Reading Age Controls Research Articles

Neural Correlates of Visual Attention and Short-Term Memory in Children with Reading Difficulty

ABSTRACT Visual attention and memory of 20 children with reading difficulty (Mage = 134 months), 24 chronological (Mage = 138 months) and 19 reading-age controls (Mage = 92 months) were examined using object substitution masking; mask offset delay increases visual attention and visual short-term memory demands. ERP amplitude differences in the N1 (alerting), N2pc (N2-posterior-contralateral; selective attention), and SPCN (sustained posterior contralateral negativity; memory load) were expected between groups. Chronological controls performed best, but ERP results were mixed. No group differences were found for N1 or N2pc. SPCN showed enhanced negativity in reading difficulty, indicating greater memory load and anomalous inhibition.

Μελέτη της ορθογραφικής επεξεργασίας μέσω οφθαλμοκίνησης στην ελληνική γλώσσα

The present study investigated the differences between children with reading difficulties (RD) and their controls (Grade 3 and Grade 6) on an orthographic processing task (OP), using eye-tracking technology. Grade 3 typically developing readers were used as reading age controls for the Grade 6 RD group. During the OP task, the participants had to identify the correct word in pairs of correctly spelled and phonologically correct but misspelled words. Two oculomotor movements, fixations and saccades, were recorded using an eye-tracking technology (EyeLink® 1000 Plus eye-tracker). The results revealed that Grade 6 RD group produced significantly longer fixations, shorter first fixations, and more saccades than their CA controls, suggesting a lack of established orthographic representations in their mental lexicon. No differences were observed in eye movements between Grade 3 groups and between Grade 6 RD group and their RA controls, showing that these groups follow a similar strategy to identify the correctly spelled word. Discussion centers around the role of eye tracking technology in providing valuable information about the mechanisms involved in reading and spelling..

Effects of inter-character spacing on saccade programming in beginning readers and dyslexics

ABSTRACTThe present study investigated the impact of inter-character spacing on saccade programming in beginning readers and dyslexic children. In two experiments, eye movements were recorded while dyslexic children, reading-age, and chronological-age controls, performed an oculomotor lateralized bisection task on words and strings of hashes presented either with default inter-character spacing or with extra spacing between the characters. The results of Experiment 1 showed that (1) only proficient readers had already developed highly automatized procedures for programming both left- and rightward saccades, depending on the discreteness of the stimuli and (2) children of all groups were disrupted (i.e., had trouble to land close to the beginning of the stimuli) by extra spacing between the characters of the stimuli, and particularly for stimuli presented in the left visual field. Experiment 2 was designed to disentangle the role of inter-character spacing and spatial width. Stimuli were made the same physical length in the default and extra-spacing conditions by having more characters in the default spacing condition. Our results showed that inter-letter spacing still influenced saccade programming when controlling for spatial width, thus confirming the detrimental effect of extra spacing for saccade programming. We conclude that the beneficial effect of increased inter-letter spacing on reading can be better explained in terms of decreased visual crowding than improved saccade targeting.

Not all phonological awareness deficits are created equal: evidence from a comparison between children with Otitis Media and poor readers.

Children with reading difficulties and children with a history of repeated ear infections (Otitis Media, OM) are both thought to have phonological impairments, but for quite different reasons. This paper examines the profile of phonological and morphological awareness in poor readers and children with OM. Thirty‐three poor readers were compared to individually matched chronological age and reading age controls. Their phonological awareness and morphological awareness skills were consistently at the level of reading age matched controls. Unexpectedly, a significant minority (25%) of the poor readers had some degree of undiagnosed mild or very mild hearing loss. Twenty‐nine children with a history of OM and their matched controls completed the same battery of tasks. They showed relatively small delays in their literacy and showed no impairment in morphological awareness but had phonological awareness scores below the level of reading age matched controls. Further analysis suggested that this weakness in phonological awareness was carried by a specific weakness in segmenting and blending phonemes, with relatively good performance on phoneme manipulation tasks. Results suggest that children with OM show a circumscribed deficit in phoneme segmentation and blending, while poor readers show a broader metalinguistic impairment which is more closely associated with reading difficulties.

