Incomplete Meaning Processing: Moses Illusion And Metaphor Understanding

EXTENDED ABSTRACT This talk will present an ACT-R model that uni-es two phenomena in text comprehension: Moses illusion and metaphor understanding. Empirical data about Moses illusion shows that, in about 45% of cases, people are not able to detect distortions in sentences like How many animals of each kind did Moses take on the ark?, in spite of being instructed to look for distortions and in spite of knowing that it was Noah and not Moses the one who took animals on the ark. On the other hand, studies in the metaphor comprehension literature prove that sometimes metaphors are easier to be understood when the context precedes them; that is, sentences like The sky is lled with drops of molten silver are less dii-cult than Drops of molten silver lled the sky (Gerrig and Heally, 1983). The model I will be talking about regards both Moses illusion and metaphor comprehension as instances of incomplete meaning processing. Specifically , word meanings are represented as consisting of a number of features. Each time a word is processed , only few of these features are actually retrieved. The context in which the word appears (if existent and strong enough) guides the extraction of features. However, if a strong context does not exist (for instance, if we are at the beginning of the sentence), the features extracted from each word are used to nd the right context in memory. Therefore, the model always has a candidate context for the current utterance. Thus, for Moses illusion sentences, since the distorted word (Moses) is processed only superrcially, there are quite strong chances that the features retrieved will match features extant in the representation of Noah (given that Moses and Noah share some salient attributes), and thus the distortion will remain unnoticed. On the other hand, a metaphoric sentence like The sky was lled with drops of molten silver can be regarded as a distorted sentence (in the sense of Moses illusion), with the metaphor being the distortion. Given that the information preceding the metaphor is rich enough, it is possible to nd the right context in which this sentence could be put. Thus, the features common to drops of molten silver and stars are readily retrieved. In the same way, the metaphoric sentence Drops of molten silver lled the sky can be considered to be distorted, with the distortion the sky. However, the context evoked by …