Do negative polarity items facilitate the processing of decreasing inferences?

Negative polarity items occur within the immediate scope of operators that support decreasing inferences. It is natural to expect the presence of a licensed NPI to facilitate the processing of decreasing inferences based on the licensor. In joint work with L. Bott and B. McElree I conducted a series of experiments to test this. We found no facilitation in terms of either verification accuracy or processing speed; instead, the presence of an NPI slowed down the processing of valid inferences. The talk will report on the experiments and consider various theories of licensing as potential explanations.