Interpreting Developmental Surface Dyslexia within a Comorbidity Perspective.

Pierluigi Zoccolotti,Maria De Luca,Chiara Valeria Marinelli

doi:10.3390/brainsci11121568

Abstract

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.

Highlights

Deficits in reading, spelling, and math are closely associated with each other and with other developmental deficits
As described in greater detail below, we propose that, when reading is viewed within a comorbidity perspective, it is possible to see surface symptoms as due to a general domain factor that accounts for the partial association among reading, spelling, and math
As stated above it does not explicitly consider the role of eye movements or executive function; it does not focus on visual processing, which is preliminary to any form of acquisition subtending reading; it is specific for the task/measure considered

Summary

Introduction

Deficits in reading, spelling, and math are closely associated with each other and with other developmental deficits. Tests of reading (and spelling) that require the retrieval of memory-specific information (such as performing an orthographic decision task or spelling an ambiguous word) predicted reading (and spelling) and predicted calculation (in particular, accounting for the same portion of variance as the Tables test). To interpret this complex pattern, we proposed that the cognitive factors which account for learning skills (and potentially for learning disturbances) should be viewed at three separate levels of analysis, i.e., competence, performance, and acquisition. Our working hypothesis has been that tasks calling on the retrieval of specific instances may play a key role in accounting for the comorbidity of learning disorders

Aims of the Present Report

Interpretations of Surface Dyslexia in Acquired and Developmental Cases

Conclusions