequency processing, and spatial attention, and left hemisphere (LH) lateralization for visual word and local feature processing. Compared to right-handed individuals, lateralization patterns of left-handed and especially those who are RH-dominant for language deviated from this ‘typical’ pattern. Our results support the notion that face and word processes come to be lateralized to homologue areas of the two hemispheres, under influence of the RH- and LH-specializations in global form, local feature, and low and high spatial frequency processing. As such, we present a more unified understanding of lateralized vision, providing evidence for the input asymmetry and causal complementarity principles of lateralized visual information processing. The absence of correlations between spatial attention and lateralization of the other processes supports the notion of their independent lateralization, conform the statistical complementarity principle.

The conception of comprehension in two eye movement tracking models: Just and Carpenter (1980) and Rayner and Pollatsek (1989)

Las investigaciones previas sobre la comprensión del texto escrito se han centrado generalmente en el método de seguimiento de movimientos oculares, puesto que permite dar cuenta de los procesos de lectura y el acceso léxico en tiempo real. Este método tiene como objetivo observar los procesos de comprensión de todo el contenido del texto. La contribución de estos estudios es innegable, a pesar de que el procesamiento visual de las palabras no es una garantía de su comprensión. Por esta razón, en este trabajo se compara cómo se concibe la comprensión en dos modelos de seguimiento de movimiento ocular del procesamiento del lenguaje durante la lectura: el modelo de Just y Carpenter (1980) y el modelo de Rayner y Pollatsek (1989). Ambos modelos ofrecen una interesante visión sobre el término comprensión de texto. Este artículo se centra en las similitudes y diferencias entre modelos y, principalmente, hasta qué punto el término procesamiento podría utilizarse de manera alternativa para referirse a la comprensión.

Morphemes as letter chunks: Discovering affixes through visual regularities

During visual word processing readers identify chunks of co-occurring letters and code for their typical position within words. Using an artificial script, we examined whether these phenomena can be explained by the ability to extract visual regularities from the environment. Participants were first familiarized with a lexicon of pseudoletter strings, each comprising an affix-like chunk that either followed (Experiment 1) or preceded (Experiment 2) a random character sequence. In the absence of any linguistic information, chunks could be defined only by their statistical properties - similarly to affixes in the real language, chunks occurred frequently and assumed a specific position within strings. In a later testing phase, we found that participants were more likely to attribute a previously unseen string to the familiarization lexicon if it contained an affix, and if the affix appeared in its typical position. Importantly, these findings suggest that readers may chunk words using a general, language-agnostic cognitive mechanism that captures statistical regularities in the learning materials.

Probing language processing in cochlear implant users with visual word recognition: effects of lexical and orthographic word properties

ABSTRACT Deaf individuals who learned a spoken language with the aid of a cochlear implant (CI) often experience difficulties with reading. In the present study, we investigate this issue by assessing the impact of lexical and orthographic predictors on visual word recognition in early and late deaf CI-users. Early deaf CI-users were comparable to age-matched hearing controls, for both response accuracy and latencies, whereas late deaf CI-users were slower albeit similarly accurate with respect to age-matched controls. Analyses of the impact of lexical and orthographic predictors, however, revealed that early deaf-CI users were slower than controls in recognising low frequency words and words with high proportion of consonants. In conclusion, early deaf individuals who developed their language using a CI show qualitative differences in visual word processing, above and beyond the overall performance. This suggests that typical overall performance may emerge also in the context of atypical lexical and word form representations.

