Word associations in deep dyslexia Annette Colangelo, a Kathy Stephenson, b Chris Westbury, b and Lori Buchanan a a The University of Windsor, Ont., Canada b The University of Alberta, Edmonton, Alta., Canada Accepted 7 May 2003 Abstract Deep dyslexia is an acquired reading disorder resulting in the production of semantic errors during oral reading and an inability to read aloud nonwords. Several researchers have postulated that patients with deep dyslexia have both phonological and semantic access impairments but the data supporting these claims are not convincing. In fact, the hallmark feature of deep dyslexia—the semantic errors—strongly implies that these patients can access semantic information from printed words. We test the integrity of the semantic system in two such patients through auditory and visual word association tasks. The data support the notion that semantics remains intact and that the disorder and associated errors arise through a selection impairment related to failure of inhibitory connections in the phonological lexicon. Ó 2003 Elsevier Inc. All rights reserved. 1. Introduction Deep dyslexia is a form of reading impairment in- volving the production of semantic errors to words read aloud, as well as an inability to read nonwords. Several models account for deficient reading performance in deep dyslexia by positing multiple loci of damage in a dual-route system for which functionally distinct pho- nological and semantic–lexical pathways are postulated (e.g., Morton & Patterson, 1980; Plaut & Shallice, 1993). To account for the inability to read aloud nonwords, these models propose that deep dyslexia involves dam- age to the sublexical phonological route such that it is rendered unavailable for reading (e.g., Glosser & Friedman, 1990; Morton & Patterson, 1980; Plaut & Shallice, 1993). As a consequence, deep dyslexics are assumed to completely lack the capacity to assemble phonology. Instead, these models propose that reading is entirely accomplished by a semantically mediated lexical route. If intact, the semantic–lexical route is ca- pable of supporting normal reading through whole word access. However, a selective impairment is also assumed for the semantic–lexical route and it is the extant dam- age to this reading system that is postulated to lead to semantic errors in deep dyslexia. Thus, according to these models of deep dyslexia, the primary deficit is an inability to process phonology, with additional deficits in the semantic system. However, current research with deep dyslexia is not concordant with traditional multiple damage formulations of deep dyslexia. Importantly, several recent findings have challenged the conceptualization of deep dyslexia as an inability to process phonology. For example, Buchanan, Hilde- brandt, and MacKinnon (1999) demonstrated that some patients with deep dyslexia evidence preserved implicit phonological processing for nonwords that they can no longer read aloud. Other authors have established that implicit phonological knowledge contributes to word recognition performance in deep dyslexic patients (Hil- debrandt & Sokol, 1993; Katz & Lanzoni, 1992, 1997). Cumulatively, these results indicate automatic activa- tion for word and nonword phonology. Furthermore, evidence for intact implicit phonological processing of nonwords implies that the primary locus of the deficit in deep dyslexia is not sublexical. However, whether se- mantic errors necessarily represent a deficit in semantic processing is an issue yet unresolved. It has been argued that an impaired ability to address entries in the phonological output system alone can accommodate the numerous error types produced in deep dyslexic reading patterns (Buchanan et al., 1999). According to this view, a failure to inhibit activated Brain and Cognition 53 (2003) 166–170 www.elsevier.com/locate/b&c 0278-2626/$ - see front matter Ó 2003 Elsevier Inc. All rights reserved. doi:10.1016/S0278-2626(03)00102-7