Do reading and spelling share a lexicon?

Cross-modal interactions in language production: evidence from word learning

Literate adults are able to produce the same word in different language modalities-for instance, through speaking and writing. Yet how speaking and writing interact is not well understood. The present study takes a new perspective on the question of the co-activation of phonological and orthographic representations in speaking and writing by examining the acquisition of novel words. We tested how novel words get integrated into modality-specific lexicons by biasing novel word acquisition toward speaking or writing and assessing cross-modal transfer at the first stages of learning. Participants learned novel words paired with pictures of novel objects and practiced them overtly through speaking or typing. At test, typed training led to higher recall accuracy than spoken training whether words were recalled through typing or speaking. Performance in typing (RT and durations) benefited more from typed than spoken training. Crucially, performance in speaking did not benefit specifically from spoken training and was similar after spoken or typed training. Results are compatible with an asymmetric integration in the phonological and orthographic lexicons according to the modality of training, with representations created in the orthographic lexicon directly transferring to the phonological lexicon, while the opposite doesn't seem to occur. Cross-modal transfer dynamics are discussed according to the level of lexical activation.

Developmental surface dyslexia and dysgraphia in a child with corpus callosum agenesis: an approach to diagnosis and treatment

We present a case study detailing cognitive performance, functional neuroimaging, and effects of a hypothesis-driven treatment in a 10-year-old girl diagnosed with complete, isolated corpus callosum agenesis. Despite having average overall intellectual abilities, the girl exhibited profound surface dyslexia and dysgraphia. Spelling treatment significantly and persistently improved her spelling of trained irregular words, and this improvement generalized to reading accuracy and speed of trained words. Diffusion weighted imaging revealed strengthened intrahemispheric white matter connectivity of the left temporal cortex after treatment and identified interhemispheric connectivity between the occipital lobes, likely facilitated by a pathway crossing the midline via the posterior commissure. This case underlines the corpus callosum's critical role in lexical reading and writing. It demonstrates that spelling treatment may enhance interhemispheric connectivity in corpus callosum agenesis through alternative pathways, boosting the development of a more efficient functional organization of the visual word form area within the left temporo-occipital cortex.

Atypical characteristic changes of surface morphology and structural covariance network in developmental dyslexia

BACKGROUND

Developmental dyslexia (DD) is a neurodevelopmental disorder that is characterized by difficulties with all aspects of information acquisition in the written word, including slow and inaccurate word recognition. The neural basis behind DD has not been fully elucidated.

METHOD

The study included 22 typically developing (TD) children, 16 children with isolated spelling disorder (SpD), and 20 children with DD. The cortical thickness, folding index, and mean curvature of Broca's area, including the triangular part of the left inferior frontal gyrus (IFGtriang) and the opercular part of the left inferior frontal gyrus, were assessed to explore the differences of surface morphology among the TD, SpD, and DD groups. Furthermore, the structural covariance network (SCN) of the triangular part of the left inferior frontal gyrus was analyzed to explore the changes of structural connectivity in the SpD and DD groups.

RESULTS

The DD group showed higher curvature and cortical folding of the left IFGtriang than the TD group and SpD group. In addition, compared with the TD group and the SpD group, the structural connectivity between the left IFGtriang and the left middle-frontal gyrus and the right mid-orbital frontal gyrus was increased in the DD group, and the structural connectivity between the left IFGtriang and the right precuneus and anterior cingulate was decreased in the DD group.

CONCLUSION

DD had atypical structural connectivity in brain regions related to visual attention, memory and which might impact the information input and integration needed for reading and spelling.

Morphological processing in written word production is based on orthography rather than semantics

Written word production is influenced by central and peripheral processes. Evidence suggests that the activation of morphological units in the lexicon influences the dynamics of handwriting. In this study, we designed two priming experiments to examine the representation level of morphological information in the lexicon during written word production in the French language. In both experiments, target words (e.g., chanteur, "singer") were primed by a derived (e.g., chanter, "to sing"), a pseudo-derived (e.g., chantier, "work site"), or an unrelated (e.g., baleine, "whale") prime. We used the pseudo-derivation condition to disentangle two distinct levels of representation: the sublexical (also known as morpho-orthographic) and the supralexical (morpho-semantic). In Experiment 1 (learning-recall task), we measured the writing latency and writing duration of the target words. In Experiment 2 (word pair copying task), we measured the inter-word duration and writing duration of the target words. We observed morphological priming effects in both experiments: The processing of a derived prime influenced target writing compared to an unrelated prime, but the effect was observed on latencies in Experiment 1 and on target writing duration in Experiment 2. We found similar patterns of priming in the derived and pseudo-derived conditions in both experiments. The findings revealed that morphemes are processed at the morpho-orthographic representation level in written word production. Morphemes serve as grouping units during handwriting, a process that operates independently of their meaning.

