The contribution of discrete-trial naming and visual recognition to rapid automatized naming deficits of dyslexic children with and without a history of language delay

Training rapid automatized naming in children with developmental Dyslexia

The recommended rehabilitation procedures for Developmental Dyslexia (DD) are not well defined, and there is currently a large debate on which therapeutic approaches are shown to be more useful and effective. Among the trainings focused on general dysfunctional cognitive processes associated with a reading disorder, recent studies suggested the efficacy of trainings on Rapid Automatized Naming (RAN) compared to others. The present study was aimed at confirming the effectiveness of RAN training (RANt) to improve the reading performances of children with DD (n = 32) compared to children on a waiting list (WL, n = 25) and to children in different treatment groups, one following a text reading training (RT, n = 26) and the other combining RAN and text reading exercises (RANt+RT, n = 20), through an online platform that allows intensive and self-adaptive activities. Results confirmed the efficacy of RANt in improving reading speed and accuracy compared to the WL group (r2 ranging from small (.16) to medium (.48)) and found the absence of differences with the other active control groups. The single-subject level analysis confirmed the results, a high inter-subject variability in treatment response and pre-post differences were found. Further studies could consider such variability in the functional profile of the DD subjects, but RANt was confirmed to be a valid tool for improving decoding skills.

The metrics of reading speed: understanding developmental dyslexia

We compared reading words and pseudo-words presented in single displays (as typical of psycholinguistic research) with stimuli presented in multiple displays (as typical of real-life conditions and clinical testing) under controlled conditions. Italian sixth-grade children with and without a reading deficit showed an advantage in reading times for multiple over single displays. This finding was partly ascribed to the capacity to overlap the non-decisional component of the response, an effect present in control readers as well as children with dyslexia. Furthermore, there were several indications in the data that the requirement to read sequentially taxes performance by augmenting the relative impact of the experimental manipulations used. This effect was present in both groups of children, but proportionally stronger in children with dyslexia. The study contributes to filling the gap between single and multiple displays, a condition more like real-life situations.

Success Is Not the Entire Story for a Scientific Theory: The Case of the Phonological Deficit Theory of Dyslexia

In a recent paper, Share discussed four different “Common Misconceptions about the Phonological Deficit Theory of Dyslexia” and described this theory as “a model of true scientific progress” and a clear “success story”. In this note, I argue that at least part of the success of this theory is due to the lack of explicit predictions which make it very difficult (if possible) to test its predictions, and, possibly, falsify the theory. Some areas of pertinent research, including categorical phoneme perception, picture naming, and phonological awareness are summarized. Furthermore, two lines of research in which groups of researchers have attempted to formulate more explicit predictions are briefly outlined. It is concluded that, although much research has variously referred to the phonological deficit theory of dyslexia, the resulting large body of evidence presents a complex pattern of results which, in the absence of an explicit formulation of the theory, is extremely difficult to frame within a unitary interpretation. Overall, what seems needed is a theoretical formulation that, on the one hand, can account for the complex pattern of available evidence and, on the other hand, provide testable predictions for future research.

Fixation-related potentials in naming speed: A combined EEG and eye-tracking study on children with dyslexia

OBJECTIVE

We combined electroencephalography (EEG) and eye-tracking recordings to examine the underlying factors elicited during the serial Rapid-Automatized Naming (RAN) task that may differentiate between children with dyslexia (DYS) and chronological age controls (CAC).

METHODS

Thirty children with DYS and 30 CAC (M_age = 9.79 years; age range 7.6 through 12.1 years) performed a set of serial RAN tasks. We extracted fixation-related potentials (FRPs) under phonologically similar (rime-confound) or visually similar (resembling lowercase letters) and dissimilar (non-confounding and discrete uppercase letters, respectively) control tasks.

RESULTS

Results revealed significant differences in FRP amplitudes between DYS and CAC groups under the phonologically similar and phonologically non-confounding conditions. No differences were observed in the case of the visual conditions. Moreover, regression analysis showed that the average amplitude of the extracted components significantly predicted RAN performance.

CONCLUSION

FRPs capture neural components during the serial RAN task informative of differences between DYS and CAC and establish a relationship between neurocognitive processes during serial RAN and dyslexia.

SIGNIFICANCE

We suggest our approach as a methodological model for the concurrent analysis of neurophysiological and eye-gaze data to decipher the role of RAN in reading.

Naming processes in reading and spelling disorders: An electrophysiological investigation

OBJECTIVE

Reading fluency deficits characteristic for reading disorders (RD; F81.0) have been shown to be strongly associated with slow naming speed (e.g. in rapid automatized naming tasks). In contrast, children with an isolated spelling disorder in the context of unimpaired reading skills (iSD; F81.1) show naming speed task performances that are similar to typically developing (TD) children. However, the exact nature of the naming speed deficit and its relation to RD and the question whether children with iSD are also on the neurophysiological level similar to TD children is still unresolved.

METHODS

The time-course and scalp topography of event-related potentials (ERP) activity recorded during a delayed digit-naming task was investigated in ten-year-old children with RD and iSD compared to a TD group.

RESULTS

ERP activity differed between the RD and the TD group at around 300 ms after stimulus presentation (left occipito-temporal P2). In contrast, there were no neurophysiological differences between the TD and the iSD group. The P2 component correlated with behavioural performance on the RAN task.

