Morphology and spelling in French students with dyslexia: the case of silent final letters

Frequency Effects on Spelling Error Recognition: An ERP Study

Spelling errors are ubiquitous in all writing systems. Most studies exploring spelling errors focused on the phonological plausibility of errors. However, unlike typical pseudohomophones, spelling errors occur in naturally produced written language. We investigated the time course of recognition of the most frequent orthographic errors in Russian (error in an unstressed vowel in the root) and the effect of word frequency on this process. During event-related potentials (ERP) recording, 26 native Russian speakers silently read high-frequency correctly spelled words, low-frequency correctly spelled words, high-frequency words with errors, and low-frequency words with errors. The amplitude of P200 was more positive for correctly spelled words than for misspelled words and did not depend on the frequency of the words. In addition, in the 350–500-ms time window, we found a more negative response for misspelled words than for correctly spelled words in parietal–temporal-occipital regions regardless of word frequency. Considering our results in the context of a dual-route model, we concluded that recognizing misspelled high-frequency and low-frequency words involves common orthographic and phonological processes associated with P200 and N400 components such as whole word orthography processing and activation of phonological representations correspondingly. However, at the 500–700 ms stage (associated with lexical-semantic access in our study), error recognition depends on the word frequency. One possible explanation for these differences could be that at the 500–700 ms stage recognition of high-frequency misspelled and correctly spelled words shifts from phonological to orthographic processes, while low-frequency misspelled words are accompanied by more prolonged phonological activation. We believe these processes may be associated with different ERP components P300 and N400, reflecting a temporal overlap between categorization processes based on orthographic properties for high-frequency words and phonological processes for low-frequency words. Therefore, our results complement existing reading models and demonstrate that the neuronal underpinnings of spelling error recognition during reading may depend on word frequency.

The "Sound of Silence": Sensitivity to Silent Letters in Children With and Without Developmental Language Disorder

Purpose Children with developmental language disorder (DLD) demonstrate general spelling difficulties. This study investigated accuracy on and sensitivity to silent letters in spelling in children with and without DLD. Investigating silent-letter production provides a window into orthographic and morphological knowledge and enhances understanding of children's spelling skills. Method A group of children with DLD (M _age = 9;11 [years;months]) and two control groups of typically developing children (n = 30 in each group) were given a dictated spelling task of 44 words that each contained a derivational or a nonderivational silent letter. We coded the silent letter in each word and counted 1 point for each correctly spelled letter in order to examine accuracy on silent letters. Two error patterns were distinguished to analyze sensitivity to silent letters: silent-letter substitutions and silent-letter omissions. Results Repeated-measures ANOVA showed that children with DLD produced significantly more errors on silent letters than did both control groups. Both control groups showed a greater sensitivity to silent-letter endings, as they tended to substitute incorrect silent letters where they made errors. In contrast, children with DLD tended to omit silent letters in their spelling attempts. Conclusions Our results suggest that silent-letter production is a major source of difficulty for spellers, especially for those with DLD, who appear to lack sensitivity to silent letters. These results highlight the importance of promoting spelling instruction to enhance orthographic knowledge in children with DLD.

A general role for ventral white matter pathways in morphological processing: Going beyond reading

The ability to recognize the structural components of words, known as morphological processing, was recently associated with the bilateral ventral white matter pathways, across different writing systems. However, it remains unclear whether these associations are specific to the context of reading. To shed light on this question, in the current study we investigated whether the ventral pathways are associated with morphological processing in an oral word production task that does not involve reading. Forty-five participants completed a morpheme-based fluency task in Hebrew, as well as diffusion MRI (dMRI) scans. We used probabilistic tractography to segment the major ventral and dorsal white matter pathways, and assessed the correlations between their microstructural properties and performance on the morpheme-based fluency task. We found significant correlations between morpheme-based fluency and properties of the bilateral ventral tracts, suggesting that the involvement of these tracts in morphological processing extends beyond the reading modality. In addition, significant correlations were found in the frontal aslant tract (FAT), a dorsal tract associated with oral fluency and speech production. Together, our findings emphasize that neurocognitive associations reflect both the cognitive construct under investigation as well as the task used for its assessment. Lastly, to elucidate the biological factors underlying these correlations, we incorporated the composite hindered and restricted model of diffusion (CHARMED) framework, measured in independent scans. We found that only some of our findings could be attributed to variation in a CHARMED-based estimate of fiber density. Further, we were able to uncover additional correlations that could not be detected using traditional dMRI indices. In sum, our results show that the involvement of the ventral tracts in morphological processing extends to the production domain, and demonstrate the added value of including sensitive structural measurements in neurocognitive investigations.

