In this project, we investigated masked morphological priming in 80+ L1 Italian-L2 English speakers. We tracked the participants' L2 proficiency profile with a wide battery of tests on their lexical, morphological, phonological, spelling, and semantic abilities. We find that masked priming in L2 is critically modulated by proficiency; genuine morphological priming only arises as proficiency grows, and opaque (corner-CORN) and orthographic priming (brothel-BROTH) shrink as L2 competence increases. Age of acquisition was also evaluated, and did not affect the priming pattern. Furthermore, we showed that L2 priming is also modulated by sensitivity to graded, probabilistic relationships between form and meaning, as tracked by Orthography--to--Semantics Consistency (OSC). Overall, these data illustrate the trajectory towards a fully consolidated L2 lexicon, and show that masked priming is a key tracker of this process.

All data, stimuli and analysis code behind this paper are available at https://osf.io/jnrvy/. A pre-print is also available at https://osf.io/xdsng/.