One factor that influences how easily this can be done is the regularity of the mapping from spelling to sound. Visual word recognition depends in large part on being able to determine the pronunciation of a word from its written form. Zevin, in Encyclopedia of Neuroscience, 2009 Mapping from Spelling to Sound in Visual Word Recognition Therefore, this chapter assumes a theoretical perspective based on the interactive-activation model and its subsequent variants but directs the reader to further discussion of this issue in relation to distributed-connectionist models ( Coltheart, 2004 Rastle & Coltheart, 2006). They offer no coherent account of the most elementary of these tasks-deciding whether a letter string is a known word (i.e., visual lexical decision). However, although these models have been very effective in helping us to understand the acquisition of quasi-regular mappings (as in spelling-to-sound relationships in English), they have been less successful in describing performance in the most frequently used visual word recognition tasks. This chapter highlights some of the most important insights that these models have offered to our understanding of reading. In recent years, a different class of theory based on distributed-connectionist principles has made a substantial impact on our understanding of processes involved in mapping orthography to phonology ( Plaut, McClelland, Seidenberg, & Patterson, 1996) and mapping orthography to meaning ( Harm & Seidenberg, 2004).
The major theories of visual word recognition posit that word recognition is achieved when a unique representation in the orthographic lexicon reaches a critical level of activation ( Coltheart et al., 2001 Grainger & Jacobs, 1996 Perry et al., 2007).
Representations in the orthographic lexicon can then activate information about their respective sounds and/or meanings. Some theories assert that letter information goes on to activate higher-level sub-word representations at increasing levels of abstraction, including orthographic rimes (e.g., the -and in “band” Taft, 1992), morphemes ( Rastle, Davis, & New, 2004), and syllables ( Carreiras & Perea, 2002), before activating stored representations of the spellings of known whole words in an orthographic lexicon. Information from the printed stimulus maps onto stored representations about the visual features that make up letters (e.g., horizontal bar), and information from this level of representation then maps onto stored representations of letters. The interactive-activation model of visual word recognition ( McClelland & Rumelhart, 1981 Rumelhart & McClelland, 1982).