Paper title: Cognitive-linguistic profiles of Chinese typical-functioning adolescent dyslexics and high-functioning dyslexics

(1)This study investigated the cognitive-linguistic profiles of the typical-functioning dyslexics and high-functioning dyslexics with longitudinal cohorts of Chinese-speaking adolescents diagnosed with childhood dyslexia. These two dyslexic groups of fifty students (with 25 typical- functioning dyslexics) were assessed in Grade 2 (Time 1) and in Grade 8 (Time 2), whereas 25 typically developing controls were assessed at Time 2. Students were administered measures of phonological awareness, morphological skills, visual-orthographic knowledge, rapid naming, verbal working memory, and literacy skills. Findings highlight the importance of rapid aiming deficits as potential universal causes of dyslexia and the utility of targeting visual-orthographic knowledge and morphological skills in supporting the development of dyslexic adolescents. (2)This study specifically examined whether high-functioning dyslexics and typical- functioning dyslexics would exhibit different cognitive-linguistic profiles from those of the typical-developing adolescents and, if so, in what way. The performance of both dyslexic groups was therefore compared to the typically developing adolescents of the same chronological age control (CA) in the four cognitive-linguistic constructs, namely visual-orthographic knowledge, morphological skills, rapid naming, verbal working memory, and literacy skills at Time 2. (3)The paper is well written. The Introduction and Background sections provide useful information for the readers and the author makes clear the intended practical application of the research, as well as its novelty. so The aim of the study and outcome measures are clearly defined with appropriate reference to the literature.

