Cerebral laterality in dyslexic children: Implications for phonological word decoding deficits

The study evaluated a substantially updated version of Orton's (1937) classical idea of a significant relatonship in dyslexic children between cerebral lateralization and their word decoding deficits. Attentional lateralization was examined under the assumption that covert spatial attention when directed contralaterally interacts with ageinvariant cerebral asymmetries for receptive speech. Thirty dysphonetic dyslexic children were compared to 30 younger normal readers who were matched to the dyslexics in reading comprehension. The children were tested in left ear (LE) and right ear (RE) directed attention dichotic listening (DAD), and in pseudoword decoding, word recognition, reading comprehension, spelling, arithmetic, and in general intelligence (IQ). Group comparisons in DAD failed to show any differences, confirming the mounting evidence that dyslexia is not related to incomplete lateralization. Entering the DAD scores of the dyslexics (LE first, LE second, RE first, RE second) as predictors of achievement revealed that, independently of chronological age (CA) and IQ, their ability to recall items from the LE first produced a negative regression which predicted 42 percent of the variance in pseudoword decoding. Selective report from the LE also produced small but significant negative correlations with visual recognition of real words and spelling; but no relationship to reading comprehension. IQ was related to reading comprehension and to the ability to shift attention from the LE to the RE. Eventhough the dyslexics were lateralized normally, weak lateralization was related specifically to phonological word decoding, a core deficit in dyslexia. However, unlike Orton's concept, these findings suggest that dyslexics suffer from exuberant right hemisphere processing in response to spatial attentional demands that, in turn, interferes transcallosally with the development of the sound-symbol representations that are required for fluent reading. Lateralization, per se, is unaffected by the disorder.     

Letter processing in reading and spelling: Some dissociations

We describe the complex pattern of spared and impaired performance observed in a neurologically impaired subject on a number of letter processing tasks including: written letter naming, alphabetization, matching across typecase and font, oral and written spelling to dictation, and across-case letter priming. The observed dissociation in performance between the naming of written letters and the naming of letters in oral spelling as well as the dissociation between oral spelling and written spelling are shown to support a model of letter processing in which a distinction is drawn between visuo-spatial and abstract levels of letter representation. We also describe symmetrical deficits in the reading and writing of letters. These can be understood: in reading, as the result of an impairment to the processes which mediate the conversion of visuo-spatial letter representations to abstract representations, and in writing, as a deficit to the processes which negotiate the apparently reverse operation. This finding is interpreted within the context of the notions of neural and functional proximity and we raise the possibility that processes which perform distinct computations may, nonetheless, share certain computational resources.Requests for offprints should be addressed to Brenda Rapp or Alfonso Caramazza. The research reported in this paper was made possible through the support of NIH (NINCDS) NS22202 and the Seaver Institute. We would like to express our appreciation to J. E. for his participation in this study and we thank Roberta Ann Goodman-Schulman and Cristina Romani for their helpful comments and Paul Mullin for his generous programming assistance.     

Reliability and prevalence of an atypical development of phonological skills in French-speaking dyslexics

