In an auditory interpretation study, Frazier and Clifton (1998; F&C) tested sluices with two indefinite possible antecedents:
With the embedded object (someone) accented, object responses (who was hiding) reached 69%, while accenting the matrix subject (tourist) produced 46% object responses. Accent position significantly affected interpretation, presumably by helping focus the accented element, but object responses remained even with subject accent. This object bias was traced to focus more indirectly, through perceivers' general tendency (in English) to assign focus clause-finally. However, these results could also result from a preference specifically for object antecedents, or for antecedents not separated from the sluice by additional clause boundaries. Additionally, this work explored focus only in indefinite sluices, though other types exist (Romero 1997, Merchant 2001).
An auditory questionnaire addressed alternative explanations using sluices with two VP-internal indefinites:
Two further experiments extended this work to the processing of contrast sluices (with 'else' indicating contrast with a definite antecedent, instead of an indefinite) as in (3):
In a written questionnaire, sentences like (3) received 86% object responses, showing that the preference for a clause-final antecedent holds for contrast sluices. In an auditory questionnaire, object responses fell to 42% with the subject (Alice) accented, vs. 88% with the object (Bill) accented (p's.001). With the verb or both arguments accented, object responses were at 76% (each differed from the subject/object accent conditions, p's.05). These results show that exclusive accent on only one argument is needed to raise focus assignments to that argument, not just the presence of an accent. Finally, despite strong accent effects, an overall bias towards the lower antecedent remains, showing that the position of default focus is important in all sluices tested. The implications of these results for ellipsis processing and the relation between accent and focus will be discussed.