(4)Methods

1-The Participants for the present study came from a sub-sample of the group of 254 Hong Kong Chinese-speaking students with dyslexia recruited for a longitudinal study. They had been followed from Grade 2 to Grade 8, having been referred by the local education authority and other non-governmental organizations. The sample was representative of three regions: Hong Kong Island, Kowloon, and New Territories in Hong Kong. 2-The typical-functioning students with dyslexia were assessed by professional psychologists in accordance with the diagnostic criteria based on the Hong Kong Test of Specific Learning Difficulties in Reading (HKT-SpLD) (Ho, Chan, Tsang, & Lee, 2000) and an intelligence test from the Hong Kong Wechsler Intelligence Scale for Children (HK-WISC) at Time 1. 3- The HKT-SpLD is a diagnostic test used to assess Hong Kong primary school children with developmental dyslexia. Local norms are available from 6 years 1 month to 10 years 6 months. This assessment battery (HKT-SpLD) includes 12 subtests that are grouped under five domains, namely, literacy skills (Chinese Word Reading, One-Minute Reading, and Chinese Word Dictation), rapid naming, phonological awareness, verbal working memory, and orthographic awareness. 4- Details of these literacy and cognitive-linguistic measures are further discussed in the Assessment section. Raw scores of each subtest were converted to 12 scaled scores according to children’s age levels and the scaled scores ranged from 1 to 19, with 10 being the mean. The literacy composite scores and at least one of the cognitive-linguistic composite scores of the children in the group were at least 1 standard deviation (SD = 3) below the normative mean (M = 10) of their respective ages in the HKT-SpLD (cutoff score = 7). These 12 subtests have overall reliability coefficients over 0.7. Also, required was a normal intelligence IQ of 85 or above using the Hong Kong Wechsler Intelligence Scale for Children (HK-WISC, Psychological corporation, 1981). 5- Furthermore, the study carried out has the students were carefully screened to ensure that they had sufficient learning opportunities (e.g., new immigrants were excluded) and that they did not have any suspected brain damage, uncorrected sensory impairment, serious emotional and behavioral problems. Twenty-five typical-functioning dyslexic students with 5 females and 20 males (mean age = 159.76 months, SD = 12.40) from grade 8 were selected to age match with the high-functioning dyslexics group.
6-The grouping criteria of high-functioning dyslexics were based solely on their literacy skills at Time 2. Particularly, their composite scores of Chinese Word Reading, One-Minute Reading, and Chinese Word Dictation in The Hong Kong Test of Specific Learning Difficulties in Reading and Writing for Junior Secondary School Students (HKT- JS) (Chung, Ho, Chan, Tsang, & Lee, 2007) were higher than the cutoff score = 7 (or 1 standard deviation below the normative mean), where the normative mean and standard deviation were M = 10 and SD =3 respectively. These literacy composite scores were aligned with the composite scores of literacy skills (Chinese Word Reading, One-Minute Reading, and Chinese Word Dictation) used in identifying students with dyslexia at Time 1. The HKT-JS is a standardized test for the diagnosis of developmental dyslexia with norms in Hong Kong. 7- in this study, This assessment battery consists of 15 subtests grouped under five domains, namely literacy skills, morphological skills, visual-orthographic knowledge, rapid naming, and verbal working memory and Details of these subtests are described in the Assessment section. Fifteen of these subtests have reliability coefficients over 0.7. 8-Assessment measures for time 1, At Time 1, each of the five domains of interest, namely literacy, phonological awareness, orthographic awareness, verbal working memory, and rapid naming, was assessed using multiple measures from HKT-SpLD (Ho et al., 2000). The composite score of each domain was calculated by averaging the standardized scores of all relevant measures as outlined below. 9- Literacy There were three literacy tests: Chinese Word Reading, One-Minute Reading, and Chinese Word Dictation. In the Chinese Word Reading test, students were asked to read aloud 150 Chinese two-character words graded according to levels of difficulty. This test was discontinued when the participants failed to read 15 words consecutively. In the One-Minute Reading test, participants were requested to read aloud 90 two-character words as quickly and accurately as possible within 1 minute. In the Chinese Word Dictation test, participants were asked to write 48 two-character words. Testing stopped if the participants failed to write eight consecutive words correctly. 10- Phonological awareness The Rhyme Detection and Onset Detection tests consisted of 18 and 15 trials. In each trial of the subtests, students heard three Chinese syllables presented. The Chinese syllables were names of common objects. The participants were asked to indicate which two among the three syllables sounded similar. 11-Orthographic awareness The Left/Right Reversal, Lexical Decision, and Radical Position tests were used to assess individuals’ knowledge of Chinese character structure. The Left/Right Reversal subtest consisted of 70 simple Chinese integrated characters and Arabic numbers. 12-Based on the above regarding the author's Methods: I think the process of subject selection is very clear and the methods valid and reliable.

