Neighborhood effects in visual word recognition: effects of letter delay and nonword context difficulty.

The role of a target's orthographic neighborhood in visual word recognition was investigated in 2 lexical decision experiments. In both experiments, some stimuli had 1 letter delayed relative to the presentation of the rest of the stimulus. Experiment 1 showed that delaying a letter position, which yielded a potentially competitive neighbor, was more costly to target recognition than delaying a position that yielded no neighbors. This effect was strongest when one of these neighbors was of higher frequency than the target itself. Additionally, the effect was reduced for words with a high friendly-to-unfriendly-neighbor ratio (friendly neighbors being those words containing the delayed letter). In Experiment 2 the difficulty of the word-nonword discrimination was manipulated by varying the density of the nonwords' neighborhoods. Only when the nonwords had many neighbors at several positions did the word responses show neighborhood competition effects.