Orthography influences the perception of speech in alexic patients

Interactive models of reading propose that phonological representations directly activate and/or constrain orthographic representations through feedback. These models also predict that spoken words should activate their orthographic forms. The effect of word orthography on auditory lexical access was investigated in two patients with alexia without agraphia. Several theories of alexia suggest that letter-by-letter reading results from impaired access to orthographic representations. Although alexics can often correctly identify orally spelled words and spell to dictation, it is unknown whether they can access the whole orthographic "word-form" as a unit via auditory presentation. The nonobligatory activation of orthography was examined in an auditory lexical decision task, in which the orthographic and phonological similarity between prime and target was manipulated. In controls, the combined effect of phonological and orthographic relatedness (OP) produced greater facilitation than phonological relatedness alone, indicating that orthography can influence auditory lexical decisions. The alexics displayed patterns of facilitation comparable to controls, suggesting they can quickly access whole-word orthographic information via the auditory modality. An alternate account posits that the OP advantage does not require on-line access of orthography, but instead is a developmental by-product of learning to read an orthographically inconsistent language. The results have implications for cognitive theories of alexia and provide support for interactive models of word recognition.