INDIVIDUAL-DIFFERENCES AND PROBABILISTIC CONSTRAINTS IN SYNTACTIC AMBIGUITY RESOLUTION

Two experiments investigated the role of individual differences in rea ding span in the comprehension of ambiguous sentences that were resolv ed with a syntactically simple interpretation. Previous research showe d that high but not low reading span subjects had longer reading times for such sentences compared to unambiguous controls, a result that ha d been attributed to high span subjects maintaining more alternative i nterpretations of the ambiguity than did low span subjects (MacDonald, Just, & Carpenter, 1992). Experiment 1 replicated this reading time p attern but also showed that the individual differences were attributab le to differential sensitivity to probabilistic constraints in the sti muli, in that only high span subjects were sensitive to the relative p lausibility of alternative interpretations of the ambiguity. Experimen t 2 demonstrated that the source of these differences was in the abili ty to use plausibility constraints during comprehension, not in constr aint knowledge across the two groups. The implications of these result s for studies of individual differences and for theories of syntactic ambiguity resolution are discussed. (C) 1995 Academic Press. Inc.