Syntactic adaptation leads to updated knowledge for local structural frequencies.

Syntactic adaptation has been shown to occur for various temporarily ambiguous structures, wherein an initially unexpected resolution becomes easier to process after repeated exposure. More controversial and less replicated is the claim that this adaptation towards a locally frequent structure occurs due to a strategic shifting of expectations to match short-term statistical regularities such that readers adapt away from the a priori more frequent structure. Experiment 1 replicates the initial adaptation towards a coordination garden path structure using self-paced reading; however, this paradigm has been criticised for its low reliability for detecting such small effects. To this end, Experiments 2 and 3 use a combination of self-paced reading and sentence completion tasks to replicate initial adaptation towards both coordination and reduced relative garden path structures and show evidence for a preference for these structures over their a priori more frequent alternatives. Together, these data reveal that participants may be tracking local structural statistics in real time; however, they may not be able to rapidly use that information to update processing behaviours.