The Influence of Explicit Markers on Slow Cortical Potentials During Figurative Language Processing

The Influence of Explicit Markers on Slow Cortical Potentials During Figurative Language Processing Christopher A. Schwint (schw6620@wlu.ca) Department of Psychology, Wilfrid Laurier University 75 University Avenue West, Waterloo Ontario, N2L 3C5, Canada Todd R. Ferretti (tferrett@wlu.ca) Department of Psychology, Wilfrid Laurier University 75 University Avenue West, Waterloo Ontario, N2L 3C5, Canada Albert N. Katz (katz@uwo.ca) Department of Psychology, University of Western Ontario Social Science Center, University of Western Ontario, London Ontario, N6A 5C2, Canada directly if the preceding context is sufficiently constraining (Gibbs, 1994). The constraint-based model holds that the literal and figurative meanings of sentences compete for activation and the most activated meaning is determined by the relative strength of different sources of information for those competing meanings (Katz & Ferretti, 2001). A growing body of research has provided evidence that it cannot be the case that people always construct a literal interpretation before considering possible figurative interpretations (e.g., Gibbs, Bogdanovich, Sykes, & Barr, 1997; Katz & Ferretti, 2001). Nonetheless, recent research using event-related brain potential methodology (ERP) has shown that people have more difficulty integrating words into contexts when they are to be interpreted figuratively rather than literally (Coulson & Van Petten, 2002; Katz, Blasko, & Kazmerski, 2004), even when no differences are found in self-paced reading times involving the same materials (Ferretti, Schwint, & Katz, under review). Abstract Recent event related brain potential (ERP) results show that figurative interpretations of proverbial phrases (e.g., lightning never strikes the same place twice) elicit sustained slow cortical potentials that are more negative over the front of the head than for literal interpretations of the same phrases (Ferretti, Schwint, & Katz, under review). We extend this research by examining the influence of explicit markers placed before the proverbs, such as literally speaking and figuratively speaking, and by contrasting two literal conditions in which there either is overlap or no overlap between content words in the proverbs and the preceding contexts. The results show that slow cortical potentials were most negative for proverbs interpreted in figurative contexts, and most positive for literal contexts that contained overlapping words. Moreover, markers directed readers toward the contextually appropriate interpretation of the proverbs earlier than found in previous research. These findings have direct relevance for theoretical explanations of figurative language processing. Slow-cortical potentials and figurative language processing Previous research using ERP methodology to examine figurative language processing has primarily focused on single word indices of text integration difficulty, such as the N400 and Late Positivity. The N400 is the most widely used ERP measure for investigating the semantic integration of words in text (more difficult words produce larger N400s, Kutas & Hillyard, 1980), and are often followed by a brain potential that is more positive for words that are more difficult to integrate (Coulson & Van Petten, 2002). These measures have been useful for investigating manipulations involving the final word of statements that are to be taken literally or figuratively (Coulson & Van Petten, 2002; Katz et al., 2004). However, using single word ERP indices to investigate text integration difficulty for statements can be problematic when discourse contexts have an influence that begins early and is maintained across the figurative statements. One can still use these indices to investigate differences between conditions on the word in which the differences between conditions first appear, but the Introduction In recent years, researchers have begun to examine how people comprehend figurative statements when they are placed in contexts that are consistent with either their figurative or literal meanings. Different models of figurative language processing make distinct predictions about how and when figurative interpretations of text are constructed. Some posit that figurative statements are constructed only after an initial literal interpretation is determined to be inconsistent with the preceding context (Grice 1975). Alternatively, other approaches focus on different variables that may increase or decrease the activation of figurative meanings relative to literal meanings during language processing, such as arguing that one is obligated to process salient meaning regardless of literalness (Giora, 2003), or positing that the figurative meaning of a phrase is accessed