Multi-step treatment for acquired alexia and agraphia (part II): a dual-route error scoring system

Dual-route neuropsychological models posit two distinct but interrelated pathways for reading and writing: the lexical and the sublexical. Individuals with reading/writing deficits often rely on the combined power of the integrated system to perform print-processing tasks. The resultant errors reflect varying degrees of lexical and sublexical accuracy in a single production; however, no system presently exists to analyze errors robustly in both routes. The goal of this project was to develop a system that simultaneously, quantitatively, and qualitatively captures changes in lexical and sublexical errors following treatment. Errors are evaluated hierarchically in both routes according to proximity to a target. This dual-route error scoring (DRES) system was developed using data from a novel treatment study for eight patients with acquired alexia/agraphia; a computerised version of the system was also developed (ADRES). Repeated-measures multivariate analyses of variance and post hoc analyses revealed significant dual-route treatment effects. Qualitative analyses revealed unique patterns of change across participants, reflecting the benefits of error evaluation beyond a binary correct/incorrect judgment. Finally, categorical error shifts were observed via group-level analysis. The results of this study indicate that treatment-induced evolution of reading/writing can be meaningfully and comprehensively represented by this novel scoring system.