What Can Visual World Eye-tracking Tell Us about the Binding Theory?

A question of central importance at the interface of the grammar and the language processing system is how grammatical constraints are deployed during sentence processing. This paper focuses on how the grammatical constraints of the syntactic Binding Theory (BT)—the structural constraints on reflexives and pronouns—apply during online processing. Our study is presented against a background literature proposing a variety of models for the application of the BT during processing. The Initial Filter approach (Nicol and Swinney 1989) suggests that the BT constraints constrain from the very beginning of processing which potential antecedents people consider during processing; the Defeasible Filter approach (Sturt 2003) posits that initially people consider only potential antecedents consistent with the BT, but may at a later stage of processing consider antecedents not sanctioned by the BT; and the Multiple Constraints approach (Badecker and Straub 2002) claims, instead, that the constraints of the BT apply alongside other processing constraints throughout processing. Using a novel visual world eye-tracking method which manipulates the gender of potential antecedents visually, we find clear evidence that listeners consider gender-matching potential antecedent NPs for reflexives and pronouns that match in gender regardless of whether they are licensed structurally by the BT, consistent with the Multiple Constraints view. We also consider how our results also bear on the formulations of the BT, favoring an approach that recognizes that the constraints of the BT apply differently for reflexives and pronouns, in particular appearing to be less robust for the latter.