Sentence processing without empty categories

Theories of sentence processing have standardly made use of grammatical theories with empty categories, and have therefore postulated a process known as “gap-filling”. In contrast, this paper provides evidence that the processing of unbounded dependencies does not make use of empty categories. We propose instead that there is a direct association between the extracted element and its subcategoriser. To show that gap-filling cannot take place, we consider a number of examples where there is material separating the assumed empty category and the subcategoriser, and then present a formal argument, based on patterns of dependencies in sentences involving multiple cases of extraction. We then sketch a linguistic account of unbounded dependencies that does not use empty categories, and which can serve as the basis of a processing model. We conclude that empty categories are not psychologically real.