Morphological decomposition compensates for imperfections in phonological decoding. Neural evidence from typical and dyslexic readers of an opaque orthography

The current study examined the widely held, but un-tested, assumption that morphological decomposition can compensate for missing phonological information in reading opaque orthographies. In addition, we tested whether morphological decomposition can compensate for the phonological decoding deficits in readers with dyslexia. Hebrew provides a unique opportunity to test these questions as it has a rich Semitic morphology, and two versions of script: a transparent orthography (with diacritic marks, 'pointed') and an opaque orthography (without diacritic marks, 'un-pointed'). In two experiments, one behavioral and one fMRI, skilled and dyslexic readers read aloud Hebrew nouns: half bi-morphemic (root + pattern) and half mono-morphemic (non-decomposable). Each word was presented both in the transparent orthography (pointed), and in the opaque orthography (un-pointed). While skilled readers were faster, and showed no effects of diacritics or morphology, dyslexic readers read pointed words more slowly than un-pointed words and bi-morphemic words faster than mono-morphemic words. The imaging results showed: 1) In both groups a morphological effect was found in un-pointed words, in left inferior and middle frontal gyri, associated with morpho-phonological decomposition. 2) Only readers with dyslexia showed a morphological effect in pointed words in the left occipito-temporal cortex, associated with orthographic processing. 3) Dyslexic readers also showed a positive association between morphological awareness and activation in the left occipito-temporal cortex during reading of all words, and activation in inferior frontal cortex during reading of un-pointed bi-morphemic words. Altogether, these findings suggest that in both typical and dyslexic readers morphological decomposition can compensate for the missing phonological information in an opaque orthography. The results also show that readers with dyslexia can rely on morphological decomposition to compensate for their deficits in phonological decoding. Finally, these results highlight the way in which unique language specific properties shape the neural mechanisms underlying typical and atypical reading.

The Development of Morphological Knowledge and Spelling in French

The Frenchorthographic system is particularly difficult to learn because nearly 30% of words in the lexicon end with a silent letter. One metalinguistic skill that has been identified to facilitate spelling acquisition in French is morphological knowledge. This cross-sectional study investigated the construct of morphological knowledge, its development and its role in building accurate orthographic representations in a sample of francophone elementary students. We proposed that morphological knowledge, a superordinate process, encompasses children's implicit use of morphemes in everyday language and their conscious, targeted manipulation of morphemes. In the present study, we assessed children's recognition of morphogrammes, the silent-letter endings (SLEs) of root words that become pronounced in suffixed forms (e.g., the silent t in chant/ʃã/ [song] → chanteur /ʃãtœʀ/ [singer]). When spelling root words, children may mark morphogrammes by recalling morphologically related words in which the morphogramme is not silent - thus, morphological knowledge was hypothesized to positively predict morphogramme spelling. One hundred and twenty-three children in grades 1-3 were assessed on four measures of morphological knowledge, two measures of spelling recognition and a dictation of pseudowords to explore their inclusion of silent-letter endings in novel words. As expected, morphological tasks that required explicit morphological manipulations were harder than implicit ones. Moreover, first graders struggled to complete explicit morphological tasks, while third graders were near ceiling performance on implicit tasks. Nevertheless, the four tasks converged on a single morphological knowledge construct as confirmed by a factor analysis. Importantly, morphological knowledge explained unique variance in children's accurate representation of silent-letter endings after controlling for grade, reading for pleasure and general orthographic recognition of words. Finally, children rarely used silent-letter endings when spelling pseudowords; however, when they did, they displayed sensitivity to the appropriate phonological context for the letter used. The findings are in accord with theoretical models suggesting that the representations of letters without phonological value are difficult to construct and may remain fuzzy.

Phonological and orthographic reading routes in French-speaking children with severe developmental language disorder

PURPOSE

This study aims to assess written word recognition in French-speaking children with severe developmental language disorder (DLD), using a task of reading in silence. The objective is to determine if the balance between the phonological reading route and the orthographic route of these children is similar to that of typically developing children, on the basis of the so-called "dual route" model.

