Abstract

ion of metaphorical meanings (much as in the sequential categorization models discussed earlier). This conventionalization process results in the existence of alternative meanings for words that once were active metaphors (Gentner & Wolff, 1997). For example, the verb ‘boil’ now has a metaphorical meaning -‘to become emotionally agitated [like a boiling liquid]’ -as well as its literal meaning. There are also more global metaphoric systems. For example, Gentner, Imai and Boroditsky (in press; Gentner, 2001) showed that space-time metaphors are comprehended in terms of two different global systems of mappings, rather than on an individual lexical basis. In particular, there are two main spatial metaphors for time. In one, an individual moves through time (e.g., "We are approaching Christmas."). In the other, time moves toward the individual (e.g., "Christmas is approaching.") Gentner et al. showed that people are faster at processing a sequence of temporal sentences if the sentences remain in the same space time metaphor; there appears to be a processing cost for a shift from one of these metaphor systems to the other. Further, Boroditsky (2000) demonstrated that the mapping is asymmetric: people conceptualize time in terms of space. In one study, people were primed with pictures of individuals moving past objects or of objects moving on a conveyor belt past people. Then, they were given the sentence "Wednesday’s meeting has been moved forward two days," and were asked to state on what day the meeting would occur (McGlone and