Lack of word superiority effect in processing letter features

Letter recognition is typically faster in words than ih nonwords. In this study, we tested the word-superiority effect obtained when either subletter features or misalignment of letters had to be detected. Subjects were presented with both high- and low-frequency words and with legal and illegal nonwords. Space among the letters varied. In the regular space condition, letters within a string were separated by normal spaces; in the irregular space condition, letters were separated by normal spaces, small spaces, or large spaces. In Experiment 1, subjects were required to detect the presence of a bold segment contained in one of the letters of the string. No word-superiority effect was obtained. Furthermore, spacing affected neither latencies nor response accuracy. In Experiment 2, subjects were required to detect the presence of a letter misaligned with respect to the others. Again, no word-superiority effect was obtained. However, spacing affected this task, irregularly spaced strings being responded to more slowly and less accurately than regularly spaced strings. The results indicate that at the first stages of analysis, words and non-words are similarly coded. The pattern obtained is consistent with a multistage model of word recognition in which parallel feature extraction processes are followed by a level at which spatial relationships are computed and by a third level at which abstract grapheme identity is recovered from letter shapes.