Syntactic Comprehension in Reading and Listening

This study examined syntactic comprehension in French children with dyslexia in both listening and reading. In the first syntactic comprehension task, a partial version of the Epreuve de Compréhension syntaxico-sémantique (ECOSSE test; French adaptation of Bishop’s test for receptive grammar test) children with dyslexia performed at a lower level in the written but not in the spoken modality, compared to reading age–matched children, suggesting a difficulty in handling syntax while reading. In the second task, syntactic processing was further explored through a test of relative clause processing, in which inflectional markers could aid in attributing roles to the elements in a complex syntactic structure. Children with dyslexia were insensitive to inflectional markers in both reading and listening, as was the reading age control group, while only the older normal reader group appeared to make use of the inflectional markers. Overall, the results support the hypothesis that difficulties in comprehension in dyslexia are strongly related to poor reading skills.

Evidence for a Specific Impairment of Serial Order Short‐term Memory in Dyslexic Children

In order to better understand the nature of verbal short-term memory (STM) deficits in dyslexic children, the present study used the distinction between item and serial order retention capacities in STM tasks. According to recent STM models, storage of verbal item information depends very directly upon the richness of underlying phonological and semantic representations. On the other hand, storage of serial order information appears to reflect a language-independent system. Hence, if there is a fundamental STM deficit in dyslexia that is not to be explained only by the poor phonological processing abilities that characterize dyslexia, then difficulties in serial order STM should also be observed in dyslexic children. We administered tasks maximizing either serial order or item retention capacities to dyslexic children and reading age (RA) and chronological age (CA) matched controls. Dyslexic children performed significantly poorer than the CA controls on the item STM measure. Furthermore, the dyslexic group obtained inferior performance than both CA and RA control groups on the serial order STM measure. These findings highlight a severe impairment of STM for serial order information in dyslexia that cannot be reduced to a phonological processing impairment. Implications of serial order retention deficits for reading acquisition and dyslexia are discussed.

Cognitive Processing Skills and Developmental Dyslexia in Chinese

The purpose of the present study was twofold: (a) to examine the extent to which Chinese dyslexic children experience deficits in phonological and orthographic processing skills and (b) to examine if Chinese dyslexia is associated with deficits in Planning, Attention, Simultaneous, and Successive (PASS) processing. A total of 27 Grade 4 children with dyslexia (DYS), 27 Grade 4 chronological age (CA) controls, and 27 Grade 2 reading age (RA) controls were tested on measures of phonological awareness, rapid naming, phonological memory, PASS, reading accuracy, and reading fluency. The results indicated that the DYS group performed significantly poorer than the CA and RA groups on both measures of phonological awareness and on a measure of orthographic processing but comparably to the RA group on a measure of rapid naming and both measures of phonological memory. In regard to the PASS processing skills, the DYS group performed worse than the CA controls on Successive and Simultaneous processing but comparably to the RA group on all PASS processing skills. Implications of these findings for early identification and intervention of reading difficulties are discussed.

Auditory temporal processing and dyslexia in an orthographically consistent language

We examined two hypotheses relating auditory processing to dyslexia in Greek, an orthographically consistent language. Study I examined the “P-center” or “beat detection” hypothesis (Goswami et al., 2002) in a sample of Grade 6 dyslexics, Grade 6 chronological age (CA) controls, and Grade 4 reading age (RA) controls. Study II examined the “temporal processing,” or “rapid auditory processing” hypothesis (Tallal, 1980) in a sample of Grade 7 dyslexics, CA controls, and in two groups of CA matched children with low frequency discrimination or low tone sequencing performance. Both studies indicate that (a) as a group, dyslexic children did not perform significantly worse on auditory processing measures than the control groups; (b) measures of auditory processing mostly did not account for unique amount of variance in phonological processing, reading, or spelling; and (c) at an individual level of analysis, some of the dyslexic children experienced auditory temporal processing deficits. Implications on the importance of auditory processing in reading in orthographically consistent languages are discussed.

