Letter position coding in printed word perception: Effects of repeated and transposed letters

We report four experiments investigating the effects of repeated and transposed letters in orthographic processing. Orthographically related primes were formed by removing one letter from the target word, by transposing two adjacent letters, or by replacing two adjacent letters with different letters. Robust masked priming in a lexical decision task was found for primes formed by removing a single letter (e.g., mircle -MIRACLE), and this was not influenced by whether or not the prime contained a letter repetition (e.g., balace vs. balnce as a prime for BALANCE ). Target words containing a repeated letter tended to be harder to respond to than words without a letter repetition, but the nonwords formed by removing a repeated letter (e.g., BALNCE) were no harder to reject than nonwords formed by removing a non-repeated letter (e.g., MIRCLE, BALACE). Significant transposition priming effects were found for 7-letter words (e.g., sevrice -SERVICE), and these priming effects did not vary as a function of the position of the transposition (initial, final, or inner letter pair). Priming effects disappeared when primes were formed by replacing the two transposed letters with different letters (e.g., sedlice -SERVICE), and five-letter words only showed priming effects with inner letter transpositions (e.g., ponit -POINT). We present a revised "open-bigram" scheme for letter position coding that accounts for these data.