Pictogram naming in dyslexic and normal children assessed by SLO

Is learning a logographic script easier than reading an alphabetic script for German children with dyslexia?

PURPOSE

Developmental dyslexia in alphabetic languages (DD) is characterized by a phonological deficit. Since logographic scripts rely predominantly on visual and morphological processing, reading performance in DD can be assumed to be less impaired when reading logographic scripts.

METHODS

40 German-speaking children (18 with DD, 22 not reading-impaired-group C; 9-11 years) received Chinese lessons. Eye movements (EM) were recorded during naming single alphabetic words, pictures (confrontational) and Chinese characters to be named in German and Chinese. The main outcome variables were: Articulation latency, numbers and durations of fixations. Quality of life (QoL) was assessed by questionnaires.

RESULTS

While reading alphabetic words, articulation latencies and numbers of fixations were significantly higher for group DD than for group C (AL-DD = 1.13, AL-C = 0.84, p< .001; FN-DD = 3.50; FN-C = 2.00, p< .001). For naming pictures and Chinese characters in German and in Chinese, no significant group differences were found for any of the EM variables. The percentage of correct answers was high for German naming (DD = 86.67%, C = 95.24%; p = .015) and lower for Chinese naming in both groups, but significantly lower in group DD, especially for Chinese naming (DD = 56.67%, C: 83.77%; p = .003). QoL differed between groups from the children's perspective only at posttest. Parents of group DD perceived their children`s QoL to be lower compared with parents of group C at pre- and posttest.

CONCLUSIONS

Children with dyslexia performed as well as group C during naming Chinese characters in German and in Chinese regarding their EM variables, presumably because they processed Chinese characters by the visuo-spatial pathway with direct access to the semantic system. However, the significantly lower percentage of correct answers especially during Chinese naming showed that group DD had more difficulties naming Chinese characters than group C, which could be attributed to their phonological deficit, among other factors.

TRIAL REGISTRATION

German clinical trials register (DRKS00015697).

Evidence from ERP and Eye Movements as Markers of Language Dysfunction in Dyslexia

Developmental dyslexia is a complex reading disorder involving genetic and environmental factors. After more than a century of research, its etiology remains debated. Two hypotheses are often put forward by scholars to account for the causes of dyslexia. The most common one, the linguistic hypothesis, postulates that dyslexia is due to poor phonological awareness. The alternative hypothesis considers that dyslexia is caused by visual-attentional deficits and abnormal eye movement patterns. This article reviews a series of selected event-related brain potential (ERP) and eye movement studies on the reading ability of dyslexic individuals to provide an informed state of knowledge on the etiology of dyslexia. Our purpose is to show that the two abovementioned hypotheses are not necessarily mutually exclusive, and that dyslexia should rather be considered as a multifactorial deficit.

Eye movements in German-speaking children with and without dyslexia when reading aloud

PURPOSE

The phonological difficulty and orthographic regularity of a language influence reading strategies. Only a few studies have been conducted in readers of German, which has a high grapheme-phoneme correspondence. The aim of this study was to investigate, firstly, the influence of different levels of phonological difficulty of reading material in German on reading in children and, secondly, to compare the reading strategies of German children with findings in English-speaking readers.

METHODS

  Eye movements in 16 German children with dyslexia and 16 age-matched control children (mean age 9.5±0.35years) in the third and fourth grades of school were recorded by scanning laser ophthalmoscope while they read aloud two texts of differing levels of difficulty.

RESULTS

  In the dyslexia group, reading speed was slowed, and the number of saccades and regressions was raised markedly, although the percentage of regressions only slightly. The number of eye movements increased in both groups with increasing text difficulty, although much more in the dyslexia group than in the control group, whereas fixation duration was not influenced.

CONCLUSIONS

  Phonological difficulty influences reading speed and eye movement pattern: children with dyslexia markedly increase their number of eye movements and analyse the text in smaller units per fixation, but keep fixation duration constant. This strategy reflects their favouring of the indirect, sublexical route of grapheme-phoneme conversion, whereas readers of English-language texts are more likely to prefer the whole-word approach, i.e. the direct, lexical route that is associated with orthographic memory.

Word length and word frequency affect eye movements in dyslexic children reading in a regular (German) orthography

We combined independently the word length and word frequency to examine if the difficulty of reading material affects eye movements in readers of German, which has high orthographic regularity, comparing the outcome with previous findings available in other languages. Sixteen carefully selected German-speaking dyslexic children (mean age, 9.5 years) and 16 age-matched controls read aloud four lists, each comprising ten unrelated words. The lists varied orthogonally in word length and word frequency: high-frequency, short; high-frequency, long; low-frequency, short; low-frequency, long. Eye movements were measured using a scanning laser ophthalmoscope (SLO). In dyslexic children, fixation durations and the number of saccades increased both with word length and word frequency. The percentage of regressions was only increased for low-frequency words. Most of these effects were qualitatively similar in the two groups, but stronger in dyslexic children, pointing to a deficient higher-level word processing, especially phonological deficit. The results indicate that reading eye movements in German children are modulated by the degree of difficulty, and orthographic regularity of the language can determine the nature of modulation. The findings suggest that, similar to Italian but unlike English readers, German children prefer indirect sub-lexical strategy of grapheme-phoneme conversion.

[A critical view of alternative methods for treating visual complaints]

Irlen therapy, visual training, training of ocular motor control, and the correction method of H.-J. Haase represent a diversity of treatment methods that are mainly aimed at dyslexia, fatigue while reading, and general lack of concentration. We summarize the theoretical background of these methods, treatment approaches, and related clinical trials. None of these methods, because of incorrect theoretical concepts and an attempt to simplify the underlying causes, was found to have a specific influence on the patients' complaints. The absence of specific therapeutic effects and the high costs and time expenditure required should discourage practitioners from recommending these methods.

The eye movements of dyslexic children during reading and visual search: Impact of the visual attention span

The eye movements of 14 French dyslexic children having a VA span reduction and 14 normal readers were compared in two tasks of visual search and text reading. The dyslexic participants made a higher number of rightward fixations in reading only. They simultaneously processed the same low number of letters in both tasks whereas normal readers processed far more letters in reading. Importantly, the children's VA span abilities related to the number of letters simultaneously processed in reading. The atypical eye movements of some dyslexic readers in reading thus appear to reflect difficulties to increase their VA span according to the task request.