Distinct effects of visual and auditory temporal processing training on reading and reading-related abilities in Chinese children with dyslexia

The impact of temporal processing on reading in dyslexia with rapid automatized naming deficits

In the present study, we aimed to investigate the different impacts of temporal processing on reading by Chinese children with and without dyslexia. In total, 27 children with dyslexia who had a deficit in rapid automatized naming (RAN) (D_R), 37 children with dyslexia who had deficits in both RAN and phonological awareness (PA) (D_RP), and 40 typically developing children (TD) were recruited in Taiwan. The children were asked to complete non-verbal intelligence, PA, RAN, Chinese character reading tasks and an auditory temporal order judgement (ATOJ) task. Our results of a multiple regression model showed that the ATOJ accounted for unique variances in the reading differences between the children in the D_R and TD groups; performance was controlled for non-verbal intelligence, PA and RAN tasks. Theoretically, we provide possible explanations for the controversial findings in the field of Chinese children with dyslexia and, practically, suggest different interventions should be provided for children with dyslexia with different underlying impairments.

Impaired Ability in Visual-Spatial Attention in Chinese Children With Developmental Dyslexia

A growing body of evidence suggests that children with dyslexia in alphabetic languages exhibit visual-spatial attention deficits that can obstruct reading acquisition by impairing their phonological decoding skills. However, it remains an open question whether these visual-spatial attention deficits are present in children with dyslexia in non-alphabetic languages. Chinese, with its logographic writing system, offers a unique opportunity to explore this question. The presence of visual-spatial attention deficits in Chinese children with dyslexia remains insufficiently investigated. Therefore, this study aimed to explore whether such deficits exist, employing a visual search paradigm. Three visual search tasks were conducted, encompassing two singleton feature search tasks and a serial conjunction search task. The results indicated that Chinese children with dyslexia performed as well as chronological age-matched control children in color search tasks but less effectively in orientation search, suggesting a difficulty in the rapid visual processing of orientation: a deficit potentially specific to Chinese dyslexia. Crucially, Chinese children with dyslexia also exhibited lower accuracy, longer reaction times, and steeper slopes in the reaction times by set size function in the conjunction search task compared to control children, which is indicative of a visual-spatial attention deficit.

How Does Visual Temporal Processing Affect Chinese Character Reading in Children With Dyslexia? From the Perspective of Inhibition

Given that inhibition interacts with visual temporal processing (VTP), the past evidence regarding the influence of VTP on the Chinese character reading of children with dyslexia may not disclose the whole picture without considering inhibition. Thus, the present study is among the first to investigate VTP and cognitive inhibition as well as their relationships to Chinese character reading. We compared the performances of 62 Chinese-speaking children with dyslexia in primary school (n = 62, Mage = 11.36 years) on VTP and inhibition tasks to those in a chronological-age-matched group (CA; n = 62, Mage = 11.57 years) and reading-level-matched group (RL; n = 62, Mage = 8.98 years). The results revealed that children with dyslexia performed worse than both the CA-matched and RL-matched groups in VTP and inhibition after controlling for age, nonverbal intelligence, and attention. Moreover, the relationship between VTP and Chinese character reading was moderated by inhibition in children with dyslexia. VTP is positively related to Chinese character reading, but this relationship is observed only at higher levels of inhibition. Our results suggest that inhibition plays a potential role in VTP and Chinese character reading, especially for those with dyslexia whose proficiency in inhibition is not as intact as that of typically developing children.

Temporal processing tele-intervention improves language, attention, and memory in children with neurodevelopmental disorders

Objective

Temporal processing is the brain's ability to process rapid successive stimuli, and children with neurodevelopmental disorders showed temporal processing deficits. Empirical evidence suggests that in-person intervention on temporal processing improves various cognitive functions of these children, and the present study aimed to study the effects of temporal processing tele-intervention (TPT) on the cognitive functions of children with neurodevelopmental disorders.

Methods

Ninety-five children with neurodevelopmental disorders were recruited and randomly assigned to remotely receive either TPT or conventional language remediation (CLR) in 20 parallel group-based intervention sessions once per week. Their cognitive functions were assessed before and after the intervention.

Results

The TPT group demonstrated a specific and significant improvement in working memory (p < .001). While there was an overall significant improvement in sustained attention in terms of processing speed after both types of intervention (p = .006), the positive effects of TPT might be more prominent than that of CLR given the significant pre-post difference after receiving TPT (p = .012) but not CLR (p = .21). Regarding rapid naming accuracy which had marginally significant improvement after the intervention (p = .03), the trend of improvement in TPT (p = .05) also seemed more apparent than that of CLR (p = .18). Finally, the TPT group had significant improvement in word knowledge (p < .001), rapid naming speed (p < .001), sustained attention in terms of accuracy (p < .001), and verbal learning and memory (p < .01) to an extent similar to that of the CLR group.

Conclusions

These findings suggest that TPT can be a potential intervention for improving cognitive functions in children with neurodevelopmental disorders. Clinical trial registration number: NCT05428657 at ClinicalTrials.gov (https://clinicaltrials.gov/).

