Transposing two internal letters of a word produces a perceptually similar item (e.g., CHOLOCATE being processed as CHOCOLATE). To determine the precise nature of the encoding of letter position within a word, we examined the effect of the number of intervening letters in transposed-letter effects with a masked priming procedure. In Experiment 1, letter transposition could involve adjacent letters (chocloate-CHOCOLATE) and nonadjacent letters with two intervening letters (choaolcte-CHOCOLATE). Results showed that the magnitude of the transposed-letter priming effect – relative to the appropriate control condition – was greater when the transposition involved adjacent letters than when it involved nonadjacent letters. In Experiment 2, we included a letter transposition condition using nonadjacent letters with one intervening letter (cholocate-CHOCOLATE). Results showed that the transposed-letter priming effect was of the same size for nonadjacent transpositions that involved one or two intervening letters. In addition, transposed-letter priming effects were smaller in the two nonadjacent conditions than in the adjacent condition. We examine the implications of these findings for models of visual-word recognition.

How does the brain encode the letter positions within a word? This is a key question for the choice of an input coding scheme in computational models of visual-word recognition (e.g., how can the cognitive system distinguish between causal and casual?). In recent decades, a growing body of data has shown that transposing two adjacent letters of a word (e.g., jugde from judge) results in a perceptually similar word that can be read with little cost (Grainger & Whitney, 2004; Rayner, White, Johnson, & Liversedge, 2006). In masked priming experiments, transposed-letter nonword primes not only produce form-priming effects relative to the appropriate orthographic control (e.g., jugde-JUDGE vs. jupte-JUDGE; Perea & Lupker, 2003b; see also Christianson, Johnson, & Rayner, 2005; Duñabeitia, Perea, & Carreiras, 2007; Forster, Davis, Schoknecht, & Carter, 1987; Perea & Carreiras, 2006a