Alternating dual-task interference between visual words and faces

The many-to-many hypothesis proposes that face and visual word recognition share and even compete for high-level perceptual resources in both hemispheres. However, it is still not clear whether the processing performed by the two hemispheres on faces and visual words is equivalent or complementary. We performed an alternating dual-task experiment to determine if the processing of visual words and faces interfered with each other, and if such interference depended upon the stimulus attribute being processed. Subjects saw a series of alternating stimuli and made same-different judgments comparing the current stimulus with the one two trials before. In some blocks faces or visual words alternated with colored gratings, in other blocks they alternated between different sets of words or different sets of faces. In the key experimental blocks they alternated between visual words and faces. Subjects were also asked to focus on different properties of the stimuli (identity or speech sounds for faces, handwriting or word content for visual words, color or orientation for gratings). There was no evidence of specific interference when subjects alternated between face and word attributes thought to be processed by opposite hemispheres (e.g. face identity and word identity, facial speech and handwriting). Rather interference occurred when subjects alternated between attributes that may be processed by the same hemisphere. The results support a modified version of the many-to-many hypothesis which takes into account complementary functions of the left and the right hemispheres in the processing of faces and visual words.

Homophone auditory processing in cross-linguistic perspective

Previous studies reported conflicting results for the effects of homophony on visual word processing across languages. On finding significant differences in homophone density in Japanese, Mandarin Chinese and English, we conducted two experiments to compare native speakers’ competence in homophone auditory processing across these three languages. A lexical decision task showed that the effect of homophony on word processing in Japanese was significantly less detrimental than in Mandarin and English. A word-learning task showed that native Japanese speakers were the fastest in learning novel homophones. These results suggest that language-intrinsic properties influence corresponding language processing abilities of native speakers.

The right visual field advantage for word processing is stronger in older adults

The human brain is functionally asymmetric. Producing and understanding language, for instance, engages the left hemisphere to a larger extent than the right in most people. Recent research showed that lateralization for auditory word processing increases with age. The present study extends these findings to the visual domain. We measured lateralization for visual word processing with the visual half field task in young (20–30 years) and older participants (70–80 years). The older cohort had a larger right visual field advantage in terms of reaction time (p = .016, dolder adults = 0.16, dyounger adults = 0.13) and accuracy (p = .053, dolder adults = 0.73, dyounger adults = 0.25). This difference was mainly driven by a weaker performance for words presented in the left visual field. Our findings suggest that hemisphere dominance for language increases with aging. Alternatively, the findings could be explained by delayed inter-hemispheric communication in older adults.

Holistic word processing is correlated with efficiency in visual word recognition.

Holistic processing of visual words (i.e., obligatory encoding of/attending to all letters of a word) could be a marker of expert word recognition. In the present study, we thus examined for the first time whether there is a direct relation between the word-composite effect (i.e., all parts of a visual word are fully processed when observers perform a task on a word part) and fast access to the orthographic lexicon by visual word experts (i.e., fluent adult readers). We adopted an individual differences approach and used the word-frequency effect (i.e., faster recognition of high- than low-frequency words) in an independent lexical decision task as a proxy of fast access to lexical orthographic representations. Fluent readers with larger word-composite effect showed smaller word-frequency effect. This correlation was mainly driven by an association between a larger composite effect and faster lexical decision on low-frequency words, probably because these lexical representations are less stable and integrated/unitized, hence allowing differentiating among fluent readers. We thus showed that holistic processing of visual words is indeed related to higher efficiency in visual word recognition by skilled readers.

Matrices of the frequency and similarity of Arabic letters and allographs.

Indicators of letter frequency and similarity have long been available for Indo-European languages. They have not only been pivotal in controlling the design of experimental psycholinguistic studies seeking to determine the factors that underlie reading ability and literacy acquisition, but have also been useful for studies examining the more general aspects of human cognition. Despite their importance, however, such indicators are still not available for Modern Standard Arabic (MSA), a language that, by virtue of its orthographic system, presents an invaluable environment for the experimental investigation of visual word processing. This paper presents for the first time the frequencies of Arabic letters and their allographs based on a 40-million-word corpus, along with their similarity/confusability indicators in three domains: (1) the visual domain, based on human ratings; (2) the auditory domain, based on an analysis of the phonetic features of letter sounds; and (3) the motoric domain, based on an analysis of the stroke features used to write letters and their allographs. Taken together, the frequency and similarity of Arabic letters and their allographs in the visual and motoric domains, as well as the similarities among the letter sounds, will be useful for researchers interested in the processes underpinning orthographic processing, visual word recognition, reading, and literacy acquisition.