The Comprehension of Conventional and Novel Metaphors: An ERP Study

Vicky Tzuyin Lai, Tim Curran & Lise Menn

Abstract for poster presented at
The 13th Annual Conference on Architectures and Mechanisms for Language Processing
Turku, Finland
24-27 August 2007

Past research exploring metaphor processing using Event-related Potentials (ERPs) have been inconsistent because different types of metaphors with varying degrees of conventionality were used (Coulson and Van Petten, 2002; Iakimova et al., 2005). The current study examines the processing of conceptual metaphors (Lakoff and Johnson 1980). We hypothesize that metaphors require more effort to process than literal sentences and novel metaphors require more effort than conventional ones. 104 4-tuples were created (see example), in which the same word ended literal, conventional metaphorical, novel metaphorical, and anomalous sentences. Pretests ensured that the conventional metaphors were familiar and easy to interpret, and the novel metaphors were unfamiliar and difficult to interpret. Sentences were presented word-by-word to 24 normal adults who were instructed to make a sensicality judgment. Reaction time (RT) and ERPs were recorded starting from the onset of the sentence-final target word. Literal targets received the fastest RT while conventional metaphors were faster than both novel metaphors and anomalous conditions. ERPs from the central and parietal electrode sites were measured from 320-420 ms for analysis of the N400 component, known to be related to semantic integration effort. Both conventional and novel metaphors elicited an N400 as large as the anomalous sentences. However, after the N400, the ERPs to novel metaphors remained equivalent to anomalous sentences, but ERPs to conventional metaphors became more similar to literal sentences. Our results suggest that conventional metaphors require a short burst of processing effort while novel metaphors require a sustained effort. Our findings are consistent with the indirect access models, where literal and metaphorical meanings are available at different times.

Example
Metaphor type	Stimuli
Conventional	Every point in my argument was attacked
Novel	Every second of our time was attacked
Anomalous	Every drop of rain was attacked
Literal control	Every soldier in the frontline was attacked

Iakimova, G., C Passerieux, J Laurent, and M Hardy-Bayle. 2005. ERPs of metaphoric, literal, and incongruous semantic processing in schizophrenia. Psychophysiology 42 (2005), 380-390

Coulson, S. and C Van Petten. 2002. Conceptual integration and metaphor: An event-related potential study. Memory & Cognition 30(6), 958-968

Lakoff, G and M Johnson. 1980. Metaphor we live by. Chicago: University of Chicago Press

Vicky Tzuyin Lai is a PhD student in the joint PhD program in Linguistics and Cognitive Science at the University of Colorado at Boulder. She can be reached at:Vicky.Lai@Colorado.edu.

Tim Curran is an associate professor of Psychology at the University of Colorado at Boulder. Lise Menn is a Professor Emeritus of Linguistics at the University of Colorado at Boulder.