A processing-based account of subliminal wh-island effects

Wh-island effects are notorious for their cross-linguistic variation. However, experimental syntax studies observed super-additive wh-island effects in some languages which were previously argued to be immune to them. In four acceptability judgment experiments, we investigate the origin of super-additivity in acceptable wh-islands, so-called “subliminal island effects,” focusing on Hebrew. Our first experiment reveals a super-additive wh-island effect in Hebrew. However, we suggest that the super-additivity measure for wh-islands is contaminated by processing factors. Specifically, we propose that in this case, the decrease in acceptability reflects interference caused by the simultaneous maintenance of two dependencies, rather than grammatical islandhood. The following experiments demonstrate that super-additivity can be observed in binding structures, where it cannot be attributed to a violation of a grammatical constraint, but rather to processing costs related to interference for maintenance processes. We also show that when minimizing these costs, super-additivity does not emerge in Hebrew wh-islands. We conclude that processing costs underlie the apparent wh-island effect in Hebrew, and perhaps in additional languages, and that the super-additivity paradigm should be fine-tuned in order to avoid these confounds.