Age of exposure and subject/object asymmetries when wh-movement goes rightward

We report an experiment addressing the comprehension of LIS interrogatives in three adult populations with different times of exposure to sign language: native signers, early signers, and late signers. We investigate whether delayed exposure to language affects comprehension of interrogatives and whether there is an advantage for subject dependencies over object dependencies, as systematically reported for spoken languages. The answer to the first question is positive: there is evidence that natives outperform nonnative signers, confirming permanent effects of delayed exposure to sign language even decades after childhood. However, the performance in subject interrogatives was lower than in object interrogatives in all groups of participants. We discuss several possible reasons for this unexpected finding.