The Effects of Orthographic Neighborhood Size and the Influence of Individual Differences in Linguistic Skills During the Recognition of Chinese Words

There are still inconsistencies as to whether frequency and orthographic neighborhood size affect the reading and recognition of Chinese words. In addition, research on Chinese reading still adheres to the view that "all skilled readers read in the same way" and pays little attention to the influence of individual differences in linguistic skills on word recognition. In this research, we studied the recognition of Chinese two-character words in a lexical decision task (LDT) by manipulating neighborhood size and word frequency and controlling the frequency of the initial constituent character. Individual differences in linguistic skills were assessed through tests of spelling and reading comprehension. The results showed that: (1) A larger orthographic neighborhood size of the initial character had a facilitative effect on Chinese word recognition. The orthographic neighborhood size effect is modulated by word frequency, but this modulation effect was not stable. (2) Spelling and reading comprehension skills are good indicators to assess individual differences in Chinese linguistic skills, and they are significantly correlated. (3) Individual differences in linguistic skills influence the neighborhood size effect, which is moderated by word frequency.

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.

Word skipping during the lexical acquisition process

During reading, most words are identified in the fovea through a direct fixation; however, readers also identify some words in the parafovea without directly fixating them. This word skipping process is influenced by many lexical and visual factors including word length, launch position, frequency, and predictability. Although these factors are well understood, there is some disagreement about the process that leads to word skipping and the degree to which skipped words are processed. The purpose of this study was to investigate the word skipping process when readers are exposed to novel words in an incidental lexical acquisition paradigm. Participants read 18 three-letter novel words (i.e., pru, cho) in three different informative contexts each while their eye movements were monitored. They then completed a surprise test of their orthographic and semantic acquisition and a spelling skill assessment. Mixed-effects models indicated that participants learned spellings and meanings of words at the same rate regardless of the number of times that they were skipped. However, word skipping rates increased across the three exposures and reading times decreased. Results indicate that readers appear to process skipped words to the same degree as fixated words. However, this may be due to a more cautious skipping process used during lexical acquisition of unfamiliar words compared to processing of already known words.

Individual differences in spelling ability influence phonological processing during visual word recognition

In the research reported here, we investigated how phonological processing in the lexical decision task is influenced by individual differences in the reading and spelling abilities of participants. We used phonological neighborhood spread as a measure of phonological processing. Spread refers to the number of phoneme positions in a word that can be changed to form a phonological neighbor. Replicating previous research, we found that words forming neighbors across three positions (P3) were recognized more rapidly than those forming neighbors across only two positions (P2). Importantly, we found that this spread effect interacted with spelling ability. The difference between P3 and P2 was largest when spelling recognition was high and spelling production low. These opposing effects of spelling ability are explained in terms of a language system that consists of separate orthographic systems for reading and spelling. Although these two orthographic systems are separate, they share information through a shared response buffer (Jones & Rawson, 2016). Within this framework, it is argued that lexical decisions are made once the information in the response buffer reaches threshold and that time to reach this threshold is influenced by two sources. One is the quality of the orthographic connections in the reading system and is measured by spelling recognition. The other is the quality of the orthographic connections in the spelling system and is measured by spelling production.

Reading strategies of good and poor readers of German with different spelling abilities

Reading and spelling abilities are thought to be highly correlated during development, and orthographic knowledge is assumed to underpin both literacy skills. Interestingly, recent studies showed that reading and spelling skills can also dissociate. The current study investigated whether spelling skills (indicating orthographic knowledge) are associated with the application of orthographic strategies during reading. We examined eye movements of 137 third- and fourth-graders who were either good or poor readers with or without a spelling deficit: 43 children with typical reading and spelling skills, 28 with isolated spelling deficits, 28 with isolated reading deficits, and 38 with combined reading and spelling deficits. Although we expected to find reduced reliance on orthographic reading processes among poor spellers, this was evident for the group with combined deficits only. Both isolated deficit groups applied sublexical and lexical processes in a similar amount to typically developing children. Our findings suggest that reading rests on orthographic strategies even if lexical representations are poor as indicated by a deficit in spelling skills. Findings also show that dysfluent reading does not result only from overreliance on decoding.

Developmental dysgraphia: An overview and framework for research

Developmental deficits in the acquisition of writing skills (developmental dysgraphias) are common and have significant consequences, yet these deficits have received relatively little attention from researchers. We offer a framework for studying developmental dysgraphias (including both spelling and handwriting deficits), arguing that research should be grounded in theories describing normal cognitive writing mechanisms and the acquisition of these mechanisms. We survey the current state of knowledge concerning developmental dysgraphia, discussing potential proximal and distal causes. One conclusion emerging from this discussion is that developmental writing deficits are diverse in their manifestations and causes. We suggest an agenda for research on developmental dysgraphia, and suggest that pursuing this agenda may contribute not only to a better understanding of developmental writing impairment, but also to a better understanding of normal writing mechanisms and their acquisition. Finally, we provide a brief introduction to the subsequent articles in this special issue on developmental dysgraphia.