Variability in the word-reading performance of dyslexic readers: Effects of letter length, phoneme length and digraph presence

The marked word-length effect in dyslexic children suggests the use of a letter-by-letter reading strategy. Such a strategy should make it more difficult to infer the sound of digraphs. Our main aim was to disentangle length and digraph-presence effects in word and pseudoword reading. In addition, we examined differences in intra-individual variability between dyslexic and normal readers. Word and pseudoword naming tasks were administered to 24 dyslexic readers individually matched to chronological-age and reading-age controls. As expected, dyslexic and younger children displayed stronger length effects. In contrast to our expectations, the dyslexic and younger children were faster in reading (pseudo)words with a digraph than in reading (pseudo)word of similar letter length but without a digraph. Normal readers were equally fast on both types of (pseudo)words. However, considering phoneme-length effects, digraph presence caused an additional delay in all reading groups, but only for pseudowords. In addition, this effect was stronger for the dyslexic and younger readers. Finally, dyslexic readers’ intra-individual variability in reading was larger than the variability in both groups of normal readers. Proportionally, the largest difference in variability with the normal readers was found on the short words.

Size does not matter, frequency does: Sensitivity to orthographic neighbors in normal and dyslexic readers

This study examined the influence of the number of orthographically similar candidates, neighborhood size, on the word and pseudoword naming performance of normal, dyslexic, and beginning readers. Participants were 23 Dutch dyslexic fourth-graders matched to 23 fourth-grade chronological age controls and 17 second-grade reading age controls. Unexpectedly, neighborhood size had similar effects in all groups: It did not affect word naming and facilitated the naming of pseudowords. However, the presence of a high-frequency neighbor had different effects. In contrast to normal readers, words with a high-frequency neighbor were named more slowly by beginning and dyslexic readers. These findings suggest a dissociation between global and specific effects of neighbor words. Nevertheless, both findings seem to be compatible with the view that orthographic representations of beginning and dyslexic children are not (yet) sufficiently specified.

Developmental dyslexics and unimpaired children’s reading and memory for words in a transparent orthography

Word reading and short-term memory performance of forty two developmental dyslexics (mean age 10.1 years, SD = .7) and thirty three unimpaired reading age matched (mean age of 8.5, SD = .5) and thirty six unimpaired chronological age matched children (mean age of 10.6, SD = .7) was investigated in transparent Polish orthography. Fifty of the children were instructed that they were expected to recall the list of (12 high frequency mainly concrete) words after reading them aloud (Condition A), whilst others had no such instructions (Condition B). Word reading was tested by recording the time taken to read aloud the list of words in seconds and by taking into account errors in pronunciation. Overall, word reading was significantly slower for developmental dyslexics compared to reading age (RA) and chronological age (CA) controls. However, developmental dyslexics’ recall of words was comparable to CA and significantly superior to RA both in conditions A and B of the experiment. The implications of these results in relation to the impact of spelling transparency on memory performance of impaired and unimpaired readers are discussed.

Developmental dyslexia in an orthography of intermediate depth: the case of European Portuguese

Fifteen Portuguese children with dyslexia, aged 9–11 years, were compared with reading and chronological age controls with respect to five indicators related to the phonological deficit hypothesis: the effects of lexicality, regularity, and length, implicit and explicit phonological awareness, and rapid naming. The comparison between groups indicates that Portuguese children with dyslexia have a phonological impairment which is revealed by a developmental deficit in implicit phonological awareness and irregular word reading (where younger reading level controls performed better than dyslexics) and by a developmental delay in decoding ability and explicit phonological awareness (where dyslexics matched reading level controls). These results are discussed in relation to the idea that European Portuguese is written in an orthography of intermediate depth.

