A failure to replicate rapid syntactic adaptation in comprehension.

Language comprehension requires successfully navigating linguistic variability. One hypothesis for how listeners manage variability is that they rapidly update their expectations of likely linguistic events in new contexts. This process, called adaptation, allows listeners to better predict the upcoming linguistic input. In previous work, Fine, Jaeger, Farmer, and Qian (PLoS ONE, 8, e77661, 2013) found evidence for syntactic adaptation. Subjects repeatedly encountered sentences in which a verb was temporarily ambiguous between main verb (MV) and reduced relative clause (RC) interpretations. They found that subjects who had higher levels of exposure to the unexpected RC interpretation of the sentences had an easier time reading the RC sentences but a more difficult time reading the MV sentences. They concluded that syntactic adaptation occurs rapidly in unexpected structures and also results in difficulty with processing the previously expected alternative structures. This article presents two experiments. Experiment 1 was designed as a follow-up to Fine et al.'s study and failed to find evidence of adaptation. A power analysis of Fine et al.'s raw data revealed that a similar study would need double the items and four times the subjects to reach 95% power. In Experiment 2 we designed a close replication of Fine et al.'s experiment using these sample size guidelines. No evidence of rapid syntactic adaptation was found in this experiment. The failure to find evidence of adaptation in both experiments calls into question the robustness of the effect.