METHOD

A visual lexical decision task was used in 19 children with severe DLD (average age: 11.01 years), 19 control children of the same reading level (RC children, average age: 8.12 years), and 19 children of the same chronological age (AC children, average age: 10.84 years). This task included words and pseudowords associated with these words: pseudohomophones, pseudowords phonologically close but visually distant to the true words, visually close but phonologically distant pseudowords.

RESULTS

The groups did not process the pseudowords in the same way. Children with severe DLD were more successful than RC children for pseudohomophones. They tended to be less successful for phonologically close and visually distant pseudowords. They were similarly successful for visually close and phonologically distant pseudowords. Children with severe DLD were less successful than AC children with each type of pseudowords.

CONCLUSIONS

These results suggest that children with severe DLD do not simply present a homogeneous delay in their ability to recognize written words but rather a deviant development compared to RC children, with a stronger reliance on the orthographic reading route compared to the phonological one. It is likely that the phonological difficulties of children with severe DLD have hindered the development of their phonological reading route which, in turn, have hindered the development of their orthographic route.

Differences in the literacy skills of Danish dyslexic students in two types of higher education programmes

Previous research has treated high-functioning dyslexic students as a homogeneous group. This study explores the clinical observation that dyslexic students attending university programmes differ from dyslexic students attending tertiary education professional programmes in some aspects of their literacy skills. Four groups, dyslexic university students (n = 32), dyslexic students attending professional programmes (n = 32), control university students (n = 31), and control students from professional programmes (n = 30), were assessed on measures of pseudoword reading, phonological choice, vocabulary, reading and spelling of morphologically complex single words, and reading aloud from a syntactically complex text. The results showed that the two dyslexic groups were comparable only on the phonological tasks, the dyslexic university students outperforming the professional programme students in all reading and spelling measures. Controlling vocabulary and number of semesters studied, the difference was no longer significant. Nevertheless, the analyses indicate that phonological deficits underlie the performance of professional programme students with dyslexia across a wide range of tasks, whereas university students with dyslexia may be able to limit the impact of phonological deficits to some extent by relying on some alternative cognitive attributes. Reading experience, orthographic learning, and working memory efficiency are discussed as possible explanations for this pattern of results.

Orthographic Transparency Enhances Morphological Segmentation in Children Reading Hebrew Words

Morphological processing of derived words develops simultaneously with reading acquisition. However, the reader's engagement in morphological segmentation may depend on the language morphological richness and orthographic transparency, and the readers' reading skills. The current study tested the common idea that morphological segmentation is enhanced in non-transparent orthographies to compensate for the absence of phonological information. Hebrew's rich morphology and the dual version of the Hebrew script (with and without diacritic marks) provides an opportunity to study the interaction of orthographic transparency and morphological segmentation on the development of reading skills in a within-language design. Hebrew speaking 2nd (N = 27) and 5th (N = 29) grade children read aloud 96 noun words. Half of the words were simple mono-morphemic words and half were bi-morphemic derivations composed of a productive root and a morphemic pattern. In each list half of the words were presented in the transparent version of the script (with diacritic marks), and half in the non-transparent version (without diacritic marks). Our results show that in both groups, derived bi-morphemic words were identified more accurately than mono-morphemic words, but only for the transparent, pointed, script. For the un-pointed script the reverse was found, namely, that bi-morphemic words were read less accurately than mono-morphemic words, especially in second grade. Second grade children also read mono-morphemic words faster than bi-morphemic words. Finally, correlations with a standardized measure of morphological awareness were found only for second grade children, and only in bi-morphemic words. These results, showing greater morphological effects in second grade compared to fifth grade children suggest that for children raised in a language with a rich morphology, common and easily segmented morphemic units may be more beneficial for younger compared to older readers. Moreover, in contrast to the common hypothesis, our results show that morphemic segmentation does not compensate for the missing phonological information in a non-transparent orthography, but rather that morphological segmentation is most beneficial in the highly transparent script. These results are consistent with the idea that morphological and phonological segmentation processes occur simultaneously and do not constitute alternative pathways to visual word recognition.