Lower prosodic sensitivity in Chinese children with dyslexia and its impact on Chinese reading

The current study aims to examine prosodic sensitivity in Chinese children with dyslexia and its relation to Chinese reading in children with and without dyslexia. A total of 172 Chinese children from third grade to sixth grade in Taiwanese primary schools were recruited. Thirty (14 male) children were identified as having dyslexia, and the remaining children (N = 142; 67 male) were typically developing children matched with those with dyslexia as carefully as possible with respect to school, grade, and gender. Our results indicated that group differences were found for all three types of prosodic sensitivity. Moderation analyses showed that group had no significant interaction with prosodic sensitivity in predicting Chinese reading, so the participants in the two groups were combined in the following analyses. The results of the stepwise regression analyses showed that only lexical tone awareness could significantly predict Chinese character reading after controlling for phonological awareness, while only intonation awareness could significantly predict reading comprehension after controlling for Chinese character reading. The results provide preliminary evidence on the issue of prosodic sensitivity in Chinese children with dyslexia and its role in Chinese reading, which might provide a novel approach to the teaching of Chinese languages.

Dyslexia treatment studies: A systematic review and suggestions on testing treatment efficacy with small effects and small samples

Poor response to treatment is a defining characteristic of reading disorder. In the present systematic review and meta-analysis, we found that the overall average effect size for treatment efficacy was modest, with a mean standardized difference of 0.38. Small true effects, combined with the difficulty to recruit large samples, seriously challenge researchers planning to test treatment efficacy in dyslexia and potentially in other learning disorders. Nonetheless, most published studies claim effectiveness, generally based on liberal use of multiple testing. This inflates the risk that most statistically significant results are associated with overestimated effect sizes. To enhance power, we propose the strategic use of repeated measurements with mixed-effects modelling. This novel approach would enable us to estimate both individual parameters and population-level effects more reliably. We suggest assessing a reading outcome not once, but three times, at pre-treatment and three times at post-treatment. Such design would require only modest additional efforts compared to current practices. Based on this, we performed ad hoc a priori design analyses via simulation studies. Results showed that using the novel design may allow one to reach adequate power even with low sample sizes of 30–40 participants (i.e., 15–20 participants per group) for a typical effect size of d = 0.38. Nonetheless, more conservative assumptions are warranted for various reasons, including a high risk of publication bias in the extant literature. Our considerations can be extended to intervention studies of other types of neurodevelopmental disorders.

The 100 Top-Cited Studies on Dyslexia Research: A Bibliometric Analysis

Background: Citation analysis is a type of quantitative and bibliometric analytic method designed to rank papers based on their citation counts. Over the last few decades, the research on dyslexia has made some progress which helps us to assess this disease, but a citation analysis on dyslexia that reflects these advances is lacking. Methods: A retrospective bibliometric analysis was performed using the Web of Science Core Collection database. The 100 top-cited studies on dyslexia were retrieved after reviewing abstracts or full-texts to May 20th, 2021. Data from the 100 top-cited studies were subsequently extracted and analyzed. Results: The 100 top-cited studies on dyslexia were cited between 245 to 1,456 times, with a median citation count of 345. These studies were published in 50 different journals, with the "Proceedings of the National Academy of Sciences of the United States of America" having published the most (n = 10). The studies were published between 1973 and 2012 and the most prolific year in terms of number of publications was 2000. Eleven countries contributed to the 100 top-cited studies, and nearly 75% articles were either from the USA (n = 53) or United Kingdom (n = 21). Eighteen researchers published at least two different studies of the 100 top-cited list as the first author. Furthermore, 71 studies were published as an original research article, 28 studies were review articles, and one study was published as an editorial material. Finally, "Psychology" was the most frequent study category. Conclusions: This analysis provides a better understanding on dyslexia and may help doctors, researchers, and stakeholders to achieve a more comprehensive understanding of classic studies, new discoveries, and trends regarding this research field, thus promoting ideas for future investigation.

The Moderation Effect of Processing Efficiency on the Relationship Between Visual Working Memory and Chinese Character Recognition

To investigate the underlying mechanism of the relationship between visual working memory (VWM) and Chinese character recognition, and the moderation effect of processing efficiency on this relationship, 154 first-grade students were administered a battery of tasks for VWM, rapid temporal processing, and Chinese character reading. In the VWM task, the children were asked to remember the jumping routes of a frog and report these routes in reverse sequence. The longest span for which each participant could respond correctly at least four times out of six was the VWM index. In the task of temporal order judgement, the participants were asked to select which of two balls was presented first, with stimulus onset asynchronies varying from 8 to 492 ms according to an adaptive psychophysical procedure. Visual temporal order threshold (VTOT) was utilized as an indicator of processing efficiency. The participants were asked to read 100 characters aloud to measure their word-level reading abilities in Chinese character recognition. After controlling age, non-verbal intelligence, visual short-term memory, morphological awareness, and orthographic awareness, the results of a moderation effect analysis showed that (1) both VWM and visual VTOT predicted Chinese character reading, and (2) the moderation effect of VTOT on the VWM-reading link was significant (p = 0.001). The correlation between VWM and Chinese character reading was positive and significant when VTOTs were above average (i.e., smaller than 87.14 ms); however, the correlation was negative at relatively poor levels of VTOTs (i.e., larger than 231.44 ms).