Examining mental simulations of uncertain events.

A great deal of research into the experiential nature of language has demonstrated that our understanding of events is facilitated through mental simulations of the described linguistic input. However, to date little is understood about how contextual uncertainty about the described event might influence the content and strength of these mental representations or the cognitive effort involved. In this article, we report a single experiment in which participants read sentences such as "The old lady [knows/thinks] that the picnic basket is open." Following a delay of 250 or 1,500 ms, they responded to pictures that varied in the physical form of the target object (matching vs. mismatching). Results revealed an expected facilitation effect for matching images, but more important, they also showed interference effects (longer reaction times) at the shorter interstimulus interval (ISI; 250 ms) following the uncertain verb thinks, as compared with the certain verb knows. At the longer ISI, this effect was no longer present. This suggests that at the short ISI, uncertain conditions required extra time to construct and map a simulation of events onto the available image. Results are discussed in terms of the mechanisms involved in representing possible events and with reference to related literature on perspective taking.