We tested the predictions of the error-based implicit language learning model of syntactic priming in second (L2) and first (L1) language speakers. We compared L2 and L1 French speakers’ production of fronted/non-fronted temporal phrases and active/passive structures when primed with and without lexical overlap. We also measured the effect of attention and motivation on priming. Our findings are compatible with the general predictions of the model: we observed immediate and long-term priming, and lexical boost effects; individual differences in attention modulated priming strength. Moreover, the results suggest that priming with and without lexical overlap relies on different mechanisms. Nonetheless, some findings contradicted the model’s predictions: immediate abstract priming only arose for the fronting alternation; L2 speakers did not show consistently larger priming effects than L1 speakers; patterns of syntactic priming varied highly across syntactic alternations, even within individuals. Overall, the study highlights the importance of comparing priming of different structures within speakers.

The aim of the present study was to conduct a particularly stringent pre-registered in-vestigation of the claim that there exists a level of linguistic representation that “includes syntactic category information but not semantic information” (Branigan & Pickering, 2017: 8). As a test case, we focussed on the English passive; a construction for which previous findings have been somewhat contradictory. On the one hand, several studies using different methodologies have found an advantage for theme-experiencer passives (e.g., The girl was shocked by the tiger; and also agent-patient passives; e.g., The girl was hit by the tiger) over experiencer-theme passives (e.g., The girl was ignored by the tiger). On the other hand, Messenger et al. (2012) found no evidence that theme-experiencer and experiencer-theme passives vary in their propensity to prime production of agent-patient passives. We therefore conducted an online replication of Messen-ger et al (2012) with a pre-registered appropriately powered sample (N=240). Although a large and significant priming effect (i.e., an effect of prime sentence type) was ob-served, a Bayesian analysis yielded only weak/anecdotal evidence (BF=2.11) for the crucial interaction of verb type by prime type; a finding that was robust to different coding and exclusion decisions, operationalizations of verb semantics (dichoto-mous/continuous), analysis frameworks (Bayesian/frequentist) and – as per a mixed-effects-multiverse analyses – random effects structures. Nevertheless, these findings do no not provide evidence for the absence of semantic effects (as has been argued for the findings of Messenger et al, 2012). We conclude that these and related findings are best explained by a model that includes both lexical, exemplar-level representations and rep-resentations at multiple higher levels of abstraction.

We examined whether language input modality and individual differences in attention and motivation influence second language (L2) learning via syntactic priming. In an online study, we compared French L2 English and L1 English speakers’ primed production of passives in reading-to-writing vs. listening-to-writing priming conditions. We measured immediate priming (producing a passive immediately after exposure to the target structure) and short- and long-term learning (producing more target structures in immediate and delayed post-tests without primes relative to pre-tests). Both groups showed immediate priming and short- and long-term learning. Prime modality did not influence these effects but learning was greater in L2 speakers. While attention only increased learning in L1 speakers, high motivation increased L2 speakers' learning in the reading-to-writing condition. These results suggest that syntactic priming fosters long-term L2 learning, regardless of input modality. This study is the first to show that motivation may modulate L2 learning via syntactic priming.