Generating Predictive Inferences when Multiple Alternatives are Available
Cranford, Edward Andrew
Garrison, Teena Marie
Bradshaw, Gary L.
The generation of predictive inferences may be difficult when a story leads to multiple possible consequences. Prior research has shown that readers only generate predictive inferences automatically, under normal reading conditions, when the story is based on familiar events for which the reader has readily available knowledge about what may happen next, there is enough constraining information in the text so that the inference is highly predictable, and there are few or no alternative inferences available (McKoon & Ratcliff, 1992). However, some evidence shows predictive inferences were generated when the likelihood of the targeted inference was reduced and the story implied an alternative consequence could occur (Klin, Murray, Levine, & Guzmán, 1999). It is possible, though, that the alternative was not a likely enough consequence to affect processing of the targeted inference. Prior research did not examine whether the alternative inference was drawn or whether multiple inferences could be entertained simultaneously. The experiments in this dissertation were designed to further assess the nature of interference when multiple consequences are possible by increasing the likelihood of the alternative so that both inferences were more equally likely to occur. The first two experiments used a word-naming task and showed that neither inference was activated when probed at 500 ms after the story (Experiment 1A) or when probed at 1000 ms (Experiment 1B), suggesting the alternative inference interferes with activation of the targeted inference. Experiments 2 and 3 used a contradictory reading paradigm to assess whether the inferences were activated but only at a minimal level so that they were not detected in a word-naming task. Reading time was slower when a sentence contradicted both inferences but not when it contradicted only one inference, even after reading a lengthy filler text. Reading time was also slower in Experiment 3 when the filler text was removed. These results imply both inferences were generated at a minimal level of activation that does not strengthen over time. The results are discussed in the light of comprehension theories that could account for the representation of minimally encoded inferences (Kintsch, 1998; Myers & O'Brien, 1998).