Interpreting Developmental Surface Dyslexia within a Comorbidity Perspective

Recent evidence underlines the importance of seeing learning disorders in terms of their partial association (comorbidity). The present concept paper presents a model of reading that aims to account for performance on a naturalistic reading task within a comorbidity perspective. The model capitalizes on the distinction between three independent levels of analysis: competence, performance, and acquisition: Competence denotes the ability to master orthographic–phonological binding skills; performance refers to the ability to read following specific task requirements, such as scanning the text from left to right. Both competence and performance are acquired through practice. Practice is also essential for the consolidation of item-specific memory traces (or instances), a process which favors automatic processing. It is proposed that this perspective might help in understanding surface dyslexia, a reading profile that has provoked a prolonged debate among advocates of traditional models of reading. The proposed reading model proposes that surface dyslexia is due to a defective ability to consolidate specific traces or instances. In this vein, it is a “real” deficit, in the sense that it is not due to an artifact (such as limited exposure to print); however, as it is a cross-domain defect extending to other learning behaviors, such as spelling and math, it does not represent a difficulty specific to reading. Recent evidence providing initial support for this hypothesis is provided. Overall, it is proposed that viewing reading in a comorbidity perspective might help better understand surface dyslexia and might encourage research on the association between surface dyslexia and other learning disorders.

Default stress assignment in Russian: evidence from acquired surface dyslexia

This paper re-examines theoretical constructs used in the analysis of Russian word stress, employing data from speakers with acquired surface dyslexia, a symptom which is characterised by impaired lexical access and preserved grapheme–phoneme correspondence rules. Russian stems have been traditionally analysed as lexically accented or unaccented, with a default rule deriving surface stress in the latter case. In the study reported here, we found no differences in the production of accented and unaccented stems. Instead, the analysis of errors revealed that the significant factors determining stress placement include stress neighbourhood and stress position. The speakers produced fewer errors in consistently spelled words, and there was a strong tendency to shift stress to the final syllable in consonant-final words, and to the penultimate syllable in vowel-final words. These results indicate that distributional properties play an important role in stress assignment in both accented and unaccented stem types.