Morpheme-Based Reading and Writing in Spanish Children with Dyslexia

It has been well documented that morphemic structure (roots and affixes) have an impact in reading, but effects seem to depend on the reading experience of readers and lexical characteristics of the stimuli. Specifically, it has been reported that morphemes constitute reading units for developing readers and children with dyslexia when they encounter a new word. In addition, recent studies have stated that the effect of morphology is also present in spelling, as morphological information facilitates spelling accuracy and influences handwriting times. The goal of this study was to investigate the role of morphology in reading and spelling fluency in Spanish children with dyslexia. For that purpose, a group of 24 children with dyslexia was compared with an age-matched group of 24 children without reading disabilities in performing a word naming task and a spelling-to-dictation task of isolated words. Morphological condition (high frequency base, low frequency base, simple) and lexicality (words vs. pseudowords) were manipulated. We considered, for the naming task, reading latencies, reading durations, reading critical segment (three first phonemes) durations and naming accuracy; and, for the spelling task, written latencies, writing durations for the whole word, writing critical segment (three first letters) durations and spelling accuracy. Results showed that Spanish children (with and without dyslexia) benefit from a high frequency base to initiate reading and writing responses, showing that they are familiar with the letter chunks that constitute a morpheme. In addition, base frequency impacts reading critical segment duration only for children with dyslexia, but for both groups in writing. In summary, children with dyslexia benefit from a high frequency base to read and spell unfamiliar stimuli.

Morpheme-based Reading and Spelling in Italian Children with Developmental Dyslexia and Dysorthography

Italian sixth graders, with and without dyslexia, read pseudowords and low-frequency words that include high-frequency morphemes better than stimuli not including any morpheme. The present study assessed whether morphemes affect (1) younger children, with and without dyslexia; (2) spelling as well as reading; and (3) words with low-frequency morphemes. Two groups of third graders (16 children with dyslexia and dysorthography and 16 age-matched typically developing children) read aloud and spelt to dictation pseudowords and words. Pseudowords included (1) root + suffix in not existing combinations (e.g. lampadista, formed by lampad-, 'lamp', and -ista, '-ist') and (2) orthographic sequences not corresponding to any Italian root or suffix (e.g. livonosto). Words had low frequency and included: (1) root + suffix, both of high frequency (e.g. bestiale, 'beastly'); (2) root + suffix, both of low frequency (e.g. asprigno, 'rather sour'); and (3) simple words (e.g. insulso, 'vapid'). Children with dyslexia and dysorthography were less accurate than typically developing children. Root + suffix pseudowords were read and spelt more accurately than non-morphological pseudowords by both groups. Morphologically complex (root + suffix) words were read and spelt better than simple words. However, task interacted with morphology: reading was not facilitated by low-frequency morphemes. We conclude that children acquiring a transparent orthography exploit morpheme-based reading and spelling to face difficulties in processing long unfamiliar stimuli. Copyright © 2017 John Wiley & Sons, Ltd.

The Training of Morphological Decomposition in Word Processing and Its Effects on Literacy Skills

This study set out to examine the effects of a morpheme-based training on reading and spelling in fifth and sixth graders (N = 47), who present poor literacy skills and speak German as a second language. A computerized training, consisting of a visual lexical decision task (comprising 2,880 items, presented in 12 sessions), was designed to encourage fast morphological analysis in word processing. The children were divided between two groups: the one underwent a morpheme-based training, in which word-stems of inflections and derivations were presented for a limited duration, while their pre- and suffixes remained on screen until response. Another group received a control training consisting of the same task, except that the duration of presentation of a non-morphological unit was restricted. In a Word Disruption Task, participants read words under three conditions: morphological separation (with symbols separating between the words' morphemes), non-morphological separation (with symbols separating between non-morphological units of words), and no-separation (with symbols presented at the beginning and end of each word). The group receiving the morpheme-based program improved more than the control group in terms of word reading fluency in the morphological condition. The former group also presented similar word reading fluency after training in the morphological condition and in the no-separation condition, thereby suggesting that the morpheme-based training contributed to the integration of morphological decomposition into the process of word recognition. At the same time, both groups similarly improved in other measures of word reading fluency. With regard to spelling, the morpheme-based training group showed a larger improvement than the control group in spelling of trained items, and a unique improvement in spelling of untrained items (untrained word-stems integrated into trained pre- and suffixes). The results further suggest some contribution of the morpheme-based training to performance in a standardized spelling task. The morpheme-based training did not, however, show any unique effect on comprehension. These results suggest that the morpheme-based training is effective in enhancing some basic literacy skill in the population examined, i.e., morphological analysis in word processing and the access to orthographic representations in spelling, with no specific effects on reading fluency and comprehension.