Building complex reference objects from dual sets

There has been considerable psycholinguistic investigation into the conditions that allow separately introduced individuals to be joined into a plural set and represented as a complex reference object (e.g., Eschenbach, et al., 1989; Garrod & Sanford, 1982; Koh & Clifton, 2002; Koh et al., 2008; Moxey et al., 2004; Sanford & Lockhart, 1990). The current paper reports three eye-tracking experiments that investigate the less-well understood question of what conditions allow pointers to be assigned to the individuals within a previously undifferentiated set, turning it into a complex reference object. The experiments made use of a methodology used in Patson and Ferreira (2009) to distinguish between complex reference objects and undifferentiated sets. Experiments 1 and 2 demonstrated that assigning different properties to the members of an undifferentiated dual set via a conjoined modifier or a comparative modifier transformed it into a complex reference object. Experiment 3 indicated that assigning a property to only one member of an undifferentiated dual set introduced pointers to both members. These results demonstrate that pointers can be established to referents within a plural set without picking them out via anaphors; they set boundaries on the kinds of implicit contrasts between referents that establish pointers; and they illustrate that extremely subtle properties of the semantic and referential context can affect early parsing decisions.