Masaya Yoshida, Northwestern University

The real-time processing of Forward and Backward Sluicing

Ellipsis constructions present many challenges to incremental sentence processing.  As shown by the example in (1), in an embedded wh-interrogative context, a string that is compatible with ellipsis is normally compatible with non-ellipsis continuations as well. Though the fragment sentence (1) can be continued as ellipsis as shown in (1a), ellipsis is just one of many possible continuations, i.e., the fragment can be followed by a variety of different clauses as (1b) and (1c) illustrate. 

(1) John was writing something, but I don¹t know what

a.         Ellipsis

b.         he was writing

c.         motivates him to write so much.

Therefore there is a problem of ambiguity resolution, namely, whether the parser licenses ellipsis when both ellipsis and non-ellipsis are possible structures. In other words, does the parser initially prefer a sluicing structure in cases where sluicing is possible? Or does it, rather, prefer a full clausal continuation, without ellipsis?

There is another challenge that ellipsis raises. Even if the parser chooses ellipsis as a continuation, it is not clear how the parser constructs the structure associated with ellipsis, and how it searches for the appropriate antecedent for the ellipsis.

This study tries to answer these questions through online studies on forward and backward sluicing constructions. Specifically, we try to show that the parser prefers the ellipsis structure to the others and it actively searches for the antecedent of ellipsis, thus trying to associate the ellipsis site and the potential antecedent clause as soon as possible.

Based on the results of the experiment, we further argue that the ellipsis structure that the parser builds is associated with a detailed hierarchical syntactic structure.