In the present study, conducted with French-speaking children, we examined the reliability (group study) and the prevalence (multiple-case study) of dyslexics’ phonological deficits in reading and reading-related skills in comparison with Reading Level (RL) controls. All dyslexics with no comorbidity problem schooled in a special institution for children with severe reading deficits were included in the study (N = 15; Chronological Age [CA]: 111 ± 8 months; RL: 80 ± 3 months). For the group study, the 15 dyslexics were matched pairwise on reading level, non-verbal IQ, and gender to 15 younger RL controls (CA: 85 ± 4 months). For the multiple-case study, the RL control group included 86 average readers (CA: 83 ± 4 months; RL: 85 ± 5 months). To assess the relative efficiency of the sublexical (or phonological) and lexical reading procedures, we relied on two comparisons: pseudowords vs. high-frequency regular words (the comparison mainly used in languages with a shallow orthography); and pseudowords vs. high-frequency irregular words (the comparison mainly used with English-speaking dyslexics), pseudowords and irregular words being either short or long. The dyslexics’ skills in the domains supposed to explain their reading deficit were also examined: phonemic awareness, phonological short-term memory and rapid naming. In the group study, the dyslexics lagged behind the RL controls only when they were required to read long pseudowords. The results of the multiple-case study indicated that the prevalence of this deficit was high (the accuracy scores of all but two of the 15 dyslexics being more than 1 SD below the RL control mean), and that deficits in phonemic awareness were more prevalent (seven cases) than deficits in phonological memory (one case) and in rapid naming (two cases). Three unexpected results were observed in the group study: the difference between regular words and pseudowords (to the detriment of pseudowords) was not greater for the dyslexics; the difference between irregular words and pseudowords (to the benefit of pseudowords) was more significant for the RL controls; and there were no significant differences between the groups in reading-related skills. To explain these results, the severity of the dyslexics’ reading deficit and the remediation they have benefited from must be taken into account. In addition, the fact that the outcomes of the comparison between pseudoword vs. regular or irregular word reading were not the same will make it possible to understand some discrepancies between studies carried out either in English or in a language with a shallower orthography (French, for instance).

Phonological and visual processing deficits can dissociate in developmental dyslexia: Evidence from two case studies

The present study describes two Frenchteenagers with developmental reading andwriting impairments whose performance wascompared to that of chronological age andreading age matched non-dyslexic participants.Laurent conforms to the pattern of phonologicaldyslexia: he exhibits a poor performance inpseudo-word reading and spelling, producesphonologically inaccurate misspellings butreads most exception words accurately. Nicolas,in contrast, is poor in reading and spelling ofexception words but is quite good atpseudo-word spelling, suggesting that hesuffers from surface dyslexia and dysgraphia.The two participants were submitted to anextensive battery of metaphonological tasks andto two visual attentional tasks. Laurentdemonstrated poor phonemic awareness skills butgood visual processing abilities, while Nicolasshowed the reverse pattern with severedifficulties in the visual attentional tasksbut good phonemic awareness. The presentresults suggest that a visual attentionaldisorder might be found to be associated withthe pattern of developmental surface dyslexia.The present findings further show thatphonological and visual processing deficits candissociate in developmental dyslexia.     

Exploring support for dyslexic adults in the English workforce: lessons learnt from the story of an adult dyslexia group

Dyslexia support is likely to be in place for students within educational establishments in England. However, there are a significant number of adults with dyslexia in the English workplace who are no longer involved in education and for whom ongoing support is necessary to enable them to reach their potential in a world of increasing literacy demands. Legislation has led to significant moves towards inclusion in the English workplace, but there has been a lack of public recognition of the concerns and needs articulated by adults with this invisible disability. The formation of local voluntary groups provides one model of support for adults with dyslexia. This article examines the setting up of one such group and highlights issues involved in this process. The nature of the group structure and the support offered is discussed, including its impact on the individuals concerned. Finally, the author makes recommendations for stakeholders in the inclusion of adults with dyslexia.     

Chicken or the egg: Longitudinal analysis of the causal dilemma between goal orientation,self-regulation and cognitive processing strategies in higher education

The aim of this study was to investigate the direction of the effect between goal orientation, self-regulation and deep processing strategies in order to understand the impact of these three constructs on students’ achievement. The participants were 110 freshmen from the engineering faculty at the Université catholique de Louvain in Belgium, who were followed during the first three years of their university studies. Data were analyzed through structural equation modeling. The main finding was that mastery goal orientation increased students’ subsequent deep processing which in turn enhanced subsequent self-regulation. Deep processing and self-regulation also appeared to be mutually influential from year 2 to year 3. The implications of our results for the understanding of the interplay between cognitive and motivational processes in higher education are discussed.