(5)Results：

1-Of the 50 students diagnosed with dyslexia at Time 1, 25 were identified to be high-functioning dyslexics whereas the other 25 were considered to be typical-functioning dyslexics. The average mean scaled scores on each of the literacy and cognitive-linguistic subtests for the two groups are shown in Table 2. 2-This table reports the means, standard deviations, t- values, and Cohen’s d values for both groups on literacy, phonological awareness, orthographic awareness, verbal working memory, and rapid naming. In the group comparison analyses at Time 1, no significant differences were found in the measures between these two groups of students.
3-At Time 2, the high-functioning dyslexics and typical-functioning dyslexic adolescents were matched with the chronological-age control (CA) group as shown in Table 3. The performances of all three groups were transformed into standard scores with a mean of 10 and a standard deviation of 3. Table 3 shows the means, standard deviations, and F-values from one-way analyses of variance (ANOVAs) comparing the three groups on literacy, visual- orthographic knowledge, morphological skills, verbal working memory, and rapid naming. The high-functioning dyslexic group performed significantly better than the typical- functioning group but worse than the CA on literacy, visual-orthographic knowledge, and morphological skills. Both dyslexic groups were performed less well than the CA for rapid. 4-Table 3 shows Means and standard deviations on various measures for the high-functioning dyslexics, typical- functioning dyslexics, chronological-age control group, and f values for group differences on various tasks at Time 2. 5-The four domains of literacy, visual-orthographic knowledge, rapid naming, and verbal working memory were analyzed across Time 1 and Time 2. The time (Time 1 and Time 2) by group (high-functioning dyslexics and typical-functioning dyslexics) repeated measures ANOVAs on the cognitive-linguistic measures indicated significant group-by-time interactions on literacy, F(1,48) = 14.53, p < .001, and visual-orthographic knowledge, F(1,48) = 8.25, p < .01, but were non-significant for rapid naming, F(1,48) = 3.45, p = .074, and verbal working memory, F(1,48) = 0.20, p = .66. 6-this study adopted the criterion of at least 1 standard deviation (or equivalent to a scaled score below 7) below the normative mean as the cutoff criteria for impairment. Table 4 shows the number and percentage of high-functioning dyslexic and typical- functioning dyslexic individuals for each domain and measure at Time 1. Two groups exhibited similar cognitive-linguistic deficits profile. On average, 10%, 29%, 17%, and 56% of the high-functioning dyslexics exhibited deficits in phonological awareness, orthographic skills, verbal working memory, and rapid naming respectively. Similarly, 8%, 24%, 24%, and 48% of the typical-functioning dyslexics displayed deficits in phonological awareness, orthographic skills, verbal working memory, and rapid naming. 7-Two proportions of z- tests were used to investigate the difference in the proportion of deficits between the two groups. As shown in Table 4, there were no statistically significant differences between the groups with respect to all the cognitive-linguistic domains (all p > .5). 8-Comparing the proportion differences between high-functioning and typical-functioning dyslexics, two proportions of z-tests showed that the high-functioning group had a marginally.
9-Table 4 The number of individuals in the high-functioning dyslexics and typical-functioning dyslexics exhibiting deficits in the various cognitive-linguistic areas at Time 1.
10-Table 5 The number of individuals in the high-functioning dyslexics and typical-functioning dyslexics exhibiting deficits in the various cognitive-linguistic areas at Time 2. 11-Table 6 Number of individuals in the high-functioning dyslexic and typical-functioning dyslexic group with deficits in each cognitive-linguistic area and their corresponding mean ages, and literacy skills at Time 1. 12- In this study, the Categories grouped appropriately and the text in the results adds to the data. 13-The data in this study presented in an appropriate way. 14-Tables and figures are relevant and clearly presented and Titles, columns, and rows labeled correctly and clearly.

