Knowledge of statistics or statistical learning? Readers prioritize the statistics of their native language over the learning of local regularities

A large body of evidence suggests that people spontaneously and implicitly learn about regularities present in the visual input. Although theorized as critical for reading, this ability has so far been demonstrated only for non-linguistic materials. We tested whether local statistical regularities are also extracted from materials that closely resemble one’s native language. In two experiments, Italian speakers saw a set of letter strings modelled on the Italian lexicon and guessed which of these strings were words in a fictitious language and which were foils. Unknown to participants, words could be distinguished from foils based on their average Italian letter bigram frequency. Surprisingly, in both experiments, we found no evidence that participants learnt this statistic. Instead, lexical decisions were guided by minimal bigram frequency, a cue rooted in participants’ native language. We discuss the implications of these findings for accounts of statistical learning and visual word processing.