In this chapter, lexical access during reading will be discussed. Reading is the process of extracting pronunciation and meaning from print, and researchers (linguists, cognitive- and neuropsychologists, and more recently neuroscientists) have long been interested in these reading processes, particularly for English.

The direct-access hypothesis postulates that the lexical access of meaning results directly from orthography without recourse to phonological encoding (e.g. Smith, 1971), while the indirect access hypothesis assumes that transcoding from orthography to phonology is necessary before lexical access can occur (e.g. Gough, 1972; van Orden, 1987; van Orden, Pennington & Stone, 1990). Further, the dual encoding hypothesis postulates that lexical access can occur through either indirect phonological or direct orthographic codes (e.g. Coltheart et al., 2001; Rastle & Coltheart, 1999). The latter is also known as a dual-route reading model, and represents the most popular and influential theory of reading processing. The model has been developed on the basis of, and in order to explain, empirical data from both normal readers (e.g. Patterson & Coltheart, 1987), and neurological patients with acquired reading disorders (e.g. Coltheart, Patterson & Marshall, 1980; Patterson et al., 1985).

Dual-route versus single-route reading models in English

The dual-route models typically assume two distinct routes for reading: lexical (whole-word) and nonlexical (subword) routes. In the lexical route, orthographic, semantic, and phonological representations of words are functionally independent, and are stored in the orthographic (input) lexicon, semantic system, and phonological (output) lexicon respectively.