Learning L2 grammar from prediction errors? Verb biases in structural priming in comprehension and production

This study tests whether prediction error underlies structural priming in a later-learnt L2 across two visual world eye-tracking priming experiments. Experiment 1 investigates priming when learners encounter verbs biased to double-object-datives (DO, “pay”) or prepositional-object-datives (PO, “send”) in the other structure in prime sentences. L1-German–L2-English learners read prime sentences crossing verb bias and structure (DO/PO). Subsequently, they heard target sentences – with unbiased verbs (“show”) – while viewing visual scenes. In line with implicit learning models, gaze data revealed priming and prediction-error effects, namely, more predictive looks consistent with PO following PO primes with DO-bias verbs. Priming in comprehension persisted into (unprimed) production, indicating that priming by prediction error leads to longer-term learning. Experiment 2 investigates the effects of target verb bias on error-based priming. Priming and prediction-error effects were reduced for targets with non-alternating verbs (“donate”) that only allow PO structures, suggesting learners’ knowledge of the L2 grammar modulates prediction-error-based priming.