Diversity matters: The sensitivity to sublexical orthographic regularities increases with contextual diversity.

Readers capture statistics about letter co-occurrences very rapidly. This has been demonstrated with artificial lexicons and/or with restricted sets of orthographic regularities. The aim of the study was twofold: To examine the learning of new orthographic regularities in a more incidental exposure paradigm, and to investigate the impact of the diversity of letter contexts in which new orthographic regularities appear. For 2 months, participants played detection games for 20 min per day and were exposed to a large set of pseudowords, some of which included new bigrams (e.g., GK). Half of the new bigrams occurred in eight different items (high contextual diversity) and the other half were presented in only two items (low context diversity). At six time points, the participants performed a "wordlikeness" task in which they chose between two new pseudowords the one that was more similar to the items previously exposed (e.g., PUGKALE vs. PUGZALE). The results showed that the participants very rapidly developed a preference for items with a frequent new bigram and that this sensitivity increased steadily over the 2 months. Furthermore, the sensitivity to these new orthographic regularities was higher in cases of high letter contextual diversity. The latter result parallels what is observed at a lexical level with semantic contextual diversity.