CONCLUSIONS

Slow naming speed in RD might result from a slowed-down access and prolonged processing of the word (lexical) form.

SIGNIFICANCE

The study establishes a relation between neurophysiological processes of naming tasks and RD.

Training RAN or reading? A telerehabilitation study on developmental dyslexia

Rehabilitation procedures recommended for developmental dyslexia (DD) are still not fully defined, and only few studies directly compare different types of training. This study compared a training (Reading Trainer) working on the reading impairment with one (Run the RAN) working on the rapid automatized naming (RAN) impairment, one of the main cognitive deficits associated with DD. Two groups of DD children (N = 45) equivalent for age, sex, full IQ, and reading speed were trained either by Reading Trainer (n = 21) or by Run the RAN (n = 24); both trainings required an intensive home exercise, lasting 3 months. Both trainings showed significant improvements in reading speed and accuracy of passages and words. Bypassing the use of alphanumeric stimuli, but empowering the cognitive processes underlying reading, training RAN may be a valid tool in children with reading difficulties opening new perspectives for children with severe impairments or, even, at risk of reading difficulties.

Are RAN deficits in university students with dyslexia due to defective lexical access, impaired anchoring, or slow articulation?

The purpose of this study was to examine different hypotheses in relation to RAN deficits in dyslexia. Thirty university students with dyslexia and 32 chronological-age controls were assessed on RAN Digits and Colors as well as on two versions of RAN Letters and Objects (one with five items repeated 16 times and one with 20 items repeated four times). In addition, participants were tested on discrete letter and object naming, phonological awareness, orthographic knowledge, and speed of processing, and the RAN Letters and Objects total times were partitioned into pause times and articulation times. Results showed first that the dyslexia group was slower than the control group on all RAN tasks and the differences remained significant after controlling for discrete naming time. Second, both groups were slower in the large item set condition (20 × 4) than in the small set condition (5 × 16). Third, the dyslexia group was slower than the control group in both the pause and the articulation times. Although none of the processing skills was sufficient on its own to eliminate group differences in RAN Letters components, phonological awareness, and orthographic processing were sufficient on their own to eliminate group differences in the RAN Objects pause time. Taken together, our findings suggest that the deficits in RAN are not due to impaired anchoring, but rather due to subtle impairments in lexical access (specific to alphanumeric RAN), serial processing, and articulation.

Visual motion and rapid auditory processing are solid endophenotypes of developmental dyslexia

Although a genetic component is known to have an important role in the etiology of developmental dyslexia (DD), we are far from understanding the molecular etiopathogenetic pathways. Reduced measures of neurobiological functioning related to reading (dis)ability, i.e. endophenotypes (EPs), are promising targets for gene finding and the elucidation of the underlying mechanisms. In a sample of 100 nuclear families with DD (229 offspring) and 83 unrelated typical readers, we tested whether a set of well-established, cognitive phenotypes related to DD [i.e. rapid auditory processing (RAP), rapid automatized naming (RAN), multisensory nonspatial attention and visual motion processing] fulfilled the criteria of the EP construct. Visual motion and RAP satisfied all testable criteria (i.e. they are heritable, associate with the disorder, co-segregate with the disorder within a family and represent reproducible measures) and are therefore solid EPs of DD. Multisensory nonspatial attention satisfied three of four criteria (i.e. it associates with the disorder, co-segregates with the disorder within a family and represents a reproducible measure) and is therefore a potential EP for DD. Rapid automatized naming is heritable but does not meet other criteria of the EP construct. We provide the first evidence of a methodologically and statistically sound approach for identifying EPs for DD to be exploited as a solid alternative basis to clinical phenotypes in neuroscience.

Predicting the reading skill of Japanese children

OBJECTIVE

To clarify cognitive processes underlining the development of reading in children speaking Japanese as their first language, we examined relationships between performances of cognitive tasks in the preschool period and later reading abilities.

METHODS

Ninety-one normally developing preschoolers (41 girls and 50 boys; 5years 4months to 6years 4months, mean 5years 10months) participated as subjects. We conducted seven cognitive tasks including phonological awareness tasks, naming tasks, and working memory tasks in the preschool period. In terms of reading tasks, the hiragana naming task was administered in the preschool period; the reading times, which is a composite score of the monomoraic syllable reading task, the word and the non-word reading tasks, and the single sentence reading task, was evaluated in first and second grade; and the kanji reading task (naming task) was tested in second grade. Raven's colored progressive matrices and picture vocabulary test revised were also conducted in first grade. Correlation analyses between task scores and stepwise multiple regression analyses were implemented.

RESULTS

Tasks tapping phonological awareness, lexical access, and verbal working memory showed significant correlations with reading tasks. In the multiple regression analyses the performances in the verbal working memory task played a key role in predicting character naming task scores (the hiragana naming task and the kanji reading task) while the digit naming task was an important predictor of reading times. Unexpectedly, the role of phonological (mora) awareness was modest among children speaking Japanese.

CONCLUSION

Cognitive functions including phonological awareness, digit naming, and verbal working memory (especially the latter two) were involved in the development of reading skills of children speaking Japanese.