Letter-by-letter processing in the phonological conversion of multiletter graphemes: searching for sounds in printed pseudowords.

Current models of word reading differ in their descriptions of how print-to-sound conversion is performed. Whereas a parallel procedure is generally assumed, the dual-route cascaded model developed by Coltheart and colleagues (Coltheart, Rastle, Perry, Langdon, and Ziegler, 2001) holds that the nonlexical conversion operates letter by letter, serially from left to right. An interesting aspect of the hypothesized serial procedure is that only the first letter of two-letter graphemes is thought to cause activation of its corresponding phonological code, the second letter of multiletter graphemes being directly merged with the preceding letter to form a complex grapheme. This hypothesis was examined in a task in which participants had to detect target phonemes in visually presented pseudowords. The data suggest that phonological codes associated with all the letters of the multiletter graphemes are activated.