Comparing phonological skills and spelling abilities in children with reading and language impairments

Bishop and Snowling (2004) proposed that children with language impairments (LI) and children with reading difficulties (RD) can be considered to be on a (phonological) continuum of risk for reading impairments. The first aim of the present study was to address two specific hypotheses about the relationship between RD and LI. The severity hypothesis proposes that LI is a more severe form of RD. In contrast, the dyslexia-plus hypothesis proposes that children with LI share the same phonological deficit as children with RD, but also have impairments in non-phonological language skills. The second aim of the study was to further our understanding of the spelling skills of children with LI. Twenty-three children with primary language impairments (LI) and 22 children with primary reading impairments (RD) matched on chronological and reading age were compared with typically developing children. The children's performance on tests of phoneme deletion, phonological memory, and spelling accuracy and phonetic spelling was compared. Children with LI showed poorer phonological memory performance than children with RD and age controls, whereas both clinical groups performed significantly worse than the age controls on the phoneme deletion task and comparably to reading-age controls. Children with LI and RD were impaired for their age at phonetic spelling, the children with LI showing the more severe impairment. Further exploration of the data identified two different profiles among children with LI; some of these children had poorer phonological skills than predicted from receptive vocabulary, supporting the severity hypothesis. The other group showed a profile with concurrent impairments in vocabulary and phonological skills, in line with the dyslexia-plus hypothesis. The findings suggest that a subgroup of children with LI may be experiencing a severe form of dyslexia. The results further suggest that children with LI have difficulty producing phonologically plausible spellings.

Computerized screening for visual stress in children with dyslexia

Visual stress-a condition in which unpleasant visual symptoms are experienced when reading-has been reported to be more prevalent in dyslexic individuals but at the present time the relationship between dyslexia and visual stress remains controversial. ViSS, a computerized visual stress screener that incorporates reading-like visual search, has recently shown promise in studies with unselected samples of primary and secondary school children. This study investigated the use of ViSS with dyslexic children. Dyslexic children identified as having high visual stress showed significantly higher per cent increases in reading rate with a coloured overlay and reported significantly higher critical symptoms of visual stress, compared to dyslexic children with low visual stress. The same results were found for reading-age controls, indicating that ViSS can be equally effective with normal readers as well as with children with dyslexia. Compared to reading-age controls, dyslexic children were found to have significantly higher susceptibility to visual stress, significantly larger per cent increases in reading rate with an overlay, and significantly higher critical and non-critical symptoms of visual stress. Extrapolated to unselected population samples, the data also suggest that visual stress is more likely to be found in people with dyslexia than in people who do not have dyslexia. These results, which point to an important link between the two conditions, are discussed in relation to current theories that attribute visual stress to either a magnocellular dysfunction or cortical hyperexcitability.

Toward a Resolution of Inconsistencies in the Phonological Deficit Theory of Reading Disorders

This study examined whether high- and low-IQ poor readers differed in patterns of reading performance. Ten-year-old poor readers with IQ scores of 110 and higher showed difficulty in taking a phonological approach to reading, failing to show an advantage in reading high-frequency regular versus irregular words and showing impaired nonword reading accuracy for their reading age. However, poor readers with IQ scores of 90 and below showed a more phonological approach to reading, with better reading of regular than irregular words of both high and low frequency, and with nonword reading skills slower than, but as accurate as, those of reading-age controls. We concluded that the high-IQ poor readers experienced difficulty in taking a phonological approach to reading, whereas the low-IQ poor readers had much less marked phonological problems, supporting Stanovich's phonological-core variable-difference model.

The effect of word length on lexical decision in dyslexic and normal reading children

In the present study, the effect of word length on lexical decision in dyslexic and normal reading children was investigated. Dyslexics of 10-years old, chronological age controls, and reading age controls read words and pseudowords consisting of 3 to 6 letters in a lexical decision task. Length effects were much stronger in dyslexics and reading age controls than in chronological age controls. These results support the contention that dyslexics continue to rely on a predominantly sub-lexical reading procedure, whereas for normal readers the contribution of a lexical reading procedure increases. The relevance of the findings for current computational models of reading is discussed.

