Communicative predictions can overrule linguistic priors.

Predictions allow for efficient human communication. To be efficient, listeners' predictions need to be adapted to the communicative context. Here we show that during speech processing this adaptation is a highly flexible and selective process that is able to fine-tune itself to individual language styles of specific interlocutors. In a newly developed paradigm, speakers differed in the probabilities by which they used particular sentence structures. Probe trials were applied to infer participants' syntactic expectations for a given speaker and to track changes of these expectations over time. The results show that listeners fine-tune their linguistic expectations according to the individual language style of a speaker. Strikingly, nine months after the initial experiment these highly specific expectations could be rapidly reactivated when confronted with the particular language style of a speaker but not merely on the basis of an association with speaker identity per se. These findings highlight that communicative interaction fine-tunes and consolidates interlocutor specific communicative predictions which can overrule strong linguistic priors.