Generalized Event Knowledge Activation During Online Language Comprehension

Generalized Event Knowledge Activation During Online Language Comprehension Ross Metusalem (rmetusal@cogsci.ucsd.edu) University of California, San Diego 9500 Gilman Dr. #0515 La Jolla, CA 92093-0515 USA Marta Kutas (kutas@cogsci.ucsd.edu) University of California, San Diego 9500 Gilman Dr. #0515 La Jolla, CA 92093-0515 USA Mary Hare (mlhare@bgnet.bgsu.edu) Bowling Green State University Department of Psychology, BGSU Bowling Green, OH 43403-0228 USA Ken McRae (kenm@uwo.ca) University of Western Ontario Department of Psychology, UWO, Social Science Centre 7418 London, ON, Canada Jeffrey L. Elman (elman@cogsci.ucsd.edu) University of California, San Diego 9500 Gilman Dr. #0515 La Jolla, CA 92093-0515 USA Abstract Online language comprehension is guided by knowledge regarding real-world events. However, it remains unclear whether activation of event knowledge during language comprehension is constrained by the linguistic context or is generalized, including a wide variety of information associated with the event even if that information has not been mentioned previously and does not satisfy constraints imposed by the local linguistic context. The present study addresses this issue by analyzing event-related brain potentials recorded as participants read brief scenarios describing typical real-world events. The amplitude of the N400 elicited by a contextually anomalous word was reduced if that word was related to the event described. This result suggests that online language comprehension involves construction of rich event representations that include information beyond that which is relevant to the processing of the current linguistic input. Keywords: event knowledge; online language comprehension; event-related potentials; ERP; N400 Background Online language comprehension is a rapid and incremental process guided by a wide variety of information sources. Some researchers characterize this process as the incremental mapping of linguistic structure onto real-world event structure, mediated in part by the comprehender’s prior knowledge associated with the described event (e.g., Altmann & Mirkovic, 2009). Recent research has highlighted the importance of event knowledge to online language comprehension. At the lexical level, priming studies have shown, for example, that verbs activate agents, patients, and instruments typically associated with the specific actions denoted by the verbs (Ferretti, McRae, & Hatherell, 2001), that agent, patient, instrument, and location nouns activate verbs denoting the events in which they typically participate (McRae, Hare, Elman, & Ferretti, 2005), and that word triplet priming with lexically unassociated primes and targets reveals rapid activation of script information (Chwilla & Kolk, 2005). Such findings suggest that processing words in isolation activates event knowledge, resulting in subsequent activation of other entities and/or actions associated with the event. At the sentential level, self-paced reading (Bicknell, Elman, Hare, McRae, & Kutas, 2008) and eye-tracking (Kamide, Altmann, & Haywood, 2003) studies have demonstrated that comprehenders can rapidly integrate information provided by a verb in combination with its preceding agent in order to predict likely upcoming patients. For example, Kamide et al. monitored participants’ eye movements around a visual scene as the participants listened to sentences such as The [man/girl] will ride the [motorbike/carousel]. They found more anticipatory looks to the picture of the motorbike when the agent of ride was man than when the agent was girl (and similarly more looks to the carousel for girl will ride than for man will ride), even though both a motorbike and carousel are equally plausible patients of the verb ride. This result demonstrates that thematic role assignment is not guided by the verb alone,