Quality of phonological representations, verbal learning, and phoneme awareness in dyslexic and normal readers

This study of dyslexia was concerned with the quality of phonological representations of lexical items. It extended the studies of verbal learning in dyslexia from learning new vocabulary items (pseudo-names) to the learning of more well-specified variants of known words. The participants were 19 dyslexic adolescents in grades 4 to 6 and 19 younger normal readers in grade 2 matched on single word decoding. The dyslexics were significantly outperformed by the reading-age controls in non-word reading and in phoneme awareness. The dyslexics also took longer time to learn to associate a set of pseudo-names with pictures of persons although the dyslexics learned to associate familiar names with pictures as quickly as the controls did. The acquisition of new phonological representations of words was studied in an imitation task with maximally distinct pronunciations of long, familiar words. The dyslexics gained less than the controls in this task. They also gained less on one measure taken from a phoneme substitution task with the same words as in the distinctness task. The results are interpreted in the light of the hypothesis that poorly specified phonological representations may be an underlying problem in dyslexia.

Process dissociation of sight vocabulary and phonetic decoding in reading: A new perspective on surface and phonological dyslexias

Recent research on developmental dyslexia has suggested a phonological core deficit hypothesis (e.g., Manis, Seidenberg, Doi, McBride-Chang, & Peterson, 1996; Stanovich, Siegel, & Gottardo, 1997) whereby pure cases of developmental phonological dyslexia (dysfunctional phonetic decoding processing but normal sight vocabulary processing) can exist, but pure cases of developmental surface dyslexia (dysfunctional sight vocabulary processing but normal phonetic decoding processing) should not. By applying Jacoby's (1991) and Lindsay and Jacoby's (1994) process dissociation procedure to the reading of regular and exception words, we present a method that serves to estimate readers' reliance on sight vocabulary and phonetic decoding during real word recognition. These reliance estimates are then used in Castles and Coltheart's (1993) regression-based approach to identify normal readers and developmental dyslexics. This new method: (1) allows one to explore normal reading acquisition and both the delay and deviance accounts of developmental dyslexia, (2) provides an alternative to matching dyslexics to both chronological-age and reading-age control groups, and (3) uses only real words. We present evidence that pure cases of developmental surface dyslexia can be obtained with both Castles and Coltheart's measure as well as our own, and that developmental surface dyslexia is not simply a delayed reading deficit. The theoretical importance and utility of estimates of reliance on sight vocabulary and phonetic decoding is discussed.

Word length, phonemic, and visual similarity effects in poor and normal readers

Serial order recall for visually and auditorily presented stimuli was examined in a group of 12-year-old poor readers and 7-year-old reading-age controls. With pictorial presentation, the poor readers showed a visual similarity effect, no word length effect, and a smaller phonemic similarity effect than that of controls. However, with visual presentation of printed words and with auditory presentation, poor readers showed word length and phonemic similarity effects of similar magnitude to that of controls. It is concluded that poor readers rely on visual information in tasks where the presented images are highly codable, and where verbal recoding is not obligatory, but that they will make use of phonological coding when the stimuli are not as easily codable visually in memory.

Morphological awareness in developmental dyslexia

This study examines morphological awareness in developmental dyslexia. While the poor phonological awareness of dyslexic children has been related to their difficulty in handling the alphabetical principle, less is known about their morphological awareness, which also plays an important part in reading development. The aim of this study was to analyze in more detail the implications of the phonological impairments of dyslexics in dealing with larger units of language such as morphemes. First, the performance of dyslexic children in a series of morphological tasks was compared with the performance of children matched on reading-level and chronological age. In all the tasks, the dyslexic group performed below the chronological age control group, suggesting that morphological awareness cannot be developed entirely independently of reading experience and/or phonological skills. Comparisons with the reading-age control group indicated that, while the dyslexic children were poorer in the morphemic segmentation tasks, they performed normally for their reading level in the sentence completion tasks. Furthermore, they produced more derived words in the production task. This suggests that phonological impairments prevent the explicit segmentation of affixes while allowing the development of productive morphological knowledge. A second study compared dyslexic subgroups defined by their degree of phonological impairment. Our results suggest that dyslexics develop a certain type of morphological knowledge which they use as a compensatory reading strategy.