Processing of written and spoken words: Evidence for common coding

Common processing systems involved during reading and listening were investigated. Semantic, phonological, and physical systems were examined using an experimental procedure that involved simultaneous presentation of two words: one visual and one auditory. Subjects were instructed to attend to only one modality and to make responses on the basis of words presented in that modality. Influence of unattended words on semantic and phonological decisions indicated that these processing systems are common to the two modalities. Decisions in the physical task were based on modality-specific codes operating prior to the convergence of information from the two modalities.