(1)Discussion and CONCLUSION

1-This longitudinal study examined the profiles of Chinese adolescents identified as typical- functioning and high-functioning dyslexics. These two groups of 50 dyslexic adolescents (with 25 typical-functioning dyslexics) were assessed in both Grade 2 and Grade 8. Another 25 typically developing adolescents were selected as a control group and were assessed at Grade 8 only. All students were administrated measures of cognitive-linguistic skills and literacy skills. 2-The results showed that both dyslexic groups performed generally less well than the control group on the measures of rapid naming, visual-orthographic knowledge, morphological skills, verbal working memory, reading, and writing skills. In particular, visual-orthographic and morphological deficits appeared to be a greater problem for typical-functioning dyslexics than the high-functioning group with 46 vs 24% exhibiting visual-orthographic deficits and 42 vs 18% with morphological deficits. Compared with the high-functioning dyslexics, the typical- functioning group showed a higher incidence of multiple cognitive-linguistic deficit profiles with significant deficits in rapid naming, suggesting that rapid naming is the most prominent. 3-The current findings further confirm that for the typical- functioning dyslexics and high-functioning dyslexics, rapid naming is the most prominent deficit that persists from childhood through adolescence. 4-Surprisingly, the study findings indicated that the typical-functioning dyslexics, the high- functioning dyslexics, and the controls did not differ in verbal working memory abilities, indicating that working memory deficits may not be a defining feature in distinguishing between different profiles of dyslexia, or adolescents with versus those without dyslexia. These findings are somewhat inconsistent with previous studies identifying deficits in verbal working memory as a major contributor to dyslexia, and reading and writing difficulties, in both English and Chinese (Archibald & Gathercole, 2006; Chik et al., 2012a; Chik et al., 2012b; Sela, Izzetoglu, Izzetoglu, & Oral, 2012). At this stage, based on this one initial study, it is hard to produce a conclusive explanation for such inconsistency. One possible explanation is that our controls were recruited through teachers’ nominations and were matched solely by chronological age. 5-the profile analysis showed that approximately 56 and 12% of the high-functioning dyslexics had single and double cognitive-linguistic deficits predominantly caused by problems with rapid naming. As in the case of the typical-functioning dyslexic group, nearly 52 and 20% of the single and two cognitive-linguistic deficits were frequently found in conjunction with the rapid naming, visual-orthographic and morphological deficits. It is noteworthy that compared to the high-functioning dyslexics, the typical-functioning group showed a greater tendency toward multiple impairments in one or more cognitive-linguistic domains. However, in most cases, the typical-functioning dyslexics, who had multiple cognitive-linguistic deficits, also showed lower scores in their literacy tasks, thereby suggesting that some typical- functioning dyslexics have difficulty with reading and writing skills. 6-In accordance with previous studies (Chung et al., 2010, 2014), this study found that the number of cognitive-linguistic deficits is linked with varying degrees of literacy difficulties, particularly with reading impairment, and moreover, Chinese adolescents with dyslexia frequently exhibit multiple deficits with rapid naming being the primary cause. Our findings concur with the multiple deficit perspective (Pennington, 2006; Peterson & Pennington, 2012) proposing that multiple pathways to dyslexia are involved in the presence of single and multiple cognitive-linguistic deficits. 7-The current study had at least five limitations that warrant further investigations: 1-the study was mainly focused on literacy performance at word-level skills. In order to have a broader view of literacy development in adolescents with and without dyslexia, future studies should also include the measures of text-level skills, for example, sentence reading and reading comprehension in both primary (Time 1) and secondary (Time 2) school grades. 2-given that vocabulary knowledge is highly correlated with word reading and reading comprehension in Chinese (Zhang & Koda, 2018) and English (Binder, Gote, Lee, Bessette, & Vu, 2017), the inclusion of vocabulary knowledge measure is necessary in future research in order to investigate whether vocabulary knowledge may be different among the typical-functioning dyslexics from both high-functioning dyslexics and typically developing adolescents and how it, in turn, affects individuals’ reading and writing skills. 3-future studies may incorporate the measure of morphological skills in Time 1 to provide a better comparison in determining the underlying morphological deficits from childhood to adolescence. Fourth, it is possible that the high-functioning dyslexics, identified in the present study, might have received different forms of intervention, for example, from their parents, who might have hired a private tutor to provide more intensive training, or simply provided relevant simulation through daily interaction, compared to the typical-functioning dyslexics. 4-the typically developing students’ IQ was not measured due to logistic issues. In the results, seven typically developing students were found to have some difficulties mainly in verbal working memory. In future work, it may be worthwhile to include an IQ test such as WISC as well as measures of students’ socioeconomic status and family background information to screen potential adolescents with cognitive and learning difficulties. Finally, the control group of typically developing students was not included in Time 1. It may be useful in the future to embrace a control group in addition to the two dyslexic groups in order to track the development of cognitive-linguistic skills and literacy performance in the three groups. 5-The results discussed from multiple angles and placed into context without being over-interpreted. 6- The study aims are answered. The findings of the study were discussed critically. The paper reads well and methodology is powerful and also the subject significantly original to merit publication following revision. The author made use of tables and open data. Tables were accustomed to comprehensively report model specification and results and also the figures were accustomed visualize the leads in a fashion that allowed the reader to draw their own conclusions. the information is public and thus afford independent verification of the results. All of those aspects of the manuscripts were greatly appreciated.